Baader Telecentric TZ3 for PST Mod?

[Bastelhannes]

Hi folks,

I am just thinking about a, maybe most stupid, idea:

Would it be possible to use the new Baader SunDancer II Telecentric System TZ-3S https://www.baader-planetarium.com/en/s ... ystem.html in front of the PST40 etalon (without it's collimating lens?

Maybe I can improve the sweet spot?

[MalVeauX]

Hi,

Yes, its common practice to use a PST etalon without both of its collimating lenses after any telecentric as a doubles stack.

The challenge is getting a good PST etalon with good uniformity and luminosity for high transmission.

So instead, you could look into other air spaced etalons, like a Lunt 50 pressure tuned, or a Lunt 80 DS II module. Another alternative is doing a Lunt 40 tilt tune a have a 3D printed cell that holds it and allows tilt inside of a chamber. Odds of getting a great etalon from these 3 options is much higher than finding a good PST etalon these days.

And so, another way to look at it, is to figure another primary etalon and use the Solar Spectrum (Sundancer, same thing cloned) as the double stack.

Very best,

[marktownley]

In other words you need to have a hand picked PST etalon for this to work properly

[Bastelhannes]

Ooookay...

Looks like Lunt is my new friend. I tested the last few days a lot of PST etalons. Looks like they are becoming worse.