Dome help

Hi all,

I am new to the housed slr world. I recently purchased a sea & sea housing for my 5dm2. I got an 8 inch dome port to accompany the 16 to 35mm lense I plan to shoot. the problem is, the lense is backordered. I have the 24 to 105 kit lense that is physically the same size as the 16 to 35 if i dont zoom. The image seems fine out of the water. So long way around to the question... Does the dome need to be submerged for me to get an idea if i can use this lense. does the image look the same in and out of the water. sorry for my ignorance (and poor typing skills) but any help would be appreciated.

thanks,

Kris

Hi Kris

Yes You will need to put the dome in the water to see if the lens will work because of the virtual image that the dome creates.

Hi all,

I have the 24 to 105 kit lense that is physically the same size as the 16 to 35 if i dont zoom. Does the dome need to be submerged for me to get an idea if i can use this lense. does the image look the same in and out of the water. sorry for my ignorance (and poor typing skills) but any help would be appreciated.

thanks,

Kris

Hi Kris,

Bill is 100% correct, that testing in water is the best way to know.

Your 24-105 lens only focuses down to 17.7", which may be a problem when using the lens in a dome port; a closer focusing lens would be better. When you test the port and lens combination in water, be sure and try to focus to a distance greater than 10 feet or more. If the lens will focus to greater than 10 feet, then you may be able to use your 24-105.

The lens HAS to be tested in water to know if it will work. Just because the lens does not vignette with your port, does not mean you have a good combination. Also, corner to corner sharpness may not be acceptable, the reason Bill and I manufacture our ports.

Good luck,

Barry

www.bareports.com

www.keywordworkflow.com

Probably it will not work as is, behind a dome, but should work ok with a +2 or +3 diopter, on the lens, before you put on the dome port. That allows it to focus closer, on the virtual image the dome creates in the water.

When you add a diopter a lot of things happen. The extent of theses changes depend on the len's and diopter and conditions. The Diopter will allow the lens to focus closer and that may be necessary, It will reduce the depth of field, it will degrade the picture, and it will reduce the field of view. As with anything else "your mileage may vary", the extent of these changes may not effect your shots. Good luck and hope you grab some great shots.

I had a similar thought, and tried the 25-105 out on my 5DII with a +2 diopter and behind an 8" dome. I mostly found I couldn't focus on anything underwater, and after one test dive abandoned the idea. Perhaps a little more perseverance might have helped, but I doubt the 24-105 is an award winning underwater lens.