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C14 Edge- back to F7.7

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#1 pyrasanth

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Posted 04 December 2021 - 08:06 AM

I removed the reducer from My C14 and went back to native F11.

 

However I did not feel that my sky conditions fully supported the decision to be at F11. I could barely guide at F11 where at F7.7 guiding was tolerable.

 

I don't have very good sky conditions and F11 I guess was pushing my luck. I did like the increased image scale and overall better field but I guess if you can't guide well, even with the ONAG, that negated those benefits. The main issue was that guide stars were fairly faint through the ONAG as even on a 4x4 bin my guide pixels are only 14 um. I could buy a new guide scope but that gets expensive as I need a fairly big sensor.

 

I guess I'll just have to live with the 1.2 metre reduction in focal length.

 

I wish all of you clear skies and great seeing- especially  for those with big optics at long focal lengths.

 

Best wishes

Mark

 



#2 Codbear

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Posted 04 December 2021 - 02:46 PM

Mark,

 

While I'm purely visual (though headed for part-time EAA due to a muscle disease), I have ended up going the other way so far.

 

I purchased my first 14" Edge in 2018 and almost immediately put the focal reducer in to have a wider FOV.

 

I commissioned Tom Osypowski to make a 24" f3.2 Slipstream dob for me which was ready in May of 2019.

 

The views in the 24" were very good so I stupidly sold the 14" Edge(though I never did a direct comparison). As my muscle disease has progressed, I have become too unsteady on a ladder to enjoy the views, so I put in an order in early March for another 14" Edge. Miraculously, 3 weeks later Woodland Hills got a shipment in and I drove down to pick it up (the 800 mile round trip was totally worth avoiding shipping!).

 

It has been a little over 8 months and I have yet to even take the wrapping off of my reducer, much less open the box. 

 

I have used the 24" once since I got the second 14" to do a shootout between the two. The extra focal length of the 14" made it much easier to reach higher magnification than the 24", not to mention the ease of observing with the 14". The kicker was that, while there was certainly a difference in FOV, I think the ease of observing with the 14" more than made up for what for me was a little more detail. It was much easier to push the magnification with the 14" because it was ambient, while the 24" was still cooling, not to mention better optics in the 14". It was no contest on lunar and planetary between the two - the 14" was amazing.

 

I might use the reducer at some point, but I have my 16" f4.5 for a 1.5* FOV or my NP127is for a 4* FOV.

 

When it comes time for EAA, I will probably still skip the reducer (at first at least) and go straight to F2 with the HyperStar. If that proves too difficult to manage, then perhaps the reducer may finally take center stage.

 

Take care and clear skies.

 

Sam


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#3 pyrasanth

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Posted 04 December 2021 - 04:33 PM

Thanks Sam,

 

I think at F11 I could happily live with visual however the jumping of the guide star under my mostly poor conditions made guiding unworkable and I need to be able to get exposures upto 20 minutes guided for some narrowband filters like SII.

 

I really need overall better conditions for F11 photograpgy at nearly 4 metre focal length and sadly I can't see that happening anytime soon.

 

F7.7 is a bit more palatable however the field flattening can be problematic if I'm careless with taking my flats however I have built a custom flat field box that uses an ELP panel which is totally enclosed so I can even take my flats in the day in bright sunlight.

 

I hope your illness does not present too much of an issue to your enjoyment of the starry nights.

 

Best wishes

Mark


Edited by pyrasanth, 04 December 2021 - 04:34 PM.



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