he he he
Why I can use my sigma lens with my ikelite flat port?
I know this lens can only be used in auto-focus, but my flat port is a manual one (it has a internal rig). I tried evey way to use it (even in manual, with is possible, but I can´t have the 1:1 efect, because the lens is too long), but I couldn´t =/..can any body help me?
Equipment: D100 ikelite housing, flat port with manual focus and 105mm f2.8 flat por manual focus.

Not sure I fully understand your question but if your lens is too long for your port, you need to get the correct port for it. I assume you have removed any filters off the front of the lens?

Jim Greenfield
http://www.oceaneyephoto.com