Microscope Cameras?

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Dave S
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Microscope Cameras?

#1 Post by Dave S » Fri Jun 14, 2019 10:45 am

I am looking to buy a usb 5Mp eyepiece camera for my triocular microscope.

The choice is quite wide, almost certainly all of Chines origin.

Here are a couple on my consideration list. Comments/advice welcome:

https://www.amazon.co.uk/SWIFT-Microsco ... ref=sr_1_8

https://www.amazon.co.uk/SWIFT-Megapixe ... ef=sr_1_12

I note the AMscope versions of these cameras look identical, so almost certainly from the Chinese factory.

I think that buying something like the Bresser, or similar, would lead to disappointment.

https://www.amazon.co.uk/Bresser-Micros ... E473FDWBG5
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Hobbyst46
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Re: Microscope Cameras?

#2 Post by Hobbyst46 » Fri Jun 14, 2019 11:24 am

The first two links, on my computer, only showed dog pictures and "Sorry..." or send to the Amazon home page.

The link to the Bresser camera raises questions:
1. Does the camera fit the phototube diameter of your microscope ? probably so, but I would ask to verify.
2. Are the objectives on your scope infinity-corrected ? if so, any USB eyepiece camera is likely to yield decent images or better, since the camera lenses are not specifically correcting or compensating. Otherwise, aberrations are likely to show, though not in the center of the FOV.
3. I would ask Bresser support/customer service how much of the FOV is actually captured by the camera. The example photos they show do not convey this info.
4. The said example photos are somehow adequate IMO, but I might be wrong.
5. Toupview software is IMO excellent, so I would look for a Toupcam camera or other camera that is supported with Toupview. The Micam free software is an acceptable alternative. Bresser might know it their camera is supported by Toupview.

Although, given your photography background and gear, I think you would get far better images by fitting a high-performance camera onto the trino head. Especially if it is infinity-corrected optics, you might be able to work focally, mount a DSLR body by means of inexpensive mechanical adapters. Or even afocally, in case there is a photo eyepiece for the phototube of the trino head. And even if the optics are 160mm it is possible and not terribly expensive.
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Dave S
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Re: Microscope Cameras?

#3 Post by Dave S » Fri Jun 14, 2019 12:00 pm

Thanks 'hobby', sound advice as usual.

I will weigh up all the pros & cons, and do a bit more research, before committing.

Although I have the 5D4 DSLR, there is a bit of reluctance, to stick my 'pride & joy' on a £350 microscope, when a reasonable usb eyepiece camera, would probably satisfy my curiosity.

I don't want to be spending big money on a microscope camera, as it is a secondary interest to my photography interest, but neither do I want a 'toy'

When I was into astro-imaging, my cameras were Peltier cooled CDD based, with one costing £2.5k, but that was a really serious interest, whereas for me, microscopy will likely be more of a fascinating pass time.

N.B. The ID of the photo tube is 23mm, which I believe is one of the standard sizes.

It must be something strange about phpBB software used for this forum board, as I see the 'dog' too :roll: . The 'links' work perfectly on Facebook forum pages.
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Re: Microscope Cameras?

#4 Post by Dave S » Fri Jun 14, 2019 12:49 pm

The spec for the more expensive 5Mp Swift :

Specifications:
Megapixels: 5MP
CMOS sensor size: 5.1M;1/2.5“ (5.70x4.28)
Frames per second: 7@2592x1944;27@1280x960;90@640x480
Responsivity: 0.53 V/lux-sec
Dynamic range: 66.5dB
SNRmax: 40.5dB
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Re: Microscope Cameras?

#5 Post by MichaelG. » Fri Jun 14, 2019 1:39 pm

Dave,

Having only recently purchased a secondhand 5MP Toupcam; my one regret is that the video frame-rate is so slow. ... Mine is USB-2
Whether or not you intend to record video; that frame rate affects the 'look & feel' of what you see on a monitor when adjusting the microscope.
If you only expect to use the eyepieces, that's no problem ... but if you use a screen 'live', and your computer will handle USB-3 then I would highly recommend it.

MichaelG.
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Re: Microscope Cameras?

#6 Post by Roldorf » Fri Jun 14, 2019 6:28 pm

Hi Dave,

The cameras that Bresser supply are in fact from Toupcam. I have a bresser 5mp camera and use the toupview software as it is a much later version than was supplied with the camera.
Alan
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Re: Microscope Cameras?

#7 Post by Dave S » Fri Jun 14, 2019 6:53 pm

That's interesting Alan, as the models of the Toupcam that I have seen, are very budget end, so perhaps I have yet see any of the better ones.

That said, Bresser do quite a range, from £50 to £669, and if all made by Toupcam, then Toupcam are not all 'cheapo' cameras.
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Re: Microscope Cameras?

#8 Post by Dave S » Fri Jun 14, 2019 7:30 pm

One thing that concerns me, with many of these eyepiece cameras, is that I have seen reported that they can have an image magnification factor of up to 30x, which if put behind a 40x objective is going to produce and image scale of 1200x, and an incredibly narrow Field of View.

The do have very small 'chips', which will have an inherently narrow field of view, which is far removed from what is seen through 10x ocular.

I have seen some that come with a 0.5x reducer, which I would guess is pretty much an essential item.
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Re: Microscope Cameras?

#9 Post by Hobbyst46 » Fri Jun 14, 2019 8:55 pm

Dave S wrote:One thing that concerns me, with many of these eyepiece cameras, is that I have seen reported that they can have an image magnification factor of up to 30x, which if put behind a 40x objective is going to produce and image scale of 1200x, and an incredibly narrow Field of View.

The do have very small 'chips', which will have an inherently narrow field of view, which is far removed from what is seen through 10x ocular.

I have seen some that come with a 0.5x reducer, which I would guess is pretty much an essential item.
A 0.3-0.5X reducing lens is indeed essential for my microscope.
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Re: Microscope Cameras?

#10 Post by Dave S » Fri Jun 14, 2019 10:27 pm

I have just been reading a very interesting article on microscope eyepiece cameras, by a seemingly well read individual.

Quite lengthy, and technically based, it ran for three A4 pages

In summary, it would seem that the resolution limiting factor in photo microscopy, is not so much the camera, but the microscope objective lens. It would seem that beyond a 3M pixel sensor, while the field of view increases, the resolution increase is not significant, if at all apparent.

Of course the larger the pixels, the greater the light gathering power, and the more pixels, the greater the resolution. This is fine in photography using high quality lens to go with it, but not it seems when limited by the ability of the microscope objective lens.

I have experienced this in astro photography. I had two high quality cooled CCD cameras, one with a relatively small sensor, and another with a much larger sensor. The small sensor captured a much smaller filed of view, and was no where near as sensitive (light gathering power) as the larger sensor, with its greater field of view.

The same with my DSLRs, my Full Frame camera, has infinitely better low noise/high ISO performance, than my APSC camera with its smaller sensor, and accompanying smaller field of view.

I guess the moral of the story is that, for most photomicrography purposes, a 3Mp sensor is adequate, and beyond this its a case of diminishing returns.
Brunel SP100 (with 4x, 10x, 40x,60x, and 100x (oil) plan objectives), and Canon EOS 4000d Camera (microscopy use only)

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Re: Microscope Cameras?

#11 Post by Roldorf » Sun Jun 16, 2019 9:39 am

I wonder why you would buy an eyepiece camera when you have a trinocular microscope? It seems a bit of a waste to block off one of your eyepieces with a camera when you can mount it on the trinocular tube.

I will let you know about camera resolution when I receive the T2 mount that i have ordered for my new 18Mp Canon EOS 4000d at the end of the week (bought 'brand new' at a superb knockdown price of 249 Euro to replace the 5Mp Toupcam).

The reasons for the upgrade are not so much about resolution as about movies, which are abysmal on the USB 2.0 Toupcam.

Will hopefully post some comparison pics.
Alan
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Stereo Microscope Optika SFX 90

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Re: Microscope Cameras?

#12 Post by Roldorf » Sun Jun 16, 2019 9:51 am

See here for a video demo on the Live View Software for Canon EOS cameras:
https://www.martinmicroscope.com/eos-details/

and here for some info about the 4000d camera for microscopy:
https://www.lmscope.com/en/Canon_EOS_40 ... st_en.html
Alan
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Re: Microscope Cameras?

#13 Post by Scarodactyl » Sun Jun 16, 2019 2:39 pm

I don't think a decent microscope objective (particularly at lower magnifications) is anywhere close to being limited to 3mp of resolution. Take a look over on photomacrography.net to see the kind of performance they wring out of these things. Or a detailed shootout like this one: https://www.closeuphotography.com/4x-le ... 00-dollars
Note on the objectives there is still plenty of fine detail in the 100% crops shot at 24mp.

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Re: Microscope Cameras?

#14 Post by Dave S » Sun Jun 16, 2019 3:24 pm

Roldorf wrote:I wonder why you would buy an eyepiece camera when you have a trinocular microscope? It seems a bit of a waste to block off one of your eyepieces with a camera when you can mount it on the trinocular tube.

I will let you know about camera resolution when I receive the T2 mount that i have ordered for my new 18Mp Canon EOS 4000d at the end of the week (bought 'brand new' at a superb knockdown price of 249 Euro to replace the 5Mp Toupcam).

The reasons for the upgrade are not so much about resolution as about movies, which are abysmal on the USB 2.0 Toupcam.

Will hopefully post some comparison pics.
I called in a 'eyepiece cam' as a bit of a generic term Alan, but it is intended to use is as third ocular.

I am still jumping to and fro between a new usb eyepiece camera (5Mp usb 2.0), or a second hand DSLR. I really don't want to put my £3k DSLR on a £350 microscope, as it is strictly for my primary interest, which is photography. I see microscopy as more of a fascinating pass time.

From what you say, the 5mp usb 2.0 Toupcam is really abysmal for video purposes, whereas a DSLR would cope with both video and stills. Would just have to get a suitable mount, and focal reducer. I have both Photoshop for processing stills, and Sony Vegas Movie Studio for video.

Maybe I should give some serious consideration to going down the DSLR route.

Incidentally, I traced back both AMscope, and Swift cameras to Touptek. The AMscope 3mp and 5mp being identical to the equivalent Toupcam models.
Brunel SP100 (with 4x, 10x, 40x,60x, and 100x (oil) plan objectives), and Canon EOS 4000d Camera (microscopy use only)

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Re: Microscope Cameras?

#15 Post by Dave S » Sun Jun 16, 2019 3:49 pm

Alan, I have found that I can buy a new 4000d for £229, from a major UK retailer. Some serious thinking to do I reckon. :)

P.S. £220 from Amazon inc free delivery (Prime), or £229 with the 18-55 kit lens, which would make it easier to sell on, if needed.
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Re: Microscope Cameras?

#16 Post by Hobbyst46 » Sun Jun 16, 2019 4:37 pm

The price of the 4000D is decent. The only small issue that I see it is that the LCD screen is fixed. However, the camera can be remote-controlled, so perhaps that is not an issue at all.
If the optics on your microscope is finite (160mm tube length), it is likely that aberrations in the objectives need compensating eyepieces. If so, you might consider installing the camera for afocal shooting, that is, with an appropriate photo eyepiece on the trino tube. Then if one uses a 10X eyepiece, the best camera lens focal length will be 40mm.
Last edited by Hobbyst46 on Sun Jun 16, 2019 4:50 pm, edited 1 time in total.
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Re: Microscope Cameras?

#17 Post by Dave S » Sun Jun 16, 2019 4:45 pm

I would need to ascertain that it had HDMI out, for live view on the PC monitor.

Another thing that I am sure of, whereas I can easily source both a T2 mount/adapter, and a T2 to 23mm adapter, I wonder how I would incorporate a focal reducer in line, and what size reduction would be needed to bring the APSC sensor image, close to the eyepiece view.?
Brunel SP100 (with 4x, 10x, 40x,60x, and 100x (oil) plan objectives), and Canon EOS 4000d Camera (microscopy use only)

Hobbyst46
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Re: Microscope Cameras?

#18 Post by Hobbyst46 » Sun Jun 16, 2019 4:52 pm

Dave S wrote:I would need to ascertain that it had HDMI out, for live view on the PC monitor.

Another thing that I am sure of, whereas I can easily source both a T2 mount/adapter, and a T2 to 23mm adapter, I wonder how I would incorporate a focal reducer in line, and what size reduction would be needed to bring the APSC sensor image, close to the eyepiece view.?
Please see my edited response, above. There are various methods of connection.
Afocal: For an APSC sensor, and a 10X photo-eyepiece, a 40mm camera lens.
Focal: Neither the camera lens nor the photo eyepiece.
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Re: Microscope Cameras?

#19 Post by Roldorf » Sun Jun 16, 2019 6:00 pm

The 4000d has HDIM out and wifi.
I have tried both and they work fine with my laptop with the USB connection and wifi and my Apple IOS tablet with wifi.
I have also tried linking Topview to the software supplied with the camera (EOS utility software) which also works well you take a picture and Toupview software automatically launches with the picture transferred automatically into the Toupview window for further editing.
You can also setup any image processing software to open with the image file such as photoshop.

The EOS software also allows you to view in real-time the image from the camera by lifting the mirror before it captures the image which also helps to reduce vibration on image capture.

By the way Bresser also sells an adaptor for DLSR cameras, see here:-
https://www.bresser.de/Mikroskopie/Zube ... 5x-4x.html
Alan
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Re: Microscope Cameras?

#20 Post by Dave S » Sun Jun 16, 2019 6:09 pm

Thanks Alan, that does answer some of the questions. Are yo connecting the camera to the trioc port, via T2 to 23mm adapter, with no focal reducer, if so is the image image highly magnified compared to the eyepiece view.

Just for the fun of it, I removed the lens from an old webcam, and tried it on trioc tube, if focused ok, but the image was highly magnified.
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Re: Microscope Cameras?

#21 Post by Dave S » Sun Jun 16, 2019 6:18 pm

Hobbyst46 wrote:The price of the 4000D is decent. The only small issue that I see it is that the LCD screen is fixed. However, the camera can be remote-controlled, so perhaps that is not an issue at all.
If the optics on your microscope is finite (160mm tube length), it is likely that aberrations in the objectives need compensating eyepieces. If so, you might consider installing the camera for afocal shooting, that is, with an appropriate photo eyepiece on the trino tube. Then if one uses a 10X eyepiece, the best camera lens focal length will be 40mm.
The distance from the top of the trioc tube, to the 10x objecetive, is approximately 160mm, but this with the adjustable (screw) focus adjusting tubes removed.

For and extra £10 making the camera £229, I can get it with the 18-55 kit kit lens, with given the 1.6 crop factor makes it 29 - 88mm. so comfortably meeting the 40mm criteria.

Buying it with the lens would also make it easier to sell on, if needed.

However, I'm sure how I would mount the camera and lens on the trioc tube, for afocal capture. Much easier to go with a T2 to 23mm adapter, if I can find a suitable focal reducer.

Plenty of them around with a 1.25" barrel for attaching to a telescope.
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Re: Microscope Cameras?

#22 Post by Roldorf » Sun Jun 16, 2019 6:23 pm

The Microscope has Plan Infinity lenses so shouldn't need anything else but I will see when the T2 canon ring arrives sometime on Friday I think. Ordered it from Conrad (No Postage or delivery, goes direct to store all I have to do is collect it 13 Euro). I have C mount fitting from USB camera that I will use.
Alan
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Re: Microscope Cameras?

#23 Post by jfiresto » Sun Jun 16, 2019 6:27 pm

Dave S wrote:... it would seem that the resolution limiting factor in photo microscopy, is not so much the camera, but the microscope objective lens.... For most photomicrography purposes, a 3Mp sensor is adequate, and beyond this its a case of diminishing returns.
I would like to read that article to see how they determined a 3 megapixel sensor is adequate. I have recently been estimating and testing how much camera resolution a Wild M7S will need, and it is certainly more than that.

I measured a numerical aperture (NA) for its objective of 0.07 at the M7S's maximum, 3.1X magnification (to the camera sensor). Using the Rayleigh criterion, the smallest distance between two points (or lines) the objective can resolve is:

Code: Select all

             lambda
    R = 0.61 ------
               NA
where lambda is the light wavelength.

Using 550 nm (a blue-green), the objective can resolve:

Code: Select all

             550 nm                1000
    R = 0.61 ------ = 4.79 µm (or ------ = 209 line pairs / mm)
              0.07                4.79µm
An ideal camera sensor would need four pixels to resolve each line pair of an image, because of the Nyquist limit. For an objective image that has been magnified 3.1X, the sensor would need a pixel every

Code: Select all

    4.79 µm x 3.1 ÷ 4 = 3.71 µm
That is very close to the pixel spacing, 3.74 µm, of a 16 megapixel, 4:3 format, four-thirds camera sensor. A 3:2 full frame sensor covering the same image field-of-view diameter would need 2% fewer pixels because it captures slightly less of the view. I calculate 58.8% instead of 61.1%, if the sensor's diagonal just spans the image's – but it has been a long day and please don't ask me to publish that calculation. :)

Real camera sensor can not resolve up to the Nyquist limit. Perhaps a good one might need six pixels to resolve a line pair. For a Wild M7S, you might then need 2.25X as many pixels (1.5 times as many in each dimension) to match the resolution of the objective – or a 36 megapixel camera.
-John

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Re: Microscope Cameras?

#24 Post by Hobbyst46 » Sun Jun 16, 2019 6:45 pm

Roldorf wrote:The Microscope has Plan Infinity lenses so shouldn't need anything else but I will see when the T2 canon ring arrives sometime on Friday I think. Ordered it from Conrad (No Postage or delivery, goes direct to store all I have to do is collect it 13 Euro). I have C mount fitting from USB camera that I will use.
As far as I could see from the Bresser site, their optics are in general 160mm, although there is one micorscope that is specifically described as having infinity corrected optics. But I might be wrong.
Roldorf wrote:The 4000d has HDIM out and wifi.
I have tried both and they work fine with my laptop with the USB connection and wifi and my Apple IOS tablet with wifi.
May I ask:
Do you connect the HDMI to a USB port ?
I assumed that the 4000D can be connected via USB CABLE to a PC (or laptop), and remotely controlled, without WiFi (in addition to WiFi control). Is that so ?
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Re: Microscope Cameras?

#25 Post by Scarodactyl » Sun Jun 16, 2019 7:06 pm

jfiresto wrote: I would like to read that article to see how they determined a 3 megapixel sensor is adequate. I have recently been estimating and testing how much camera resolution a Wild M7S will need, and it is certainly more than that.
....
Real camera sensor can not resolve up to the Nyquist limit. Perhaps a good one might need six pixels to resolve a line pair. For a Wild M7S, you might then need 2.25X as many pixels (1.5 times as many in each dimension) to match the resolution of the objective – or a 36 megapixel camera.
That sounds about right from having recently tried my canon t6 (18mp) on my m7.

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Re: Microscope Cameras?

#26 Post by Dave S » Sun Jun 16, 2019 7:15 pm

Ok, decision made.

I have ordered an EOS 4000d, a compatible T2 to M42 adapter, and a Bresser M42 to 23mm (male) tube.

I'll hold fire on a focal reducer, until I see what is needed.
Brunel SP100 (with 4x, 10x, 40x,60x, and 100x (oil) plan objectives), and Canon EOS 4000d Camera (microscopy use only)

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Re: Microscope Cameras?

#27 Post by Dave S » Sun Jun 16, 2019 7:35 pm

jfiresto wrote: An ideal camera sensor would need four pixels to resolve each line pair of an image, because of the Nyquist limit. For an objective image that has been magnified 3.1X, the sensor would need a pixel every

Code: Select all

    4.79 µm x 3.1 ÷ 4 = 3.71 µm
That is very close to the pixel spacing, 3.74 µm, of a 16 megapixel, 4:3 format, four-thirds camera sensor. A 3:2 full frame sensor covering the same image field-of-view diameter would need 2% fewer pixels because it captures slightly less of the view. I calculate 58.8% instead of 61.1%, if the sensor's diagonal just spans the image's – but it has been a long day and please don't ask me to publish that calculation. :)

Real camera sensor can not resolve up to the Nyquist limit. Perhaps a good one might need six pixels to resolve a line pair. For a Wild M7S, you might then need 2.25X as many pixels (1.5 times as many in each dimension) to match the resolution of the objective – or a 36 megapixel camera.
Thank you for that input, both informative, and appreciated. :)

Dave
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Re: Microscope Cameras?

#28 Post by jfiresto » Sun Jun 16, 2019 7:45 pm

Scarodactyl wrote:
jfiresto wrote: I would like to read that article to see how they determined a 3 megapixel sensor is adequate. I have recently been estimating and testing how much camera resolution a Wild M7S will need, and it is certainly more than that.
....
Real camera sensor can not resolve up to the Nyquist limit. Perhaps a good one might need six pixels to resolve a line pair. For a Wild M7S, you might then need 2.25X as many pixels (1.5 times as many in each dimension) to match the resolution of the objective – or a 36 megapixel camera.
That sounds about right from having recently tried my canon t6 (18mp) on my m7.
A 12 megapixel Olympus E-PL1 definitely did not match the objective, but I was impressed by what that little, old camera could do with the pixels it had. I am now trying a 16 megapixel E-PL7. I think getting 65-70% of the available resolution would keep me happy for quite a while.
-John

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Re: Microscope Cameras?

#29 Post by Roldorf » Sun Jun 16, 2019 8:32 pm

The 4000d also has a USB port.
Alan
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Re: Microscope Cameras?

#30 Post by Dave S » Mon Jun 17, 2019 1:46 pm

Found this handy little table, which might prove useful to some:
sensors_2.jpg
sensors_2.jpg (147.56 KiB) Viewed 5379 times
Brunel SP100 (with 4x, 10x, 40x,60x, and 100x (oil) plan objectives), and Canon EOS 4000d Camera (microscopy use only)

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