Telescopic camera adapter for RaspPi


#1

I have just got a telescopic camera attachment (the clip-on kind labelled “12x Metaltelephoto Lens”) for my RaspPi birdbox project and am having trouble getting any kind of decent image out of it. The camera itself is fine as you can see but all I get it when I attach the lens is a blur or at best a small circular image. Are there any other lenses for the Pi or do I need to mount the lense I have differently?

martymarty2

Many thanks!


#2

@edjones, I have this lens too, and found I have to increase the distance between the camera module and the rear lens of the telephoto lens, by ~5mm. Expect vignetting in every corner of the image. In perfect world, the image sensor would be in plane with every axis, accurately centered. That’s hard just using the clip with a camera module.
Try also the camera module lens focusing tool.
Here’s an image from my quick test, shot at 2560x1440, downscaled for upload. Only slight vignette showing on the right top and bottom corners:


#3

Glad to see you are getting far better results than me! How have you achieved the separation you mention between the camera eye and the lens as when I do it just by hand as a test the results I get are still pretty bad?


#4

@edjones, like with almost every RPi project, these parts don’t exist… You have to build them yourself, or use whatever you have.

If you haven’t touched the stock cam module lens focus, it should be ok. Otherwise, focus it to infinity.

Start with a cut of black tube, about the same diameter as the screw mount on the clip, about 5-7 millimetres of length. Place this between the clip, with the camera module at the rear. The extension tube should be completely “light tight”. Prepare to adjust the length of the tube. It depends on many factors you will find out.

Check the plane of the cam module, if it’s wonky by even a degree, heavy vignetting will appear. A custom camera module mount plate would be nice. It could be as simple as piece of black plastic, with cuts for the cam module lens and the tiny connector, and screw holes, light tight.

Now, moving the parts carefully, you can start searching the “sweet spot” for the cam module lens. It has to be centered properly. I’m sure you will eventually get there.

A 3d printed adapter for this would be great!


#5

I will certainly give this a try, thanks for your help and advice!


#6

@edjones, did you get your project running?
See this article for your inspiration:


#7

Hi, I did yes thanks! Not got nearly as nice pictures as that link you shared, and the mounting of the lense was a lot neater than mine but got there. It does give me a push to further enhance my own project!


#8

Glad to hear you got there! :)