Which sigma to pick
 

I 'm thinking about buying one of the following to use with a nikon 35mm adapter:

sigma 20mm f1.8 (about 300€)
sigma 24mm f1.8 (about 280€)
sigma 28mm f1.8 (about 200€)
sigma 30mm f1.4 (about 300€)

Has anyone used these? I really like the fact that the 30mm is f1.4...but it's no longer a wide angle. I have used the 28mm on the past and I really like it. The 20mm is also very appealing for some "epic framing". The 24mm is basically out of the game since I already have a 24-70mm f2.8.

I would love to see some footage if possible.

Just found out the 30mm doesn't have an aperture ring...so out of the game with it. I'm very inclined to go with the 20mm.

You will find some scientific tests on the following link, the mount if not important so check all mounts. Many Sigma lenses were tested:

http://www.photozone.de/8Reviews/index.html

Thanks, John. Very usefull. I'm probably go with the 20mm.

The Sigma f1.8 20mm is good. You may find it a bit soft at f1.8 when you are forced to wide-open in low light but sharper at higher aperture numbers.

Don't let the sliding focus ring confuse you.

Outdoors at f4, I think you will like it very much, especially with sun behind cameraman during magic hour.

Absolutely important. To get the best out of this lens, or any wide-ultrawide lens on a 35mm, the backfocus ( or collimation?? ) to the groundglass must be spot on.

( Now the debate about why use ultrawides on 35mm adaptors and not use full open apertures is about to begin again. )

Personally I think ultrawides are a waste of time on an adapter. I tried several including tamron 14mm and sigma 20mm and I had probelms with vignetting, soft image, focus is difficult to get right, the lenses are massive. If you stop down the depth of field is large which rather defeats the purpose.

At the end of the day I just wanted a useable super wide image and couldn't get one from ultra wide/adapter combo. Now I've got a Bolex Aspheron wide angle for my XH-A1 (about 16mm equivalent I think) which gives me a sharp super wide image with minimal distortion without any of the hassles associated with the adapter.

I forgot to mention, shooting direct-to-camera is a better option for the wide shots as you want absolutely the best resolution for those which you really should have.

But if you want a consistent look out of the box, then the wide lens through the adaptor gives you this. On the wide view adaptors like the Brevis, SGPro, you also get a bonus of a wider available view than offered by the wide-end of the direct-to-camera lens.

There is of course, the add-on wide-angle lenses for direct-to-camera imaging. These however may introduce barrel distortion or chroma issues unless you buy a good one.

You have to be the judge on whether expense of the ultra-wide is worthwhile and the final arbitor of the look you want.

Bob

I agree with you that wide lenses should be closed down when possible. Heres a sample shot i took with a sigma 20mm f2.8 closed down to f5.6 cuz the sun was so bright. The wide fov presented by cheap wide 35mm lenses simply cant be achieved with WA adapters available for me. i go this route to achieve consistent look all throughout.
Ted

Let me guess now.

A Morotai May-June sky, which-way featherlight breezes, cloud base not yet formed, probably about 9-30am. So at Bohol, might be your November-December, about the same time, facing west?

Even if I am wrong, it is a good reminder.

By your use of the 20mm f1.8, I am furthur guessing you have another adaptor besides your own medium format version.

Ted, the thumbnail looks nice but as I found you have vignetting and the image is very soft :P

Anyways each to his own :-)

Bob

You are right! Hahaha! well, close around 10 am yesterday. Facing West!
And yeah your right again, i was testing yesterday a new adapter i made on my diy support rods.
So i wont hijack this thread i'll post a new one comparing it with my mid format adapter for your comments. You were so influential in the making of my adapters i want you to see the results of the new gg i used.


Andy,

your right on the softness and slight vignette, heres some of the causes.
1, I cheated on the zoom to get more area, i compromised on the TV safe areas.
2, I didnt bring with me my NDs so i had to step down to 5.6. the lens is a constant f2.8.
3, I was rushing to the seaside promenade get those clouds i didnt get the adapter propery aligned on my rods. these things have very small tolerances.
4, had no external monitor with me that time to get dead on focus which is so hard to get with a wide lens.


Ted

I use my Sigma 20mm f1.8 all the time. look at my Kew Gardens short on my website to see how nice it can look. This was actually wide open most of the time. I should have stopped down a little to get it even sharper. Next time...

http://web.mac.com/philip.bloom/Bloo...14_Blog_5.html