Flocking evidence

[greglloyd]

Sorry to bring this thread up again, but I'm wondering if simply using an Astrozap Dew Shield on the front of my 12" Dob would give me similar benefits to flocking the tube?

I don't really want to disassemble the OTA right now and I observe in my back garden so there is no stray light as such (no bright light). My garden remains quite dark (but enough light to see around).

I'm just wondering if throwing an Astrozap dew shield on the front would give me the benefits of improving contrast since the overall OTA length will be well extended past the secondary and at the same time getting some dew prevention benefits for the secondary?

Anyone just went the dew shield approach rather than flocking the full tube? I know people have posted pictures showing the difference flocking makes to the darkness of the tube inside, but these are daylight pictures with lots of light entering the tube and not taken at night pointing to the sky. Far less chance of stray light entering into the OTA at night - especially with a dew shield on the front I would have thought?

[Caldwell14]

I remember Simon's post - it was irrefutable proof the tube was darker inside - even in broad daylight the results were stunning. As for measuring wavelengths of light - not needed - the visible spectrum was enough to see the reduction in light reflected around the OTA.

In fact - it was that post which convinced me to flock my 300P at the time.

I concur, the pic was evidence enough to convince me!

[Caldwell14]

I might have to report you - 8" newts have rights too

Indeed they do, especially nice new 1/10 wave Orion Optics ones

[Laurie61]

Sorry to bring this thread up again, but I'm wondering if simply using an Astrozap Dew Shield on the front of my 12" Dob would give me similar benefits to flocking the tube?

I don't really want to disassemble the OTA right now and I observe in my back garden so there is no stray light as such (no bright light). My garden remains quite dark (but enough light to see around).

I'm just wondering if throwing an Astrozap dew shield on the front would give me the benefits of improving contrast since the overall OTA length will be well extended past the secondary and at the same time getting some dew prevention benefits for the secondary?

Anyone just went the dew shield approach rather than flocking the full tube? I know people have posted pictures showing the difference flocking makes to the darkness of the tube inside, but these are daylight pictures with lots of light entering the tube and not taken at night pointing to the sky. Far less chance of stray light entering into the OTA at night - especially with a dew shield on the front I would have thought?

A dew shield would help, it's all about stopping off axis light getting to the eyepiece.

[greglloyd]

Ok, thanks for that. I thought a dew shield would certainly help shield out stray light.

Question is, how effective would it be compared with flocking the tube? After only recently cleaning the mirror and reassembling the scope I don't plan to rip it apart any time soon. So a dew shield would be preferable if it gave almost the same results.

[Caldwell14]

Again is all about small gains, it would help a little bit, everything helps a little bit, flocking and what have you all helps a little bit. Add them all together, I'll let you work out the maths....

[John]

I flocked my Orion Optics 10" F/4.8 newt but could not see any difference afterwards in all honesty. Maybe Orion Optics interior blackening is darker than some other brands ?

With my 12" Orion Optics dob I use a half-moon dewshield opposite the focuser and it works well in keeping stray light out of the top of the tube so I'd recommend one of those.

If you do flock you don't need to do the whole tube. The area opposite the focuser (ie: behind the diagonal) and around the tube for around 10 inches above the mirror is just as effective although, as I said, I notised no difference with my 10".

[DRT]

Are all flocking materials the same?

The stuff sold by FLO seems expensive, small and is out of stock. I found this, which is in much larger rolls but I don't know if it is the same stuff.

Is there such a thing as astronomical flocking material {no jokes please } or will this other stuff do just as good a job?

[SnakeyJ]

Are all flocking materials the same?

The stuff sold by FLO seems expensive, small and is out of stock. I found this, which is in much larger rolls but I don't know if it is the same stuff.

Is there such a thing as astronomical flocking material {no jokes please } or will this other stuff do just as good a job?

I think the protostar flocking is best rated - http://www.fpi-protostar.com/flock.htm, though the DC-Fix did me just fine.   There is now the ultimate carbon nanotube stuff at less thatn 0.03% reflectivity, but not commercially available.

[Laurie61]

Are all flocking materials the same?

The stuff sold by FLO seems expensive, small and is out of stock. I found this, which is in much larger rolls but I don't know if it is the same stuff.

Is there such a thing as astronomical flocking material {no jokes please } or will this other stuff do just as good a job?

I have used A4 sheets from hobby craft and the d-c-fix in rolls. 

http://www.wilko.com/sticky-back-plastic/d-c-fix-original-deco-self-adhesive-film-velour-black-348-0005/invt/0309578

[DRT]

Thanks, Laurie.

Do you know if Wilko's sell that stuff in store?

[Laurie61]

Not sure if its stocked nation wide but my sister in law picks it up while out shopping in either Bolton or Lancaster.  

[laser_jock99]

Before-and-after. Same exposure settings

[Uplooker]

Thanks, Laurie.

Do you know if Wilko's sell that stuff in store?

Yes they do sell it in store.

Ian

[DRT]

Thanks, Laurie.

Do you know if Wilko's sell that stuff in store?

Yes they do sell it in store.

Ian

I bought some from our local store last week and started flocking my SkyWatcher FlexTube 300p

I'll finish it this weekend if it doesn't rain too much.

[Stu]

On the subject of effectiveness of flocking, I wonder if it is more effective in light polluted areas where there are likely to be more reflections from external light sources?

I would have thought at a reasonably dark site that so long as you have decent baffling/blackening in the focus tube that there may not be as much to gain.

Feel free to shoot this down in flames, it is pure hypothesis and speculation!

Stu

[Dave_D]

On the subject of effectiveness of flocking, I wonder if it is more effective in light polluted areas where there are likely to be more reflections from external light sources?

Stu

i'd say it's true... i've been plagued by an annoying vertical spike in my images that is hugely less visible now i flocked the tube

[DRT]

Feel free to shoot this down in flames, it is pure hypothesis and speculation!

The lifeblood of any good internet forum

[AndyWB]

On the subject of effectiveness of flocking, I wonder if it is more effective in light polluted areas where there are likely to be more reflections from external light sources?

I would have thought at a reasonably dark site that so long as you have decent baffling/blackening in the focus tube that there may not be as much to gain.

I've wondered the same thing...

[RikM]

Before-and-after. Same exposure settings

That's the first picture to make me consider it might be worth the effort

[laser_jock99]

On the subject of effectiveness of flocking, I wonder if it is more effective in light polluted areas where there are likely to be more reflections from external light sources?

I would have thought at a reasonably dark site that so long as you have decent baffling/blackening in the focus tube that there may not be as much to gain.

Feel free to shoot this down in flames, it is pure hypothesis and speculation!

Stu

I never bothered flocking my scopes used at the dark sky site. With a SQM reading of 21.8 or better it's not going to do much. On the other hand at my suburban site it's definately worth it.

If shooting with the moon nearby in the sky it might be a consideration?

[Stu]

I never bothered flocking my scopes used at the dark sky site. With a SQM reading of 21.8 or better it's not going to do much. On the other hand at my suburban site it's definately worth it.

If shooting with the moon nearby in the sky it might be a consideration?

Crikey, who'd a thought it. I might just have been right!! :-)

[Alien 13]

Crikey, who'd a thought it. I might just have been right!! :-)

Im sure its equally valid with fracs too probably more so because you have refraction and reflections to deal with.

Alan

[moriniboy]

This is a photo of a sample piece of flocking placed within my 300px flextube, I was so impressed I fully flocked the top and bottom sections.

The increase in contrast was really evident and I have to varying degrees flocked every scope I have owned since.

[greglloyd]

That's the first picture to make me consider it might be worth the effort

Agreed that it makes the inside of the OTA darker. No disputing that.

But, as with almost all before and after shots they are taken in broad daylight - not at night from a back garden when pointed up at just a dark sky. I still can't tell if there would be any benefit flocking a 12" scope that is used visually in a back garden with mag 5 to 6 skies? (i.e. Milky Way and Andromeda galaxy clearly visible with naked eye on transparent nights).

Yes, when I look into my OTA pointed to the sky during the day I can see light reflecting in the tube revealing what can be described as swirly strokes in the paint. But, when looking down the same OTA at night it is very black looking.

I also wonder that if you simply put a quality dew shield on the front then you basically get the same benefits of flocking since shields like the astrozap are flocked inside and will stop any light getting far enough in to reflect off any paint within the OTA. Surely all light will be stopped right up at the dew shield?