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Old 16-01-2014, 09:51 PM
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alpal
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Quote:
Originally Posted by RickS View Post
Some of the camera manufacturers do make fairly small, lightweight cameras. Starlight Xpress and QHY are examples I'm familiar with but there are probably others. However, if you want a big sensor and deep, well regulated cooling then you need a larger camera with multi-stage Peltier, fans and heatsinks. Then you need large filters to minimize vignetting (at least 7 of them) and a rigid filterwheel to avoid tilt. That all comes at a cost in weight.

Cheers,
Rick.


Hi Rick,
Sure - it's difficult to reduce weight in large format cameras.

Maybe we'll see a new generation of light but large format cameras?

I think we'll see more of these ideas in the future & some are already here:

(1) Drill out the heatsink with enough holes to halve it's weight.

(2) Use lighter materials such as magnesium in as many parts as possible.

(3) Using unmounted filters to create a super light filter wheel.

(4) design everything as thin as possible.

(5) place the CCD sensor as close as possible to the outside of the housing - reduce back focus - to reduce the size of the housing & lower leverage.

(6) Place 4 little fans on the outside of the heatsink instead of one big heavy one at the rear - lowering the leverage.


Numbers 1 & 6 could be done by the camera owner.


The fact is that any weight suspended from a "lever" is going to cause flexure forces -
weight versus angle of flexure is what people need to know.
Do any telescope manufacturers provide such graphs for their focusers?

Another good idea is what Bert has done with his RH200 -
breaking new ground by mechanically removing all sideways force on the focuser.


cheers
Allan
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