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Old 09-02-2021, 05:42 PM
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gregbradley
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Join Date: Feb 2006
Location: Sydney
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Thanks Adrian.

I will do that. I have gotten quite a few eyepieces all of a sudden and hardly any clear nights to explore them so yes time on a particular eyepiece was limited.

I may set up my CDK for visual next time I get a clear night with it. Also the AP RHA (that means reinstalling the focuser).

I also want to try all these eyepieces out with my CFF105 F6 which is super sharp.

So much to do, so little clear sky to do it!

I must say though I did find the 100 degree eyepiece view a "wow experience". Looking to get the 9mm APM SWA next.

Greg.


Quote:
Originally Posted by AG Hybrid View Post
I have to say Greg. Your sudden interest in visual/observational astronomy and all the threads you've made has brought back some life into the eyepiece forums.


In regards to your post, I think you should look into how much deeper you can see with certain eyepieces at similar focal lengths, and have a better understanding about eyepiece design can affect how well you can see objects. Not just in field correction but also light scatter.


My case in point is this. The target I chose with a mag 10 star cluster. Normally cake from dark sky but from the middle of Sydney - oddly difficult even in my 12".
I tested a 9mm ES 100 against a Delos 8mm and Pentax XW 10mm.
I found in both cases the Delos 8 and Pentax XW10 could see deeper then the 9mm 100. When I say deep I mean stars that needed averted vision in the 9mm 100 could be seen with direct vision in the 8 and 10.



I attributed this to the ES 9 have 12-13 pieces of glass in it and the Delos and Pentax XW only having 6-7, maybe also better coatings and a finer polish on top of that. All these little things start to add up.



You have a few eyepieces around 7-9mm. I'd be interested to see what results you find if any you can discern.
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