Sigma 18-35mm F1.8 on FF Sensor

S

Simon Shasha

Well-known member
Hey guys,


Not sure if anyone has pointed this out before, but last night I was messing around with my Sigma 18-35mm F1.8 on my Sony A7S. Once attached to the A7S, I reminded myself that I was going to have to swicth it to APS-C mode. However, to my surprise, the lens wasn't vingetting, even though the A7S was in full-frame mode. Eventually, it did vingette, but not until around 24mm. I consluded that between 26-35mm, this lens is absolutely fine for full-frame sensor use. You can even get away with 24mm, which produces a very slight vingette (if you letterbox your footage, it would hide the vingete at 24mm).


Anyway, just thought I'd point it out.


Enjoy!
 
Thanks for posting. A full frame 26-35mm f/1.8 that doesn't break the bank will be interesting for some users.
 
Not only will it not break the bank, it's an amazing lens. By far the most beautiful image that I have ever owned.
 
Samuel H said:
Thanks for posting. A full frame 26-35mm f/1.8 that doesn't break the bank will be interesting for some users.
Click to expand...

All good :)

I agree, it's a damn beautiful lens, and given my favourite focal-length on full-frame is 28mm, I'm over the moon about this discovery :). And like you said, a 26-35mm F1.8 full-frame, at this price and quality, is a steal :grin:

At first, I didn't like the size and weight of the 18-35mm, but I've grown accustomed to it and actually enjoy it now.

I have never liked zoom lenses in general, with the exception of the Canon 70-200mm F2.8L II, especially coming from a strict "prime-lens only" mindset/background - but the Sigma 18-35 just keeps on proving itself, time and again.
 
I was thinking of doing the same thing after listing my Canon 24-70 f/2.8L I for sale

I was going to go with the Sigma 24-105 f/4 IS or the 18-35 f/1.8

The 24-105 would be handy with IS but F/1.8 would be sweet at either APS-C range or FF range.
 
Yes I found this lens mostly covers FF from 24-35mm and have used it on my Speedbooster on S35 and it appears it could work alright with hardly noticeable vignetting on the A7S at FF too. On my speedbooster on S35 I can use it as a 16-24mm f1.3 lens, which is quite nice...
 
I present a quick test with a 5D:

Sigma_18-35_on_5D_Tests_20150421.jpg

Curiously, while at 35mm it has the least falloff wide open, it's at 26mm that it has the most edge coverage when fully stopped down. (Testament to how complex this lens is!)

My conclusion and opinions for FF use:
Wide open - mostly unusable, falloff is extreme. 35mm just about OK if cropping 16:9 or wider.
Stopped down - if cropping the frame (say, from 4K), then 24-35 can be usable because the corners are not too bad.

Bear in mind this quick test didn't include intermediate f-stops.
Also, sensors with shallower photosites (or film!) may show less falloff.
 
If shooting in 2.35:1 at 24mm I think it'd still be useable. Maybe even have an interesting character.

What I'd be interested to know is the DOF when on full frame at those lengths. Are you able to do a simple test with that?

thanks in advance and thanks for those!
 
Hey Geoff, interesting conclusion regarding the difference between stopping down vs wide-open.

For those interested in vignetting while shooting wide-open, I did this quick little test. P.S. llirik, I will try and do a DoF test if I get a chance/spare time.

Regarding my vignetting test, I just pointed my A7S + Sigma 18-35mm F1.8 at a plain white wall. Shot in 1080P at 24FPS in full-frame mode. Here are the results:

24MM WO.jpg

25MM WO.jpg

26MM WO.jpg

27MM WO.jpg

28MM WO.jpg

35MM WO.jpg
 
Thanks for all the tests.

Geoff shot 3:2 stills, Shasha shot 16:9 video.

For me this would be definitely usable as a 24-35mm f/1.8 for 16:9 video, and even wider than that if I know I'm cropping for 2.40:1 in post.

Though I must say I add a vignette in post to almost everything I post online anyway, so, YMMV...
 
My 18-35 could well be permanently affixed to my A7S. A glorious lens.
Next one they announce will be in my shopping cart the same day!
 
Unfortunately, it is not available in either A- or E-mounts. Maybe it will be later on.
 
impoze said:
I was thinking of doing the same thing after listing my Canon 24-70 f/2.8L I for sale

I was going to go with the Sigma 24-105 f/4 IS or the 18-35 f/1.8

The 24-105 would be handy with IS but F/1.8 would be sweet at either APS-C range or FF range.
Click to expand...

The Sigma 24-105 f/4 is an absolutely beautiful lens. However, it is not parfocal. So when you zoom in and focus, then zoom out, the focus will shift. This is a deal breaker and ultimately led me to purchase the Canon 24-105mm f/4. The image quality of the latter, however, is significantly worse IMHO.
 
You must log in or register to reply here.
Back
Top