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Black 2.0 anyone?

ATM DIY reflector Celestron
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#1 tomb1

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Posted 18 March 2019 - 05:55 PM

I'm starting a project taking an orange-tube Celestron Comet Catcher and modifying it for better performance.  One of the first things on the list is to re-paint the inside of the tube to improve stray light control.  Googling "blackest paint" I came across "Vantablack" which is unobtainium and "Black 2.0" which is available from Amazon, but is an acrylic.  Articles of Black 2.0 seem to indicate it's quite black.  

 

Does anyone out there have any experience with this product or have any suggestions for something else?

 

thanks,

 

Tom

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#2 ImNewHere

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Posted 18 March 2019 - 06:52 PM

I do have the black 2.0 paint, and it is great for the inside of focusers and the like, but get Scope Stuff flocking instead for doing the inside of the tube.



#3 Richard O'Neill

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Posted 18 March 2019 - 06:55 PM

 A long, dark interior dew cap greatly reduces internal reflection to the point I haven't experienced a need to blacken the interior of my Comet Catcher.


Edited by Richard O'Neill, 18 March 2019 - 07:31 PM.


#4 Oregon-raybender

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Posted 19 March 2019 - 02:10 AM

 2.0 is OK, but 3.0 is the best. Here is an image of them on a sample gloss blackboard.

 

Starry Nightswaytogo.gif

 

 

 

             3.0                    Old Model Engine black                 2.0                                         gloss black

                                                  -    -

                                                    - -

                                                     -

Attached Thumbnails

  • Black 3.0,EB,2.0,Gloss blk 03052019 copy.jpg

Edited by Oregon-raybender, 19 March 2019 - 02:12 AM.

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#5 stargazer193857

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Posted 19 March 2019 - 02:24 AM

There was a thread on the 2.0 not long ago. It is black, but you can't touch it or it runs off. Hence why some say to only put it in the focuser, a low traffic area.



Here is the Vantablack:
https://www.google.c...ory?id=57384851

Edited by stargazer193857, 19 March 2019 - 02:25 AM.


#6 stargazer193857

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Posted 19 March 2019 - 02:48 AM

The reason black "is not black" is be because the index of refraction is different from that of air. Even though the color is black, there is 4-8% reflectance off the surface before the light even hits the black.

Air is 1.0, water 1.3, many bilogical substances 1.3, and most other substances 1.5 - 1.6.

Candle soot is so black in part because it likely has an index if refraction near 1.3, giving 1/4 the reflection.

Candle soot is wax that underwent incomplete combustion. I wonder if there is a way to efficiently mass produce it. Once it is coated with acrylic, we are back to 4%.


Black 3.0 claims to absorb only 98-99% of light. That is not better than velvet.

#7 stargazer193857

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Posted 19 March 2019 - 02:51 AM

If you really want black with current technology, use gloss black, but at an angle so the light does not come near the eyepiece. A few baffles may be needed.

#8 Pinbout

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Posted 19 March 2019 - 06:49 AM

2.0 if fine, especially for the amount and quality of light at night

 

and no it doesn't fall off if you touch it.

 

https://www.youtube....h?v=5JCPw9jvqhg


Edited by Pinbout, 19 March 2019 - 06:49 AM.


#9 fishhuntmike

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Posted 19 March 2019 - 09:15 AM

I just received some Black 2.0 from amazon several days ago. I plan on painting the interior of my wood 8" F5.9 refractor in a few days. Maybe i will post my impressions and a pic or two. My scope interior was spray painted previously with hardware store flat black. I also just ordered a 31mm nagler for it. Hopefully i will be pleased with the results. Unfortunately the moon is out in full force.

#10 tomb1

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Posted 20 March 2019 - 10:51 AM

Thanks all for your comments,suggestions.

 

 2.0 is OK, but 3.0 is the best. Here is an image of them on a sample gloss blackboard.

 

Starry Nightswaytogo.gif

 

 

 

             3.0                    Old Model Engine black                 2.0                                         gloss black

                                                  -    -

                                                    - -

                                                     -

OK, so 2.0 is available from Amazon.  Where do you get 3.0?  Your testing makes it appear that 3.0 is quite a bit blacker that 2.0.

 

Also, I noticed another thread entitled "Of Blacks, Blacker, Blackest" that addresses the same issues.  Sounds like the best flocking material for lining the inside of the tube would be Syfabrics "Plush Triple Velvet Black".



#11 stargazer193857

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Posted 20 March 2019 - 11:36 AM

Thanks all for your comments,suggestions.

OK, so 2.0 is available from Amazon. Where do you get 3.0? Your testing makes it appear that 3.0 is quite a bit blacker that 2.0.

Also, I noticed another thread entitled "Of Blacks, Blacker, Blackest" that addresses the same issues. Sounds like the best flocking material for lining the inside of the tube would be Syfabrics "Plush Triple Velvet Black".


I googled it recently. You can pre-order two 150 mL bottles of 3.0 if you donate $25. They also give you a mug.

Syfabrics "Plush Triple Velvet Black".
Will look into that. Joanne's is expensive sometimes.

Edited by stargazer193857, 20 March 2019 - 11:37 AM.


#12 tomb1

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Posted 20 March 2019 - 01:21 PM

I googled it recently. You can pre-order two 150 mL bottles of 3.0 if you donate $25. They also give you a mug.

Syfabrics "Plush Triple Velvet Black".
Will look into that. Joanne's is expensive sometimes.

Well, I guess the price must be going up.  I Googled same and found the deal for two bottles at $47 shipped to US.  I think I'll go with the 2.0 for now to paint the spider, etc. and "upgrade" to the 3.0 when it's realwear available via Amazon (don't like to give out CC info out to international concerns and I want a delivery date).  

 

Clear skies grin.gif



#13 careysub

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Posted 20 March 2019 - 04:01 PM

Semple is projecting general availability of Black 3.0 in September:

 

https://www.cultureh...lic-paint-150ml



#14 stargazer193857

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Posted 20 March 2019 - 05:44 PM

2.0 sounds good for the edge of secondary mirrors. I'll put velvet elsewhere.


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