Canon T3i to microscope

Starting out in microscopy? Post images and ask questions relating to the microscope and get answers from our more advanced users on the subject.

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rjlittlefield
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Post by rjlittlefield »

Looking ahead to after you get the optics sorted out...
jeaton wrote:I also usually publish these as stereo pairs which is a bit tricky at this working depths, but I'll figure that out.
There's a very simple and painless way to make stereo pairs these days: just use the "synthetic stereo" capability of Zerene Stacker.

Very briefly, you shoot one stack, then use some processing options in Zerene Stacker to generate stacked outputs showing what the subject would have looked like from two different off-axis angles. See https://zerenesystems.com/cms/stacker/d ... eticstereo for more information. For validation, using a subject about the same size as your teeth, see https://www.photomacrography.net/forum/ ... hp?t=33923 .

--Rik

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Post by ChrisR »

And I don't understand what you meant by:
"With a 4X objective I won't be able to take pictures of specimens much larger than this one. Is there something odd about this microscope that I am limited to 2 mm with a 4X objective?"
What I think is happening is that the camera's view is what you'd be seeing if you couldn't get your eye close enough to the eyepiece - only the middle.
The Eyepoint of the eyepiece should be high, such as would be needed by spactacle wearers, such that one's eye - or entrance pupil of a camera lens - coincides with it.
Entrance pupils are back somewhat, in zoom lenses.

Simple camera lenses have the E-P nearer the front. Maybe you can borrow one to try? Know anyone with a camera on a phone?!
Chris R

jeaton
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Post by jeaton »

Once again, thanks to all of you for your help. About the field of view of the 4X objective with the 10X eyepiece as per my post of December 31, about 2 mm is the size limit with this set up - it might get better with a camera lens that improves the field of view so I can see the entire field present in the eypiece. I will adjust the ISO - ! had not thought to do that and it was set very high. rj - the Zerene Stacker stereo feature sounds lovely - which version of that program is that available on - that program can get pretty pricey for the top versions. Chris - I will also attempt the direct view through the objective - I did want to test that before buying anymore stuff (although I could not find item numbers on Ebay and wasn't sure I was looking at the correct parts). Still lots of things to try . . . (glad I'm retired and have the time to experiment!).
Jeff Eaton

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Post by jeaton »

Chris - I build an 150 mm tube with PVC and beveled a PVC junction such that the tube fit tightly in the head. So I was able to attach the camera mount and try to see what the image looked like just through the objective. The image was about the same size as it is afocal through the eyepiece but was very washed out almost impossible to focus on. So, as usual, what did I do wrong!
Jeff Eaton

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Post by zzffnn »

Jeff,

High iso = more noise in image and may interfere with stacking too, depending on your subject.

Please also try smallest possible spot (camera) metering and exposure compensation too and maybe use a grey background, instead of white background.

Washed out image may be improved by blackening inside of your PVC tube. And maybe better camera metering.

Definitely try a prime lens of 40-50mm focal length. Your small image cone, as recorded by camera, might be caused by your zoom lens. Each zoom lens is different, but in general, prime lenses are easier to work with in afocal imaging.
Last edited by zzffnn on Thu Jan 04, 2018 11:22 am, edited 1 time in total.

jeaton
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Post by jeaton »

The best reviews I get for lenses for my camera is the Canon 40 mm f2.8 pancake lens (most say it is better than the f1.8 50 mm). Anyone had any experience with that lens?
Jeff Eaton

rjlittlefield
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Post by rjlittlefield »

jeaton wrote:rj - the Zerene Stacker stereo feature sounds lovely - which version of that program is that available on
Synthetic stereo is in all versions. I'm such a great fan of stereo that I couldn't stand to leave that out of anything!

--Rik

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Post by ChrisR »

Sorry Jim, Nikon got stuck in my brain.
Canon is easier. Olympus 50mm f/1.8 is good and cheap, and the adaptors should be cheap enough.
Yes the Canon 40mm STM is a great little lens. (I think the 50mm STM is a tad sharper but for your purpose it might be slightly long) Plenty of used ones about.
Adapters - if you go direct. The hardest bit is to the dovetail. Search on
olympus m42 dovetail. There's a seller in Spain micro-cystal,
and one on Belarus, Rafcamera. I can only currently see adapters to M42 x 0.75 which is T2 on ebay. M42 tubes are 1mm pitch thread.


At Rafcamera's site:
https://www.rafcamera.com/adapter-dt46-to-m42x1m-wide
https://www.rafcamera.com/microscope-do ... m-to-m42x1
He would put one on ebay if you want to go that way.


Yes - internal reflections and light-leaks are worse than you might think! Protostar is the standard flocking stuff in the US afaik.

With 6" from objective rear, to sensor, are you seeing about 5mm field with a 4x objective?

Not sure which exact scope you have, when you take the head off, is there any glass in the lower part. CH2s have none, CH30s have a thick lump, of which I don't know the purpose. I took it out.
Chris R

jeaton
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Post by jeaton »

Hi Chris - there is no glass above the objective - this must be a CH2 configuration. The view from the objective to the sensor with a 150mm tube is 3mm as shown on this photo of a mm scale:
Image
I did paint the interior of the tube black, but the image I get is still VERY weird:
Image
I'm trending towards the afocal approach through the lens - I did order the Amscope 4X lens and am still contemplating what to do about an EOS lens - still oscillating between a 50mm f1.8 and th 40mm f2.8. Anyway here is my latest effort using my 18-55mm lens with ISO set <400 at f5.8:

Image
Jeff Eaton

zzffnn
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Post by zzffnn »

jeaton wrote: Image
This image looks much better than previous ones. So it came from afocal imaging? I would say this is good enough for publication, though you can still improve it further.

And the image above it is direct projection?

Your field of view is slightly more than 3mm (closer to 3.5mm), I think.

And note painting a tube black may not be enough to kill internal reflection. You need to place light absorbing material inside. That Doodlebug Beetle Black Card stock from Hobby Lobby (which was recommended by Rik) would work.
Last edited by zzffnn on Thu Jan 04, 2018 9:24 pm, edited 1 time in total.

jeaton
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Post by jeaton »

The good image is from using the afocal approach with 59 stacked images; the awful one is from direct imaging - I don't know why it is so bad. Perhaps lots of light leakage at the top where the camera is merely resting on PVC.
Jeff Eaton

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Post by jeaton »

Okay - here is my very first stack (still using photoshop) using the Amscope 4X objective with an Amscope 10X widefield eyepiece (I did this becuase I also got the 5X eyepiece which works fabulously to increase the size of specimens I can photograph). I shot this with the Canon EF40/2.8 STM lens at f5.8. The field of view is much larger than previous attempts, everything is sharper, and even the individual shots have much greater depth of field. This first attempt is without stepdown rings (ordered, but coming from China - it will be awhile) so the lens was exposed to outside light; the lens was about 0.8 mm from the eyepiece. The lighting is less than ideal and there is not enough diffusion (I just wnated to see how the lens would work), but I think I'm getting there. Here is an unedited shot showing the complete field of view:
Image
This is what the B&W, cropped, and cut out specimen looks like:

Image
I still have work to do, but am certainly getting publishable images. My thanks to all of you for your help and patience.
Jeff Eaton

ChrisR
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Post by ChrisR »

Good to see the improvement. I think there's more to come, but well done so far :)
Chris R

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