cristiansub

Well with the D800 you can safely use ISO 3600 and a smaller f/stop/faster shutter-speed. Maybe that's where the problem lies.

There's something wrong if it's require to use the closest f/stop (16-22), with the 10,5mm at f8 at the same distance and condition don't make this problem in the border.
I have 2 D700 and 1 D800, ok they are good to the high ISO but the sharpness the you have ant the minimum ISO is better.

Cristian.

Maybe you got a 'bad' one. It looks like a DOF problem. What F/stop were you using and what were the relative distances?

Can I direct to http://wetpixel.com/...opic=46334&st=0

The lens that I have tested, it's not mine.
I have used f8 1/125 @ 200iso at the minimum distance that permit the 15mm Sigma. In similar situation of shoot the 10,5mm Nikon with D80 and D800 work better.

Cristian.

That's interesting Cristian. I sold both my 10.5 and 16 Nikkors because I never used them. Always Tokina 10-17 and Sigma 15. I think it depends very much on your dome set-up. I get fantastic edge-to-edge sharpness. In fact only today I saw a full-page layout using a small side section of one of my pics.

John, I have tested the Sigma 15mm on land, in a mine shooting and at the the minimum distance, the lens that I have used was terrible on the border of the image, this is one of the images (nef file) develop with captureNX2:


I hope the Nikon make a 16mm like the 10,5mm.

Cristian.

I have tested the 15mm Sigma with D700 and I see a big problem of sharpness on the border of the images. The 16mm Nikon and the 10,5mm Nikon are in an other level.

Cristian.