Using Camera Optics and lasers

Anyone ever check out what happens when you point a laser through a large SLR camera lens? Many high end lenses have dozens of optics inside the barrel which could really do some interesting stuff to the beam.

You could also in theory point a laser through the view finder on an SLR, then focus the lens so that when the dot is sharp on your target, the target is in focus.

My concern though would be could a high power laser (such as 200mW or greater) do damage to the lens assembly or any of it's optical parts (possibly damage some coating on the high end lenses.

It would look cool if you had like an old SLR that you didn't use and take the lens off and shine a beam into the mirror which would shoot it up to and through the eyepiece... Might make a cool macro photo showing the way light travels through a camera. However I wouldn't want any power laser to hit the sensor of the camera so I would be very careful not to press the shutter button when the beams passing through!

Just shooting a laser through an SLR lens doesn't do much of anything. All those elements are in there to improve chromatic and spherical aberrations, which aren't much of an issue with a monochromatic light source, located at (virtual) infinity.

If you have two camera lenses, you can mount them front to front or back to back to make a ridiculously over-engineered beam expander, I guess. You would want to be careful with a high-powered beam - there are apertures and baffles inside the lens that could be badly effected by being overheated.

DiRollin said:

It would look cool if you had like an old SLR that you didn't use and take the lens off and shine a beam into the mirror which would shoot it up to and through the eyepiece... Might make a cool macro photo showing the way light travels through a camera. However I wouldn't want any power laser to hit the sensor of the camera so I would be very careful not to press the shutter button when the beams passing through!

Click to expand...

I would shine it in the eyepiece, not in the lens, that way if you somehow do hit the shutter the mirror flips up and can't do anything.

Yeah, good point. I bet if you took apart a lens you could play with the individual elements but combine they're not meant to really change light that much so it wouldn't do much to the beat.

Very old lenses, not DSLR lenses might be ok to try as modern lenses have all sorts of anti-UV and Anti IR fogging coating on them.

An old telescope 10x or 20x with beam from laser fired backwards into the aperture lens could provide a VERY powerful focussing rig!

Seoul_lasers said:

An old telescope 10x or 20x with beam from laser fired backwards into the aperture lens could provide a VERY powerful focussing rig!

Click to expand...

...and fire into the eyepiece, telescopes make fantastic beam expanders.

-Trevor