4 Telescopes Tested: Doublet vs. Triplet vs. Quadruplet vs Quintuplet

[@NebulaPhotos]

To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/NebulaPhotos/

[@rukiddin0669]

Congrats on going full time youtube/astro. Im sure it feels amazing!

[@luboinchina3013]

I have a question about your ASI2600. I am really considering to buy one, but I have heard they often develop an oil leak. How are you satisfied with yours? Are yours from the early batch or from the later batch where they claimed they fixed the problem?

[@LeeMize]

I have signed up.

[@NebulaPhotos]

@@luboinchina3013 Later batch (both bought in 2022) - so far, no issues.

[@luboinchina3013]

@@NebulaPhotos Thank you. I pulled the trigger, sold my upright bass and ordered the color version. Unfortunately the weather is getting worse 😂

[@Andros_Gaming]

The fact Nico took the rare clear nights to do this long comparison really shows how much he cares about creating good content. Clear skies are a rare thing precious thing.

[@Cult1022]

.. or he's run out of targets. We will never know.

[@timwilde4200]

Depends on where you live. Have a setup in outback Australia and it's the dead opposite. :)

[@crosisofborg5524]

I get clear skies nightly

[@DawgcityClev]

Clear skies are rare in your locations. Out west they are in abundance!

[@andrewwellum6472]

One of the few channels you can trust for an unbiased review, well done Nico!

[@meianoitee01]

This type of video is so important. Nowadays the social medias and forums are full of people who spread so much misinformation and make beginners much more confused. I have a WO Z61 and I'm so happy with that. But when I asked on Facebook groups about this scope. Many people said stupid things like doublett are terrible for astrophotography and I should not buy it etc.

[@NebulaPhotos]

Exactly, I've heard many people repeat that kind of thing without backing it up - the photos don't lie! Clear skies, Nico

[@meianoitee01]

@@NebulaPhotos Yup, some days ago I did see one of those comments on Facebook and I just checked the profile of the guy who gives the "tips". He didn't have a telescope. All his picture were taken with camera lenses. Camera lenses are great also, but the guy shouldn't advice another person about buying a telescope without have experience with one. 😅😂

[@johnkulczycki3021]

My Talahashi FS-60C is a doublet. It will take fine pics with either its reducer or flattener.

[@anuranjan0101]

I have wo zs61 and am so happy and infact for me the takeaway msg was WO61 is better bcz of performance and convenience of bahtinov mask and filter intake .

[@gghana]

I image with an Astrotech 80ed doublet. Yes there is a bit of CA. Does it cause a huge issue? No. My next scope will be a quadruplet, but there is absolutely nothing wrong with imaging with a doublet. Great video as always Nico.

[@mfaison]

The worst thing about Galileo's telescope wasn't the chromatic aberration, but the tiny, tiny exit pupil, due to using a concave (diverging) eyepiece. This made it look like you were viewing through a straw. We have a replica of Galileo's 30x telescope, and it's crazy to compare the view of Jupiter or the moon through the replica and through a cheap 90mm refractor. It's amazing that Galileo could discover anything with that thing!

[@NebulaPhotos]

Ooh, I should try that some time. Would love to actually see the difference! Thanks for the comment!

[@kalikiller1771]

Probably a lot easier back in the day without light pollution

[@Sciguy95]

​@@kalikiller1771I think they're talking about the tiny hole you have to look through making it more difficult to see anything through it, regardless of light quality.

[@alexiscolin1830]

And that's why we follow you : you do the job no one does. Plus the fact that your tutorials are incredibly useful, yeah 😅 Thank you very much

[@CuivTheLazyGeek]

Excellent overview Nico! My first real astrophoto scope was a doublet, and it was great!

[@microreniassance2929]

The Askar over all performance seems to be exceptional. The final image seems to pop and appear more visually interesting as opposed to the others. I'm impressed. Thanks for these great comparison videos. They are much appreciated and fascinating. I am surprised the doublet held it's own and excelled in some instances compared to the scopes with more glass. Great vido, Nico. Thanks much for your time.

[@AGCipher]

The intro, explaining the differences between the doublet-quintlet, was very clear and informative, thank you! :)

[@spunbearing]

I got my Sky Watcher APO 120 ED from All Star Telescopes years ago. They were very hands on in getting me everything I needed. It was an excellent experience. Great video to.

[@Astrolavista]

Oh man that was super interesting in a number of ways! Well worth the huge amount of work this must have taken to put together, it's going to be a very popular video. Congratulations on being full time on KZbin Nico, a feat not easily achieved but well deserved.

[@LogansAstro]

I have recently received my Askar 65PHQ and started to image with it so I was very encouraged by the results you got from that telescope.

[@ferenc-x7p]

Ahh, this is so excellent! where was this video 3 years ago, when I was browsing for a scope! Nico just made it easy! Just the fact that there are so little to none real reviews out there, and everyone is literally playing Russian roulette with thousands of dollars, Nico saves us with this video and I'm just gonna steer everyone here with the same question, that keep popping up on social media about what scope to get.

[@briankotak403]

Really useful comparison Nico. Thanks for taking the time to do this. My first telescope was an Orion EON 110mm doublet, bought 2 years ago. At the time I really hemmed and hawed over doublet vs triplet. Triplets were so much more expensive. Still happy with my decision as the optics are very good. Now I’ve added the WO ZenithStar 61. Nice little wide field scope. Dr B from Manitoba, Canada 🇨🇦

[@Wolfie6020]

Thank you for this video. Incredibly helpful when considering a new scope.

[@Si-fp2ij]

Thanks for posting this Nico, it’s going to help me in the selection of my first refractor 👍🏻

[@darcyf.5455]

thank you Nico, your videos never fail to give me free, quality content. clear skies.

[@TevisC]

This is a great video. It's important we get comparisons between similar hardware in one video. The Astrophotography community really needs an Rtings like site that will put the scopes through a battery of tests to verify manufacture claims and to disclose the quirks of use. Use a dial indicator to measure focuser slop, both side to side and in-out for use with an EAF. etc.etc. Mounts as well..

[@FrankB064-q6k]

I ended up going to All Star Telescope today and buying the WO61. Great review, thank you.

[@ycanerol]

What a fantastic video! This hobby really benefits from these type of data-backed comparisons, and I really appreciate that you are producing such comparisons with transparent disclosures of where the telescopes come from; such integrity is rare to come by these days. Another aspect which might not be apparent is that you switched the scope three times, during each imaging session to keep the test consistent; while most of us are barely managing a single set up! I for one am backing all the way off once I confirm the test shots look okay, let alone change the telescope after 50 minutes :D, kudos Nico!

[@joaomoreiraastrophotographer]

Another excelent vídeo 🤩 You inspire me to start astrophotography 1 year ago and i only can say "thank you so much for your vídeos". Can you do a top 5 telescopes vídeo? like Doublet top5 and triplet top 5?😁 thank you again 😁

[@BennyColyn]

The loss of star color in the last scope is at least in part due to the stretch PixInsight uses in its ScreenTransferFunction (it's basicly a HistogramTransformation) - a color-preserving stretch with ArcSinh or Generalized Hyperbolic Stretch will show that the stars very much still have color (until you burn out the core)

[@NebulaPhotos]

Great point! I thought about cutting that out because I realized it was sort of silly to be judging star color on the auto stretch for the exact reason you mentioned.

[@TheTonyairaero]

Hello, thanks in advance for the great videos. I would like to know your opinion about the Antlia Triband RGB Ultra filter. Or some video. Thanks for the reply Tony.

[@kristiankrekac1112]

A week away from my first imaging, last parts will soon arrive for the setup. I'm very excited to be able to do my own astrophotography images after years of wondering about it :D Nice video

[@Jaymz007]

Excellent video Nico! I know I had a discussion with you about the Askar 80 but ended up going with the Askar 65PHQ with the reducer. It worked out to be a bit better for the focal length needs. I am so happy with the scope. My only beef is the focuser is just a bit stiff on it. Not terrible both other than that, it really does a great job at color correction and has a super flat field. The reducer does a great job and doesn't detract from image quality. Best bang for the buck in my opinion! Cheers

[@tpolakis]

Nice job, Nico. Very calm style, with clear explanations.

[@masterxyr]

I always always enjoy the ride through your thoroughly informative videos! Seems a bit chilly there, for some reason! Thanks!

[@NebulaPhotos]

😁

[@markmayer9290]

Great comparison as always. I'm very happy with my WO triplets plus flatteners. There's a much better option for dealing with inserting filters, which as you show is quite difficult for some of these scopes: a filter drawer (e.g. from ZWO). Fits right into the standard 55 mm back focus requirement, and swapping filters is super easy, without disturbing your imaging train.

[@Wheeljack678]

I really wish more people would do honest reviews like these. They are really helpful and feels trustworthy. As someone who also has the Sharpstar EDPHII, my experiences are pretty much the same as yours (elongation in the corners, even with the reducer/flattner). The telescope is probably decent enough for its price, but I think the design of the reducer and the image quality is a bit meh compared to other, similar telescopes.

[@MrTimeuMorin]

after buying a eq35pro and a asiair mini the biggest astrograph i was able to fit in my budget was the askar fma 135. a gigantic 30mm f4.5 triplet with a field flat. results a very similar to the 65phq. i love it. and i can put a 1.25 filter in front of the scope.very economic :-) thank you for this great info.

[@ferenc-x7p]

Excellent little scope that literally almost fits in your pocket! I have it and I used it already once, unfortunately I can't buy clear skies and it's been very rare this last 3 months! Don't underestimate that tiny scope! It has a better corrected starfield than many camera lens that cost 3x.

[@astroindianx]

THX MAN, I WANT THIS KIND OF VIDEO.

[@LeeMize]

Amazing video, Nico. I haven't purchased a scope yet, but this information will help me for when I do.

[@jster91]

Another great video! Interesting to see how well an inexpensive doublet can do. I'm looking forward to using new AT80EDT triplet soon. Getting it set up... Just got my WO50mm guide scope from Agena Astro today and the ASI220mm mini. Waiting a day yet for the WO saddle handle. They were hard to find.

[@thomaskallenbach87]

I love my at80edt

[@jster91]

@@thomaskallenbach87 I'm still waiting on the field flattener from AT. So it's been a challenge to get focus without it.

[@mirko-astro]

Nico! Wonderful comparison! Love the fact that you point out minor differences. I think my favorite is the WO.

[@artiraina5857]

Love your videos Nico. I always wait for your videos and they really help in choosing the right gear for astrophotography. Great job Sir...👍

[@paulgagnon3124]

Hi Nico! I saw you walking around at NEAF 2023 but didn't get the chance to say hi. Just wanted to say thank you for the great content you are putting on your channel.

[@NebulaPhotos]

Hi Paul, glad to hear you are enjoying the videos! NEAF was a whirl-wind, but always fun to see everything in one place like that.

[@Rotceh-r4g]

Nico, nice job. Clear. Thorough. Well presented. Thanks for posting!

[@AndreH3d]

Thanks Nico! love this kind of tests!

[@alandyer910]

Excellent testing, as always! Thank you! I think the EON 70mm quad Astrograph Orion sells might be the same unit as the Meade 70mm you tested, and that I did as well a few years ago for S&T.

[@NebulaPhotos]

Ah, great to know. Thanks Alan!

[@evastronomy8048]

Thank you for this valuable information, I am at the point to buy my refractor and this video helped me very much to take the decision. Keep up the great job. Clear Skies!

[@fritzarken74]

Sei il migliore, i tuoi video sono esautivi, sono ottimi i paragoni dei vari telescopi che presenti, complimenti.

[@SvbonyOfficial]

Very Nice Comparison Reviews. GOOD JOB Nico.

[@stanmacdonald1073]

Thank you for your effort and clear, dark nights to test and put together a documentary on these scopes. - It is interesting to see how little the differences are between these scopes. The main difference appears to be the diameter and perceived brightness of the stars. They particularly difficult to compare because amount of stretch will vary with the exposure. - One possible solution might be to only integrate 2 or 3 images from the faster scopes to match the signal to noise ratio of the images and stretch the stars so their peak brightness match using the same transformation curve.

[@nr-nj7ur]

Thanks a lot for a very detailed information... Nick... Can you make one video the differences if using DSLR and telephoto compared to telescopes as a DSLR lens

[@calummckinney]

amazingly informative video - I learned so much

[@kevinashley478]

HALLELUJAH AND THANK YOU!!! I needed this shootout. I have just started, but I did have a smile seeing that you had to dig out some snow...lol, we didn't see a single snowflake at all this year.

[@groundhoppingwlkp3622]

Great review. So it's mostly question what is more important - F-stop, tighter stars, better handling because differences in raw image are minor. IMO Askar wins in that comparison, but suprisingly WO with flattener is pretty close on 2nd, Sharpstar last

[@poruatokin]

Not surprising IMO, the WO FPL-53 glass is far superior to the Sharpstar's "undisclosed" glass specs.

[@harshraojr]

Astrophotography is very expensive hobby, thanks for seating out in chilly ice cold night to reviews these scopes in detail. Appreciate the effort.

[@lichasvocke8642]

Great and interesting Video! Do you have any plans when you will do the critique stream/video? Really looking forward to it

[@NebulaPhotos]

Thanks! Can't give a date on the critique, but I'm making progress going through the submissions - it's just me, so it takes a long time. Clear skies, Nico

[@davids2000]

Hello. I enjoy your videos. Would you do a video about the new strain wave mounts? Im interested in the Nyx and wonder if companies like Celestron will offer these new types of mounts.

[@NebulaPhotos]

I reviewed a couple strain wave mounts in December -- the AM5 and HEM27: kzbin.info/www/bejne/d6OVoYV-rNF7iqs I'd love to check out the NYX-101 in the next round-up - thanks for the input.

[@GrundleStiltSkin]

word is celestron is working on one.

[@geldingmakr]

Thanks for another great video 👏

[@jedashford8579]

I'm new, but learning fast and love this comparison! Thank you for putting in this work for the community!

[@63sgjunior]

An excellent test and analysis thanks for taking the time. I'm sure a lot of people will be interested as we're all probably scope junkies at heart and who doesn't want a new scope? Well we can't afford to test them all so thanks for the comparison.

[@s.m8766]

That intro track is actually kinda sick!

[@randalljames1]

appreciate the videos and the information you share out... I did a few shots with a good 105mm on a tripod and had success.. So... your videos convey the fact that if you are going to spend? best spend on what your expectations are going to need.. with that... eqr6 pro, askar 65phq, a smallish guide scope combo svbony 105/106... I am actually going to run my first sessions with a wide FOV on my 105mm F2.8 Nikon lense.. cost as much as the telescope but is really a great lense I use regularly. I already have plenty of SBC (raspberry pi) that I have installed "astroberry" on and have been working with a number of different software combo's.. Seems no one has a lock on this part of the hobby... I am now trying to find where you buy "clear sky" time.... I called the city... no go.... .

[@olivierrevert8165]

Excellent video, very well done and interesting 👍👍👍

[@johnellsphoto]

Quite engaging and worthwhile. Thanks!

[@kevinashley478]

Hey Nico. Your videos are an absolute go-to for anyone just getting into the hobby or someone thinking about getting into it. And you have covered reflecting and refractor telescopes in-depth, and the different camera types as well. Could you do a video on what I call the mash up telescopes, like Richey Chretien Reflecting and MAK, and SCT (although isn't a MAK just a sublevel of the SCT? )?? I have been looking at a few MAK's and they seem to be more along the lines of what I want. Good for astrophotography and visual. I think it would be very helpful to do a video reviewing those three, pros and cons, and what separates them from what I would call "classical" telescopes.

[@NebulaPhotos]

They are popular telescope designs for solar system objects (sun, moon, and planets) both visually and photographically. The typical issue with these telescopes for deep sky astrophotography is they are usually slower (f/10+), and can be fussy to collimate. I might get to them eventually on the channel.

[@kevinashley478]

@@NebulaPhotos oh ok. Good to know. After watching this video, I am thinking that the Quint would be my best bet, for the money.

[@VideoSlave01]

Good show sir! 👏 ❤ 🔥 🌟 📷 fantastic video, I am literally scratching my head trying to start my astro photography journey. Looking for a basic scope to sit on my EQ5 and there is so much info out there but not as many clear and informative comparisons like this. Bless you 🙏🏽

[@ayahibrahimahmedismaiel2174]

i try to understand what said in the episodes , i proud to be member in this channel.

[@JeanLegros_mtl]

Really well done. Thank you!

[@GhostSenshi]

Thanks for the video Nico

[@fgandola76]

First of all, thx a ton for putting that together. this is extremely usefull, especially for me who is still on the beginer side, and was wondering this exact same question about the usefullness of triplet APO vs a simple doublet while shooting narroband..I am confused with something though: you mention in your test testing Doublet but as you say later in the video you tested the williams optic with the extra flattener, which makes it doublet from a chromatic perspective but in essence a triplet but i am fine with that other than you could have mentionned the extra cost i suppose. My question is more about the Sharpstar. It is presented as triplet APO. If i understand well its design, from a chromatic perspective it has 2 optical elements, and because one is ED then is can be called APO. The third element is the flatener, is that correct ? Now for the review result, do you have an explanation about the fact the quintuplet works better than the doublet + flatener ? is it link really to the fact it is quintuplet or could it be quality of the maker that makes the diference. If you get the opportunity, i d love to see the same test with same manufacturer doublet + flatener and quadruplet or quintuplet ;-) Again thx a ton for sharing your experience !!! (i apologize for potential inacuracy, i am no expert...)

[@OlliesSpace]

Great job Nico at looking at these four scopes, really useful information. 👍

[@jimmirow]

Im a newbie newbie and im grateful for this honest assesment

[@dmintz88]

Great video, Nico!

[@jamesf2697]

Love your videos! Possible the reason for the three screw extra rotation ring might be in case you are using a circular polarizing filter so you can rotate the filter compared to the camera?

[@rickspeedygonzales]

That was a great review, well done

[@JoeJaguar]

great video even though i dont do imaging anymore iam sure will help alot people

[@alpsalish]

Yeah, damn Niko/Nico. Great video!

[@PATTACAT72]

We need people like him, Good stuff!

[@-donkey_696_]

New subscriber Nico ,just got my new mount EQ6R PRO ,had to wait 11 months to get got a 12sct want to get a apo ,thanks for the comparison, very well done ,just waiting for clear skis been cloudy for the last week :( Look forward to more video's and comparisons

[@alfredobeltran611]

Thanks for these detailed review, Nico. If I were in the market for one of those four telescopes, I think it would be the Askar. Much better stars and seems to have a similar SNR (while a little on the lower side). Any of those seems to be a keeper, though.

[@gregerianne3880]

Great, thorough review as always, Nico. Terrific. I didn't see that the IR-Cut filter you used from Astonomik has a very different profile from the IR-Cut filter used on the ASI2600MC Pro. Was there a reason you chose to use this for your OSC images? Loved the review! Thanks again for the hard work and time you put in for this, Nico.

[@NebulaPhotos]

Yes, old habit as I used to never be able to remember which Astro cameras have IR cut and which just have clear AR windows so I almost always use one, but in this case wasn’t necessary as the ASI2600MC does use IR-cut as most the modern models do.

[@gregerianne3880]

@@NebulaPhotos Ah, okay. Thanks, Nico. Wanted to be sure I didn't need to get one of those!! 🙂

[@yangyunbo1]

nice comparison！well done！！

[@dirkfierce2525]

Excellent video as always. Can you tell me what the backfocus of the Meade is? I have one on the way.

[@NebulaPhotos]

It doesn’t have a specific backfocus you have to hit, but if you use the standard 55mm you will have focus travel to work with in both directions.

[@astrozeugs]

Hi, the small rotator with screws on the reducer (second telescope) makes sense, because if you screw your dslr on and it is in an awkward position, you can adjust it once. You don't need to use the main rotator with the focuser and turn it to an awkward position. Regards Andreas

[@NebulaPhotos]

Ah, didn’t think of that. Thanks

[@charlesdufrene6244]

Just bought a 102mm SVbony duplet on an Amazon lightning sale and am concerned about losing green light as achromats aren't RGB like an Apo. This video implies may not be a deal breaker for a beginner in astrophotography?

[@hunterwells7647]

Great review! As far as cost goes, at 4:50 you mentioned that these prices include the field flatteners, but the links in the description for the William Optics scope bring the total to over $1000. The Sharpstar comes out to over $900. What am I missing? Edit: I figured it out, the links are in CAD. Whoops

[@Westlake]

Always terrific content Nico! Congrats on the move to doing Nebula Photos full-time!

[@mrbaab5932]

The tripet objective or more elements in the objective can also correct for secondary axial color. Also axial color can blur the spot decreasing the contrast before you can actually see the color change in the spot.

[@4mikeyd]

Thank you very much for making this Comparison video. I have the William Optics 72mm Doublet. I haven't used it yet. But I believe that William Optics OTA ED APO Doublet can hang with the Quadruplet, and Quintuplet with ease. The Triplet does have a wider Field of view. But the clarity is not as good as the Doublet, Quadruplet and Quintuplet. I believe that it's really not worth buying the other OTA's unless you are buying a faster and larger OTA. I think that the clarity from the William Optics OTA ED APO Doublet is Amazing. Thank You again for making and sharing this video out. Clear Skies. Michael.

[@kevinashley478]

Hey Nico, i was wondering, given how much astrophotography equipment is, would you recommend insuring it? I mean, based on what i have seen, you can accrue $20,000-$30,000 worth of gear rather quickly. You can drop $100-$400 on each filter, $1,000-$3,000 on each scope, and $2,000-$5,000 per mount, and that doesn't count accessories like power supplies, laptops/tablets, software, etc.

[@NebulaPhotos]

Yes, PPA has a good program for that. Or add as a rider to your homeowners.

[@Ronbo765]

Thanks!

[@mikelockwood2104]

very good learning experience watching this video....this is well done sir

[@exif6839]

Doublet is not doublet. It depends extremely to the used glass: Flint/Korn or ED-Doublet or FPL53/ZK7 and also very important: the level of perfection in terms of strehlvalue, polysrehl, depends on the speed of the doublet. So with the FPL53/ZK7 on f11 you can get Strehl levels over a high quality triplet with f7 (e.g. from TAK) in the area of 0,99. So also a doublet can be called „Superapo“

[@siegfriednoet]

Very interesting comparison, though hard to see with the KZbin compression. So about placing the filters, if I saw it right than the William Optics scope was the only one where the filter sit "backwards" than ?

[@NebulaPhotos]

That’s correct

[@DanielSuh]

So much appreciate when you do this type of comparisons. I own an Explore Scientific AR 102 that I purchased with astrophotography in mind but every time bright stars turn into purple that are very difficult to remove even in post-processing. I hope to sell it and buy a APO under $1000 and your videos help me a lot.

[@gregl4791]

Wonderful presentation. Bravo!

[@sofjanmustopoh7232]

Thank you for the in depth test

[@sergeyt.7564]

Hi Nico, thank you for nice comparing video. But you miss to compare initial frame in fits format. We have a nice stacking and processing result. It will be more honestly. What you think?

[@kalebanderson6564]

Since youve used both the fra300 and the phq65 what are your opinions about both? I am torn between the two, and the fra400, theres no videos or reviews comparing the different lines. The only thing I've heard is that the phq line has slightly sharper stars but since its slower it will take a lot longer. I would also most likely get the reducer for the phq just to make it a bit faster but not sure if it would be better to just get the fra300 at that point.

[@NebulaPhotos]

Hi Kaleb, they are both great optically so just get whichever Field of View appeals to you more. Check out blackwater skies imaging toolbox or telescopius to visualize the field of view with these telescopes and your camera. You may also want to check out my review of the Askar V: kzbin.info/www/bejne/eJ-7noSQjpx2hZo which is a new option they have that offers lots of focal length options in one system.

[@kalebanderson6564]

@@NebulaPhotos that telescope definitely caught my eye but it is slightly out of my price range and I mainly want to stick to a wider field of view anyways. And this will be my first telescope so I don’t have anything specific in mind that I really want to go after. just looking to go after nebulae and maybe do mosaics. If you said both have great optics then I guess I’ll settle on the fra400 because it’s faster and I heard that makes a big difference for mosaics. And I can always get the reducer to make it every faster. Thanks for your input!

[@ptanawong]

May I ask if the Sharpstar also good for visual observation? Especially the faint DSO because the aperture seems to be quite small.

[@NebulaPhotos]

I wouldn't recommend any of these for visual observation. For DSOs, you'd be much better off with a dobsonian. Bigger is better, but keep in mind the weight and practicality of moving it.

[@ptanawong]

@@NebulaPhotos thanks a lot for your reply.

[@ronboff3461]

excellent job! thank you

[@erocoptics5642]

As an astronomical Optical technician. Nice tutorial.

[@raytbrown2]

How funny! I viewed the Askar as a more civilized picture as it was less "a mess with noise". Of all 4,it was my preferred image. Maybe less true to life, but better looking.

[@TheJimtanker]

What kind of camera would you recommend for a beginner?

[@poruatokin]

Second hand DSLR's such as a Canon crop sensor are ideal

[@sreeshab4093]

Great review, much needed.

[@randydewees7338]

I want to point out a mistake - you comparing the size of a human eye pupil to the size of a camera sensor doesn't make any sense. The eye pupil does not collect light at the focal plane, it does at the exit pupil of the eyepiece. The eyepiece has a lens or lenses that act as a "field lens", redirecting off axis cones inward in the eyepiece, to create the exit pupil of the telescope system. By definition a field lens is at or very near the focal plane. So, a very wide part of the focal plane can make it into the eye via the exit pupil. The actual situation is that when viewing by eye, wide field views are at low power. Therefore the increased blur caused by the field curvature of a simple objective is not magnified very much.

[@NebulaPhotos]

The first paragraph makes sense to me, the second one I’m still puzzled by. You are saying we can see the field curvature but it’s not magnified enough to really make out the distortion? Why is coma on a reflector so clear to see then? Why do visual folks often use coma correctors, but not field flatteners?

[@NebulaPhotos]

And wanted to add. Thank you for your comment. I jumped right into astrophotography so visual is a weak spot for me, and I always want to learn more. Helpful comments like yours are very much appreciated! - Nico

[@randydewees7338]

@@NebulaPhotos First, my response were very brief and incomplete, trying to explain these things thoroughly is like writing a chapter in a textbook. I do kind of enjoy trying to condense a subject but sometimes the result isn’t very clear. Also, I can’t just throw in a diagram. Diagrams are an optics tradition right back to ancient times. Down below I’ve expanded my explanations a bit. And I’m suggesting a couple of references for those snowy nights. "Modern Optical Engineering", by Warren J. Smith --- General optical subjects including first order principles and aberrations. Warren was one solid dude, but he died in 2008, so any edition any year "Star Testing Telescopes", by Harold Richard Suiter, Telescope subjects - design, testing, aberrations. A must have very readable wealth of optical knowledge. I like the first edition - elegant black and white, but Harold is a good guy and he’s alive, so maybe buy a new one. What I tried to say in the second part of my comment was that the field curvature aberration in these small simple refractors does not increase enough at wider fields of view to be bothersome in visual use. The aberration is relatively small with these F6-F8 refractors. Since the focal “plane” has spherical curvature, the aberration increases to the square of the image height. So, if at 5mm off axis the aberration is 10 microns, at 10mm off axis it is 40 microns. This is bad for imaging, but hard to see in visual observing because that is still a pretty small blur. The eyepiece is essentially a magnifier the observer uses for examining the image. To see a wide field the eyepiece must have a long focal length, or low magnification. That compensates and the apparent field curvature aberration only increases in a linear fashion with field. For visual observing the quality of the eyepiece is of more importance for sharp wide fields. It is a bit different with Newtonians. The field curvature of Newts is less than for these refractors, so that’s not as much of a problem. But coma is. It has a linear scaling with field and aperture diameter. But it has a cubed scaling with F-number! Your typical 8”F6 Dob doesn’t have bothersome coma for visual use. And such like is seldom used for imaging unless just playing around. But a common imaging Newt is a 8”F4. This scope has 3.4 times the coma of the F6. It has become noticeable in visual use and I’d think very limiting in imaging. Now double the size to a fairly common 16” and you can see why coma correctors (ComaCor) are popular. I had an 18”F4.2 for a while and it was borderline, a coma corrector was useful but not absolutely necessary. An, even more so than the F6 refractor, fast Newts require high quality eyepieces.

[@NebulaPhotos]

@@randydewees7338 Thanks you very much for taking the time Randy! I was able to follow your comment perfectly. I think the missing piece for me was your note that the quality of the eyepiece is just as important for a crisp wide view, and the notes about on-axis vs. off-axis performance. I wasn't thinking about the fact that an eyepiece is altering the image (for better or worse). I've admittedly never invested in eyepieces with a wide FOV, which is why intuitively a super-wide field (perhaps even wider than the the DSLR FOV?) didn't occur to me. Thanks again! Nico

[@rimantasri4578]

To be honest, looking at the last comparison pictures (13:26), it seems like the quintuplet really shows not only much sharper stars, but the DSO itself, while all other scopes (they're of very similar performance) produce somewhat soft-feeling images.