Should I house my Sigma 17-70 for La Paz & Rangiroa/Fakarava trips?

I currently have a 7D in an Aquatica. My lens/port combos are a Tokina 10-17 in a mini-dome and a Canon 100m L macro in a flat port. These lenses worked great for my first trip with them to Borneo and Philippines. However, it seemed like for shark pictures, the 10-17 was a bit wide.

My dilemma is this: I have a Sigma 17-70, but housing it would require that I buy another dome port, and these trips are already setting me back a pretty penny. For whale sharks in La Paz I know the 10-17 is what I want, but in the passes at Rangiroa/Fakarava, I'm not sure what I'll need. Do I need the 17-70?

Also, for the Rangiroa/Fakarava trip, do I leave my macro lens at home (I hear Air Tahiti can be a huge pain about luggage weight)?

Thanks in advance.

Hi, I know what you mean.

I often shoot a slightly longer lens than the Tokina for sharks and a Canon 10-22 is my first choice. I do also own the Sigma 17-70 but I've never felt that I needed reach longer than the Canon glass other than for shooting portraits.

Your most cost effective and travel friendly solution is to put a x1.4 Kenko teleconverter behind the Tokina. You'll only need to take a longer zoom gear and a short port extension as your mini dome will work fine. This is a great combo for CFWA shots too.

Hope this helps, Tim

Hi, I know what you mean.

 

I often shoot a slightly longer lens than the Tokina for sharks and a Canon 10-22 is my first choice. I do also own the Sigma 17-70 but I've never felt that I needed reach longer than the Canon glass other than for shooting portraits.

 

Your most cost effective and travel friendly solution is to put a x1.4 Kenko teleconverter behind the Tokina. You'll only need to take a longer zoom gear and a short port extension as your mini dome will work fine. This is a great combo for CFWA shots too.

 

Hope this helps, Tim

Thanks, that sounds like a good suggestion. I am still a newbie with DSLR (this will be my second trip) and a newbie overall (6th trip with a camera of any kind) -- is the teleconverter challenging to get used to? Also, would I need to take it off for whale shark shots?

The sigma 17-70 mm lens is a good scouting lens, I often use it when I don't know what to expect from a dive site.

It is good for medium size fish shots and some almost macro shots since it focus close. You can take pics of bumpheads and seahorses with it.

Ok, not supper familiar with all the mini domes out there. So dumb question, why do you need a New dome port? Anything you shoot the 10-17 behind should work for the 17-70 right? You should just need port extensions.

Ok, not supper familiar with all the mini domes out there. So dumb question, why do you need a New dome port? Anything you shoot the 10-17 behind should work for the 17-70 right? You should just need port extensions.

Nope. The mini dome will not work with the Sigma 10-17 or indeed any glass 'longer' than the Tokina.

No, rectilinear lenses don't work in minidomes.

No, rectilinear lenses don't work in minidomes.

I keep seeing this comment, and would like to know why people say that. Alex Mustard's article on minidomes only states that rectilinears don't give quite the same central subject magnification for CFWA as fisheyes. Optically isn't it just a matter of close focus distance and nodal point locations as with any other lens? Or perhaps are you just indicating these specific minidomes are not designed for RL WA ?

I know the pictures themselves kind of suck, as I was just playing in the pool (and seeing my own lower half on the bottom looks like a corpse) but here's a couple shots from a Sigma 8-16mm at 8mm behind a 5" dome (Bill Libecap custom, uwcamerastuff.com) and to my eye there's no issues aside from the totally pedestrian subject matter and lack of strobes. Out of camera JPEGs with only EV correction if anything so I could try to judge sharpness around the corners a bit better. Both shots are at wide apertures (4.5, the widest the lens goes) so I'm not benefiting from a deep DOF selection intentionally, and the closer view was maybe 8" from the dome to the hose nozzle.

8mmFar_f4.5 by rtrski, on Flickr

8mmClose_f4.5 by rtrski, on Flickr

The geometry distortion in the rectilinear frame is obvious (as it would be above water). But I can't see why one would say the dome isn't working. Am I just missing the obvious here?

For me the tokina 10-17 is the best lenses for French Polynesia.

All the pictures below were taken with this lens

The 1.4 converter could be useful for some of the more skittish sharks

So nice macro opportunities especially in Fakarava but given the big game action my macro lenses staid dry all the time

Make sure you spend at least 2 days diving the southern channel in Fakarava!

I keep seeing this comment, and would like to know why people say that. Alex Mustard's article on minidomes only states that rectilinears don't give quite the same central subject magnification for CFWA as fisheyes. Optically isn't it just a matter of close focus distance and nodal point locations as with any other lens? Or perhaps are you just indicating these specific minidomes are not designed for RL WA ?

 

I know the pictures themselves kind of suck, as I was just playing in the pool (and seeing my own lower half on the bottom looks like a corpse) but here's a couple shots from a Sigma 8-16mm at 8mm behind a 5" dome (Bill Libecap custom, uwcamerastuff.com) and to my eye there's no issues aside from the totally pedestrian subject matter and lack of strobes. Out of camera JPEGs with only EV correction if anything so I could try to judge sharpness around the corners a bit better. Both shots are at wide apertures (4.5, the widest the lens goes) so I'm not benefiting from a deep DOF selection intentionally, and the closer view was maybe 8" from the dome to the hose nozzle.

 

The geometry distortion in the rectilinear frame is obvious (as it would be above water). But I can't see why one would say the dome isn't working. Am I just missing the obvious here?

Hi, the results you have obtained with your five inch dome and 8-16mm seem pretty good. What length extension are you using? With the same glass, a 200mm Zen and 40mm extension requires an aperture of at least f/8, preferably f/11 or smaller to obtain acceptably sharp corners.

Hi, the results you have obtained with your five inch dome and 8-16mm seem pretty good. What length extension are you using? With the same glass, a 200mm Zen and 40mm extension requires an aperture of at least f/8, preferably f/11 or smaller to obtain acceptably sharp corners.

The dome is Bill's from UWCamerastuff.com. I'm in an Ikelite housing, and the extension he recommended for this lens was the 5510.16. I haven't tested the rest of the focal length range yet as those first shots were with no zoom ring, but I've since figured out that the standard Ike zoom ring's 2 internal 'ridges' that are supposed to interlock with a clamp will dig into the rubber grip on the Sigma 8-16mm just fine with no clamp at all. Just had to trim them back a little so they didn't dig into the rubber texture near the mount and just engage the zoom ring piece on the lens. (That, and you have to put the sleeve in such that it doesn't hit the AF/M switch near the mount collar, but that's easy enough to do since the 8-16mm only needs about 45-50 degrees of rotation thru its whole zoom range.)

I'd still like to know why Alex T. says rectilinears don't work in minidomes. I've parroted that statement myself in the past (simply assumed it was true early on from similar posts, when researching lenses and wanting to go to a smaller dome) and was corrected by Bill and Alex M. both, and since then did spring for the dome the pics above were taken with. I know it's only a pool test shoot (next trip isn't until Jan...I may in fact go crazy before then!) but it certainly looks good to me. If there's something I'm going to experience like inability to focus to infinity (or what passes for that underwater) that keeps others saying RLWA's don't work in small domes, I'd like to know.

I also did some test shots holding objects up right in front of the dome and they looked good up to the limit of what I was comfortable with (about 1" from the dome outer face). Maybe the biggest issue is that a 200mm dome is significantly smaller in diameter than my 5", and RLWA lenses don't tend to have quite as good of a close focus distance as fisheyes?

p.s. to the OP - sorry for all the hijacking. Pertinent to your original post, I have a Sigma 17-70mm that I'm attempting to use behind a 6" dome from Ikelite (5503.80), with a +2 diopter. Initial pool shots look promising, although it vignettes at the widest end and will 'crash' the dome with the diopter edge at about 60mm at the longer end, so I've gotta figure out a way to pad the teeth on the diopter so it won't scratch (at least the front element doesn't rotate with zoom or focus, so they're not 'sawing' the dome surface). Still, seems to be fairly clear to the corners at f8 wide and down to larger apertures long. Don't think that helps you that much, with your Aquatica setup, though. I suspect the lens both has too poor a near focus distance and too much length change to be very good behind a small dome, and behind a flat with a different extension than your macro you'll probably lose much of the wider range to vignetting, plus the flat face robs width. I did want to test it behind my 5" dome with perhaps a different extension...but at this point think it's probably a waste of time.

Maybe the biggest issue is that a 200mm dome is significantly smaller in diameter than my 5"

My 200mm Zen is 3" wider in diameter and should, in theory, return sharper corners than your 5" dome all other things being equal. I'm pretty sure the 230mm Zen out performs my 200mm with the 8-16mm. The 8-16mm is a great lens and offers some of the best rectilinear perspectives available. It would be great to see a really objective u/w review of the 8-16mm across the whole platform of dome sizes. Chris Parson shot a great review but only through the 230mm.