Re: [hobby] Re: ATM thin mirror alternative cell

["Geoff Nelson" <gjnelson@absamail.co.za>]

John Sherman wrote:-
>
>The other problem with bubble wrap is that air is compressible. 
>As you move from the horizon to the zenith your collimation is 
>likely to change, and your focus will change.
>

How much change is acceptable? Would a less compressible material be better/worse? 

Some ideas that may work as alternatives.   All of these against an isotropic planar backing board to give the support simlar to what Jerry originally described.

1) small round neoprene pads
2) blobs of silicone , similar to what Richards Berry  describes but lots more of them.
3) other low memory foam or soft material

The number or blobs or pads would have to be optimised so that there is suficient sompression to get the levelling effect due the correct ratio of support area versus mass.

Geoff