Spatial Filtering Video

[planters]

You are correct...sir. Place the longer FL lens last to increase the beam size and to decrease the divergence by that ratio. Orient the curved surfaces toward the beams that are the most parallel ie away from each other, to reduce the potential for spherical aberration.

[Tesa]

can anyone tell me where to buy a 35mm and a 85mm lens in good quality?

[jors]

Anyone know detail from these ie: 35mm FL lenses? Spherical or aspherical...sizes?
many thanks!

[planters]

These are spherical lenses. The focal lengths are not very important. What matters is the ratio of the focal lengths and keep in mind that the longer the focal lengths, the easier the alignment will be.

[absolom7691]

Eric, how often do you find yourself playing with the alignment as far as regular maintenance goes? I would imagine that the precision required for spatial filtering would make this very susceptible to alignment drift.

[planters]

I don't move my projectors (hardly) and they do not need much realignment. Once every few months I'll open them up and try to nail the alignment and a little improvement is gained. The flexmounts as well as the razors need to be tweaked to about the same amount. When I do move them to the LEM near Boston, the projectors all need a small tuning, but it requires only a few minutes.

[absolom7691]

This doesn't sound bad at all. When I get back to my build, I may set up a 462nm diode with spatial filtering to get a really tight and clean beam. Thanks for the info!