C11 EDGE HD focus and screws

[jambouk]

Two questions if I may.

1. Can the three screws marked by yellow arrows in the picture below be used to mount a second finder shoe on the C11 EDGE HD scope, permitting both a straight through and a right angle finder to be fitted?

2. The EDGE has field flattening optics inside; is the distance from the visual back to the chip critical, or by making adjustments to the position of the mirror to achieve focus on a chip say 250mm away from the visual back mean the field will still be flat at that distance?

Thanks.

James

 

[Cosmic Geoff]

13 hours ago, jambouk said:

1. Can the three screws marked by yellow arrows in the picture below be used to mount a second finder shoe on the C11 EDGE HD scope, permitting both a straight through and a right angle finder to be fitted?

I don't know about the C11, but on the C8, any screws in that position (domed head, not countersunk) can be used to attach whatever you like. That's what they are there for.  My C8 has a red dot finder (straight through, mostly for aligning the GoTo) and a RACI finder (not always fitted, used with planetary imaging).  If you fit a RACI you do not need a straight through as well? Straight through finders are a pain in the neck unless only required for aligning your GoTo.

[ngwillym]

According to the Edge HD white paper, page 15, for the C11, optimal back focus distance is 146mm.

See https://s3.amazonaws.com/celestron-site-support-files/support_files/edgehd_whitepaper_final.pdf.

 

Neil

[jambouk]

Thanks both.