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Old 27-02-2012, 06:13 PM
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pmrid (Peter)
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Quote:
Originally Posted by alistairsam View Post
Hi Peter,

I've had a look at John's scope and we both had the same question on the reducer/flattener.
I believe the current F ratio is F7.5, we've tried a DSLR as well as John's DSI.
Wouldn't a 0.5x reducer or similar be required to widen the FOV and image DSO's like eta carina or the rosette? Else is it dependent on the imaging chip?
and once he uses a 0.5x reducer would that then need a flattener?

The current field is flat but what would it be like with a reducer?
Also, wouldn't the reducer lower imaging time to achieve the same apparent brightness?
Yes, a reducer will widen the field - and reduce exposure times. WHether it produces some optical side effects will depend a bit on the reducer. I can't speak for the ones mentioned in the original post I'm afraid.
A combination reducer/flattener would answer both needs.
Peter
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