Help setting up logitech optics module

Hy i found your awesome open microscope and try to make one for teaching purposes, on Argentina.

First of all thanks, i coudn’t afford one to teach.

my issue comes when i try to mount the optics of the camera, i dont know if i mounted it correcly, i read that the lens has to be mounted backwards, is this correct or just with the “extention tube” that was printed it will work??. i didn’t go with the pi camera aproach i went with a Logitech C270, i didn’t found much info on the assembly procedure, any help is welcome

thats the way i mounted it, lens faicing foward, if you need more info please request it thanks

The lens should be reversed, as in the side facing out of the tube should be the one that would normally face the camera.

The Logitech camera and the Pi camera are both small sensors. In normal use the scene is big and a long way from the lens. A small image is formed on the sensor which is close to the lens. Because this is not a symmetrical 1:1 imaging system the lens is not symmetrical: there is a side that faces the small image and a side that faces the large scene. In the microscope we have a small sample close to the lens and a large image on the sensor a long way from the lens. We have effectively switched the positions of the scene and the sensor so the lens needs to be backwards.

It should be possible to remove the lens from the holder to turn it over. I have done this with the Pi lens extension tube very gently with the help of a pin.

Hi @gaspar and welcome! The C270 optics module is one I’ve not used in a while, so apologies in advance for it not having received much in the way of updates or documentation. I believe it should still work, though the magnification is higher than I would like.

There are (old) instructions on how to disassemble the webcam hidden in the repository. As we don’t regularly test this, they probably won’t make it into the new revisions of the official documentation - but I should probably archive this somewhere that’s slightly easier to find!

The lens holder unscrews from the PCB with two small screws, and you should then be able to twist the knurled rim of the lens to remove it from the square holder.

Currently there’s only a tall version of the C270 optics; this means the image is more zoomed-in than I would like. It would be great to have a version that’s more like the “camera platform” we use for the basic Raspberry Pi-based optics module, but we’ve not done the CAD to make that work.

thanks for your reply, i have done that and it works, as @r.w.bowman mentions the zoom is way out there, but it isn’t enough to see the nucleus of a cell, and is way to blurry i cant get it to focus correctly, i will try to get an RMS microscope lens and try again

thanks for your reply, i saw the post that you send me, it works, as you mention the zoom is way out there, but it isn’t enough to see the nucleus of a cell, and is way to blurry i cant get it to focus correctly, do you have any tips? or did i make something wrong , i will try to get an RMS microscope lens and try again,

The optics module for the C270 has grown longer since I last tested it - if it’s a plant cell you may well find that it is too zoomed-in to fit the whole nucleus in the image. If it won’t focus at all, it may be that you can’t get the lens close enough to the sample. It should be possible to loosen the optics module and slide it upwards, then re-tighten the mounting bolt - hopefully that might help? I often use the edge of a scalpel or the edge of a piece of paper as a sharp target and manually move it up and down while looking at the image, just to figure out if I am getting it in focus at any point…