Sigma 14mm f2.8 EX

Is this a good wide angle lens for underwater photo?

along with Canon 40D, Ikelite housing.

Thanks

If Ike gives a dome combination for it, it can't be all bad. But that's a 14mm on FF...isn't that a whole lotta lens and not terribly wide on a crop sensor?

[if you are looking for popular wide angle lens and port options for ikelite housings have a look at the chart on this page.

http://uwcamerastuff.com/modular_5_dome.htm

Personally I prefer the Tokina 10-17 or the Tokina 12-24

Because I have this lens in the dry box for long time,

I'm thinking may be its a good chance I could use it and no need to buy a new lens!!

The 6" dome seems a good deal from Ikelite also!

Because I have this lens in the dry box for long time,

I'm thinking may be its a good chance I could use it and no need to buy a new lens!!

The 6" dome seems a good deal from Ikelite also!

a 6'' dome is a bit too small IMO, I would go with their 8" one, you will get better results (and be able to do over/under shots with this dome as well)

I have the Nikon version and used it intensively befor I got the Tokina 10-17mm and Sigma 10-20mm, there is no way I would have used it behind a 6" dome port if I could have been avoided.

a 6'' dome is a bit too small IMO, I would go with their 8" one, you will get better results (and be able to do over/under shots with this dome as well)

 

I have the Nikon version and used it intensively befor I got the Tokina 10-17mm and Sigma 10-20mm, there is no way I would have used it behind a 6" dome port if I could have been avoided.

Does it make a different between FF and 1.6 x crop. camera?

Not as much, but there is still a difference in performance and the bigger dome will results in better corner quality at equal aperture than it would with a smaller one.