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Explore Scientific eyepieces for CPC1100


Bartman

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I am looking at getting a few ES eyepieces for my CPC 1100 (F10). I looked at televue but can’t justify the extra cost when the ES ones should be more than good enough with this scope. I am wanting wide fields as obviously the scope naturally had a narrow FOV. I have a 2 inch clicklock visual back and 2 inch diagonal so I am thinking of the following and would like to hear people’s opinions on if you think these are a good choice/mix of eyepieces. 
 

ES40mm 68 degree

ES 30mm 82 degree

ES 20mm 100 degree

ES 9mm 100 degree.

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Your 40/30/20/9 are evenly spaced in terms of focal length but they will give an uneven spread in terms of magnification (70x / 93x / 140x / 310x) and field of view (1.0/ 0.9/ 0.7/ 0.3o).

To me it looks like the 40mm & 30mm are too similar and there is too big a gap from the 20mm to the 9mm.

Keeping to the same ranges of eyepieces but changing the 30mm for the 24mm and the 20mm for the 14mm will give you a magnification range of 70x / 116x / 200x / 310x and field of view range of 1.0/ 0.7/ 0.5/ 0.3o - both much more evenly spread.

It does depend on what you want to view, of course.  Maybe you want more lower mag / wider fields views?

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With the extremely long focal length of a C11 (2800mm), adding a tele-extender doesn't make much sense.  You'll already be working at powers that may be too high for typical UK seeing conditions with that 9mm.

You might also want to investigate the APM XWA HDC eyepieces.  Reports here and on CN generally regard them as slightly sharper, lighter, and less costly than their ES-100 counterparts.

At the other end of the power spectrum, you might want to consider a 56mm Meade 4000 Plossl or similar to get to a 5.6mm exit pupil for OIII filter usage at 50x.

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10 minutes ago, Louis D said:

With the extremely long focal length of a C11 (2800mm), adding a tele-extender doesn't make much sense.  You'll already be working at powers that may be too high for typical UK seeing conditions with that 9mm.

You might also want to investigate the APM XWA HDC eyepieces.  Reports here and on CN generally regard them as slightly sharper, lighter, and less costly than their ES-100 counterparts.

At the other end of the power spectrum, you might want to consider a 56mm Meade 4000 Plossl or similar to get to a 5.6mm exit pupil for OIII filter usage at 50x.

I know I’ll be pushing it with the 9mm for most nights but would be a nice option to have for those rare times? I will take a look at those eyepieces you suggest too, thank you. 

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