Altitude/azmith graduations for DOBS ?

[Clarry (Clayton)]

Originally Posted by SteveCav

Brett, How did you turn the numbers around 180 degrees?

You don't actually turn the numbers around. Look at Spanrz's second image, where he has cut away a section of his dob base so he can see the numbers. If you make that cut-out directly below your EP rack instead you of in the front, then you can view it from where you are sitting instead of peering at the front of the base to get your azimuth reading. You still set up where the scope is looking at the direction you want it to look, but the readout will be side on, however east will still be 90 deg and so on regardless.

[Visionoz (Bill)]

Clayton

SteveCav is right when asking Spanrz as to how he had the numbers turned around 180 degrees - not so much as in his ability to view the numbers from the EP position only as opposed to looking at it from behind - but rather that the numbers themselves are printed 180 degrees to what Rob Willett's online apps actually prints them out as.

Rob's apps prints the numbers reading from the inside direction of the center of the circle (so to speak) to the outside direction of the circle; however Spanrz has his numbers printed out reading from the outside towards the inside direction of the circle looking from above and hence this is easier to read from any dob's EP position, otherwise the numbers would appear to be upside down!!

Perhaps he modded Rob's Postscript source code methinks

Cheers
Bill

[Clarry (Clayton)]

Ahh, I see, I stand corrected.

[Visionoz (Bill)]

Hopefully Spanrz would actually give us an answer as to how he did it as it would certainly assist those of us who would benefit from contributions from fellow amateur astronomers - in the same spirit that John Ward contributed to the community with his "gift" of the Crayford focuser invention without earning a single cent from it and Rob Willett for the setting circles apps!

Cheers
Bill