close focus with a macro converter question

[Divezilla]

Hi
I have a Nikon P7100 and Fantasea housing.

This camera will focus as close as 1 inch away from the lens.

This works.. but the short working distance is hard to work with and scares away shy creatures.

I can add a wet close up diopter to this kit.

Would this allow me to zoom in a bit and get a bit more working distance to my subjects?

Thanks in advance!

 

[KeithG]

the answer is "yes, but maybe not in the way you think..."?

at telephoto setting adding a wet lens will shorten the minimal focus distance. Super Macro Underwater Photography - The Definitive Guide, Part 2B

i assume your 1 inch focus distance is being attained at full wide angle 28mm of you camera. at this setting a wet diopter will have minimal "magnifying" effect and may even vignette.

what is your minimal focus distance at full telephoto? likely too far away to shoot "macro"? this is where the wet lens helps. for my canon g16 a +10 diopter reduces my minimal focus distance at 140mm from around 30ish inches to about 4ish inches (give or take a few inches, i forget the exact distances) without the dioptor i must stay too far away from my subjects so they are small, not really macro. with the diopter i can get much closer so they are much bigger.

on my prior camera a wet lens was a bit of a wash in image size. the lens max zoom was 70mm but it was able to focus at less than 1 inch at that setting. adding a wet lens forced the minimal focus point out to about 5 inches. but i ended up with the subject being the same size since i had to move further away.

the reefnet guys have a handy calculator that will give you an odea of how much magnification you can expect at various zoom settings https://reefnet.ca/products/subsee/

 

[Divezilla]

Thanks from a fellow Canuck.

That's how I thought it would work.

Thanks for the links as well. Very useful.