TheSkySearchers

A thought occurred to me from a comment one of our members either here or at AF made in a past posting.

The comment that the member made was that satellite interiors were painted gloss black since it was easier to clean and proper baffling/ light traps took care of any reflected light.

We always are looking for the blackest materials of either velvet, flocking or paint to blacken our refractor tubes with.
Some TeleVue tubes do not even have baffles relying instead on a rough interior finish which some people have simulated using silica or rough sandpaper.

So my question is, if a tube is properly baffled does the colour of the interior actually matter as much as we seem to think?

Using my C6-R as an example, I have changed out the three factory baffles for five that are spaced to let the shadow of the forward baffle fall on the face of the one behind.

Would this be enough in itself to make the interior colour of the tube a non issue?

I do know of one manufacturer that was considering hemispherical baffles as well as conical baffle at one point.

I think that color still matters. Sure if you are at a truly dark site you can get away with practically anything. But if you have a neighbor that flips on a porch light the incoming light is going to be at an odd angle that baffling might not defeat. Flat black is baffling's backup. Defend in depth and don't skimp I think.

Assembling a satellite in a clean room is one environment. Having to deal with random lights impinging on the objective from wacky angles... is different.

One of the reasons I was thinking about this is the way the baffles in my C6-R are currently spaced, the shadow falls on 10% or so of the face of the trailing baffle and I was thinking of adding two more to get it closer to 20-25% in shadow.

The tube interior and baffles are painted in a flat black somewhat in between Ultra Flat and Chalkboard paint.
So I was curious if deeper shadow and trapping reflected light trumps interior colouring.

As nFA says flat black is a part of the defense. Whether it helps a lot or little, there is no reason to paint inside of the tube white, right?

Flat white perhaps?
I do know how much a tube can be darkened by just installing one extra baffle.
I am not planning on using a different colour but the gloss black comment intrigued me.
It seems the standard number of baffles is three but I have seen more premium tube with up to nine placed in them.
So how much does the extra baffling account for?
With the C6-R and two extra baffles it went from reasonably dark to unlit tunnel black when pointed at a light source.

In an urban/suburban setting the off axis is a worry.

The dewshield is already flocked, do you think a series of baffles in it would help?

Lady Fraktor wrote: ↑Wed Sep 25, 2019 8:16 pm The dewshield is already flocked, do you think a series of baffles in it would help?

Baffles in front of the objective will act like aperture stops reducing effective aperture of the scope.

Bigzmey wrote: ↑Wed Sep 25, 2019 9:00 pm

Lady Fraktor wrote: ↑Wed Sep 25, 2019 8:16 pm The dewshield is already flocked, do you think a series of baffles in it would help?

Baffles in front of the objective will act like aperture stops reducing effective aperture of the scope.

Right! Baffling belongs behind a flat black and maybe rough dew shield.

I believe making an extra long slightly conical dewshield is a better strategy (than dewshield baffles). I use 3-5mm charcoal crafting foam. It is already flat black, lightweight and actually works better for dew prevention than metal dewshield. For the scopes with none-removal dewshield I just make a dewshield extension.

One caveat. As long as any dew shield baffles are as large or larger than the objective it’s good.

I’m interested in Kasai’s Nero planetary Newtonian which has a baffle right at the front of the ota. The AstroTech imaging Newtonians also have good baffling schemes up front.

There is a clearance of 6mm around the inside of the dewshield to the ID of the dewshield so lots of room for a series of baffles.
I am not much for foam on my telescopes so I make dewshields out of light gauge metal or plastic.
The one I have on the C6-R currently is 380mm long and does not vignette the objective.

Lady Fraktor wrote: ↑Thu Sep 26, 2019 4:36 am There is a clearance of 6mm around the inside of the dewshield to the ID of the dewshield so lots of room for a series of baffles.
I am not much for foam on my telescopes so I make dewshields out of light gauge metal or plastic.
The one I have on the C6-R currently is 380mm long and does not vignette the objective.

That sounds like very careful protection. Excellent, even!

Hmmm, I just measured from the edge of the lens cell flange to edge of objective retaining ring is 14.5mm
It would be quite easy to make a slightly oversized shield with deeper troughs between baffles.
That may even trap air a bit better as well.

After reading the postings of most of the membership for the last three years I find it hard to believe there are only 2 other people with opinions on the original topic

Lady Fraktor wrote: ↑Thu Sep 26, 2019 5:01 pm After reading the postings of most of the membership for the last three years I find it hard to believe there are only 2 other people with opinions on the original topic

Yes, but we are the experts!

When I feel like I am not getting enough traffic I post at CN. Always plenty of opinions there. Sometimes you want a fancy restaurant and sometimes just looking to pick a bar fight.

Well I am not in the mood for a bar fight before bed, I have been banned from CN before

Maybe I will post the question over there in the morning and see how long it takes a mob to form!

Bigzmey wrote: ↑Thu Sep 26, 2019 7:19 pm

Lady Fraktor wrote: ↑Thu Sep 26, 2019 5:01 pm After reading the postings of most of the membership for the last three years I find it hard to believe there are only 2 other people with opinions on the original topic

Yes, but we are the experts!

When I feel like I am not getting enough traffic I post at CN. Always plenty of opinions there. Sometimes you want a fancy restaurant and sometimes just looking to pick a bar fight.

I second that emotion!

But when I want a bar fight I try to find an Irish pub with IRA money laundering ties. It's easier to walk away whole from that than from CN!

Lady Fraktor wrote: ↑Thu Sep 26, 2019 7:22 pm Well I am not in the mood for a bar fight before bed, I have been banned from CN before

Maybe I will post the question over there in the morning and see how long it takes a mob to form!

Just be sure that when you see the torchlights and pitchforks get out! I never learned that lesson.....

notFritzArgelander wrote: ↑Thu Sep 26, 2019 7:29 pm

Lady Fraktor wrote: ↑Thu Sep 26, 2019 7:22 pm Well I am not in the mood for a bar fight before bed, I have been banned from CN before

Maybe I will post the question over there in the morning and see how long it takes a mob to form!

Just be sure that when you see the torchlights and pitchforks get out! I never learned that lesson.....

What do you mean? This when the fun begins.