Disclaimer: I purposely have the focus mechanism and boom inverted from how Amscope shows it.
Trinocular head:
I had a project that I wanted to do a video of
https://www.eevblog.com/forum/projects-designs-and-technical-stuff/video-of-design-and-build-of-precision-kelvin-banana-jacks-and-header-pins/msg148204/#msg148204 and a lot of it would need to be done under the microscope. I also wanted to be able to take still shots thru the scope also. So I decided to try an eyepiece microscope camera on my Amscope SM-3B zoom binocular microscope. I talked to Amscope sales and they said the MU series of camera were the best they had in the reasonable price range and it also had the best software. So I got a MU500 camera (5Mpixel) and tried it in the eyepiece tube. The camera worked fine but it's not real convenient to try to look thru the other eyepiece with the camera hanging out of the other eyepiece. It also would mean that every time I wanted to take a picture or video clip I would have to remove one eyepiece and insert the camera. So it was pretty obvious that I needed a trinocular head so the camera could always be ready and I could look thru the eyepieces while I filmed. I got a SM745T zoom trinocular head to replace my binocular head. This head has a slide rod that switches the camera tube in but simultaneously blanks the left eyepiece. You lose your stereo vision which is harder to work without. (A scope that keeps both eyepieces working while the camera tube is active costs well over $1000.00 so I will live with it). You can get used to looking with both eyes open even though the left eyepiece is black but you still have no depth perception.
Lesson learned: Don't think any video based system of magnification is going to be great to directly work with. The Stereo microscope is popular for a reason, depth perception. Video is great for documentation but not great to work under.The camera tube has an adjustment to allow the camera to be focused while the eyepieces are in focus. My suggestion (if you are buying a scope) is even if you don't think you will ever want to take pictures or video it only costs $19.40 more for the trinocular head, so buy it if you can.


Camera:
Very solid, heavy all metal enclosure. Feels like you could drive nails with it without hurting it.
The lowest resolution (640x 480) at 57 fps of the 5M pixel camera seemed a little grainy so I also tried the 10M pixel camera whose lowest resolution was (912 x 684) at 27 fps. It turns out that the obtainable fps is also computer dependent and I got
WAY lower fps numbers than claimed. Slower than about 20 fps is not very useable since it gets hard to focus or follow motion on screen. The real Gotcha is that the fps drops even more when you actually record a video clip compared to just viewing it live on the computer screen. So it turns out the 5M pixel worked better for all around use since I could get a consistent >30 fps while actually recording. It also has 1280 x 960 @ 18 fps (8 fps actual) and 2592 x 1944 @ 5 fps (1.8 fps actual) resolutions that work great for still picture capture. So don't think more M pixels is better for microscope camera work. Even if you are only taking still shots trying to focus at 1.8 fps is a frustrating experience. The image gets sharper as the resolution goes up so even if you pre-focus at at the lowest resolution you still need to fine focus at the higher resolutions.
Software:
This is the first microscope camera software I have used but I am impressed with it. It seems like it has just about anything you could want in image capture and manipulation and the manual is actually understandable and is terse but complete. The real bonus to me as a machinist was all the measurement features that you can use on still shots. This is where the higher resolutions for still shots is usefull. You can calibrate for multiple magnifications and save the constants then switch to whatever power you are using. There is a catch with zoom so see my detent mod below for an explanation. I did a lot of testing with the calibration and accuracy of measurements and it is impressively accurate.
Camera screen with all the function tabs on the left.

Measurement screen with random measurement examples on the still picture

Lens protection mod:
I do a lot of tool grinding and soldering under the scope so I cut some polycarbonate circles that are the diameter of the LED light ring. I stick these on the light ring with three very little pieces of the thick clear double stick tape. This protects the lenses from solder smoke and exploding grinding disks and grinding swarf.

Laptop shelf:
I made the shelf out of a worn out acrylic glass bead cabinet window and a chunk of pet plastic. I used the knob from the stop collar that came with the scope. It just clamps to the main post of the base.



Cover:
Make yourself a cover for the scope it keeps the whole unit and especially the eyepieces clean. This is just a shopping bag cut and heat sealed in a few places. I uncover just the eyepieces when I use it and leave the cover on all the time.

Slide shelf:
I do a lot of things where I need a lot of space below the focal plane like using a dremel tool or inspecting cutting tools in the toolholders. And I also do a lot where I want to put a small part on the table under the lens. So I just put a piece of 3/8” x 6” x 18” steel plate between the feet of the base of the microscope. This can be slid back out of the way when necessary or pulled out to put your work on. With this setup I hardly ever have to move the scope up and down on the main post.


Zoom knob detent mod:
When you calibrate for
MEASUREMENT in the software for a particular magnification you have to be able to repeat that exact zoom amount or your calibration is no good. That means you can only do the two extremes of zoom where the knob stop gives you a repeatable position. Or calibrate every time you want an intermediate zoom location and don't touch the zoom or you will have to recalibrate again. So I modified the zoom knob to have spring ball detent stops at every magnification marking on the zoom knob. This allows calibrating all the settings once and saving the constants so I can pick whatever mag I am on and measure instantly.
