C/CS mount adapter for DIN microscope objectives

General
1

A few weeks ago I found a cheap used inverse microscope, supposedly for kids, “Telmu inverse microscope”. The mechanics were crap but it did have a sturdy revolver with din objectives. After initially trying to mount a Raspberry Pi v1.2 camera module into the tube, I eventually scrapped the whole thing for parts.

I designed a quick and dirty C mount adapter to mount those DIN objectives on the Raspberry Pi HQ camera with FreeCAD. I have several Heights available, and you can make your own by changing the parameters in the spreadsheet. The longer versions are most necessary/useful for the lowest magnification lens. I know virtually nothing about optics, long ago it was a topic in some kind of physics for Veterinarians class. The model is parametric though.

The picture quality is quite ok.

2

Cool work, thanks for posting this.

I’m considering building a higher-resolution OFM, but am still getting up-to-speed on what’s possible here.

For imaging yeast cells, feels like I need a decent objective of at least 40x or even as high as 100x.

Wondering if you, or anyone else who has used your adapter, has gotten to a successful OFM build with that level of magnification.

thank you

3

40x to 100x work well for viewing cells. Even the simple Pi lens has been used, see: Now I'm hooked on this world of microbes
I would not suggest using the HQ camera. For looking at cells you will need the motion control of the Openflexure microscope which is designed around the Pi camera V2. The HQ camera sensor is better, but it is also larger which means the other optics need to change. Simple ways of doing that end up rather large to fit in the Openflexure body.

4

Yes, but for yeast cells you’d probably want more than the simplest optics, as they only show up as circles a few pixels across with the pi camera and lens, as I found out yesterday when I stole some yeast from our bread-making efforts…

1 Like
5

Thanks William. Really helpful. I’m still catching up on details here, and it looks like the v2 camera is the right choice. Pairing that with a 100x objective; and it sounds like I will be able to produce clear images of Yeast.

Am I correct in assuming from your response that:
(1) This adapter you have on Thingiverse is only for the HQ camera…
and
(2) I don’t need an adapter at all if I go with the v2.

Very appreciative of your help. Thank you.

6

For that configuration everything you need is available on the microscope build pages. The Configure and Download STLs button is an interactive selector, with a preset selection for the parts required for the common versions. If you get a blank screen, try a different browser. It does nothing in my older version of Edge, but is fine in my version of Chrome.

7

I’m very interested in how your yeast viewing works out. I’m also looking for a yeast viewing/counting solution and am wondering if this platform will do the trick.