New trinocular microscope, what I'm doing wrong ?

[alpher]

Hi guys. Finally decided to buy a "decent" mocroscope, on a budget of course.
Bought this on aliexpress from Eakins store:
https://www.aliexpress.com/item/1005005444690281.html?spm=a2g0o.order_list.order_list_main.11.21ef1802tPSnqW
Bought the option without camera.
Then I decided to buy camera anyway and because my workbench monitor is an old LCD TV with VGA input only, bought this:
https://www.aliexpress.com/item/32911607403.html?spm=a2g0o.order_list.order_list_main.5.21ef1802tPSnqW

Set it up with 10/20 eyepieces and 0.5 objective, and while the optical part works OK I cannot get the camera to focus at the same time as the eyepiece view, to focus the camera I allways have to move the scope higher that for direct viewing through eyepieces.
Camera is hooked up with included with the scope 0.5 c mount adapter.
Is there a trick to set it all up so I wont have to readjust focus everytime i move from eyepieces to watching the screen?
Any pointers appreciated.

[jpanhalt]

What you are describing is a need to have the two optical devices (i.e., your eyepiece and camera) parfocal.

1) You need a dispersal lens between the camera and camera tube/prism.  It sounds like you have one.  Have you tried a different power? 
2) Make a focus adapter for the camera so its distance can be raised or lowered slightly.

[watchmaker]

What you are describing is a need to have the two optical devices (i.e., your eyepiece and camera) parfocal.

1) You need a dispersal lens between the camera and camera tube/prism.  It sounds like you have one.  Have you tried a different power? 
2) Make a focus adapter for the camera so its distance can be raised or lowered slightly.

IF the camera port is what appears to be the plastic cover behind the two eyepieces, then absolutely you need a camera adapter tube between the camera and the port.  This is nothing more than a tube.  For example, my B&L SZ7 camera unit came with a tube of about 150mm.  I then purchased a camera adapter (this was inexpensive) to fit my Nikon onto the tube.

The trick is to get a tube whose threads match the port threads.  Check with the seller.

[amwales]

I got a triocular from eakins too mine was WITH camera and I had the exact problem you are describing, basically the shim they provide that goes between the scope and the camera is the wrong height, give me some time and Ill try to look up the one that I got that resolved the issue. Basically if you hold the camera a small distance away from the socket where it is supposed to be mounted you can get it focused at the same time as viewed, then measure that distance ( little tricky as its hand held ), make sure you get the right mount type too.

[amwales]

Found my old order on amazon in 2020 https://www.amazon.co.uk/gp/product/B0796MXLHH/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1
I got the 5mm version. As I said, check the mount on YOUR camera.

[amwales]

Looks like the mount on your camera is C not CS so that adapter may not fit.
 

[jpanhalt]

@amwales

I have used a piece of PCV (1" as I recall) as a temporary and easily adjustable way to get the correct distance.

[alpher]

Thank you guys, regarding 5mm c-mount adapters, the camera is mounted to the scope using adjustable adapter included with the scope.


So if I put another 5mm adapter between the camera and this adapter it will help with the focus?

[amwales]

Looks like I have the adapter you show connected with addition of the 5mm adapter I linked earlier on Amazon.
See pic1 it sits between the camera and the part you showed in your last post.
You should be able to test yourself by holding the camera about 5mm away from your adapter.
pic3 is my camera and the 5mm adapter I had to get.
Hope that helps.

[alpher]

Thank you, just ordered 3 of these on amazon $10, not bad.
Much appreciated.