Jump to content

stargazine_ep45_banner.thumb.jpg.71f13bfceacd5e3df366d82c2b6f5f9b.jpg

Recommended Posts

Has anyone flocked the inside of the gold tube between the front blue lens and the Etalon?

I'm thinking that it would reduce scattered light bouncing down the tube and improve contrast.

Will be going stage 1 PST mod sometime in the future and would not hesitate flocking the donor tube so why not the PST one?

Any thoughts?

Link to post
Share on other sites

It can't hurt can it?

Whether it will improve anything, I really don't know being such a narrowband.

But if you do, do report back if it improves the image at all. :hello2:

Cheers

Ian

Link to post
Share on other sites
  • 1 year later...

PST tube flocked, attached are photos before and after.

Before (OE paint is not that bad)

post-13264-0-93181200-1370945828_thumb.j

After

post-13264-0-29533800-1370945834_thumb.j

Not a massive increase in contrast but at least I know that scattered light is less of an issue

Link to post
Share on other sites

I think scattered light is the main reason for contrast loss in all telescopes, whether it's wide band or narrow band I don't think makes any difference, it's still light at the desired frequency.

Reducing internal scattered light can do nothing but help improve contrast as I see it - for any type of telescope.

Edited by Cath
Link to post
Share on other sites

In my limited experience (ie. with my own PST) light scattering does seem to be quite a problem, so this looks like a good idea.

James

Link to post
Share on other sites

Their are some interesting articles on scattered/stray light problems in telescopes.

Here's one, although this one doesn't really show the light path bouncing off the inside tube walls ..

http://minimaestro.a...light_paper.pdf

This one shows the problem with scattered reflections off the tube inside wall ..

http://www.bro.com/r...calculation.pdf

Edited by Cath
Link to post
Share on other sites

By the way I did not stick the flocking to the tube, I cut some black card to the exact dimensions then flocked the card.

This way the card can just be removed as it is a friction fit within the tube.

Link to post
Share on other sites

The majority of light scatter during solar Ha observation comes from external atmospheric scatter. A murky yet clear day will show up as a pink haze round the Sun whereas a day of excellent transparency will show a nice black background. On a couple of PST mods we have removed the baffles in the donor telescope as forward reflections from the etalon lit up the rear of the baffles like red glowing rings, even when they were flocked. The main tube was still flocked. :smiley:

  • Like 1
Link to post
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
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • 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.