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How's my PHD doing?

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#1 Cotts

Cotts

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Posted 14 September 2018 - 08:36 AM

Would you be happy with PHD results like this?

 

I was happy with most of my pics from last night but some had oval stars when zoomed in extremely.  Seeing was poor to mediocre....

 

Difficulty:  I was imaging at 2800mm focal length with my C11 on AP 1200 but using an autoguider with a focal length of about 150mm (a 50mm finder with an Orion Starshoot AG on it.)  Perhaps a longer F.L. guidescope?  I have a 60mm/700mm refractor I could use...  Is there an ideal ratio of focal lengths for the autoguider and the imaging lens/scope?

 

All my pics from last night with this set-up are in another post on this forum...Title: Images with a C11....

IMG_0375.jpg

IMG_0376.jpg

 

Dave

 

 



#2 Ed Wiley

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Posted 14 September 2018 - 09:32 AM

Dave:

I would say pretty good, you are bouncing +/- 1" which is about as good as could be expected with the guide scope you have and you results are similar to my AP900 with a 66mm refractor. However, long focal lengths call for off-axis guiding, IMO. So I spent the money to go OAG. It's not cheap as you need a really sensitive guide camera like a Lodestar to insure you will find a guide star (the Lodestar X2 is fine, no use in buying that more expensive one just for guiding). Not a bunch of time with the OAG, but I have never failed to find a guide star and I do not have a rotator. (BTW, stars can look very distorted in a OAG image, not to worry.)

 

 

I thought about trying a barlow on the refractor to increase FL, you might try that if you don't want to spring for an OAG.

 

Ed


Edited by Ed Wiley, 14 September 2018 - 09:41 AM.


#3 t-ara-fan

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Posted Yesterday, 03:49 PM

I use a ShortTube 80mm f/5 guide scope on my HD-8. My 50mm 163mm FL guide scope was not perfect.

Consider that 0.1 pixel error on your guider might be 2 pixels error on your main OTA. Your guider will be proud of its work, but it isn't good enough.

My 80 mm is in Losmandy 108/66 rings which are very solid. http://store.losmandy.com/dvr108-66


BTW a "PrtScrn" on your laptop well take a much better pic than your cell phone.


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