Simple "Flat Maker" Holder

[Macavity]

(As ever!) No "rocket science"? Indeed I stole the basic idea
from an ever popular / commercial Bahtinov Mask designs!

Fairly self explanatory? TWO "frames" of the ubiquitous thin
white-faced hardboard... M4 nuts/bolts/washer for corners...
Nyon M6 (60mm?) bolts to hang the thing onto the scope...
Use a *hole-saw* to create appropriate... HOLE in middle!

The idea is you can TEST out a *range* (multiple layers etc)
of cling film or "bag" flats to see what material works best!
The pukka Bahtinovs rely on a tight fit of the nylon screws,
but PAN HEAD nylon bolts can be glued to the "top" frame!

As ever, there's no need to overly stretch the material tight.
Just place it between the two wooden frames and *bodge* 
the holes with a pencil or similar! 

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N.B. DO NOT use this idea for any other "Solar Filtration"!
This usually "stays put" but might blow off in high winds...
***********************************************

[Davey-T]

Have you got a Blue Peter badge 

Dave

[Macavity]

Hmmm... Y'mean the one where I *forget* to remove
one of the (several) "flat-makers" and spend AGES
wondering why the scope no longer focuses? 

[johnfosteruk]

Nice work Macgyver Chris.

[michael.h.f.wilkinson]

Nice one. I simply use an elastic band to keep the film in place, but this is neater

[james_screech]

6 hours ago, Davey-T said:

Have you got a Blue Peter badge 

Dave

No, he didn't use any sticky back plastic.

[carastro]

I am puzzled why film is being used for flats.  I just use a piece of cardboard made into a sort of lens cap so the collar fits round the scope with typing paper over the aperture end.  This is for day time flats of course, but when I used to use a EL panel, I still used typing paper, never film, so just wondering about the logic of this.

BTW I think my cardboard and typing paper and sticky tape is even more Blue Peter than the nicely carpentered one above.  

Carole 

 

[Pete Presland]

Look forward to seeing the results.

[johnfosteruk]

21 hours ago, carastro said:

I am puzzled why film is being used for flats. 

 

It's to help with uniformity isn't it?

[Macavity]

Hi Carole!

I thought I'd finally "publish" on this one. lol.

https://stargazerslounge.com/topic/296427-more-on-full-disk-flats-for-nerds-only-p/

I am certainly NO EXPERT on this topic, but it has intrigued / frustrated me...

Nocturnal Astronomers frequently use FLATS and the methodology is clear / easy?
Not so with (H-Alpha) solar work? Basically Solar telescopes pass so little light it is
not possible to find a suitable "light source" to produce a FLAT... except the SUN!

It is anecdotal (true!) that Cling Film works well for fully illuminate frames (parts
of the Sun)! Full Disks are harder... And therein lies the challenge? (See above?).