Quote:
Originally Posted by bartman
a) Does a focal reducer help me focus further 'down' when a DSLR is attached ?
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No, a focal reducer will shorten your focal length. So your focuser will have to go "up" towards the scope lens or mirror.
Quote:
Originally Posted by bartman
b) OR does a Barlow put the focal plane further back ? in other words , does it reduce the focal length of my scope? ( is that what a focal reducer does?)
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No. The Barlow will magnify your image and increase your focal length. So you'll need to focus further "down", away from your scope mirror or lens. You might need extension tubes if you "run out of focuser".
Quote:
Originally Posted by bartman
c) and would this -either of the above options- reduce the diff spikes?
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No. But if you magnify enough (x3,x5) you will start seeing Jupiter as a disc rather than a point source and your diffraction spikes won't be as overwhelming.
Quote:
Originally Posted by bartman
d) does a smaller eyepiece ( say 10mm) reduce diff spikes?
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No. If the light is close to a point source you'll still see those diffraction spikes with long exposures.
Hope this helps.
