35mm (Full Frame) / APS-C Dilemma | Describing Focal Lengths on Cropped Sensors | Opinion Piece

#35mm #APSC #Fullframe
What does '35mm equivalent' mean?
Or is simply saying 'cropped sensor' good enough?
00:10 Shooting this episode on the 300 PF
00:44 Intro on today’s episode
01:10 When did I start using the APSC?
02:54 APSC controversy
03:33 Introducing the 50mm 1.8 Viltrox
03:52 Introducing the ZFC + Z7
04:10 Showing the difference between APSC and 35mm
05:09 Many mirrorless systems allow for different sensor sizes, yet use same lenses on either sensor size
05:33 What is a 50mm lens?
06:00 What happens to a lens when it is on APSC?
06:40 How should we convey effective focal length on APSC sensors?
07:20 What is the angle of view?
07:41 What does online have to say about it?
08:31 Why do we say 35mm equivalent?
09:47 What about when you APSC crop a full frame camera?
10:25 Is in camera cropping your camera ok?
12:23 Is it semantics?
13:04 How should we communicate our lenses focal length when cropped?
14:14 Can 35mm based definitions be the standard?
14:48 Outro
15:18 Teaser for the lates 400mm f2.8 VR TC S lens video
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WEBSITE www.mattirwin.com
TWITTER / mattirwinphotog

[@MichaelAres]

I’m a professional photographer, I already know this, why am I watching this still? ……..it’s because you’re such a good teacher and speaker and I just love hearing about photography even tho I already know these things 😂

[@babiem2290]

Thank you this is the easiest explanation about photography for someone that is just trying to figure out what a camera can do; researching what’s best for them when trying to buy one. This is great. I appreciated that you acknowledged the language as not being formal, I was getting very confused.

[@MattIrwinPhotography]

Complete pleasure, and let me know if you have anymore questions. :) Cheers Matt

[@kellysparks2084]

Excellent!! I would add that you also need to multiply the aperture by 1.5 as well. So a 50mm 1.8 is an equivalent to a 75mm 2.7 lens on a crop body. (In terms of blur/bokeh) This is because DoF is greatly affected by distance, and in crop mode, to get a similar angle of view as a full frame, the camera needs to be moved away from the subject 1.5x which in turn increases the DoF on the crop body. To be clear, the light gathering capability will not change and remains 1.8.

[@okaro6595]

Multiplying by 1.5 is hard. It is simpler just to adjust it by one f-stop. That is close enough.

[@davidhatton2321]

Good presentation, Matt. As indicated by an earlier response, the confusion with so many people is getting "more reach" with a cropped sensor is a replacement for more glass. There are many "professionals" that still don't understand that they are only actually magnifying pixels.

[@steenandresen6522]

Once again. A very good video from 'down under'. Always a pleasure. What I would like is a video explaining pros and cons with full frame vs. DX.

[@carlmarch603]

Matt - I didn't know this was an issue, and I'm sorry you're having to deal with it. Even though I have my Z9 now and throwing it into DX mode for reach is programmed in my i menu, I can't bring myself to part with my D500. My 500PF sits on it most of the time, but also the 300PF, 180-400 and 70-200. It's keeping me from getting rid of all that F mount glass! Trade-in value for a D500 is only ~$650 or so. It's value to me as a wildlife guy is much greater than that!

[@garymc8956]

Great explanations. Leading to several follow up discussions; the affect of crop/full frame on image qualities such as depth of field, bokeh, etc. I would like to see side by side images of a fifty lens on crop camera and seventy-five on full and comparison. Secondly, follow up on lens issues. The fact that full frame lenses provide a 35mm image, it’s just that the smaller sensor only picks up part of it. Crop frame lenses can be made smaller and cheaper because they only have to provide a smaller image. And there are certain implications of this. So I think it’s a great discussion, worth a little more. Thanks.

[@Altitude2011]

Hi Matt, I own the Nikon 300 mm PF. This is an amazing lens. Lightweight, small and very sharp. Look forward to your video on this unique lens!

[@dance2jam]

Hey Matt, I am sure there are many who appreciate you going over this in some detail. Nice job. Quick aside: Most people when explaining the difference between APSC/FF stick to the focal length, but neglect the relative change applies to the aperture as well (does it not?). i.e. a f/2 FX lens has the "equivalent" DOF of f/3 on a Nikon DX body. Now I might have found it interesting to hear the comparison of between images of, for example, a 35mm FF lens on a DX body vs the same lens on a FF body in DX mode. Curious if there would be any noticeable changes. Never thought of doing that myself just for fun.

[@dicekolev5360]

50mm stays 50mm. f/1.8 stays f/1.8. What kind of physics is this :D The aperture is not changing from the sensor, the aperture is within the lens^^ That's why I consider getting the Zfc to experiment with the Z100-400mm rather than getting 1.4TC which is the thing changing the aperture, haha

[@dance2jam]

@@dicekolev5360 The point isn't lost on me, and obviously an f/1.8 lens stays f/1.8 (but my point is this Dice). There is a multiplication of focal length (as you know) of 1.5 for Nikon and Sony and 1.6 for Canon in terms of Equivalent field of view. Now that doesn't change the actual focal length as Matt alluded to, but it does "crop" the image to a different equivalent FOV. Point is, it doesn't change the minimum aperture, but it does change (if I understand this correctly) the equivalent depth of field at that aperture. Yes or No? Examples?

[@dicekolev5360]

@@dance2jam The DOF depends on the aperture and the lens itself while the FOV depends on the sensor, yes. You'll have the same DOF as if you use the same lens on the other Z cameras but the FOV will be less on the Crop sensor camera. The main positive side is that with Crop camera you'll have the 20MP photo while if shooting with my z6ii in Crop mode I'll have 10MP photo.

[@okaro6595]

There would not be any trivial changes: perspective, framing, depth of field. Of course there could be changes based on sharpness and other aspects relating to the lens quality but these would be dependent on the lenses and cannot be categorized by the type.

[@okaro6595]

@@dicekolev5360 No, depth of field depends also on the sensor size but in a somewhat counter-intuitive way. With the same focal length and aperture you get less depth of field on a smaller sensor because of greater magnification. Please do not argue against unless you have tested with some DoF calculator. Have some respect for me. I have actually derived the formulas. People often say that with crop you need to move back. No you do not. The formulas cover things like aperture and distance. Your cat is not in them. The subject is irrelevant to the depth of field.

[@jpdj2715]

Nice lecture. If you like to do these, I suggest to follow up with "focal length is defined at infinity focus setting" (for lenses with a fixed element arrangement). That could be followed by a discussion of the aperture number that a lens should change when you focus closer by. And when you combine the two, you can discuss zero focus breathing primes that are actually zoom lenses that, in one go, actually may cause a constant aperture number. Or Bayer sensor cameras and raw prcessing

[@roccop33437]

Matt, excellent job as always .... I use my little N1 as a walk around camera and love it. Then there is my DX, and my FX. At a given price point I would always go with the larger sensor but there are advantages for different formats. Example: My N1 is a great street shooter. Looks like a toy, feels like a toy, but give some great results. Put an adapter on it and learn how to multiply by 2.7 for all my older F mount lenses. I know you have one as well from when I saw your bird safari.

[@archivephoto]

Hi Matt. It surprises me that so many photographers have a hard time grasping the "equivalent" concept. Another way to explain it (for those that are still a little confused about it) is the way large format film photographers have understood it since the beginning of photography, which is, that to get the same horizontal angle of view (from the left-most object in your scene to the right-most object) with different format cameras (4x5, 5x7, 8x10, etc), you need a different focal length lens for each format. In other words, if the scene you want to capture with your 4” x 5” format camera requires a 150mm normal lens, then a 5” x 7” camera would require a 212.5mm lens to capture the same scene, and you'd need a 300mm lens to shoot it on 8x10. The focal length required to show the same scene with your 35mm camera would be a 45mm lens and with an APSC-sized camera (whether film or digital) you’d need a 30mm lens. Those previous examples all produce the same 43 degree angle of view (left to right) in the scene on their respective formats. 30mm on APSC and 300mm on 8x10, both show you the same left-to-right view of the scene in front of you. Another way to visualize it, is to imagine you’re looking at a scene on the ground glass of an 8” x 10" camera with a 300mm normal lens mounted on it. If you take a piece of clear 35mm film (which is 24mm x 36mm in size) and place it anywhere on the ground glass, what you will see within that 24 x 36 rectangle is exactly what your 35mm camera would see when looking through its viewfinder with a 300mm lens mounted on it. Hold up a 6cm x 6cm neg to the ground glass and that is what a 300mm lens will look like on your Hasselblad. Hold up a piece of film that is APSC-size (24mm x 16mm) to the ground glass and you will be looking at exactly what your APSC camera would see with a 300mm lens on it. That smaller APSC piece of film covers an even smaller area of the 8x10 than the 35mm piece of film does and because, for the past 50 years, most people have learned to visualize the coverage of all lenses in relation to what is seen when looking through a 35mm camera, people want to know what focal length lens would be needed on their 35mm camera - to show only what is seen in that smaller APSC piece of film. In this case, you would need a 450mm lens on your 35mm camera in order to fill the 35mm frame with only what is seen on that APSC negative. That is where and why the term “cropped” is used to describe the cropped view of the APSC neg vs. the larger 35mm neg. As you said, 300mm is always going to be 300mm no matter what camera you put it on. If I mounted a Nikon Zfc camera (with its smaller APSC sensor) behind the 300mm lens on my 8x10 camera, the resulting photo would show the same scene as if I had mounted the full-frame NIKKOR 300mm f/4E PF lens on the Zfc. And to discuss what the resulting photo looked like from either 300mm lens, we commonly say the resulting photo would be "equivalent" to the magnification seen on a full-frame 35mm camera with a 450mm lens mounted on it. Sorry for the long post; it was a personal challenge to see if I could explain the concept so that it might be understood clearly by even non-photographers.

[@okaro6595]

I use the sensor width to visualize things (I find the diagonal confusing). APS-C on Canon is 22.3 mm, Full frame is 36 mm. If you use that focal length you get as much horizontally as is the distance.

[@enricomarconi8358]

It's a good piece Matt, I would go on delving into the aperture issue though. We do know that the aperture does not change but due to the change of Focal Length perceived, the distance to the subject will be affected hence the Depth of Field (DoF) will also change accordingly. This will result in less bokeh as the distance to the subject will be different in order to obtain the same 70mm 'effect' on a DX camera and by getting further away from your subject, it will result in less blur (or bokeh). It would be like having a 70mm f/2.7 on a 35 mm FF sensor (despite the fact that the max aperture will still be mechanically at 1.8). The same will have to apply for Medium Format but in this case it will be a crop of 0.78 or 0.70 depending on the sensor's size (since they are not all the same) and same would apply to Medium Format Aperture conversions.

[@rustywendlandt5160]

I have a d5600 and z7 so I got it figured out a couple years ago. I wish there was a video like this when I went from film to the D5600. It took quite a bit of figuring it out.

[@MysticApertureStudios]

I recently got a 35mm f1.4 and i absolutely love it. I use it on my Z6 and i often find myself using it in DX crop mode when i am shooting headshots with it. The DX mode gets rid of the extreme corners that have most of the distortion. Instead of a 50mm i find 85mm more useful. That's my personal choice.

[@Joseph-iu6ip]

I have both DX and FX cameras and lenses, so I understood the assignment. 😂

[@dicekolev5360]

Hey Matt! This video popped up right when I'm thinking if I should get 1.4TC for the z 100-400S or to get Zfc and use it with the 100-400mm when on a hike while having another Z prime on the z6ii. Sounds like an exsiting combo ;D. Zfc AF doesn't seems to be worse than the one in z6ii + I'm not afraid of the noise, hmmmm. EDIT: The 300PF looks marvelous for video vlogs^^ Even I think this is one of your most pleasant looking vlogs ever :))

[@victormultanen1981]

very interesting topic to discuss though

[@cmichaelhaugh8517]

Now let’s talk about the aperture shift with APSC.

[@okaro6595]

In the film era cameras with smaller film sizes typically had a fixed lens with fixed focal length so you got what you got and the user did not think about focal lengths. Canon did have one APS film SLR which had crop factor 1.44. Also 40 years ago Pentax had an SLR that used the tiny 110-format film cassette (crop factor 2) but it used its own special lenses, not the K-mount. That means crop factor really was not an issue back then. Yes APS was a film type introduced in 1996. It was discontinued in 2011 having a life span just 15 years when the 35 mm film is soon 90 years old.

[@nelsonvazchillout]

Never thought this would be an issue for anyone, Matt. 50mm on a 35mm is 50mm but in DX becomes 75 EQUIVALENT. Easy. Now that you put the video out there just move on :-) (actually I’m also glad that you managed to stay away from the Z9 for a while!)

[@Skye_the_toller]

It seems that too many people does not realized that crop is crop! And going crop with 24 mp FX… may be too few Definition for prints…. But, your right! Move on:)

[@christopherlofquist1]

Great video Matt as always! I still have my D70s but don't use it that much. I also have a Nikon J1 and a Nikon Z5. I don't have any issue describing EQV on a crop camera or what it is on a full frame camera.

[@MattIrwinPhotography]

Awesome stuff. What is the crop on the J1?😀

[@christopherlofquist1]

@@MattIrwinPhotography The Nikon has a smaller sensor than an APsC sensor. I have an adaptor called FTZ which you can use Dx or Fx lens.

[@davidjopson6267]

@@MattIrwinPhotography Think the crop on J1 is the same as my V2which is 2.7

[@jafo1972]

Hello! Very informative video. I would love if you revisit to show us how a pocture looks with aps-c and full frame using the same full frame lens in both cameras.

[@jrarsenault1937]

Excellent content. Olympus made 'Pen series' 1/2 frame 35mm film cameras in 60s/70s. Smaller. lighter high quality with double the exposures. Cheers, JR

[@EdwardKilner]

From 1963-1971, I adored my Olympus Pen D. Sold it to a friend and he used it for years after.

[@bluste63]

Hi Matt, Thanks always for your uploads. As terminology goes you are correct, but, there are SO many "Experts" either "A" want to change the "Norm" cos they have nothing better to do and enjoy being pedantic, or "B" they are ignorant and pedantic anyway and probably speak with a very peculiar high pitched voice similar to Kenneth Williams in "Carry on Matron"

[@cheetahkid]

Very well thought out, I have many cameras with different formats. Off topic, TTartisan 7.5mm F2.0 MF Fisheye Z Lens, that I bought for my Zfc, it is wild wide and manual focusing. I find it tricky to get it sharp but otherwise is ok. Have you tried this lens for bit of fun?

[@cccycling5835]

For me this became a big issue as I shifted from Nikon DX DSLR to FF. It usually meant I would have multiple systems in the field and I’m sure it was more cumbersome. I sold all of my DX Nikon and went FX entirely. (Other than my Ricoh GR)

[@davidroberts6766]

I own the two FX Z cameras. I have recently ordered a Zfc. I own the 14-30mm S line Z lens, as well as both the 28mm and 40mm. Do you think that the 14-30, because it will only use the centre of the lens, plus its an S lens, is a better option (bulk aside) than the 16-50 DX lens, for walkabouts? I realize that it will give up some focal length eqv. on the long end, but I have the 40mm prime. I also have the 24-120mm zoom, and a bunch of S line primes. Part of my desire to get the Zfc is just to have a super light kit. Would the DX 16-50 and the super light primes be better?

[@451804]

I’d be happy if you, since we are talking Nikon here, simply used Fx and Dx “mode”. That then informs that Dx is a different mode. Not superior or inferior but a different mode. It has taken me the last few years to fully understand that Dx mode alters how the focal length and aperture interact. This is especially important to understand when photographing where pre-visualization or composition is important to you. Dx mode changes the angle of view, the depth of field and the compression appearance as well as the number of pixels of the image. With a high resolution sensor like 45 Mpx, this gives you options. There is a difference in the way the Camera renders in 2 dimensions, the 3 dimensional world. And that’s fine.

[@bfs5113]

In my case, the digital APS-C (1.5-1.6x), APS-H (1.3x) & FF are no more complicate than dealing with the SLR and MF that could be 6x4.5 (0.62x), 6x6 (0.55x), 6x7 (0.5x), 6x8 (0.45x) or 6x9 (0.43x) in the past. Nevertheless, I prefer the KISS method. While I also shoot with APS-C cameras and started out with one (a Canon D30 in 2000), I tend to use FF as my primary cameras. Hence it was an SLR like moment when I shot with the Canon 5D (& Nikon D3) the very first time. This same mindset also influenced me into buying a Leica Q as my walkabout camera, instead of considering a Fujifilm X100V.

[@irridiastarfire]

Pshh.. I refer to all my lenses by their 48-inch frame equivalent focal lengths. So that Nikon 50mm is a 1.25mm equivalent lens when mounted on an FX camera (using 0.025 crop factor). As a traditionalist I refer to aperture settings using the Uniform System (U.S.) scale, so the max aperture of that f/1.8 lens is about 0.4. Because measuring exposure times in seconds is so passe I've taken to referring to them in fortnights. So a 1/100s exposure is actually 1/120,960,000th of a fortnight. I think this makes things much easier to understand when someone asks me the settings that I used for a photo, although I admit it does take a while to explain that I prefer to list my film speed in base 7 DIN, instead of in ISO. "Oh that photo? Oh yeah, I took it at 0.6mm eqv., exposed for 1/241920000 fortnights with an aperture of 0.8 at 51 base-7 DIN."

[@MattIrwinPhotography]

Fabulous, I am moving over to this system :)

[@ytr8989]

Nikon once made a good D200 through D500 and the D7000 series. And Fujifilm pretty much ended the myth about APS-C. And now micro-four-thirds getting really good and sharp too. The big 3 (Sony, Canon, Nikon) could make some fine crop cameras to rival Fujifilm, but there money seems to be full frame.

[@okaro6595]

An important point is that if you put a full frame body in the crop mode you do not gain any extra information. You could do the same in post to get same or better results. However, video is completely different. There you actually get extra reach.

[@darthwolverine747]

TLDR; consider providing translation both ways so native DX folks can imagine the field of view in their frame of reference. E.g. “I’m shooting the 50mm 1.8 on the Z9, which looks like 33mm FOV on DX” Matt, as someone who started out with point and shoot digital cameras and then stepped up to DX when my budget allowed, hearing professional photographers equate everything to 35mm was always a bit confusing. One thing I’ve never heard folks do on KZbin or elsewhere is translate the opposite direction so that native DX/APS-C shooters know what the field of view looks like from their frame of reference. For example if you’re shooting the 50mm lens on the Z9 you could say something like “and this composition looks similar to 33mm on DX” so DX native people can picture how wide the shot is in their mind. I always understood the physics of cropped sensors, but I personally had no experience with FX or 35mm to understand what it’s like for that (35mm) to be your mental frame of reference. A decade later I bough the Z7 as my first FX camera and now after using it for several years I finally think in 35mm/FX equivalent. I now realize that pros always talking in 35mm equivalent made me feel like my gear wasn’t actually pro … and that until I had an FX camera I was having a sub-optimal experience. I know that’s not true as a 35 year old adult lol, but as a 20 year old in college with my D40 and then my D7000 I always felt one step behind.

[@Azzquee]

It could be a good idea to make a comparison on the picture of, say 24mm on a FX and 35mm on a DX, to elaborate the difference between the two in terms of depth of field and pixel quality.

[@merkin22]

Nicely explained. The equivalency tho is very much to do with field of view. Shooting DX in my FX camera to get more 'reach' on a long lens (in my world of wildlife photography) the quality (noise, resolution) of the image degrades equal to if I crop my FX file in post production, yes? The question mark is because I'm a technical dummy and may be misremembering what I've learned that has lead to me not 'DXing' my long lenses in my FX camera, to get longer focal length. Cheers!

[@okaro6595]

You really do not get any extra reach as you can and often do crop in post anyway. With DX mode you risk ruining a shot if the bird flies outside the DX frame. With a real crop body you do get extra reach as the pixel density is higher but modern high megapixel bodies with 45+ megapixels reduce the difference. If you shoot video then you do actually get extra reach.

[@okaro6595]

I think when one recommends focal lenghts it is good to use the 35 mm format if one uses that but then mention that on APS-C one should use for example 35 mm instead of 50 mm. If the discussion is clearly about some APS-C camera then use directly the proper focal lenghts and mention what equivalence in 35 mm they are.

[@Digmen1]

Matt I was lucky enough to be able to buy a Nikon FF Z6ii and a DX Zfc (for my g/f to go out and about - she wants to vlog). But I am still confused. I have 2 DX lenses and 3 FX lenses. Why do Nikon make DX lenses? Like many of us I'd like to do some wildlife or birding or airplanes in flight, so a 200mm lens is too short. And a 400 or 600 is too expensive for me to justfy. So I bought the Nikon DX 50-250mm lens as its relatively cheap and will give some extra reach. I need to go out and compare that lens on my two bodies.

[@gwhech]

It will be the same on your 2 bodies as when you put a dx lens on the first camera it selected dx mode. They make dx lens because they are cheaper and smaller

[@baronsilverton6504]

I think you make great points here - a 50mm is the equivalent "angle/field of view" as a 75mm on a full frame - this is a fact, it is mathematical. End of story. I think there is confusion on the issue of depth of field (DOF) when it comes to DX sensors. I think that many people do not realize is that you need to multiply the aperture by the crop factor (in the case of DX by 1.5) as well to determine an equivalent depth of field to what a full frame sensor would render - because you have to move farther away from your subject (by 1.5 times) you also have 1.5 times more depth of field and therefore less out of focus effect (bokeh). This one reason why full frame is generally superior for portraiture or for any application where subject separation is desired.

[@okaro6595]

Most people who are confuse have not even started to think depths of fields.

[@ronvilliotti773]

I’m actually using full frame and APS-C on my Nikons and M 4/3 on my Olympus.

[@francisirizarry2940]

the olimpus Pen D was a half frame jens wirh Interchanble lenses

[@stephenclarke8424]

the question its, does this affect still apply when using a DX lens? if so why bother producing a dx lens? surely its designed with optics to make use of the smaller sensor?

[@rickardlang8653]

Nice talk on what should be well understood. When you review the 300 mm pF could you show it on the Z50 . I’m keen to get one for my Z50. Can you also add the 1.4x with the FTZ adapter?

[@okaro6595]

The FTZ adapter does nothing to the focal length. It just allows mounting the lens at the proper distance (with proper contacts)

[@markturriff994]

I think you could have helped your explanation with the use of photographic examples Matt

[@MattIrwinPhotography]

Fair call Mark.

[@patrickmolloy6994]

agree

[@stephenclarke8424]

@@MattIrwinPhotography further to that, maybe a diagram of how a lens basically works and what happens in the fx/dx scenarios, showing lines to the sensor and if the information is available, how a dx lens is constructed diffeerently, if at all or is it just another avenue of gaining revenue from a captive market?

[@duncanwallace7760]

Equivalent is good because if you have a full frame lens on a DX, its good to know what additional zoom you're getting.

[@artsilva]

When referring to DX crop equivalents, I usually say something like the "50mm on my APS-C body now has the Field of View of a 75mm", but I still call it a 50mm lens. This also brings up a though; Being that DX Z and FX Z are the same mounts, I wide if it is necessary to actually have dedicated DX lenses being that FX lenses will fully do everything on both formats where the DX lens on a FX body is forcing the camera to crop; a 50mm FX is a 50mm on both sensors and every pixel on both sensors are utilized. The people complain the Nikon "needs" more DX lenses I sit back and scratch my head over that rant. aside form maybe size and cost, nothing is different in the real world about a 50mm DX to a 50mm FX lens. My other pet peeve about DX to FX lens Influencer talk is the mis information of Aperture [Depth of Field] equivalents. Maybe something to dive into in the future... Many say that a DX lens is slower in aperture to an FX lens and the "bokeh" is not the same... for example, someone might say that a 50mm f1.8 on a DX sensor acts like a 75mm f2.8 or something like that. Just as a 50mm lens is a 50mm, so is an f1.8 an f1.8. What these people are not mentioning or the reason being is that with that lens on a DX sensor you physically have to step back from your subject thus changing the dynamics of depth of field. It's still the same lens, same compression The sensor didn't change the lens, you just have to be aware of your field of view. I shot a small flower with my 50mm f1.8 on both my DX and FX bodies and even used crop mode on my FX for a third comparison. All the same distance from the flower (stationary tripod mounted), every shot was IDENTICAL in both DoF and bokeh, the only difference was the DX and crop mode frames were obviously cropped in and less of the scene was included. But if I stepped back a foot or two then yes, my DoF changes but the lens didn't. All it is people is your Distance to Subject and Field of View. Part of knowing photography is knowing the physics of your lenses and how it relates to image making. those guys saying that lenses changes on different camera formats is nothing but hogwash. It is the user that has to change with their formats.

[@daveyboy6210]

I see your point but for landscape I need a minimum of 18-55mm or 16-80mm to obtain a good wide view on my DX camera?.most full from Len's will be 24mm which will give a narrow view .

[@artsilva]

@@daveyboy6210 Let me understand what you're saying; For your DX body you require in FX FoV equivalency terms, a minimum 27-82 or 24-120mm [which is what the marked 18-55 and 16-80 FoV will give you]? or, are you actually talking about a 12-36 or 11-55mm to get you that 18-55 and 16-80mm field of view on the DX sensor. Keep in mind and as an option, on a 46 Mp FX body a 18-55 and the 16-80 will give you the best of both worlds meaning when you switch from FX to DX Crop setting those same lenses will give you a 27-82 and 24-120mm FoV at 19 to 20Mps, which is what Nikon DX sensors top out at anyways. BTW, "most FF lenses" are Not 24mm. There are tons of ultra wides and wide zooms like 14-24, 14-30, 17-35, ones starting at 10 or 12mm and then the cream of the crop landscape prime, the 20mm

[@okaro6595]

DX lenses typically are lighter and cheaper. This applies mainly to lenses shorter than 50 mm. 50 mm seems to be only full frame on both.

[@okaro6595]

@@artsilva He explained clearly, then you confused everything by introducing unnecessary equivalences. How he did not tell what is the problem with the kit zoom. Sigma does have 16 mm f/1.4 for Nikon Z.

[@artsilva]

@@okaro6595 DX lenses ARE cheaper and typically smaller for a good reason compared to FX versions of same focal lengths because of sensor coverage in optical designs; for DX you don't need as much glass area to cover the DX sensor but with a FX lens you have the benefit of covering Both sensors. Without having to re-watch a year old video I forgot about, I stand by what I said in context of the initial comment. Maybe you don't get the breakdown I gave but I'm sure it's not disputing what Matt said. It's just a different personal taken the subject. Maybe watch the video again and read my OP to understand, it's not rocket science but something that needs to be explained from time to time. Learning a craft and all the inner workings is like any other skill, education and detailed information and how things are the way they are is key to making decisions. Keep that in mind.

[@charlesdavis6371]

I understand an FX 50mm on DX body is going to give a 75mm view. My question is regarding DX designated lenses. example: is the DX 16-50 really a 16-50 lens, meaning does it give 16-50mm field of view? Or does give you a 24-75mm field of view a true 16-50 (FX) lens would on a DX body?

[@fetzie23]

If you could hack the firmware of an FX camera to not automatically swap to DX mode and took a photograph with a DX 50mm lens, and then took a photo with an FX 50mm lens, both photographs would be identical (other than some vignetting in the corners of the photo taken with the DX lens.

[@charlesdavis6371]

@@fetzie23 - thank you.

[@gwhech]

If you put any lens on a crop body you have to add the crop. So your 16/50 is like a 24/75

[@fetzie23]

@@gwhech Only in terms of the field of view of the final image though. Optically, it's still a 16-50.

[@okaro6595]

It is really 16-50 mm and it produces the angle of view that 16-50 mm produces on a DX sensor. Now on a FX sensor you would need 50% larger focal lenghts for the same angle of view i.e. about 24-75 mm. Hint: did you ever wonder why it starts at 16 mm? On full frame 16 mm us ultra-wide. Clearly a kit lens is not ultra wide.

[@marcusbraun8889]

HAve used the tiny j5 with it's 1inch sensor, 2.7 crop I think. It's 30-110mm lens was always '70-300' for me, give or take a few mm, I dun care. Same goes for the other Nikon 1 lenses. It's just simpler to have a 'standard' so we all know what we're taking about. Has nothing to do with one format being better than the other, they all have their purposes, it just makes life easier.

[@ytr8989]

Do some shots using the DX camera with an FX 50mm lens, and compare the images to those of the FX camera using the 50mm DX lens.

[@psoon04286]

You get a similar confusion comparing medium format lenses to 35mm lenses😉…. What’s a ‘standard’ lens for, say the Hasselblad?

[@barrantescarlos]

Recently I made a question about that in a Facebook group: "Hello, please a little help with a doubt. I know that when I use a full frame lens on a APS-C camera I need to consider the crop factor (1.5x in Sony a6400). A 35mm full frame lens will be like a 50mm when we talk about field of view. But, what happens with the flat feeling that a lens can produce while the focal lenght is bigger, (you know... more flat, without distortions, a 85mm lens do less distortions than a 35mm lens, that's why a 85mm lens can be better use as a portrait lens). Does the 35mm full frame lens in a APS-C camera also produce the same flattering effect that a full frame 50mm lens will produce in a full frame camera? Obviously the background will looks different with a full frame sensor, but I mean the flattering produced between the different planes in a picture or even better look flat faces. Thanks." So, I think you gave me the answer and the short answer is... no, no, a 50mm full frame lens in a full frame camera will not produce the same compression or flat feeling like a 35mm full frame lens in an ASP-C camera because the 35mm will be just that a 35mm and will not change their properties. Do I am right? Thanks.

[@dunnymonster]

Equivalence is not a bad thing. When I pick up a camera I kind of know instinctively how my field of view will look on a given focal length. If I do switch to APSC or M43, then mentally I can anticipate approximately how my field of view will change by multiplying my focal length by 1.5 or 2.0. I suppose the industry as a whole could get rid of focal lengths all together and express lenses by the angle of their field of view but that would likely be even more confusing and of course some equivalence would have to be calculated if say you put a full frame lens onto a cropped sensor anyway. Once you get into the term " equivalence " you open up a whole host of potential issues not only in regard to focal length but aperture as well. Frankly it's an argument I get tired of hearing and as you say, ultimately it just becomes semantics. Most experienced shooters know full well a crop is a crop and nothing more, we know crop sensors don't magically make a lense's focal length longer. Equivalence is a mental tool to help us pre visualise our field of view and this is important in many scenarios. Let's say you are shooting an event with two bodies, one FF and the other APSC. Well it would be kind of pointless having an 85mm on the FF body and a 50mm on your APSC body because both cameras would be capturing a similar field of view. Understanding equivalence means you'd perhaps put a 24mm on the crop camera to get something closer to the FF equivalent to 35mm. So both your cameras would have quite different fields of view giving you more options for wider or more telephoto shots which is part of the whole point of shooting with two bodies isn't it? 😋

[@EdwardKilner]

Any lens will project a circular in-focus image onto the plane of the sensor. The sensor will see a pert of that circle, more central for APS C and more of the circle for FX sensors. So, the field of view of the diagonal orientation is different and defining. I think the trick of the FX camera knowing it should switch into DX mode is very recent. You can manually do the switch, but if you shoot raw, you are going to edit the shot anyway and might then be able to fitness the crop. Some lenses marked DX actually project a fairly large image circle, I understand. In any case, look at the viewfinder or LCD and decide to take the shot or not. Worry less about whether an FX 50mm is the same as a 75mm DX equivalent. Who really cares? Why?

[@robertplincoln895]

The way I understand equivilance is that if you take a photograph from A, looking at B, with an m43 camera with a 25mm lens, and the meter reading is 1/200 sec, the f stop is 1.4 and the ISO is 100, and you then take a picture with an APC camera from the same position, looking at the same subject with a 33mm lens (35mm is close) and the meter reading is 1/200 sec, and the f stop is 1.8 and the ISO is 180 and then take a picture with an Full Frame camera from the same position, looking at the same subject with a 50mm lens and the meter reading is 1/200 sec, and the f stop is 2.8 and the ISO is 400, AND the sensors are from the same generation, THEN all 3 photographs will be equivilent, IE same angle of view, same depth of field and the same noise.

[@JRodPhotoArt]

FX and DX should only be an issue of discussion when interchanging DX and FX lenses. Other wise, native DX and FX lenses are what they say they are. A 50mm DX lens on a DX camera will take the same picture as a 50mm FX lens on a FX camera? Great video Matt!!! Good day !

[@gwhech]

No it won't you are totally wrong. A dx 50 on a dx body will look similar to a 75 on a ff body

[@okaro6595]

No, 50 mm on DX will not give same result as 50 mm on FX. That is the whole point of the video. Did you even watch it? You should use 35 mm on DX to get same results. Why do people watch a video and not listen what is said and instead in their mind think the speaker says their own wrong preconceptions? The focal length alone does not determine the angle of view. The combination of the focal length and the sensor size together determine it. When their ratio is the same then the angle of view is the same. FX is 36 mm wide and DX 23.5 mm So you need 50 * (23.5/36) = 32.8 mm. The closet standard focal length is 35 mm. Also FX gives vertically the same as DX horizontally. There are no FX or DX focal lenghts. A focal length is a focal length. It is a property of the lens. Where FX and DX lenses differ are the size of the image circle.

[@ronboe6325]

For me; I'm comfortable talking about 35mm equivalent when discussing APC vs. Full Frame (a bit less so when you get into medium format - but lets limit this discussion a bit or the rabbit hole gets too deep). But. When you move to cropping in post - your use of equivalent lens length in that case is the only use I've heard. Not that I get around that much so lets just say that particular use case is rare. Not in general use (in my experience anyway). One could even crop more and say 110mm equivalent (and pretty much get 110 image quality :D ). I'll submit that once in post, people think more about composition and crop ratios - not lens equivalents. So when you do that my mind goes...huh? That said, if you had compared side by side, shots taken using the same lens on the two cameras, in Capture One - and then extended that idea to 100mm, 200mm etc. that would be very helpful.

[@ronboe6325]

Oops, forgot to add, just declare what lens you're using. The reader/watcher can work it out themselves.

[@sf-gt9co]

a 35mm lens, on a APS-C will ALWAYS increase to Xmm (X= focal leght * crop factor) or, if i choose a lens that say "for APS-C", it's already compensated? thanks

[@MattIrwinPhotography]

No, a lens that says APS-C is still the same as a 35mm lens focal length, and the crop factor is still applicable :)

[@lukykentucky]

I’ve made a test by my self : Nikon d500 with 40mm voigt , Nikon z6 with 58mm Voigt at f5.6 , bunch of flowers on the table , standard profile everything at 0 sharpness etc. . My wife , her brother and me couldn’t tell the difference, I don’t know why but the look overall , colour etc. looked with the D500 more natural to the eye then Z6 , maybe the Z6 or the lens over saturated the colour everything was set a 0 . Both cameras are powerful machines you can’t go wrong with either one .

[@ihknilsen]

I don't mind the term EQV. What drives me crazy are people saying, "I don't need to spend money on a full frame camera and a 750mm lens when all I really need is APSC and a cheaper 500mm lens for the same "REACH".

[@Mr09260]

I just like Full Frame >> put a 35mm on my Z7 or ex D850, D800 , D3s etc and thats what I get >> I dont have to sit there and multiply that by 1.5 x .. I mean what is 52.5 mm on say a D500 or put a 85mm on my Z7 and on a APSC that calculates out to 127.5 mm I mean what the Dickens is that.. not to mention the better IQ on FF

[@Digmen1]

Me too. When I was younger I had 35mm SLR's then for budget reasons I went to a NIkon DX5500 with 4 DX lenses. I always hated have to think now what lens do I need for this shot. My brain knew that 50mm is normal and 35 or 28 is wide and 200mm is for medium tele etc. But I always had to do mental mathmetics to convert to DX lens from a FF lens equivalent before chosing which one. Now I have gone to FF Z6ii - with 3 lenses so I no longher need to do the mathcs, but they are much dearer and larger.

[@PilotJimL]

The difference would be a 50mm FX lens on a DX body would be an equivalent 75mm, but the depth of field would remain as a 50mm, therefore appearing deeper than a 75mm lens DOF. Am I right?

[@irutgers]

does this impact our f-stop, is f/8 the same on an APS-C as on a full frame sensor?

[@okaro6595]

Yes it is same but it does not produce same results. For same results you should use f/5.6 on APS-C.

[@ChristineWilsonPhotography]

Goodness!! Very good explanation , if people still don't know what your talking about.. well what can you do? Just get your camera and get out there more time photographing and less time talking.

[@marvinphillips382]

Hello Matt, besides understanding "equivalent" focal lengths between full frame and cropped sensor cameras, what may confuse people more is DOF comparisons between full frame and cropped sensor cameras. A 50mm lens has the same depth of field no matter what camera you put it on. This means that a 50mm lens on a crop sensor camera has an equivalent focal length of 75mm compared to a full frame camera but it will not be able to produce as much of a blurred background as an actual 75mm lens on a full frame camera. I see many arguments on this topic. Can you confirm?

[@boazsayar1193]

There is no use to identify the AQV of the lens. If you crop in post, would you compute the crop factor then?

[@johnhjic2]

Hello Matt, To around 90% of people it does not matter one bitter, if it is DX or FF. The other 10% will know what they want. A bit hard most people do not print or edit there images. So I not sure event how meany Pro soothing wedding event need full frame. As the majority of wedding yes need and want great images that DX cameras can give. It is only the top 20% of wedding will require ff or bigger and the at that point they will by an appropriate charge. Keep well, keep safe and just enjoy what life brings. PS my Z9 is now hear....and the 300mm PF is a supper lens not using it much now I have the 500mm PF both just amazing bits of kit.

[@okaro6595]

No, the confusion is huge an people have bought wrong lenses because of it. Nobody is born a master who knows everything.

[@rappler32]

Half-frame, Super35, APS-C, DX... oh my!

[@patrickmolloy6994]

its something many don't get. re your review of the z 400mm ... I wrote of the 1.4 TC giving 560 then adding the 2xTC making an equivalent 1120mm! Boy did I get flaK!

[@richardslater677]

Would a good way to describe it be: A 50mm lens on a FF and a Crop sensor (CS) take the exactly the same picture. The CS picture, however, doesn’t record as much of the scene. So, you lose some of the picture around the edges. If you then take the CS photo and stretch it to the size of the FF sensor, the CS photo will still be cropped, but the subjects in the picture will be larger. Ie zoomed in. So, a cropped photo loses a factor of 1.5 of the content of the same picture on a FF. Then, enlarge the cropped photo by a factor of 1.5 and it will be the same size as the FF photo, with less content but larger subjects. Therefore, the cropped photo looks like a 75mm lens on a FF. Hence, 75mm equivalent. I’m no pro, so I’m prepared to be corrected.

[@okaro6595]

So they do not take the same picture. Stop confusing people.

[@richardslater677]

@@okaro6595 Thank you. Have a lovely day.

[@GaryFerrao]

noo. i've started with "cropped" sensor camera. and now that i got a FF, i think in terms of "equivalent" for a "cropped" sensor. i also don't like the word "cropped" but that's a different topic lol

[@steveboys5369]

Hi Matt, a really interesting video, thanks for sharing. I found a website that can give relative values across various sensor sizes. Search for "mmcalc". I'd be interested to better understand how F stop equivalents work too based on using DX vs FX cameras and DX/ FX lens combinations .. i.e. the same usable depth of field to essentially take a near identical image.

[@okaro6595]

There is a simple rule: to get equal look on DX you need to open the aperture by one f-stop and drop the ISO by half. The same of course applies when using the DX mode on an FX. Now of course it may be that your lens does not have wide enough aperture. Then you just have to use the widest available to get as close as possible. For example if someone uses 50 mm f/4 ISO 400 to get same on DX you should use 35 mm f/2.8 ISO 200. The shutter speed will be the same if the light is the same. To verify lets use DOFmaster and assume the distance is 5 meters. FX 50 mm f/4 Depth of field Near limit 4.04 m Far limit 6.56 m Total 2.52 m DX 35 mm f/2.8 Depth of field Near limit 4.07 m Far limit 6.49 m Total 2.42 m Close enough. The maximum bokeh blur on FX will be 50 / 4 = 12.5 mm and on DX 35 / 2.8 = 12.5 mm. For Canon users 1.33 f-stops would be better but one is still pretty good.

[@aarjaycee3601]

I do not own a full frame sensor camera, I have 2 Nikon DX types, a D3500 and a D7500 The crop factor is not an issue for me All I care about is, do I like the photo/s I just took? I NEVER review my shots and wonder what the results would have looked like if I'd taken them with, for example, a D850 or if I'd used my Pentax Super A I had 40+ years ago No all that matters is am I happy with the shot/s taken To my way of thinking people need to quit thinking in terms of FX/DX 35mm(full frame)/APSC etc Just use the equipment you have and assess the results in terms of are they what I intended or are they not If you dont have a 35mm size sensor camera, why would you question your results in terms of full frame vs crop sensor using a crop sensor? you're never going to change those results unless or until you employ a full frame camera Now some will argue that you can employ different focal lengths to achieve the "equivalent" field of view, perfectly true, but will it make the question you ask when reviewing your results any different? no, it will STILL be am I happy with the results? To me, we all really need to stop fretting over this The only thing that matters is the end result Yes, there is a difference, yes, we should be aware of it, but no, it should not have us all sweating over it, it doesn't matter at the end of the day, "am I happy with the photo/s I just took?"

[@cameraprepper7938]

It would be much easier if Lenses was called by the angle of view of the Lens and not the focal length of the Lens. I have used a lot of different Cameras, 110, 126, 135 and 120 film format Cameras, as well as 4"x5" and 5"x7" inch Cameras.

[@terilapetino6337]

Good explanation as usual. But in the "more reach" world, the comparisons always seem to be about the longer lenses which can be misleading for sure. When shooting wildlife, we are always trying to get more reach with less weight and less cost. The equivalent stuff drives me crazy because it doesn't get me any closer to my subject...it just means I have less pixels!

[@ericmeekey7886]

Less pixels with something like a Canon 90D? Or a teleconverter?

[@terilapetino6337]

@@ericmeekey7886 teleconverter. Switching to dx mode reduces the pixels but really doesn't get me any closer to the subject.

[@ericmeekey7886]

Use a DX camera to maintain higher resolution then.

[@okaro6595]

With serious wildlife photography you should really look at the pixel density. Not at the crop factor. Also remember that it is the only thing that changes. The lens will remain the same with same sharpness, the conditions will remain the same so you really do not get even that amount of extra reach. The crop factor and the equivalent focal length tell just the framing. It takes no issue on the quality of the image produced. Small sensor superzoom cameras boast huge equivalences above 1000 mm. That does not mean you can use them in any serious wildlife photography.

[@kstrohmeier]

My grandfather had a half frame 35mm camera. My 6 year old brain couldn't understand anything of his detailed explanation other than twice as many pictures. Wish we still had that camera.

[@MattIrwinPhotography]

Very interesting, would love to know what it was 😀

[@kstrohmeier]

​@@MattIrwinPhotography I recall is that it was a German camera, perhaps an AGFA.

[@bratt_116]

If 35 mm FF lens on crop camera looks like 50 mm on FF camera so how about 35 mm dx lens on crop camera ? Does it look like 35 mm on FF camera ?

[@gwhech]

Any lens on a dx body has the crop factor. So both a 35dx and ff lens both look similar to a 52.5 on a ff body

[@dominiclester3232]

Canikony are all equivalate...mate. Nice to see you are well anyway.

[@MattIrwinPhotography]

Nice one. 😀

[@gainde1137]

Is there a good lens for nikon which is 35mm equivalent? E.g. 23mm

[@MattIrwinPhotography]

The closest lens would be the Z 24mm 1.8 or the Z 26mm 2.8 pancake, which was just released. Either of the these options would be great. Also Viltrox make a pretty good 23mm 1.4 full AF lens for Z mount in APSC :)

[@gainde1137]

@@MattIrwinPhotography Thank you! The 23mm Viltrox would be the most appropriate.

[@siobhanexplores]

My film and digital SLR's take the same lenses (Canon EF). The DSLR is cropped and it drives me mad figuring out the equivalent on each focal length on zoom lenses. I know that I can buy EF-S lenses for it, but not much point when they wont work with the film camera.

[@okaro6595]

The focal lengths on EF-S lenses are the same 50 mm on EF is same as 50 mm on EF-S. Sure the lenses start at smaller focal lenghts. The typical standard zoom on EF-S is 18-55 mm while on EF it is 24-70 mm or 24-105 mm.

[@siobhanexplores]

@@okaro6595 A 50mm EF lens is equivalent to 80mm when used on a body with a crop sensor. A 50mm EF-S lens is 50mm when on a cropped body. It's not the same.

[@gerryvanmoorsel9345]

what happens when you use a Nikon made DX lens on an APSC - DX camera, is a 50mm DX lens still a 50mm field of view ?

[@MattIrwinPhotography]

Gerry I believe it will be 75mm equivalent when on DX / APSC camera. There is not a seperate focal length mm system for APSC lenses. 😀

[@tiagocosta1330]

(using a 50mm (75mm APS-C equivalent) as an example) This is tricky but the field of view doesn't change. The difference (usually) is that the image circle is smaller. discarding all the extra image data that the smaller sensor would never see anyway. However, putting a DX lens on a FX camera is where it gets tricky. The DX lens will force a crop on an FX camera and effectively, it will force a change to the field of view of the FX camera/sensor. This means that effectively, the DX lenses will behave as a 75mm in a FX camera/sensor. Now, in reality, does the field of view of the FX sensor actually change? No, it's still the same, it's just that, due to the smaller image circle of the DX lens, part of the FX sensor wll not be exposed to any light. This is very easy to see in a DSLR because when you put a DX lens on a FX camera and shoot, you will get a black border around the image circle. This doesn't mean that the lenses suddendly changes from a 50mm to 75mm,. The DX lenses is just discarding light (area) by projecting a smaller image circle. This won't work with (some) mirrorless cameras because, like Matt said, they automically crop the sensor to the size of the image circle of the attached lens. Hope this makes sense but in the grand scheme of things, none of it matters beyond the fact that you get a small zoom/crop when mounting lenses on diferent sized sensors.

[@gerryvanmoorsel9345]

@@MattIrwinPhotography thanks for replying Matt, I will take a closer look to better understand this 'lens designated focal lengths' and relationships to camera bodies and what it means to making images. The reality is a 50mm lens is a true 50mm lens with a '50mm field of view'' on a full frame / FX camera only.

[@MattIrwinPhotography]

@@gerryvanmoorsel9345 yep exactly. I think I will do a follow up vid with more detail. What do think?😀

[@gerryvanmoorsel9345]

@@tiagocosta1330 Thank you for your response, I find your comment very interesting reading and I will study this topic more to improve my understanding and to help me overcome any confussion.

[@paulmaddison6755]

Matt, what everybody forgets is that when putting a full frame lens on a dx camera, the f stop also attracts the 1.5 ratio because the light gathered by the lens is not all used by the sensor. Perhaps you could expand on this in one of your episodes. Regards Paul Maddison

[@jackmarkham1516]

That is not right. Go find out why.

[@rishikksh20]

Actually, it half baked truth, Crop Sensor just works as a cropping image. If you crop any full-frame image taken on 35 mm f1.8 lens to 1.5x crop factor on photoshop, it does change the perspective (focal length) to 52mm equivalent of that image but it has no impact on the brightness/exposure (remains of f1.8) and bokeh (remain of 35mm f1.8) of that image so cropping image on photoshop only changes focal length. Similarly, if you are using a 35 f1.8 mm Full Frame designed lens on a crop sensor camera you get perspective (focal length) of 52 mm with the exposure of f1.8 but you don't get bokeh of 52mm f1.8 instead you get bokeh of the same 35mm f1.8 which is roughly equivalent to bokeh of 52mm f2.8 lens (on full-frame) and that's why people said your f-stop also impact by crop ratio. But a crop sensor camera with a crop sensor lens produces a better image with less noise because a crop sensor lens converges all lights to a cropped sensor which gives a better light per pixel.

[@paulmaddison6755]

Jack, thanks for your challenge. However I am quoting Tony Northrup who gives a very cogent explanation at: KZbin "Crop Factor: Why you multiply the aperture by the crop factor when comparing lenses". If he's wrong then it strongly points to hearing another experts view. Perhaps Matt could run something on the topic as it compliments the aps-c(dx) versus Full frame he's just aired. Not looking for argument just enlightenment.

[@okaro6595]

If you have a DX camera it does not matter a bit whether you use DX or FX lenses. Also you are very confusing on what you say.

[@stevemccrary5499]

If my 16-50 mm DX lens is the equivalent of 24-75 on my Z50 and its also the equivalent of 24-75 on my Z6, why don't we just call it a 24-75 mm lens?

[@okaro6595]

Because it is 16-50 mm. It is not 24-75 mm. With smaller sensors you must use shorter focal lengths.

[@jeffreyneville9769]

I think what screws up everyone is they think a 50mm DX lens has been optimized to give the the same angle of view as a 50mm Full Frame (FX) lens mounted on a full frame camera which is not true. A 50mm FX lens on a DX (APS-C) camera as you state would be a 75mm equivalent and a 50mm DX lens on an APS-C camera is also 75mm equiv. Correct me if I am wrong the DX lenses are designed to be lighter and more compact on an APS-C camera than their full frame counterparts and the image circle is the same size as the APSC sensor which is not the case with the FX lens on the DX (APSC) body. DX lenses on Full Frame FX bodies either won't work or the FX body will go into DX (Crop Mode) and work the same as if on the DX body.

[@charlesdavis6371]

I asked a similar question - guess I'll have to try to do some tests on this. I get the FX to DX - it's the DX designated lenses that I'm wondering about.

[@jeffreyneville9769]

@@charlesdavis6371 I use to shoot APS-C D100;D200:D300 series cameras and basically as Matt states a 50mm FX lens is a 50mm lens irregardless of what body you put it on, you always have a crop factor on the APS-C bodies regardless of the Mfg. some you multiply the focal length by 1.4; 1.5 or 1.6 depending on the Manufacturer. A 50mm DX lens is optimized regarding it being a smaller optic, lighter etc. but it still represents a 75mm lens on a Full Frame Nikon because of the angle of view. The main reason its smaller is when you put the 50mm DX lens on the Nikon APS-C body the image falling on the sensor thru the lens has been designed to cover the smaller sensor edge to edge rather than the image falling beyond the sensor that an FX lens would do on the APS-C sensor resulting in a crop factor. Nikon USA has additional info if you need it.

[@charlesdavis6371]

@@jeffreyneville9769 - thank you.

[@thomaschamberlin2485]

I'm fine with describing it either way, but too many people do the math in their head on the fly and get it wrong and that drives me crazy.

[@samuelreyes9279]

Curious, why does that drive you crazy?

[@mikelyon5595]

I'm sorry some people who can't deal with what is common parlance because they refuse to give deference to the instructor! Most of us understand exactly what you're explaining. Thank you for sharing your experiences with the rest of us!

[@stuartmeador8993]

this completely avoids the reality that the perspective of a portrait subject at (say 6 feet) is the same no matter which focal length you use or how much or less surrounding area is included.

[@fenmoods]

Personally I don't like using term "equivalent" or "equate" or anything of the like. I prefer using the term crop itself.

[@cameraprepper7938]

Have you forgot "halfframe" analog film Cameras !? Those Cameras which used 35mm film, but only 18x24mm images on the film but 72 frames on a 36 frame film.

[@MattIrwinPhotography]

Yeah CP I don't remember all the film formats, like, APS, 'disc' and '110' and there were others ... as I said in the vid I can't remember them all :). Thanks so much for sharing. :)

[@Digmen1]

Matt, you sound like Sesame Street ! This one is smaller - this one is larger! (only joking)

[@neildavies2783]

I'm not very technically minded... but I get it 😉

[@boxoweasels]

Two big problems with the "equivalency" talk irritate me: 1. Photography educators who insist everyone buying their first camera MUST know about this equivalency BS. But you don't. You don't need to know. The ONLY time this equivalency BS has any value is when you are trying anticipate what angle of view a certain lens will give across different formats with the same aspect ratio, and frankly only pros and people with a lot of experience with primes or fixed focal length cameras are going to have the slightest clue what angle of view to expect from a given focal length. 2. Sloppy language use has confused a whole lot of people about what focal length is, and we now have people who think the lens literally "becomes" a different focal length, or expect that a 50mm aps-c lens and 50mm full frame lens will behave differently somehow. Do I have a solution? No. There's not really any good way to talk about this with the variety of sensor/film sizes available. Even if lenses were all marked with angle of view for their intended format instead of focal length, do you pick horizontal? vertical? diagonal? How completely meaningless would diagonal be for people. And then you have the whole mess of focus breathing and adapting lenses, or FX lenses on DX cameras, etc.

[@roybixby6135]

Too many people get more confused over depth of field - which does not change with different sized sensors (distance and aperture do change DOF)....

[@daviddyephotography]

obviously you put a lot of thought into this video, so why not make it real clear and use a image taken with the APC anf full frame using that same 50mm lens and show side by side to make it clear as the semantics of similar angle of 75mm doesn't make it really clear

[@fetzie23]

And then you can make things even more complicated by talking about a "negative crop factor compared to FX" for medium format sensors :)

[@MattIrwinPhotography]

Yes. Good point. Hmm maybe a follow up video …. 😀

[@okaro6595]

Not negative but smaller than 1.

[@lionhawk555]

Equivalent field-of-view. Not Equivalent in any other way.

[@Digmen1]

The united Nation should outlaw micro 4/3rds and DX and then we would not have this discussion, which has been going on for 20 years!

[@ericmeekey7886]

Eventually we'll stop all this silliness and just use degrees Field of View or FOV. I sourced a table below: www.nikonians.org/reviews/fov-tables

[@captureitphotography2352]

Crop factor affects comparable field of view, ISO, and aperture. I've used both APS-C and FF, and it's how I make sure I'm getting the same look no matter the camera. Why is this contentious? People run out of things to argue about for no reason?

[@EdwardKilner]

ISO is usually selected by the photographer and usually independently of focal length. It’s the gain adjustment on the A to D converter attached to the sensor. Aperture may be chosen by the metering system and if the central part of the image is brighter than what a full frame metering system will see, yes, it will be affected to yield the correct exposure. Coming from DX, I was surprised that f4 on FX had less depth of field and better bokeh but that is just an “equivalence” issue, not a physical one.