WA Macro

So now the long awaited article in UW Photography is out! Great article and thanks for sharing your techniques Alex!

I waited for the article to ask in order to determine if the answer to my question was somewhere hidden in the article. Alas, no.

So here goes:

Why don't you just use a Sigma 15mm instead of going to the trouble of TCs on fisheyes?

Here is the reasoning--feel free to poke holes in it

The basic idea is to get a closeup of the critter in his environment--brilliant. To do this you have to get very close while still maintaining a WA perspective. In order to get the magnification you need to let a small critter fill the frame you need to increase the focal length--hence the TC.

Well the Sigma 15mm focuses nearly as close as the 10.5mm and has approx. the same focal length on cropped digital as the 10.5mm + 1.4 TC. You gain in max aperture since you can use all of the f2.8 lens, so focusing should be improved (minor detail). Sharpness should also be improved since you don't add the extra glass and the Sigma is plenty sharp. But the whole system should be more compact and simpler.

What do you think?

The main reason is to get that really close focusing ability. Loads of people have Sigma 15mm lenses, yet I have not seen them produce an image like this without cropping:

I don't own a Sigma 15mm. And it buying one is much more expensive than a TC.

I tried this technique with the 16mm in the summer and could get a close-focus wide angle look of say a whole lionfish, but not really the extra-close macro look I was after.

The other advantage of using the TC is that it gets the lens further out from the camera body, which really makes lighting much more achievable. This setup also allows even closer focusing to the dome. My setup can focus on my fingerprints - when pressed onto the dome.

Finally, I have only just started with this technique and intend to play with other teles - which will be more suited to slightly different sized critters.

But as always, if it works, it works. If you are getting the images you want with the 15mm then great. Don't bother with the 10.5mm and TC.

Alex

My setup can focus on my fingerprints - when pressed onto the dome.

I saw you mentioned in another thread your hesitation towards the Tokina 10-17mm fisheye. One of the interesting features of this lens is that it can easily focus *closer* than the dome port (as close as 1" from the lens surface).

At 10mm, my hand pressed against the port surface:

At 14mm, a tiny, tiny hermit crab (who didn't want his 20sec of fame ) held up to the dome port surface:

I didn't think to zoom all the way in to 17mm, but will next time. Regardless, the lens might be an interesting comparison to the FE+TC setup you work with.

Agreed. Looks good. Since the D3 turned out to be a D40x(!) I will get one later this month for this year's diving. Just need to sort out a zoom gear...

Alex

Agreed. Looks good. Since the D3 turned out to be a D40x(!) I will get one later this month for this year's diving. Just need to sort out a zoom gear...

 

Alex

Alex,

Take a look at the Tokina 10-17 thread. I posted some pics of what I used to adapt my EFS 60 zoom gear to the Tokina. I do not know whether this will work with any of your zoom rings but might give you some ideas.

I hope it helps.

cheers,

Nuno