Sigma 17-50mm f/2.8: How good is it for video? And for stills, is it really THAT sharp?

CaMeRaQuEsT

I need a good, cheap 3x zoom lens for my DX camera (currently D7100) that starts at least at a 28mm equivalent FOV with stabilization and constant aperture for mostly video use.

Nothing from Nikon current or since fits the bill, and although the 18-55mm VR II kit lens was good enough for starters, zooming it in darkened the image if exposure was set in manual (as will all variable aperture zooms), its zoom ring action is too sticky and focus didn't stay put while zooming.

So I read everywhere that good copies of the Sigma 17-50mm f/2.8 are as sharp as the best zooms from Nikon and that its stabilization is good for at least 2 stops (please write if your experience is otherwise), but I can't find anything about its qualities while shooting video, for example if its zooming ring action is smooth enough, if its stalibization is good enough for taking footage hand held, if it stays in focus while zooming, if its focusing motor is noisy, etc.

If you think there are better options out there for about the same price ($300 new, imported) then please do chime in.

haroldp

Most lenses for still cameras are not parafocal by design, meaning that they may not hold focus as you zoom.
Parafocal design is one reason (among many) why good cine lenses are so expensive.

... H

starralazn

I used the 17-50mm sigma for awhile on DX. but i mainly took stills at events or portraits of people with it, so i can't really comment on shooting video. OS was fine... but i never really pushed it too much. I do notice that the zoom action is stiffer and more non-linear than most of my nikons, also the focus ring moves while autofocusing... i wouldnt say its loud, but you will hear it while it autofocuses, also manual focusing isn't so great since the thread throw is kind of short.

I tended not to use it since it was so big, in comparison to the 35mm 1.8G DX( which was able to shoot everything i wanted, more or lesss). I also don't like the feel of the lens, even though its built fairly solidly.
As far as image quality... it was sharp enough on a D5000... i'm not sure how it will do on a 24MP D7100..

Ironheart

What's wrong with the 16-80 or the 17-55?

tcole1983

What's wrong with the 16-80 or the 17-55?

My guess would be price since both the Nikon's are ~$1000.

Ironheart

Yes, I saw "I need a good, cheap 3x zoom lens..." But that is relative. How good? How cheap? $1K is cheaper than the $2.5K you pay for the FX version, the 24-70E.

heartyfisher

nice review here .Has a bit more Vid focus ... I like this guys reviews :-) seen most... even if he is a Canon user ;-)

CaMeRaQuEsT

Thanks heartyfisher for leading me to the review, very informative indeed!

Thanks starralazn for your insight comments on your own experience with the lens.

Ironheart, I have a budget constrain, $300 is all I got for buying my next lens, the only Nikkor at that price is the 18-140 refurb which I really like but it's variable aperture, just like the 16-80 which is very far out of budget. The 17-55 doesn't have VR, is way too heavy and again out of budget even heavily used.

haroldp, from what I saw on the video review, this Sigma looks parfocal enough given its price. Looks like if one zooms in first, aquires focus and then zooms out it stays quite in focus, but not the other way around though, and then it just slightly goes out of focus, impressive achievement indeed for the price.

Ryukyu

The guys over at Fstoppers have a gear guide, and they like the Tamron 17-50 strictly for video. For both stills and video, they recommend the Sigma. Take a look here.
I don't do video with my Sigma 17-50, but I can tell you it gets some sharp stills.

heartyfisher

Nice link @Ryukyu

Pistnbroke

You say you like the 18-140 so why not just set it at 5.6 or above and then its constant aperture as you zoom....??
If you use a proper rifle mike ..about 15 in long in a suspension mount then you wont pick noise up from behind.....

CaMeRaQuEsT

Actually, a variable aperture zoom will always vary its aperture no matter what aperture you set it in. It's actually a misnomer, as the aperture blades don't change position as you zoom in or out, it's actually the optics letting varying amounts of light as you move through the zoom range. For example, on the 18-140, if you I start with f/5.6 at 18mm, you end up with f/9 when you reach 140mm. But this problem aside, the f/2.8 aperture on the Sigma is a great thing to have for shooting indoors with available light.

As for the mic, sometimes it's just not handy to run an external one (which I do own), so the quieter the lens is the better.

I'll use the lens for stills too, so while the Tamron has got great stabilization, it's just too soft compared to the almost prime sharp Sigma. The Tamron also uses an old style motor for AF that makes loud whirring noises. Would be nice to see both Tamron and Sigma come out with newer versions of their 2.8s, but with my budget constrain, I wouldn't be able to afford such updated glass anyways, so I'm biting the bullet and getting me a Sigma from either Japan or HK at $300 new. I just hope I don't get a soft or bad AF dud.

haroldp

Actually, a variable aperture zoom will always vary its aperture no matter what aperture you set it in. It's actually a misnomer, as the aperture blades don't change position as you zoom in or out, it's actually the optics letting varying amounts of light as you move through the zoom range. For example, on the 18-140, if you I start with f/5.6 at 18mm, you end up with f/9 when you reach 140mm.

Double check that.

I do not have the 18-140. but my other Nikon variable aperture zooms, when set to an aperture within the range of all of it's focal length's (typically f5.6) will maintain that aperture as you zoom.

.... H

Pistnbroke

Quite right Harroldp...just tested a 18-140 at f5.6 18mm and the shutter speed and iso were the same when I zoomed in to 140....Must be some basis in CaMERe assertion ..like to know what it is.....

If sound is a problem you need a boom man or a radio mike...
If you are zooming using a standard type lens then you need an extension handle of about 2 inches to smooth out the movements ...like this one
http://www.ebay.co.uk/itm/Neewer-Easy-Zoom-Focus-Handle-Lever-with-Gear-Ring-Scale-for-Camera-Lens-Blue-/261976648857?hash=item3cff066c99

Should also be remembered that Samyang do a whole range of lenses for video with no clicks etc but clearly not zooms. How often do you see a zoomed shot in a professional production ???

CaMeRaQuEsT

In video LV, or while taking a video, if you go through the zoom range you'll notice the aperture value change, even if you set the aperture at 5.6 or smaller while at the lens' widest FOV.

This lens is not going to be used for professional productions of any sorts. I use my camera to mostly take pictures and record videos of my children. For the videos I've taken, the 18-55mm VR II kit lens has filled my needs quite well (love how light it is), I'll just like to have something a little better that will also be as sharp as a prime lens for picture taking.

starralazn

sharp as a prime? i didnt know zooms in this price range were definitively sharper to equivalent primes...

but if you're worried if it'll be sharp enough, i think the sigma will do fine.

tcole1983

Ok let me clarify the changing aperture stuff. If you shoot in A mode and set your aperture at say 5.6 on a variable lens it stays at 5.6 when zooming while adjusting shutter speeds and or iso if set to auto ISO. If you have the camera on auto it is adjusting everything including the aperture.

So it depends on which mode you are shooting in.