Ikelite Housings and Zoom Lenses

I’m in the process of upgrading my camera and have narrowed it down to either the Nikon D100 or the Fuji S2 Pro. In looking at the different housings for these cameras, I ran across a note on the Ikelite web site that says a +4 diopter is required for zoom lenses. None of the other housings that I’ve looked at seem to have this as a requirement. I’ve never used diopters before and was wondering what if anything this does to image quality, depth of field, etc. Also, I’m curious why it’s needed.

I think it is due to the fact that, with Ikelite housings, you are using a dome port and most zooms do not focus close enough without the diopter

The diopter would only be required for lenses shooting through a dome port. My guess is that a micro/macro zoom lens would probably not require a diopter. I mostly shoot 60mm and 105mm through a flat port, and I haven't really done much through a dome port. Some of the folks who use the zoom lenses behind a dome port can give you a better answer, however.

Postings by jimbo1946 and scottyb are correct. Diopter is not needed for a flat port. Following link explains:

http://www.ikelite.com/web_pages/qdiopter.html

Ike, thanks for the reference - that explained it very well.

For wide angle, I am considering the 18-35mm f/3.5-4.5D AF Zoom-Nikkor. Comments about image quality, depth of field, etc. from anyone who has used this lens with a diopter would be greatly appreciated. Also, since the minimum focus distance for the lens is 1 foot, it seems to be right on the edge of whether or not the diopter is required. Again, any comments would be appreciated.

This is funny - I just answered this question on the uw-photo list for another D100 user last week.

The 18-35 requires a +4 diopter when used in the Ikelite housing. The filter ring size is 77mm and I bought a B&W diopter at David Haas's recommendation. It is good glass and doesn't degrade the image quality as far as I can tell.

Here are some shots from a winter trip to the Flowergardens (50' viz):

http://www.reefpix.org/modules.php?op=modl...showgall&gid=58

For topsides use the 18-35 is my workhorse lens. On the S2/D100 it has a field of view of a 28-56mm lens. It's also lightweight and not prone to flare.

HTH

James Wiseman

James:

Thanks. Your recommendation regarding the brand of diopter answered my final question.