Non-reflective black coatings for inside of scope tubes

[Mokusatsu (Australia)]

Is there much noticeable gain with Newtonians from using flocking paper or similar compared to flat black spraypainting the inside of the tube?

If there are materials significantly better than flat black paint, where can they be purchased and what do they cost?

Or, does anyone who has gone down this route wish to opine that it makes little difference in practice and is not worth the cost and bother for a typical backyard dob with mirrors that will soon be a bit grimy anyway...

Travis

[mswhin63 (Malcolm)]

Flocking uses the concept of the fibre to absorb and any gloss fibre will re-radiate randomly and statistically dissipate randomly reducing reflection directed to the mirror or lens.

Matt Black still has a relatively smooth surface so any reflections will radiate into a single direction concentrating back to the mirror or lens.

Flocking is the best method.

[sheeny (Al)]

There is a noticable increase in contrast (especially when viewing bright objects like planets) between flocking and matt black paint.

Flock it.

Al.

[Mokusatsu (Australia)]

Alright then, sounds like something I want to look at.

Does it drop fibres all over my mirror? Will it absorb dew and go mouldy or fade over time and become shinier?

And where do you buy it? Any old textiles place? Online?

[leon]

I used to use Flat Black on the inside of the tube, worked well if one is budget limited.
Also a trick to get it right down the tube well is to get a paint roller and straighten it out, gives you plenty of lenght for that far reaching spot.

Roll don't spray.

Leon

[Merlin66 (Ken)]

We apply sticky backed velvet sheet to all the internal surfaces of the Spectra-L200 spectroscopes. Works very well and doesn't re-radiate IR like anodising.
You can normally find suitable material in hardware/ hobby shops.
For longer larger tubes, to get a good bond, it's better to use long strips axially on the inside surface.....
As an alternative on larger Newtonian tubes I've often used a mix of blackboard paint and fine sawdust. This gives a really matt, low reflective outcome. Applied by hand.
Hope this helps.

[anj026]

A patch of black velvet or flocking inside the tube directly opposite the focuser will sometimes be enough if the rest of the tube is a painted matt black. If you look through the focuser tube without an eyepiece then the area around the diagonal mirror should be completely flocked.

Alternatively an appropriately sized baffle at the bottom of the focuser tube may achieve the same result.

[Mokusatsu (Australia)]

Yeah, alright, so has anyone got any tips on where to buy reasonably priced sticky-backed black velvet and/or flocking?

[Merlin66 (Ken)]

https://www.google.com.au/webhp?hl=e...+backed+velour

You'll find something here.....

[mswhin63 (Malcolm)]

I am a bit concerned about velvet, although it seems to have worked for most people Velvet has a very glossy appearance mainly for its designed purpose.

It would be interesting if someone has made a comparison between both Flocking and Velvet material!

[Mokusatsu (Australia)]

Velvet seems more glossy at high angles, but seems pretty matt face on. Perhaps this is a case where a small baffle might help if a patch of velvet is placed on the tube wall opposite the eyepiece.

[killswitch (Edison)]

Originally Posted by Mokusatsu

Yeah, alright, so has anyone got any tips on where to buy reasonably priced sticky-backed black velvet and/or flocking?

Protostar sells flocking boards in adhesive or snap-fit.

http://www.fpi-protostar.com/flockboard.htm

[AstroJunk (Jonathan)]

Originally Posted by Mokusatsu

Yeah, alright, so has anyone got any tips on where to buy reasonably priced sticky-backed black velvet and/or flocking?

Spotlight.

Be warned though - it is VERY sticky! One touch and its on. I used strips to make it easier to install in my SCT. It was very effective too.

[tlgerdes (Trevor)]

I protostar'd my newt thanks to Marc Aragnou. Made a huge difference when imaging from the city, I was able to gain nearly 60secs extra on each image before light pollution became problematic. 90sec to 150sec sub's with a DSLR