Canon 100mm IS with 3X TC

I'm about to head off (to the Caymans) for my first dive trip in over a year, and one of the new things I intend to try is a Kenko Pro 300 3X TC with the new Canon 100mm IS lens (camera is 5D MkII in Aquatica housing).

I know I won't be able to auto-focus, but I shoot macro primarily with MF anyway, and because the Aquatica macro port has the MF gear out at the end (and I've got a suitable ext. ring), it looks like it should work from a mechanical standpoint.

The question is whether it will actually be possible to get decent images. I expect focusing to be difficult (and DOF slim), and loss of 3 stops of light may make illumination problematic, but in theory it should work if I can get all the stars to align.

I'll post results later. Meanwhile, has anyone used a setup like this, or do any of you have advice/suggestions/warnings/thoughts?

Bruce,

Can't help you with the TC but I'm very happy to hear that you're feeling good enough to get back in the water. Congrats partner! I wish I could see your face when the warm Caribbean comes rushing over you again. Have great time in Cayman!

Cheers,

Steve

Hi Bruce,

I can't help you may end up magnifying the image 3x but not really gaining any resolution compared to a 1.4x. But it is cool to try the extremes and the proof is in the pudding. Hope to see some of your results in the future.

Have a great time!

Bart

I'm about to head off (to the Caymans) for my first dive trip in over a year, and one of the new things I intend to try is a Kenko Pro 300 3X TC with the new Canon 100mm IS lens (camera is 5D MkII in Aquatica housing).

 

I know I won't be able to auto-focus, but I shoot macro primarily with MF anyway, and because the Aquatica macro port has the MF gear out at the end (and I've got a suitable ext. ring), it looks like it should work from a mechanical standpoint.

 

The question is whether it will actually be possible to get decent images. I expect focusing to be difficult (and DOF slim), and loss of 3 stops of light may make illumination problematic, but in theory it should work if I can get all the stars to align.

 

I'll post results later. Meanwhile, has anyone used a setup like this, or do any of you have advice/suggestions/warnings/thoughts?

Hi Bruce

I do have the the Kenko Pro 300 3X Tele and have tried it with a Canon 100mm macro ( older version ). I just played around with it topside and found that the image degraded noticeably so I have not bothered to take it underwater.It may be better with the new IS version but I doubt it . However if you are prepared to proove me wrong you are welcome to try mine! In fact I will be in Seattle 11th June and could bring it down if that is not too late.

Hi Bruce

 

I do have the the Kenko Pro 300 3X Tele and have tried it with a Canon 100mm macro ( older version ). I just played around with it topside and found that the image degraded noticeably so I have not bothered to take it underwater.It may be better with the new IS version but I doubt it . However if you are prepared to proove me wrong you are welcome to try mine! In fact I will be in Seattle 11th June and could bring it down if that is not too late.

Thanks, Andre, for the offer. However, since already have both the TC and the lens, no need to borrow yours. I'm concerned about image quality degradation, too, and doubt that the new 100mm will significantly improve that vs yours, but I thought the TC might enable me to get shots of some skittish critters from a greater distance than without (that is sometimes an issue with the 100mm on full frame cameras), so that might be worth the tradeoff. Only time will tell...

BTW, to make things REALLY interesting, I'll also have a SubSee +5 wet diopter attached, and might try that AND the 3X TC at the same time (I think that would qualify as super macro). Frankly, I doubt I'll be able to focus with that setup, but hey, half the fun is in trying, right?!

Thanks for the wishes, Steve! The anticipation of getting back in the water has me feeling like a kid the night before Christmas! You don't realize how much you miss it till you can't do it for awhile!

Well, having returned from my Cayman trip (full gallery here), I did have a chance to try the 100mm IS lens with the 3X TC (on one dive - I was mostly concentrating on wide angle). While I was reasonably satisfied with the results, I wasn't overwhelmed. Here's an example:

OTOH, I was able to get similar detail and sharpness with the 100mm by itself (on a different dive), albeit with far more cropping:

These don't look too different (to me) in terms of detail. The difference is that the first photo represents about half of the original RAW frame, whereas the second only represents about 1/10 of the original frame. With 21 megapixels to work with (5D Mark II camera), severe cropping like that is possible, but the 3X TC (the first photo) has advantages in terms of preserving pixels.

Thus, the primary advantage of this setup seems to me to be the ability to shoot macro subjects and fill more of the frame at more of a distance with less cropping. The 100mm IS by itself (like the old 100mm) does a great job, but I can envision using the 3X TC in situations where I know I'll be photographing skittish little subjects and need to keep my distance.

Oh, BTW, I was able to AF enough to get "in the general area" of subjects, and then use MF to fine-tune the focus. This is the same as I do with the 100mm by itself, so wasn't much harder with the 3X TC. Of course, that requires having the AF function removed from the shutter button, but I think many of us already do that for macro anyway.