At 1080p, is there a difference between a good zoom and a prime?

Started by mannfilm, July 26, 2014, 07:03:58 PM

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mannfilm

Anyone notice  any difference between using a good zoom vs. a prime at 1080p, a very small frame size? I've done some tests between a new canon zoom and an older ziess prime, and I cannot see any difference (other then slight color variations.) I know the still photography pro's all use primes, but they are using exponentially larger frame sizes then 1080p.

Walter Schulz

Quote from: mannfilm on July 26, 2014, 07:03:58 PM
I know the still photography pro's all use primes

As far as I can tell: They Most use every tool suitable for the task at hand, including zooms.

dmilligan

The main advantage of primes, at least in my book, is the amount of aperture you get for the price. I could never afford the 70-200mm f/2.8, but the 200mm f/2.8 I can. I'd much rather have that than 70-200mm f/4, a lens that is still almost 2x expensive as the 200 f/2.8. And the difference between f/2.8 and f/4 is very noticeable.

Audionut


Midphase

I agree, a good fast prime is hard to beat for sharpness, low chromatic aberration, and generally wide aperture range.

It's not just for still photography, if you're on a film set, you'd be hard pressed to find a DP who doesn't favor primes over general purpose zooms.

Thomas Worth

I generally prefer zooms. There's hardly any difference in quality these days. A crappy prime is still worse than a great zoom. I have some "fast" primes that look terrible near their max aperture. On the other hand, my Nikon 80-200 looks awesome at any stop.

The only downside to zooms as far as I'm concerned is speed (max aperture). You won't find a good 35mm format zoom that will open up more than f/2.8. There have been times I've wanted more light, so I switched to a prime. Canon has some good, cheap primes that will give you a sharp image at f/2. The 50mm f/1.4 and 85mm f/1.8 are fast and look great. Good luck with focus at those stops. ;)

Oh and I wouldn't bother with "kit" zooms, or ones with a variable max aperture (e.g. f/3.5-5.6). They're okay for a beginner, but not useful for professional work unless you're on the sun.

Quote from: Midphase on July 27, 2014, 04:55:06 AM
if you're on a film set, you'd be hard pressed to find a DP who doesn't favor primes over general purpose zooms.
Things are changing. I wouldn't be surprised if more and more DPs start requesting two zooms per camera and that's it. Check out the Fujinon 19-90mm T2.9. A DP friend used it on some gigs and loves it. Canon also make some nice cinema zooms, a 15.5-47mm T2.8 and a 30-105mm T2.8.

Oswald

Yeah, but they cost more than black market kidney. :D

But I really like C mount zoom lenses. I have 8-48 f1.0 and I using it when shooting gigs etc. It is parfocal, relatively sharp at f3-4 anf aparture ring is smooth.

But yeah, I am amateur and I heard also that fujinon and canon cine zooms are popular. :)
7D, EOS-M & 100D.100b ΒΆ  Sigma 18-35mm, Canon 50mm F1.8, 22 STM, 8-48mm f1.0, 18-55 EF-M STM

ansius

I prefer primes for following reasons:

*) mostly you would use manual ones so old m42 mount ones are extremely cheep for their performance.
*) most primes have longer focus turn so easier to focus.
*) most primes have way less aberrations and much nicer bokeh

?) sharpness can work against you, because to sharp lens will introduce moire to any first generation DSLR when whole sensor is sampled with pixel skipping. On the other hand - sharpens is key for crop raw modes

-) good zooms are expensive
-) many of them physically change dimensions when zoomed, thus hassle with adjusting matte box

+ you can get good older cinema zooms for same price as modern photo zooms, but with all the cinema manual lens goodies.
Canon EOS 7D & 40D, EF-S 17-85mm IS USM, EF 28-300mm IS USM, Mir-20, Mir-1, Helios 44-5, Zenitar ME1, Industar 50-2, Industar 61L/Z-MC, Jupiter 37A, TAIR-3
http://www.ansius.lv http://ansius.500px.com

Thomas Worth

The Tokina 11-16mm is a great zoom, and very wide. I shot a video with a rehoused one in PL mount on an FS700 and it looks awesome. In fact, I cut between the Tokina and a Zeiss 100mm prime, and the Tokina looks every bit as good to me. It's only for APS-C cameras, though. A friend just shot a feature and used the Tokina quite a bit. There's lot of low light stuff in the movie and at f/2.8 it's not unreasonable to shoot run-and-gun night exteriors with it.

KMikhail

I own and use 85LII and 24-70L2.8II. The latter one is freakishly sharp in the center - moire is visible straight at 2.8. Not so good in the corners (at 2.8), but as zooms go - very, very good. So, as I stop down - center isn't really improving, neither sharpness nor micro contrast and this quality extends somewhere to sides.

24mm, f/2.8, 5D3, from RAW, obviously.
http://kartashovs.com/photo/2014_07_03_Randy_Tractors/2014_07_M03-2136.MP4

Once I push 85LII to f/1.8 it also becomes seriously sharp and contrasty in the center (actually this is my complain with respect to 85LII and 50L, they share this stopped-down behavior, I'd love to have it right at 1.2). At f/4 it is at optimum all over the frame and sharpness/contrast is top notch. Though, artistically it is not as fun anymore, I rarely go below 1.8. At 2.5 it is sharp everywhere, but not contrasty everywhere. Yup, I am the one geek who tests his lenses with MTF and TV charts! :) Bokeh is nice with both, with an edge to 85L. But in this case it is far, far less important than f1.2 vs. f2.8.

Hence, my point of view is: at current stage of tech zooms are very, very close to fixed lenses at the same apertures and at times actually even better (24L aint as sharp as my zoom at 2.8) due to necessity to be ultra-bright. So, it boils down to what aperture you need and how much money do you have. Though, out of newer 24/28/35 IS lenses only the last one is ~=  +- my zoom optically.

Regards,
Mikhail

dubzeebass

I'm all vintage Contax Zeiss. There is a difference between cheap Canon lenses and these pricey beasts. It starts with microcontrast and field rendering and continues from there. There's a reason so many pros use Zeiss!

reddeercity

 I have both Zooms(24-70,70-200mm) & Prime (100mm macro) EF Canon f2.8L lens these are great outdoors specifically the 24-70 f2.8L @ f4.0 - 9.1 , very sharp.
Have a look a the Sigma Primes , I have a 50mm f1.4 not very expensive  at least compared to Canon "L" lens very sharp @ f 2.0 - 2.4.
The Sigma surprised my the most , the quality is equal to Canon . I shot my last doc. with it , In fact I use it most of the time for internal  shots now.
Great low light performance for the price point.

mannfilm

Okay, but are you guys talking at the  "tiny" 1080p video frame size, or the 3X larger still photography frame sizes of 5700 X 3800?  If you can see a difference at 1/3 full size, would not the difference be humongous and hideous at full size?


Midphase

Quote from: mannfilm on July 29, 2014, 07:47:51 PM
Okay, but are you guys talking at the  "tiny" 1080p video frame size, or the 3X larger still photography frame sizes of 5700 X 3800?  If you can see a difference at 1/3 full size, would not the difference be humongous and hideous at full size?

The difference is noticeable, and even more so when shooting Raw which has more detail and dynamic information. I realize that there is a bit of a snobbish attitude among professional cinematographers when it comes to lenses. Realistically speaking, I don't know if a $18,000 Angenieux lens is 10X better looking than a good Zeiss, but I will say that the difference between low quality glass (i.e. entry level Canon) and higher end like Zeiss and Canon L primes is very noticeable when shooting video.

Audionut

When you're shooting H.264, the encoder kills fine details, so in terms of fine detail/sharpness, you can relax the lens requirements and still have the same subjective quality as some super expensive lens.

As Midphase points out, when you're shooting raw, it's an entirely different matter.  There is no sharpness limit set by the encoder, so you become lens limited.  When you've had a chance to use good glass, you fully understand why everyone says, "use good glass".


mannfilm

We're all right, and wrong at the same time. Turns out it depends on which zoom you are talking about (duh!) Prime does beat crappy zoom's, like the 24 - 70mm. But no difference between a prime and a great, modern zoom, like the 24-105 "L" , which is what I have. After a quick net search, turns out even the pro photographers are dumping their primes for the 24-105 "L", and they are shooting full rez photo's. Only difference is the primes are faster.  And honestly, I do not shoot at 1.8 anymore because the talent drifts out of focus to often when the focal range is a couple inches.   

I did a very controld shootout between the 24-105 L , a new Canon 50mm, and an older zeiss. Absolutely no difference at 1080p rez.

dubzeebass

Quote from: mannfilm on August 16, 2014, 02:38:54 AM
We're all right, and wrong at the same time. Turns out it depends on which zoom you are talking about (duh!) Prime does beat crappy zoom's, like the 24 - 70mm. But no difference between a prime and a great, modern zoom, like the 24-105 "L" , which is what I have. After a quick net search, turns out even the pro photographers are dumping their primes for the 24-105 "L", and they are shooting full rez photo's. Only difference is the primes are faster.  And honestly, I do not shoot at 1.8 anymore because the talent drifts out of focus to often when the focal range is a couple inches.   

I did a very controld shootout between the 24-105 L , a new Canon 50mm, and an older zeiss. Absolutely no difference at 1080p rez.
Except the 24-105 is regarded as a very very average L and isn't particularly sharp. Compare it at 50mm to a Zeiss 50mm 1.4 at F4 or even a Canon 50/1.2L at F4.

KMikhail

Quote from: dubzeebass on August 16, 2014, 03:30:33 PM
Except the 24-105 is regarded as a very very average L and isn't particularly sharp.

Indeed. There are tons of revealing tests, particularly the ones that compare it to a new 24-70/4, or even 24-70 2.8 II that I own. New lenses are head & shoulders above the 24-105 sharpness-wise.

The real bonus of sharp lens is the fact that in FullHD mode 5D3 isn't as sharp as in a 1:1 zoom mode and every bit of sharpness helps, while avoiding extra unsharp mask (which looks weird for FullHD, thanks to debayer - digital bayer) helps with having less noisy image too.

However, I do assume it might be hard to see the difference for not so contrasty image under imperfect conditions.

KMikhail

P.S. I like my 50L 1.2, starting from f/1.8 it is very sharp over important part of the frame. I mean moire inducingly-sharp.

peoplemerge

This has been a subject of a lot of experimentation for me.

I generally agree that unless you're shooting stills or crop modes, lens resolution/sharpness really isn't a factor since 1080p is such an incredibly low resolution.  Especially considering the detail that all still lenses are engineered to produce on full-frame film.

But there are a lot of other optical qualities that you get from a lens in it's overall rendition like contrast, flare, bokeh.  These differences are apparent if you cut with from a high contrast lens like a Zeiss prime (well, ok, *many* Zeiss primes) to a lower contrast Leica or Canon.   This is especially noticeable with a human subject.  With all of the data that we get in 14-bit raw, yes you can very easily adjust the contrast but those two shots will never look the same no matter what you do.  The point is there are difference between zooms and primes in these qualities.

There is a lot of mention in this thread of new Canon L autofocus glass.  I have the 24-70/2.8L (edition I), 70-200/2.8L (non-IS parfocal), 50/1.4, all EF autofocus.  They don't get used much because it's absurd trying to pull focus with them, I don't like camera-controlled < 10 blade aperture, and the crisp & clear look isn't what I prefer these days, it's too perfect.  All of that convenience is ideal for stills, though.  I hope I'm not off-topic here, apologies in advance...

The problem is that the selection of autofocus zooms that are also parfocal is very slim.  The opposite is true with older manual focus lenses.

I have a set of Vivitar M42 lenses, a set of Russian M42 lenses, a Canon FD set (thanks to EdMika on ebay and his adapters), scattered German, and an assortment of antique lenses for experimental use.  Collecting vintage glass to adapt to ML raw has become something of a hobby.  The only potential drawback is a time investment in finding the right adapters, and any cost you may face if the copy you're buying needs cleaning, lubricating, possibly declicking the aperture, etc.  IMO it's worth it.  I should get my act together and post samples at some point.

Anyway to get back to the OP's question, the # of lens elements of a zoom is large, so in addition to what's been said about how they resolve differently, the flare of a zoom will never look like that of a prime.  You almost never want flare in a still photo, but I see it a lot in film, and it's usually intentional.

Audionut


peoplemerge

Quote from: Audionut on August 18, 2014, 03:34:04 AM
Flare?  Did someone say J.J. Abrams  :P

Definitely accidental in that case.  8)  Someone should start a kickstarter campaign to buy the man a matte box!