Inexpensive USB 2.0 camera test with two microscope types

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Hobbyst46
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Inexpensive USB 2.0 camera test with two microscope types

#1 Post by Hobbyst46 » Thu Feb 14, 2019 1:08 pm

I purchased an inexpensive (<$70) USB 2.0 microscope camera for documentation on the stereoscope. Thought it might be interesting to test it on the Zeiss Standard microscope. Here are a few examples.

The camera is a tiny 5x5x3 cm feather-weight box, interfaced without an eyepiece, via a 23.2mm external diameter tube adapter that contains a 0.5X reduction lens. I inserted the adapter tube is into one of the binocular eyepiece tubes, and fixed its final position with cellotape. I chose the bino tube for the USB camera, rather than the photo tube of the trinocular head, since the latter carries the Canon mirrorless camera after painstaking adjustment of parfocality.

The USB camera is controlled with either the Toupview software that came with it (not all camera controls, such as exposure or WB, are supported!), or with the free MICAM software.

1) The image of the stage micrometer, with my 10X0.30 Neofluar objective, is IMHO fairly sharp and contrasty, although aberrations are obvious (as expected). In contrast to the Canon camera, the USB camera is very conveniently tethered to the PC, very convenient. Canon EOSM mirrorless cameras have no such option.

The width of the camera image is only about 40% of that of the field of view. Moreover, only about 2/3 of the image width is freefrom severe chromatic aberration (as far as I can judge). So, the useful image width is about 0.25 of that of the FOV.

2) My other test sample is a 65 micrometer long marine diatom, which I tentatively identified as Petroneis humerosa (Navicula humerosa) - please correct me if this is wrong! - mounted in NOA61. It was imaged with a 100X1.3 Planapo phase contrast, oil immersion (both objective and condenser), under blue illumination (peak about 450nm).

Images were stacked with Picolay. Photos are resized, the diatom is cropped, no other post-processing. The apparent resolution in the diatom is 0.2-0.3 micrometer.
Comments are welcome.

Edit: a small mistake - the Zeiss 10X0.30 Neofluar is NOT phase contrast, i.e. not Ph2.
Attachments
USB camera on microscope.jpg
USB camera on microscope.jpg (48.62 KiB) Viewed 19067 times
10x0.30 neofluar Ph2-1.jpg
10x0.30 neofluar Ph2-1.jpg (176.97 KiB) Viewed 19067 times
Diatom.jpg
Diatom.jpg (112.28 KiB) Viewed 19067 times
Last edited by Hobbyst46 on Mon Feb 18, 2019 8:28 pm, edited 2 times in total.

MichaelG.
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Re: Inexpensive USB 2.0 camera test

#2 Post by MichaelG. » Thu Feb 14, 2019 2:20 pm

Apart from the severe yellow fringing towards the edges ... those look to be excellent images.
... Sure to be very useful for ad hoc survey work.

It would be interesting to test it with a fully corrected objective.
[presumably the neofluar relies on some eyepiece correction]

Do you have a link to the supplier, please ?

MichaelG.
Too many 'projects'

Hobbyst46
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Re: Inexpensive USB 2.0 camera test

#3 Post by Hobbyst46 » Thu Feb 14, 2019 2:53 pm

MichaelG. wrote:Apart from the severe yellow fringing towards the edges ... those look to be excellent images.
... Sure to be very useful for ad hoc survey work.

It would be interesting to test it with a fully corrected objective.
[presumably the neofluar relies on some eyepiece correction]

Do you have a link to the supplier, please ?

MichaelG.
Example:
https://www.ebay.com/itm/5MP-USB-CMOS-C ... 2749.l2649

BTW, it is described as a 5MP camera, and the software menu includes a resolution of ~2500x~1900, but I could only get ~2000x~1500 from it in Snap mode (did not try Video yet), do not know why.
I am sure the Zeiss Neofluar relies on correction, e.g. with a KPL eyepiece. I will try with a planapo later on.

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Re: Inexpensive USB 2.0 camera test

#4 Post by MichaelG. » Thu Feb 14, 2019 2:58 pm

Thanks

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mrsonchus
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Re: Inexpensive USB 2.0 camera test

#5 Post by mrsonchus » Thu Feb 14, 2019 3:06 pm

Ditto - excellent image, no problem there I think personally. The resolution in snap-mode definitely says to me that it's a 3mp camera? In this respect would contact the seller....

Looks good though, that said.

John B.
John B

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Re: Inexpensive USB 2.0 camera test

#6 Post by MicroBob » Thu Feb 14, 2019 3:29 pm

Hi Doron,

thank you for reviewing this camera. There are often questions for a recommendation for a simple camera solution and this will probably do well enough for web resolution and documentary purposes. The object micrometer is a harsh test. In a normal image the colour error leads to a certain lack of sharpness towards the border. When using non-plan-objectives this won't do much harm. Since you have your Canon and the eyepiece cam on one microscope: Can you show comparison images? I would expect the biggest differences in corner sharpness and the ability to picture contasty objects without blowing highlights or dark areas.
Zeiss West has equalized the colour error over (nearly) the whole range of objectives. Low power objectives of other brands of this time might work even better with this camera.
I bought two cheap eyepiece camera adapters to sell of two unneeded mirrorless camera bodies, an Olympus and a Nikon One. With a bit of cropping and image editing I got very acceptable images in full-hd-resolution. The adapters will have been similar to your eyepiece camera, only made for bigger sensors.

Bob

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Re: Inexpensive USB 2.0 camera test

#7 Post by Hobbyst46 » Thu Feb 14, 2019 4:34 pm

mrsonchus wrote:Ditto - excellent image, no problem there I think personally. The resolution in snap-mode definitely says to me that it's a 3mp camera? In this respect would contact the seller....

Looks good though, that said.

John B.
Thanks John B.
Re-checked - can take 5MP pics by Snapshot, not in Live View or Video modes.
So, can't complain.

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Re: Inexpensive USB 2.0 camera test

#8 Post by Hobbyst46 » Thu Feb 14, 2019 6:04 pm

MichaelG. wrote:It would be interesting to test it with a fully corrected objective.
[presumably the neofluar relies on some eyepiece correction]
Here are some more examples.

My Olympus 10X0.30 Splan (achromat) performed quite similar to the Zeiss 10X0.30 Neofluar, although the fringes are of a different color; the Olympus is also not parfocal with the Zeiss eyepieces so performance should not be great anyway.

My Zeiss Planachromat objectives gave the same color fringes as the Zeiss Neofluars. They are not shown.

Zeiss Planapochromats - I only have two, the 40X1.0 and 63X1.4 Ph3. They are both oil immersion and were tested accordingly. They are 160/- so a coverslip is not required. From the aspect of CA, they both performed better than the Neofluars, although the 63X image corner is out of focus - perhaps imperfect mounting of the camera within the eyepiece tube (it is an 45deg inclined tube).
MicroBob wrote:When using non-plan-objectives this won't do much harm
Finally, a Zeiss 25X0.45 Ph2, not Plan, not Neofluar, performed quite well !
@Bob - I think that this is what you expected ?
I have some comparisons between the Canon and the USB cameras and will post them later or tommorow.

@MichaelG - yes, it is a survey camera.
Attachments
10X0.30 Zeiss Neofluar.jpg
10X0.30 Zeiss Neofluar.jpg (335.89 KiB) Viewed 19027 times
10X0.30 Olympus Splan.jpg
10X0.30 Olympus Splan.jpg (342.08 KiB) Viewed 19027 times
40X1.0 Zeiss Planapo oil.jpg
40X1.0 Zeiss Planapo oil.jpg (489.26 KiB) Viewed 19027 times
63X1.4 Zeiss Planapo Ph3 oil.jpg
63X1.4 Zeiss Planapo Ph3 oil.jpg (481.84 KiB) Viewed 19027 times
25X0.45 Ph2.jpg
25X0.45 Ph2.jpg (489.06 KiB) Viewed 19027 times

MichaelG.
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Re: Inexpensive USB 2.0 camera test

#9 Post by MichaelG. » Thu Feb 14, 2019 10:00 pm

Thanks for the update

I think there is great potential there.

MichaelG.
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photomicro
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Re: Inexpensive USB 2.0 camera test

#10 Post by photomicro » Thu Feb 14, 2019 10:03 pm

I wonder if I can ask what size the micrometer scale is?

thanks

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Re: Inexpensive USB 2.0 camera test

#11 Post by desertrat » Thu Feb 14, 2019 11:26 pm

That's impressive performance for a low cost sensor and reduction lens. The eyepiece camera and .3X reduction lens I bought for somewhat less cost doesn't produce images anywhere near as sharp, no matter how many focus bracketing images I take. My antique objectives are no doubt not as sharp as yours, but they produce much sharper images in the eyepieces than what I get out of the camera.
Rick

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Re: Inexpensive USB 2.0 camera test

#12 Post by Hobbyst46 » Fri Feb 15, 2019 8:23 am

photomicro wrote:I wonder if I can ask what size the micrometer scale is?

thanks
the fine division is 0.01mm = 10 micrometer
Attachments
stage micrometer.jpg
stage micrometer.jpg (78.78 KiB) Viewed 18956 times

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Re: Inexpensive USB 2.0 camera test

#13 Post by MicroBob » Fri Feb 15, 2019 8:29 am

Hobbyst46 wrote:Finally, a Zeiss 25X0.45 Ph2, not Plan, not Neofluar, performed quite well !
@Bob - I think that this is what you expected ?
Hi Doron,
One of the novelties of the Zeiss Standard system was that the color error of the stronger objectives was artificially calculated into the weaker objectives too. This allowed to use the same eyepieces for all objectives. So with all Zeiss West objectives the image quality to the border with this camera won't be perfect. For this reason I think that higher corrected objectives won't show their full advantages over simple achromats. Viewed the other way round: For simple achromats a better camera won't offer much advantage over you eyepiece camera.

Olympus used for their 160mm system a somewhat lower colour error so this camera would perform slightly better with these objectives. At least in theory.

Have you tried the eyepiece camera with your stereo microscope? They have no intentional colour error so the camera should fit very well.
In my experience images taken with the stereo microscope look quite different to those taken at the same magnification with the compound microscope, so it is worth to try both.

Bob

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Re: Inexpensive USB 2.0 camera test

#14 Post by ChrisR » Fri Feb 15, 2019 8:49 am

Bob
- tangential topic; do you happen to know where Leitz or Lomo would be on the correction scale? And did Zeiss change?
We are told, (mostly be ebay sellers!) that Lomo = Zeiss.

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Re: Inexpensive USB 2.0 camera test

#15 Post by Hobbyst46 » Fri Feb 15, 2019 8:57 am

desertrat wrote:That's impressive performance for a low cost sensor and reduction lens. The eyepiece camera and .3X reduction lens I bought for somewhat less cost doesn't produce images anywhere near as sharp, no matter how many focus bracketing images I take. My antique objectives are no doubt not as sharp as yours, but they produce much sharper images in the eyepieces than what I get out of the camera.
Perhaps the sharpness is not so much determined by the objectives, I would suspect the mounting of the camera on the microscoep. The installation of this USB camera in the eyepiece tube (or photo eyepiece tube, on the trinocular head of my scope they are identical) is extremely simple: Insertion until focus is achieved. Below is a photo of the adpater - this short adapter goes into the eyepiece tube: There is an O-ring. The o-ring is supposed to provide friction so as to stabilize the camera at a certain height. It is not a good idea, though: On my scope, friction is very high so I had to apply great force to push the adapter inside, past the O-ring, to achieve focus. Application of silicone grease on the O-ring did not make it better. So, my solution was to remove the stupid O-ring, maybe I will find a better fitting O-ring. In the meanwhile, I wrapped a cellotape around the adapter, to serve as stopper.
Attachments
USB camera adapter.jpg
USB camera adapter.jpg (26.36 KiB) Viewed 18952 times

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Re: Inexpensive USB 2.0 camera test

#16 Post by MicroBob » Fri Feb 15, 2019 9:15 am

ChrisR wrote:Bob
- tangential topic; do you happen to know where Leitz or Lomo would be on the correction scale? And did Zeiss change?
We are told, (mostly be ebay sellers!) that Lomo = Zeiss.
Hi Chris,

post war:
Zeiss West Standard: highest amount of built-in colour error, equal for (nearly) all objectives
Zeiss Jena 160mm: Low power with little colour error, higher powers with high colour error identical to Zeiss West
Leitz: A bit lower than Zeiss West (not sure about the evenness over the range. Later series had equal error for all objectives)
Olympus: A little lower than Leitz (not sure about the evenness over the range.)
Lomo 160mm: Like Zeiss Jena

So for a set of Lomo 33mm objectives you would use Huygens eyepieces for lower powers ad correction eyepieces from 20:1 and for the apos.
Zeiss Jena and Lomo 33mm are close but not equal in parfocality.

Zeiss and Olympus don't really match well but Zeiss and Leitz do acceptably and Leitz and Olympus do too.
Always keep the design parameters in mind.
Klaus Henkel carried together many of the relevant informations about this in his "Mikrofibel":https://www.mikroskopie-forum.de/pdf/mikrofibel.pdf
Peter Höbel did many very good comparisons on the colour correction topic and posted them in the german forum.

Bob

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Re: Inexpensive USB 2.0 camera test

#17 Post by 92111 » Fri Feb 15, 2019 9:23 am

hi
there is a blue hotspot in 63x

Hobbyst46
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Re: Inexpensive USB 2.0 camera test

#18 Post by Hobbyst46 » Fri Feb 15, 2019 9:26 am

Hi all,

More comparisons are in preparation.

One important point about this camera, that I should mention, is that functioning depends somehow on the USB source. Not all usb connection points are the same. For example, if I connect the camera directly to the USB on the computer itself (it is an Intel Nuc box), OK. If I connect the camera through a USB hub - even if other devices connected to the hub are disconnected - the software feels it and limits the resolution to 320X200 or something like that. Perhaps it is possible to overcome this issue with a forked USB cable, that includes a power connection in parallel, like the cable supplied with some external DVD burners. Anyway, this shoud be known. But, considering the low cost of my USB camera (and it included shipping expenses), I can live with it.
92111 wrote:hi there is a blue hotspot in 63x
Yes, and perhaps very weak hot spots with the other objectives as well. The more I read about hot spots in camera-microscope interfaces, the more it looks like random phenomena, peculiar to cetrain combination of lenses.
Last edited by Hobbyst46 on Fri Feb 15, 2019 9:30 am, edited 1 time in total.

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Re: Inexpensive USB 2.0 camera test

#19 Post by ChrisR » Fri Feb 15, 2019 9:29 am

Bob, thanks that's useful.
92111 - yes I noticed that too!

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Re: Inexpensive USB 2.0 camera test

#20 Post by Hobbyst46 » Fri Feb 15, 2019 1:33 pm

It appears that the previous photos taken with Planapo 63X1.4 oil objective were cause by a problem (bubbles?) in the immersion oil or some unnoticed operator error. Here are two new photos. The stage micrometer is oiled to the objective. Both cameras are installed. Photos are resized.
It is clear that the USB catches a smaller part of the FOV than the Canon. Also, aberrations are weaker in the Canon. Contrast in the USB is seemingly better though.
More comparisons later.
Attachments
USB -stage micrometer, 63X1.4 Ph3 oil.jpg
USB -stage micrometer, 63X1.4 Ph3 oil.jpg (449.73 KiB) Viewed 18924 times
Canon - stage micrometer, 63X1.4 Ph3 oil.jpg
Canon - stage micrometer, 63X1.4 Ph3 oil.jpg (205 KiB) Viewed 18924 times
Last edited by Hobbyst46 on Fri Feb 15, 2019 2:14 pm, edited 1 time in total.

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Re: Inexpensive USB 2.0 camera test

#21 Post by Hobbyst46 » Fri Feb 15, 2019 2:09 pm

Finally, some more comparison photos, representing various specimens and illuminations that I have been trying. Some are with the 25X0.45 Ph2 achromat, others are with 40X0.75 Neofluar Ph2. All dry.

As mentioned above, both cameras were simultaneously installed on the Zeiss GFL microscope. The USB camera with its reduction 0.5X lens and no eyepiece, the Canon M10 with its prime lens (connected through an EF-EOSM adapter) and 8X KPL eyepiece. Perfect parfocality everywhere. Both cameras are affixed to the respective photo tubes - I cannot fix the Canon "above" the microscope. The USB is tethered and is fired by the PC software. The Canon camera is fired by pressing "the air above" its small screen. Because the shutter trigger of the Canon is so sensitive, one need not touch the screen to fire it.

White balance was not the same for both cameras, actually auto white balance was used, and some color corrections were done in post processing. Hence, I cannot testify much to the color fidelity of any of these cameras (the colors are fairly OK, thats all). Yet the FOV and sharpness can be compared.

My conclusions:

1. Aberrations are weaker on the Canon.
2. FOV coverage is better on the Canon.
3. Sharpness across the FOV is better on the Canon.
3. Ease of use and convenience are better on the USB.
4. Contrast might be better on the USB - probably operators errors with the Canon.
5. The USB camera is much less expensive (by a factor of >10).

Overall, I think that the USB is a great little camera, a joy to use.
Having tried in the past a (very good, 16MP) smartphone camera, I think that the convenience afforded by the USB camera is unsurpassed.
Just a reminder - the USB camera must be fed from its own powerful USB port, not through a USB hub port.

In the future, hope to show sterescope photos with the USB camera.
Attachments
Stained animal tissue.jpg
Stained animal tissue.jpg (131.47 KiB) Viewed 18916 times
Onion skin.jpg
Onion skin.jpg (106.68 KiB) Viewed 18916 times
Moss leaf.jpg
Moss leaf.jpg (178.11 KiB) Viewed 18916 times
Sonchus pappus.jpg
Sonchus pappus.jpg (116.51 KiB) Viewed 18916 times
Cotton fibers .jpg
Cotton fibers .jpg (105.71 KiB) Viewed 18916 times

jfiresto
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Re: Inexpensive USB 2.0 camera test

#22 Post by jfiresto » Fri Feb 15, 2019 4:33 pm

Hobbyist46 wrote:... [The] short adapter goes into the eyepiece tube: There is an O-ring ... [that] is supposed to provide friction so as to stabilize the camera at a certain height. It is not a good idea, though: On my scope, friction is very high so I had to apply great force to push the adapter inside....
I had exactly the same trouble with a similarly made c-mount to 23.2/30 mm adapter. You might think it was really meant for a 30.1 mm eyepiece tube.
-John

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Re: Inexpensive USB 2.0 camera test

#23 Post by MichaelG. » Fri Feb 15, 2019 5:26 pm

Hobbyst46 wrote:Finally, some more comparison photos, representing various specimens and illuminations that I have been trying. ...
Very thorough ... and very impressive results.

Thanks for putting-in the effort, for everyone's benefit.

MichaelG.
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Re: Inexpensive USB 2.0 camera test

#24 Post by ChrisR » Fri Feb 15, 2019 9:31 pm

Thanks H46, that's a very useful appraisal

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Re: Inexpensive USB 2.0 camera test

#25 Post by desertrat » Sat Feb 16, 2019 6:52 pm

Hobbyst46 wrote:...The USB camera is controlled with either the Toupview software that came with it (not all camera controls, such as exposure or WB, are supported!), or with the free MICAM software...
Thanks for mentioning MICAM! If I had not been just skimming your post previously, I would have seen this much earlier. I did some internet searching and found the MICAM website in the Netherlands. I downloaded an older version, because I wasn't sure if the latest version would run on Windows XP, which is quite old now.

I installed it and now it's working with my 2MP eyepiece camera. So far my only complaint is it's saving the images in 640 X 480 format, where the sensor records at 1600 X 1200. However the full sized images which were saved by the Windows XP webcam driver were quite fuzzy looking at full file size, and the 640 X 480 images saved by MICAM seem to be showing about as much detail, maybe a tiny bit better.

Even better is the sample image shown by MICAM has the same size and resolution as the saved image, which has pretty much eliminated the need for the large amount of focus bracketing I needed to do with the onboard Windows XP webcam driver. The sample image for that had such poor detail that I couldn't tell if the microscope was properly focused or not. The eyepiece camera isn't perfectly parfocal with the eyepieces, so I can't count on them to get the focus right. Also, pulling out the camera a bit makes focus worse, and I don't want to start trimming the end of my vertical eyepiece tube to get parfocality.

With the reduction lens removed, the eyepiece camera seems to be able to see almost as much detail as I can see in the eyepiece, although of course the visible field is only a tiny fraction of the whole field visible in the eyepiece. If I was willing to stitch a whole bunch of images together, I could get almost as fine detail as I can see from the eyepieces, with almost the full field visible. But that seems to be a very time consuming task to get a single good image.

Another very good aspect of MICAM is the image banding problem which was pretty bad with the Windows XP webcam image capture software is much less severe. It's still noticeable looking carefully at images with lots of clear background, but it's reduced to the point I probably won't bother setting up a smooth DC power source for the microscope.
Rick

A/O 10 Series Microstar
A/O 4 Series Microstar
A/O 4 Series Phasestar
A/O 4 Series Apostar
A/O Cycloptic Stereo
Several old monocular scopes in more or less decrepit but usable condition

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Re: Inexpensive USB 2.0 camera test

#26 Post by Hobbyst46 » Sat Feb 16, 2019 9:17 pm

desertrat wrote:
Hobbyst46 wrote:...The USB camera is controlled with either the Toupview software that came with it (not all camera controls, such as exposure or WB, are supported!), or with the free MICAM software...
Thanks for mentioning MICAM! If I had not been just skimming your post previously, I would have seen this much earlier. I did some internet searching and found the MICAM website in the Netherlands. I downloaded an older version, because I wasn't sure if the latest version would run on Windows XP, which is quite old now.

I installed it and now it's working with my 2MP eyepiece camera. So far my only complaint is it's saving the images in 640 X 480 format, where the sensor records at 1600 X 1200. However the full sized images which were saved by the Windows XP webcam driver were quite fuzzy looking at full file size, and the 640 X 480 images saved by MICAM seem to be showing about as much detail, maybe a tiny bit better.

Even better is the sample image shown by MICAM has the same size and resolution as the saved image, which has pretty much eliminated the need for the large amount of focus bracketing I needed to do with the onboard Windows XP webcam driver. The sample image for that had such poor detail that I couldn't tell if the microscope was properly focused or not. The eyepiece camera isn't perfectly parfocal with the eyepieces, so I can't count on them to get the focus right. Also, pulling out the camera a bit makes focus worse, and I don't want to start trimming the end of my vertical eyepiece tube to get parfocality.

With the reduction lens removed, the eyepiece camera seems to be able to see almost as much detail as I can see in the eyepiece, although of course the visible field is only a tiny fraction of the whole field visible in the eyepiece. If I was willing to stitch a whole bunch of images together, I could get almost as fine detail as I can see from the eyepieces, with almost the full field visible. But that seems to be a very time consuming task to get a single good image.

Another very good aspect of MICAM is the image banding problem which was pretty bad with the Windows XP webcam image capture software is much less severe. It's still noticeable looking carefully at images with lots of clear background, but it's reduced to the point I probably won't bother setting up a smooth DC power source for the microscope.
Hi desertrat,
I notice that MICAM has an option which may perhaps improve the resolution of the image. The image resolution seems to depend on the frame rate. When in MICAM, from Device Options->Video Format Setting. I refer to Snapshots, not Video. In that window, there are selections of Frame Rate, Color Space/Compression and Output Size. I notice that if the Color space is the default is MJPG, the frame rate is 15 fps. But, if the color space is YUY2, the frame drops down to 2 fps, and the output size can then be maximum - 2592x1944 with my USB camera. - and the Snapshot image is a JPG file of exactly this resolution, 259sx1944. Perhaps this is the way to have the images saved at the high resolution. Again, I am talking about still photos, not Video which I did not try yet.

desertrat
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Re: Inexpensive USB 2.0 camera test

#27 Post by desertrat » Sat Feb 16, 2019 9:36 pm

Thanks.

Looking at the options you mentioned, I found the menu that allows me to pick the whole 1600 X 1200 resolution this camera can use. It also reduced the frame rate to 2 per second, as you mentioned. This also increased the banding problem to what I had with the Windows XP webcam program. But then I discovered that dropping the lamp voltage to the minimum setting on my transformer, to 2.5 volts (the lamp is rated at 6.5 volts), the banding went away completely. Although the image in my eyepieces was dim with yellow color cast, the software automatically brought it up to normal brightness and adjusted the color cast to mostly neutral.

This program has some interesting capabilities. Unfortunately, there was no way I could improve overall image sharpness from what I could get before. It's just a lot easier to adjust focus now. If I want decently sharp images, I'll have to buy a better quality image capture device.
Rick

A/O 10 Series Microstar
A/O 4 Series Microstar
A/O 4 Series Phasestar
A/O 4 Series Apostar
A/O Cycloptic Stereo
Several old monocular scopes in more or less decrepit but usable condition

Hobbyst46
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Re: Inexpensive USB 2.0 camera test

#28 Post by Hobbyst46 » Mon Feb 18, 2019 8:24 pm

MicroBob wrote:Have you tried the eyepiece camera with your stereo microscope? They have no intentional colour error so the camera should fit very well. In my experience images taken with the stereo microscope look quite different to those taken at the same magnification with the compound microscope, so it is worth to try both.
Here are some tests of the camera on my stereoscope. The bottom (trans) illuminator a a home-made warm-white LED array, + diffusers, when specimens are laid on the clear glass stage plate. The top (epi) illuminator is an inexpensive clamp-on white LED circular illuminator, when specimens are laid on the black/white stage plate. Specimens are placed, as flat as possible, on the plate.

The camera is inserted into one of the phototubes of the binocular head. Exposure time (1/shutter_speed) was manually set. Colors and contrast were optimized with the MICAM software prior to the snapshot - that is a nice feature of the software. Further color corrections were done in post processing. Single images only where recorded. (Note: the Toupview software provies similar features, this session was done with MICAM though).

Notes:
1. Often the default settings of the camera control do not match the "real" view. Probably because of the specific conditions: harsh white light, reflections, ambient light, shadows under the raised rim of the specimen, more (?).
2. On all images, the top right corner is less in focus than the rest of the image - this unfocused corner moves around when I rotate the camera around its optical axis, so the reason is possibly less than optimal coaxiallity of the camera optical axis and the microscope optical axis. Quite reasonable, given the very simple adapter and the fact that the photo tube is inclined at 45 degrees (or less).
3. There is at least one fixed alien black dot on all photos (e.g. circled in red in photo no.4). This dot originates from the camera, not the scope. I cleaned the lens thoroughly, but the dot stays. Perhaps it is dust on the sensor.. :?
4. For non-ambitious documentation, this camera is fine and a pleasure to use.

First group of photos shows trans-illumination, later on - epi illumination.
Comments are welcome.
.
Attachments
Stereoscope with top white LED illuminator.jpg
Stereoscope with top white LED illuminator.jpg (42.85 KiB) Viewed 18706 times
1) Trans illumin. sand 20X.jpg
1) Trans illumin. sand 20X.jpg (427.14 KiB) Viewed 18706 times
2) Trans illumin. sand 40X.jpg
2) Trans illumin. sand 40X.jpg (372.6 KiB) Viewed 18706 times
3) Trans illumin. onion skin stained with neutral red, 40X.jpg
3) Trans illumin. onion skin stained with neutral red, 40X.jpg (388.53 KiB) Viewed 18706 times
4) Trans illumin. egg on hair.jpg
4) Trans illumin. egg on hair.jpg (68.24 KiB) Viewed 18706 times
Last edited by Hobbyst46 on Mon Feb 18, 2019 8:56 pm, edited 1 time in total.

Hobbyst46
Posts: 4277
Joined: Mon Aug 21, 2017 9:02 pm

Re: Inexpensive USB 2.0 camera test

#29 Post by Hobbyst46 » Mon Feb 18, 2019 8:26 pm

(continued)

Note: "lavender leaf" is actually lavender flower "petal".
Attachments
5) Epi illumin. lavender floret on black disk, 10X.jpg
5) Epi illumin. lavender floret on black disk, 10X.jpg (209.21 KiB) Viewed 18706 times
6) Epi illumin. Lavender leaf on white disk, 10X.jpg
6) Epi illumin. Lavender leaf on white disk, 10X.jpg (211.07 KiB) Viewed 18706 times
7) Epi illumin. Leaf on white disk, 10X.jpg
7) Epi illumin. Leaf on white disk, 10X.jpg (223.38 KiB) Viewed 18706 times
8) Epi illumin. Sonchus pappus on black disk, 16X.jpg
8) Epi illumin. Sonchus pappus on black disk, 16X.jpg (416.43 KiB) Viewed 18706 times

MichaelG.
Posts: 3976
Joined: Mon Apr 10, 2017 8:24 am
Location: North Wales

Re: Inexpensive USB 2.0 camera test

#30 Post by MichaelG. » Mon Feb 18, 2019 8:45 pm

Hobbyst46 wrote:3. There is at least one fixed alien black dot on all photos (e.g. circled in red in photo no.4). This dot originates from the camera, not the scope. I cleaned the lens thoroughly, but the dot stays. Perhaps it is dust on the sensor

Comments are welcome.
Having suffered my fair share of dusty sensors ... I would say it's more likely that you have a dead pixel there.

... Could you let us see a crop of that small region please ?

MichaelG.
.
.
P.S. I was looking at this earlier today:
https://www.lmscope.com/en/Stereomikros ... on_en.html
The suggestion of tilting the specimen, for single camera use on a Greenough, seems very logical.
Last edited by MichaelG. on Mon Feb 18, 2019 9:11 pm, edited 1 time in total.
Too many 'projects'

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