Rigidly mounting an odd combination: T2i + 85L f/1.2

[dsiegel5151]

This company sells pretty cheap adaptors for an EF mount camera to a microscope:

http://www.martinmicroscope.com/

Really nice guys too. I mostly keep my T3i on my microscope, but I also have taken nice images with my 5D and 20D. In terms of price for good objectives, ChadS is right. They are not cheap. My Olympus phase contrast objectives were roughly $5000 a piece. Thus, I paid around $20,000 (well, the university paid) for 4x, 10x, 20x, and and 40x phase contrast objectives

Male Red-spotted Newt cloaca at 40x total magnification. Canon T3i, Olympus BX40 microscope.

[ChadS]

@dsiegel That's a cool image. Sadly, I deal with droplets and microscopic ice crystals. Not even a snowflake amongst the bunch!

[dsiegel5151]

Ha, the only crystal I ever deal with are when my students do a poor job staining grids for TEM, and those aren't the kind of crystals you'd want to look at!

[ChadS]

Wow, lots of techy-nerd-types on this forum. Guess I'm in the right place!

[ChadS]

@conropl Thanks, I plan to stabilize the camera body and lens. Everything is a rigid assembly so I can smother everything with beanbags once I'm set and ready to go. Nothing like added mass to damp oscillations.

I've been playing today and have had a modicum of success so far just hacking a few things I've got on-hand (and wow the 85 has some sharp IQ even at f/1.2). I'm shooting in live view as that's the way I have to focus. However, I can clearly hear the mirror slap. I'll pull the lens and verify that the mirror is, in fact, moving up and down. Obviously the shutter must still fire but that's not a lot of vibration - though it would be a simple matter to make an external shutter. However, I don't think I can hack my T2i to still expose when the shutter is disabled and open.

[conropl]

I'm shooting in live view as that's the way I have to focus. However, I can clearly hear the mirror slap. I'll pull the lens and verify that the mirror is, in fact, moving up and down. Obviously the shutter must still fire but that's not a lot of vibration - though it would be a simple matter to make an external shutter. However, I don't think I can hack my T2i to still expose when the shutter is disabled and open.

You could not be getting a live image on your LCD if the mirror was down, the mirror would block the sensor if it was not up. You must be hearing the shutter.

[ChadS]

You could not be getting a live image on your LCD if the mirror was down, the mirror would block the sensor if it was not up. You must be hearing the shutter.

I just confirmed (by removing my lens and looking at the mirror) that the mirror returns to the lowered position after the shot is exposed briefly before returning up. Why this is, I do not know and perhaps other bodies behave differently. And it happens after the exposure so most people would not notice the mirror slap as moving the camera for the image. However, since I'm planning on shooting a thousand or more photos from one fixed position the cumulative effect of having the mirror slap the housing could add up.

Anyone really know how to drive the USB commands outside of the documented set? I'd love to park the mirror up and leave the shutter open and yet still turn the sensor on and off when I hit the trigger. I could easily add an external shutter that's far more reliable than the one in my camera. Thanks!

[Dr Croubie]

ps also, with that manfrotto-mount i suggested earlier, it does have a 'minimum lens-body distance' if you didn't see that. A few seconds with a hacksaw can shorten the front-plate so that it slides further back, so that shouldn't be an issue...

[jrw]

Anyone really know how to drive the USB commands outside of the documented set? I'd love to park the mirror up and leave the shutter open and yet still turn the sensor on and off when I hit the trigger. I could easily add an external shutter that's far more reliable than the one in my camera. Thanks![/QUOTE]


Have applied to get the SDK to allow creating a custom sample imaging device, with MPE-65, with a unique interface for a grad students research project. Microscopes available use too small a sensor and the results of shifting and stitching images change the grayscale values too much for the bitmap conversion and subsequent image analysis.
The purpose of the SDK Canon provides is to allow programmers to create custom software to use in tethered operations. Might be something you want to look into. Language of source code is MS C++ 6.0

JRW

[Dr Croubie]

just a thought, if 85mm and f/1.2 is what you need for field/depth of view, try checking out one of these:
http://www.ebay.com.au/itm/Repro-Nik...item2c630fb122
It doesn't have a real lens mount, just a 52mm thread (so you can construct your own mount maybe including a tripod-ring) with a reversal adapter, or bellows (because it doesn't have a focussing helicoid, i hear the nikon pb4 is good, includes swing-adjustment). Not made for infinity-focussing (same as the mpe-65), and from what I hear, it's sharp as all hell straight from f/1.0. Also, for all that, surprisingly cheaper than the 85 f/1.2L...