Split level pictures

[Chris Bangs]

thanks, that will be a tricky one, I would guess that the element will have to rotate.

 

[Mike Veitch]

Hey Chris, have you tried Fred Dion at Underwater Photo Tech? I know he custom makes some filters but not sure if he can do what you want.

www.uwphoto.com

Mike

See ya next week.

 

[fdog]

Okay. Here's the final word from Steve at NPS.

Despite what it looks like, the filter on the 16mm f2.8 is an optical component. Cut away half of it, and only half will be optically correct. As in, only half will be in focus.

They've heard of ND gels being used, but they trash the filter. Also suggested getting a spare UV filter and having it half-coated, like sunglasses. (Like this wouldn't cost anything...)

Actually was suggested that a Sigma 15mm would be the best lens in this application!

Sorry I couldn't come up with a more elegant solution, Chris!

All the best, James

 

[Big Sky Dave]

I have a Nikonos. Since the 20mm is an underwater only lens, I'm thinking of using the 35 mm, shooting verticals so I can see both water and air through the view finder and screwing a standard Colkin filter holder on the lens and inserting a 2 stop neutral density filter half way across the lens. Anyone tried this? Does it work?

 

[Chris Bangs]

using the 35 to shoot such a shot will require divine intervention to work!

 

[fdog]

Dave, you can certainly try this. However the water "split" will be exceptionally difficult to place in the center of the outside lens element. And the meniscus will cover a lot of the available lens area.

This is why most shoot with a SLR and the biggest dome they can lay their hands on. You can see what's going on, and there is more room for error over 8 inches than 1/2".

But by all means try it! You might get lucky.

All the best, James

 

[Ryan]

Because the split diopter/nd filter for a rear bayonet is likely impossinble to maufacture, why not handle balancing the exposures in photoshop?

The lens you are using does not require a diopter, so I would prefer to avoid introducing that layer of cheap glass in front of my beautiful 16mm.

I'd shoot in Raw, and convert two seperate images, one with proper UW exposure, and one with the correct above water exposure, then mask them together. If you can get the above and below water captures within a stop of each other, the results doing this can be quite good.

 

[fdog]

If it's Photoshopped, it usually looks like it was pasted together. The interface is part of the art, like Mauricio's work here. Or the subject is connecting the air & water (usually why you're shooting over/under, anyway) like this image by Mr. Frink.

I'd be leary of just shooting away and counting on PhotoShop to fix the exposure. Blown highlights are gone forever.

All the best, James

 

[Ryan]

If it's Photoshopped, it usually looks like it was pasted together. The interface is part of the art, like Mauricio's work here. Or the subject is connecting the air & water (usually why you're shooting over/under, anyway) like this image by Mr. Frink.

I'd be leary of just shooting away and counting on PhotoShop to fix the exposure. Blown highlights are gone forever.

All the best, James

Thanks for the excellent examples, James.

When I see two images pasted together, I feel the exact way you describe above. However, I am referring to the same capture, with exposure altered over different segments of the image. You are absolutely right, when highlights are gone, they are gone. With as much as S.Frink is shooting digital, I'd be shocked of some of the images you've seen weren't treated this way.

 

[f0t0man]

Hi Dave,

The best way is to use a WA lens on a SLR camera. The key thing is to use a diopter on the lens. This diopter is a little darker on the top so that you can get the same exposure on the sky and underwater portions.
The trick is to get the waterline to cover up the split.
BEst done when you can stand in the water as opposed to free swimming.

As for digital point and shoots and things it can work, just have to mess with the exposures quite a bit whilst using a wide angle port

Dave

the one thing you need is a neutal density on top, and a diopter on the bottom. Now where to find one these I don't know. If you find a source let me know. I need a 72mm.

Daren