Quote:
Originally Posted by bluesilver
Thanks for the reply Martin.
That definitely simplifies things a whole heap better than what they were trying to say and go through in the book for sure.
So i am using a ASI224MC camera which is 3.75µm
I do have a modified Canon 600D but being modified it would be no good for planetary imaging without getting a dedicated UV filter to sort of bring it back to standard again.
So with the ASI224MC it should then work out to:
Poor seeing 3.75 x 3.5 = 11.25
So focal ratio F11.25 required
Average seeing 3.75 x 5 = 18.75
So focal ratio F18.75 required
Good seeing 3.75 x 7 = 26.25
So focal ratio F26.25 required
Therefore to reach F11.25 i would have to use a 2.5X Barlow or Powermate
To reach F18.75 i need a 4X Barlow
To Reach F26.5 i would need a 6X barlow.
Dose that all read and sound correct so far?
I take it that the Powermates are a far better option than a Barlow for planetary imaging?
I do have ZWO Atmospheric Dispersion Corrector, but yet to have the change to give it a try.
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Peter,
You need to use your scopes native focal ratio ( f5 ??? ) to determine what size Barlow or Powermate to use to achieve those calculated planetary focal ratios
So scopes native focal ratio x Barlow
or Powermate = Calculated focal ratio for planetary for respective seeing condition
Does that make sense ?
Your calculated planetary imaging focal ratios look ok ( I didn’t check the maths )
IMO Powermates are superior to Barlow’s for planetary imaging ( 5 times the price too )
I bought a full set ( 2 x , 2.5 x , 4 x and 5 x ) with all adapters to suit my EOS T ring about 4 years ago , prices have gone through the roof but they are supreme optical instruments, you pay for what you get
Cheers
Martin