Canon 70-200mm f2.8L underwater?

I have a Canon 70-200mm f/2.8L lens for land use. It's a great lens, and I'd love to find a way to use it uw. Unfortunately, it isn't exactly a macro lens (max. magnification is 1:5.8 and min. focus dist. is 4.6 FEET), and even with a FF camera, it's questionable as a fish lens.

Am I trying to get blood from a turnip? I'm afraid that by the time I added enough diopters, TCs, ext. tubes, etc. to get it functional (if housing that mess is even possible!), the fantastic quality of this great lens would be compromised to the point where it wasn't even worth it...

Has anyone gotten this lens to work uw in ANY housing, and is there any hope of increasing magnification and/or reducing focus distance enough to make it a good uw lens? If the answer is yes, then the next question is how to do it in a Seacam housing!

Hi Bruce,

Craig Jones and I both considered using the 70-200 F4L underwater as a macro zoom lens. With a diopter, it's quite good for this.

The only problem is that we could not get a Seacam port where we could operate the zoom and the focus. What we wanted was a focus knob on the FRONT of the port like Seacam does for the Nikon multi-port. Unfortunately, Harold never made one for us :-(

The 2.8L is too fat a lens IMO for use underwater.

Cheers

James

The 2.8L is too fat a lens IMO for use underwater.

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Too fat!?!?! You mean too heavy?

Not for me! I had to take special weight-lifting classes before they'd let me buy a Seacam housing (so I could carry it to and from boats). And for underwater, I have these really cool buoyancy rings that I made (based on a wacky design dreamt up by some drugged out Wetpixeler as I recall) that could probably make a bucket of hand grenades neutral...

No, too fat as it won't fit in the port and if it fits in the port, you can't get a gear on that will mesh w/ the zoom or focus gear in the housing.

Cheesr

James

No, too fat as it won't fit in the port and if it fits in the port, you can't get a gear on that will mesh w/ the zoom or focus gear in the housing.

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<blush> Oh...well then... <in best Rosanna Rosanna Danna voice> "Never mind."

I was thinking the main issues were with magnification and focus distance. It sounds like the real problem is girth. Thanks, James -- I'll just forget about trying to take that lens underwater.

BTW, hope you realized that my comment about the buoyancy rings (based on your buoyancy collar) were in jest; that really was a great discovery, and has made my Seacam housing permanently more manageable uw.

Thanks Bruce - yeah, I appreciate it. Sorry the 70-200 won't work for you - heck, you can always try it and see if it will fit. I'm just sceptical.

Cheers

James

My recollection is the 70-200mm f2.8 has a huge front element, making it unusable in even the largest housing port openings.....

Bruce, if you really want a long zoom telephoto to use as a macro the 70-200mm F4L as James states is very compact. I have one and for surface work it's a great optic for a relatively low price (about $550.00)

Just doesn't sound like Seacam can accommodate it as of now....But maybe if you get a gang together who will all buy a special port they'd make a few....

Just a thought.....

dhaas