Does the lens actually matter?

If you are shooting 70mm and higher on the 7D, which I own, do yourself a favor and get a lens with IS. 85mm and above that I've tried to freehand without a stabilizer gets jello VERY easily. I know, I've been there.

I too have been looking at similar lenses and am going to go with the Canon with IS. For me it is a NO brainer. Remember, you are shooting video and NOT stills, so the resolution requires on how much the 7D resolves is what, less than 600lines I believe? Sharpness should NOT be a problem and something I haven't noticed on the lenses I have used.

I bought a Sigma 70-300 lens and sold it after using it a few times. Sigma zooms are just not that great to me. The build quality was NOWHERE near the Canon or Tokina. I've not used Tamron so I cannot comment.

Now, Sigma primes, like the 30/1.4 are absolutely awesome. So is the 50/1.4 which I've used A LOT and blow away the Canon and Nikon $300 lenses I have tried already.

Also remember, full open lenses tend to have a few issues with CA and other anomalies as others will tell you, even the Zeiss lenses (as I have used them too). Stop the lens too far down and you get soft images due to diffraction limitations. So when testing a lens, take it down 1 step and see how nice it is :)

Again, I'd recommend a lens with IS. Not having used this particular Sigma, I cannot say, but remember these lens are used for stills shooting which requires MUCH MORE resolving power.
 
The lenses on high resolving modern camcorders must be pretty good,iF one SLR lens cant resolve the max detail from a DSLR it must be pretty useless, build AF flare may well be better on certain lenses but if they cant resolve current video detail they must be poo.
 
this is the site I usually turn to for lens comparisons:
http://www.the-digital-picture.com/...meraComp=453&SampleComp=0&FLIComp=3&APIComp=0

as you'll see, the tamron holds its place against the non-IS canon 70-200 f/2.8L... only at either 70mm or 200mm: in the middle ground, it is quite soft

I find it just too expensive for myself, but the IS version of the canon is the sharpest of the lot, and you definitely want IS with these lenses if you're going to shoot without a tripod (using my cheap shoulder mount, I can't get my non-IS 90mm to take consistently steady shots)

by the way: lens sharpness does matter, even in video mode; here you can see exactly what this means:
http://www.similaar.com/foto/lenstests/lenstestsv.html
 
The 550D is not a high resolver to start with and some lenses cant record its full video detail they must be crap.
 
So you tested a lens "that loses a lot of sharpness when its wide open" and found the video was ... less sharp. I'm not sure that really addresses the OP's query about the more subtle differences among expensive modern lenses. I remain skeptical that minor diffs among such lenses remain significant after reduction and compression to 1080 or 720.
 
I don't believe that cine lenses look any better with these cameras. The only real difference is that they are easier to focus.

Contrast is a funny thing, I thought filmmakers always like to get low-contrast images so actually shitty lenses with no contrast and no sharpness (less aliasing) are actually way better than high quality glass :)
 
@flinty: this is a damn nice lens; for example, at any common aperture, it is sharper than the tokina 11-16 that everybody loves so much (i know it is a different focal lenght, but that's a lens that carries a huge positive consensus on the net)

@grahamh: if you forget about the f/1.8 image and look just at the f/2.8 and f/5.6 samples, you still see a difference in video mode, even if the lens' sharpness at f/2.8 is already quite good: going from "good" to "great" has a visible impact even on video mode

join the following:
* at f/2.8, my pancolar is still not sharp enough for what a 550D's video mode can take (as proven by comparison with the same lens set at f/5.6)
* still, that vintage lens at those settings is hugely sharper than a 50mm f/1.8 set at f/2.8 (as seen on my tests)
* and in turn that canon at those settings is hugely sharper than the tamron 70-200 at 135mm and f/2.8 (as seen on tests by the-digital-picture.com)

and what you get is that the tamron 70-200, set at 135mm and f/2.8, will make your videos much, much, much softer than they need to be, and swapping that lens for a (much sharper and also much more expensive) canon 70-200 f/2.8L IS will give you videos that look a lot sharper, even if the camera is recording just 2mpix

I understand not everybody has the money for a canon 70-200 f/2.8L IS; as it stands, that extra bit of sharpness carries a price that is too high for me, but if I had loads of money laying around, that lens could make my videos sharper

@maarek: I like sharpness, but I agree with you that high-contrast is overrated; I've discarded some lenses because they were too contrasty
 
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Remember, a camcorder lens is much smaller because it covers a much smaller sensor so they are MUCH easier to manufacturer to higher standards. Pertaining to wide open, it's not softness but other things like chromatic aberrations which can degrade the image.
 
NormanBates said:
this is the site I usually turn to for lens comparisons:
http://www.the-digital-picture.com/...meraComp=453&SampleComp=0&FLIComp=3&APIComp=0
Click to expand...
Oh, that is fantastic! Thanks for that link.

I've been plinking around on that site for way too long this morning, comparing my lenses against the competition, and I am suddenly much happier. I always saw a little bit of softness and chromatic aberration when my Zeiss ZF's were used wide open, but ... comparing them to what else is out there, they're shockingly better. That's a relief. :)
 
A video frame grab comparison would be pretty interesting for me since I use my lenses solely for video. For instance, I know the Sigma 30/1.4 and I don't see that amount of CA wide open when I've shot with it. In fact, the 50mm Canon 1.8 I've seen CA in video mode wide open which in the same setting, the Sigma did not, as I specifically swapped lens to get rid of it. Maybe they have a bad 30/1.4 as I've heard stories of inconsistent 30s from Sigma.
 
Rick,

I did a really quick somewhat non-scientific test a while back where I compared all the lenses I had on hand in video mode on my T2i. The conclusion that I came to was that all but one of my lenses gave pretty much identical results, with the lone exception of an old cheap Canon kit lens from the 90's.

I'll probably do an update of this test again at some point, but also include my Canon 70-200mm lens, and light it with the Source 4 that I have on back order.

http://www.dvxuser.com/V6/showthread.php?222721-Side-By-Side-Lens-Comparisons
 
Nice! Yeah, most of the lens tests I have seen have been photographic, full sensor resolution, and even with lenses I own I have tested, I get different results in video. A perfect example is the Tokina 11-16mm lens. I have seen others post photos with CA around blown out sections of an image, yet, when I tried the same thing with video on my Tokina, I could not get that same result. I tried to shoot the SAME setup (fluorescent lights in an office ceiling) and didn't get it. With stills, yes, I could reproduce it.

We have a Canon lens that I REALLY do not like the CA I see in video, AT ALL. The hard part is judging where that cutoff point is from a higher resolution test. The best thing to do I tell people is rent the lens before you purchase. Then you can be SURE of what results and renting is cheap.

Rick
 
leaftors said:
I'm trying to decide whether to get the sigma 70-200 tamron 70-200 or canon 70-200 all f/2.8

I'm mainly using it for video and couldn't care less about the photo capabilities.

My friend was saying how Video is only 2 MP for the most part @ 1920x1080 so you wont really tell the difference. Whereas in photography its like 21mp @ 5000x8000 res
Click to expand...

Go for the Canon. More consistent.
 
leaftors said:
My friend was saying how Video is only 2 MP for the most part @ 1920x1080 so you wont really tell the difference. Whereas in photography its like 21mp @ 5000x8000 res
Click to expand...


True, but you should buy glass with the approach of it being an investment. What people speak of when talking sharpness is usally the top glass like Zeiss (who even realised a softening filter to reduce aliasing)

But yeah you should weight other qualities of a lens than sharpness, but again only a small part of the dvxuser community actually focuses on filmmaking only. So you need to sort out what advice is relevant for you.

"couldn't care less about the photo capabilities"

As a cinematographer you do NOT need to buy modern stills glass. Although not every lens you would want to can be stuck on a Canon dslr, there is OPTIONS, going out to buy L-glass as a filmmaker and think it's the best bang for the buck is plain stupid.
 
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