Quote:
Originally Posted by skwinty
Hi Mike
I read the article on modifying a newtonian for dslrs. I now understand the focus issue. However this will only affect the camera focus at prime focus and not when using eyepiece projection. I need to weigh up whether i should shorten the OTA and use a 50mm extension for eye piece visual and photographic. At prime focus for photography I do not use the 50mm extension.Am I understanding this correctly? Anyway I still have some way to go before making these decisions and would like to thank the IIS guys for their help with respect to suppliers of accessories. Steve from MyAstroshop has confirmed he will supply and ship to South Africa.
I called the extension a tube extension but should have called it a pillar tube extension. Thanks once again for IIS input.
Regards
Steve
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I am not an expert, but...
For starting out eyepiece projection is good and can allow you to take some images. However in general eyepiece projection is not so hot as you pick up all the imperfections of the mirror and of the eyepiece you are using. On the moon though it is fine.
Most people use prime focus. Once you move the mirror you can still use it for visual by getting a focus extension tube the same length as the main mirror adjustment. For example a second hand cheap 2 inch barlow, with the glass removed may be got on Astromart second hand.
Paul