Jump to content

Walking on the Moon

LS50F: is there vignetting?

Recommended Posts

I have a LS50F etalon double-stacked to a PST and it gives good results, showing a mass of sharp solar detail on good days of seeing. But, can anyone say if the Lunt etalon is vignetted by the PST's 40mm diameter objective?

When the beam leaves the back of the etalon is it narrower than when it entered, allowing it to slide through the PST objective without vignetting?

Link to comment
Share on other sites

  • 3 weeks later...

Hi Merlin

A front mounted etalon such as your LS50F has no lenses in it to focus the incomming light, 50mm aperture in at front & 50mm aperture out at back, so yes, your PST 40mm will vignette the 50mm aperture of your LS50F.

Best Regards


Link to comment
Share on other sites

As Karl said, the PST objective will act as an aperture stop to give you a 40mm f10 system.

The front etalon combo will give a reduced bandwidth (around 0.5A) and should show the solar surface in better contrast.



Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.