Matching cameras with a light meter (FS7/A7r III)

[@behrensleo]

Hey! Thanks for this video. What if I choose to use a speed booster on either of the cameras? How do I dial in that? Let's say the FS7 has a speed booster mounted, but the A7III does not. Wouldn't that also change the f-stop number? I mean, the differences between the cameras and the depth of field would be greater? The FS7 would clearly give a brighter image with more light entering the sensor because you get a stop or two more with the speed booster, don't you? Doesn't the FS7 also produce much brighter images since the native ISO is 2000? I'm just not sure how to calculate with a speed booster. Or is there no difference in what you dial in? Sorry. I'm just a bit confused. My second question is; I bought the newest Sekonic light meter, and you can choose different options such as HD 1080 or CINE style. FS7 has CINE MODE when shooting in LOG. But A7III does not. Yes, you can shoot flat with A7III, but you don't have the option to choose CINE mode. What mode would you choose in the light meter?

[@ИльсурГареев-п9ы]

Thank you Robert! It's very useful videos!

[@andyschiemo]

I think you've touched on this before, but are you exposing to the right (ETTR) or over exposing when using S-log 3? Or do you mainly go with what the light meter displays? Thanks for these videos by the way, they're very helpful!

[@cgshen7183]

Andy Schiemo I think he exposes mid-gray to 42 IRE

[@robchado]

I use a Speedbooster which gives me an extra stop of light and outputs middle gray to 41 IRE, which is the specific level published by Sony. I primarily rely on my meter to set exposure, ETTR is based off of histograms and don't have much application with waveforms. IMO, the ETTR method is not very precise and is a method I would personally not use. I'll sometimes overexpose for a lower noise floor, depending on the scene, but by very specific amounts (exactly 1 or 2 stops). For that, I'll absolutely use (and need) a light meter.

[@andyschiemo]

@@robchado Thanks!

[@davidprice5100]

Out of curiosity Robert do you find shooting in slog3 on an 8 bit camera such as a7r3 works well? (I have recently gone sony a7sii but have been using cine gamma modified profile largely so far). I had heard generally speaking to shoot log on 10 bit cameras and in scenes where dynamic range calls for it? Obviously rules can be broken and some of this stuff is tech science vs what actually works having tried it firsthand 😂

[@cgshen7183]

what if you crank up the A7R3 to 2000iso as well? would that be easier (especially with a less noisy camera like A7M3/A7S2)?

[@robchado]

I generally try to never adjust ISO, especially when shooting log. Adjusting ISO generally starts messing with dynamic range which is my priority.

[@cgshen7183]

@@robchado I agree with you on dynamic range...btw do you think that FS7 is a valid option from 2019 into the future (mainly for Film School)? I kinda like the F55 but the FZ mount don't take a speedbooster (which I really love). In theory tho FS7 can produce the same image quality of a F5 (cuz they have the same sensor and color science)?

[@cgshen7183]

@@makosports I know but that's extra money to spend...you have to buy raw recorder and new media cards...raw is too much for me, for basic color correction and grade I think 10bit 4:2:2 is enough

[@cgshen7183]

@@makosports Where I live, the F5 is just 25% more expensive than the FS7. And uhh 8bit is...fine, it just lacks that smoother tone transition...I've wasted too much time and money on different cameras, I need to settle down with a good one for at least a few years.

[@matthewroper3432]

G'day Rob, great video mate! Any chance you could explain why higher ISOs tend to give you more stops above middle grey, relative to lower ISOs? This seems opposite to what is preferable; if I'm shooting talent in a super bright daytime park, then (pretending I don't have NDs) I would logically shoot at a lower ISO because of a high ambient light level. But doing this leaves me with less highlight latitude, which is what I would want in such a scene, as there's a lot of the image (sky, sun) that would be brighter than the talent. Conversely, if I am shooting in a dark street and exposing for my talent, and bump up to a higher ISO, I'll have less data in the shadows to work with, even though the majority of the surrounding scene would be below middle grey. Doesn't this also mean that it's a blessing, in some capacity, rather than a curse, that the A7S i has a native ISO of 3200 in SLOG for daylight shooting (assuming I do have NDs)? Thanks!

[@michaelfrymus]

Question: You say you need a speedbooster with the FS7, so that means you use non-native sony lenses? what mount(s) do you use then? Since there isnt a sony to sony speed booster as far as I know

[@robchado]

That is correct. All my lenses are EF-mount.

[@PushMoreButtons]

Is that an A7 Red

[@cgshen7183]

Of course it is, it just happens to have sony on top. It's an A7 with built-in 8K vistavision sensor

[@BreadcrumbFilms]

Hi Robert. Love the vids. I am trying to practise the discipline if using a light meter. The question I have is that as we know the fs7 at 2000 iso is noisy in the shadows so I generally rate mine at 1000EI to overexposed the image to lower the noise floor in the grade. How would this work with a light meter? Should I set it up to read for 1000iso? ( I guess I would have to keep in mind the amount of latitude I have above and below middle grey will shift. eg 6 stops above middle grey will become 5) ) I ask this as you seem to use your light meter set to 2000 iso for fs7 but doesn't this give you those noisy shadows?

[@DIMITRISEMENIC]

Hi Will, I am forwarding you some answers from the FS7 group on Facebook. And if not, you can also join the group. I found some very useful answers there. 1 - "I've found that metering at 1000 on my meter, gives me accurate (middle grey at 41%) exposure when the camera is at base 2000EI. To test it just get the camera exposed at 2000EI using a grey card. Waveform will do, but false colour better. Look at your T Stop, then adjust the ISO on your meter until the T Stop is the same." 2 - "I allways (over) expose Slog3 +1 stop for less noise. So the lightmeter is on iso 1000. Allways monitor your highlights with this setting." 3 - "Monitor with “false colour” on and pack your light meter away😀" 4 - I like to use my meter to get ratios but use false color and waveform for exposure as well. Beyond their answer, I would say, do some tests, try at home differents ISO, EI and see which light you like the most, so you don't have to improvise once on the set.

[@davidprice5100]

Hi Robert thanks for the great video! I gather you calibrated your light meter via a calibration card prior to this video? Is this video how you do it? kzbin.info/www/bejne/h3fLgGhmo518n9k If not how do you do it? To clarify: In this example at the beginning you are running an slog3 to rec. 709 LUT on the small hd and using false color to check exposure levels relative to rec. 709? so skin tones are 60-70 ire for 709 LUT but in reality being recorded in camera in slog3 at 55ire. I gather in this instance you decided on an fstop of f4 (as you said your chosen middle grey) for a7r3 metered it which showed f5.6 and had the light dimmed accordingly?

[@robchado]

Yes! I go over my process on calibration in my spot metering episode. For every camera/gamma curve, I’ll calibrate via middle grey and my meter should be set. I always set skin tones via Rec709 since that’s what’s always being delivered to- I hardly check skin tones in LOG once my meter is calibrated.

[@davidprice5100]

@@robchado Thanks so much man just discovered your channel will subscribe.