Sigma 17-70 Macro

I decided to purchase the Sigma 17-70, despite already making a significant investment in the Nikon 17-55. I love the Nikon lens - it's really a quality piece of equipment, but it's close focus ability is limited and the extra range of the Sigma combined with it's close-up ability convinced me to buy it for use underwater as a general purpose "scouting" lens.

I very much doubt that the image quality will be close to the Nikon 17-55, but I intend to take some test shots this weekend with both lenses and will post the results next week some time.

I had a nice surprise when the Sigma lens arrived yesterday as the old zoom ring from my 18-35 film zoom fitted and have the lens, D200 nicely in my Subal housing. I now need to get the correct extension ring and see if I need a dioptre - hence this post.

Has anybody else got this lens working in a Subal housing yet? I believe that the 33mm EXR and FE dome is the right combination, but what about the dioptre?

Don

I decided to purchase the Sigma 17-70, despite already making a significant investment in the Nikon 17-55. I love the Nikon lens - it's really a quality piece of equipment, but it's close focus ability is limited and the extra range of the Sigma combined with it's close-up ability convinced me to buy it for use underwater as a general purpose "scouting" lens.

 

I very much doubt that the image quality will be close to the Nikon 17-55, but I intend to take some test shots this weekend with both lenses and will post the results next week some time.

 

I had a nice surprise when the Sigma lens arrived yesterday as the old zoom ring from my 18-35 film zoom fitted and have the lens, D200 nicely in my Subal housing. I now need to get the correct extension ring and see if I need a dioptre - hence this post.

 

Has anybody else got this lens working in a Subal housing yet? I believe that the 33mm EXR and FE dome is the right combination, but what about the dioptre?

 

Don

I can say that the Sigma 17-70 works great in a Nexus housing with the 170mm dome port and 40mm extension. It focuses close enough that no diopter is needed. I believe the Subal dome is about the same radius as the Nexus, so you should not need a diopter. I did not have any vignetting with the 40 mm extension, so the Subal dome and 33 mm extension should work for you.

Dave

I used behind an Ike´s 8" dome and no diopter is needed, of course for corner sharpness a +2 diopter can do the trick.

Don, I did a test between 17-70vs17-55 and really liked the sigma:

@17mm complete pics and 100% cuts on corners and center at different apertures:

http://www.afotos.net/fotos/asp/album01.as...mp;idusuario=71

@24:

http://www.afotos.net/fotos/asp/album01.as...mp;idusuario=71

@55:

http://www.afotos.net/fotos/asp/album01.as...mp;idusuario=71

Funny how even these are subjective, I really prefer the 17-55. Some shots it's really clearly better - like the CSM writing in the 24 comparison. Overall very similar though. Thanks for showing these

Thanks for all the responses above - greatly appreciated!

Don