DIY Optical rig for aligning cameras and collimators

[Corpze]

Hi - I just wanna share my latest build - based on Starlight Express optical rig in which they align their camerachip / housings before the ship them out - And i was inspired to build my own.
I am very keen to be able to do so much adjustments and tuning to my gear during the day as possible - and this is another method of doing just that, and in this case the aligning of camera tilt which can be a royal PITA during the dark and -20 degree C.

So, here is the SX article on what i was going to build: SX Article

Note: I haven't reciieved my new camera yet so the video does not contain the actual adjustment, but as soon as i get my new camera - I will show just how it works!

/Daniel
 

 

[markse68]

That's a clever idea. Is it safe to shine a laser directly at the CCD? I suppose it must be if SX do it

Mark

[Corpze]

10 hours ago, markse68 said:

That's a clever idea. Is it safe to shine a laser directly at the CCD? I suppose it must be if SX do it

Mark

I thought so too when i first saw this idea - so why not build one and try it for my self

Yes, you should probalby not use any stronger laser than the allowed 5mw i presume.
I did try it with my iPhone and can easilly see the pixels or the touch screen touch points, in a pattern with each "dot" approx. 1mm apart.

/Daniel 

[Corpze]

And here is the actual tilt aligning process

/Daniel
 

 

[kbrown]

Does it not matter if the laser and the screen are not perfectly parallel?

[markse68]

That’s great Daniel- really instructive to see it in use and it looks to work really well 👍 The sensor pixel pattern is interesting- is it little dots because of micro lenses?

btw this is my favourite laser pointer- it’s got an on/off latching switch on the back of the tube so hands free which is really unusual, all brass construction and batteries last ages as it’s nice and low power

https://cardelliniproducts.com/red-laser-pointer-lp/

Mark

[wimvb]

11 hours ago, markse68 said:

The sensor pixel pattern is interesting- is it little dots because of micro lenses?

Any edge causes diffraction, and any regular pattern will have associated with it a corresponding diffraction pattern. Microlenses will certainly affect this diffraction pattern, but not alter it in a significant way. There will be a pattern even for sensors without microlenses. The size of the grid (pixels in case of a sensor) will determine the spacing (of the dots) in the diffraction pattern. The smaller the pixels, the wider the spacing.

[wimvb]

15 hours ago, kbrown said:

Does it not matter if the laser and the screen are not perfectly parallel?

No. In fact if they were, you wouldn't be able to see the reflection. In the original article that Daniel links to, there is a clear offset between laser and screen.

https://www.sxccd.com/support/maintenance-information/aligning-the-ccd-in-an-sxvr-camera/

[Corpze]

Wim is right, couldn’t explain it vetter myself.

I will compare the grid pattern from the pixels of my Atik in the video with the ASI 2600MM when it arrives, to see how they look.

 

/Daniel