Adjusting RA/DEC for Cygnus Wall

stubblejumper

I did a GoTo NGC7000 with a 100ED (900mm focal length) and ASI1600mm Pro. I only captured a tiny portion of the wall. How can I move the center of the field of View to the Wall?

w7ay

stubblejumper How can I move the center of the field of View to the Wall?

With ASIAIR v1.5 onwards, you switch to the preview window, then hold your finger on the Preview screen until a small green circle with a "GO" appears. Lift your finger, and tap on that green circle and ASIAIR should send a GOTO to the mount to center the mount to that green circle. Tap somewhere outside that green circle if you don't wish to go ahead with the re-centering.

Conversely, just bring up the cross hairs, and use the arrow keys in the mini-GOTO window to slew your mount manually. Thats what I do for more precise centering, using about 8x sidereal slew rate.

Chen

Tech@ZWO

I think you need to use below tools to calculate FOV first:
http://astronomy.tools/calculators/field_of_view/

stubblejumper

Thx. I used CCDCalc for FOV that but I'll also try the app at the link you provided. After I posted this query something popped into my mind. ASIair has a 4 way arrow button in Preview. Maybe it's how to move the scope. If so it would be very helpful. For example, centering M81-M82 .

w7ay

stubblejumper For example, centering M81-M82

Find the "center" coordinates in your favorite planetarium program. Tap on the RA field in the small ASIAIR GOTO window. Scroll to the RA that the planetarium program tells you. Repeat for Declination. Then just click on the green GOTO button in the small window.

Chen

stubblejumper

w7ay
Much, much appreciated. I'll try it tonight if the sky is clear as forecast!

w7ay

stubblejumper I

Oh, I forget to mention... if you are asking to mount the GOTO a coordinate, remember to plate solve and then repeat Sync-and-GOTO-capture image-plate solve a couple of times so that the plate solved coordinates agree close enough to your target coordinates. If your mount has small backlash, each time you repeat the plate solve and sync-and-goto, it will get closer and closer.

Another hint: you can set it all up in the daytime, by using the View Objects menu in the Telescope Setup window, choose My Faborites, and tap on the "+ Add" button.

This is what I use for my M81/M82 frame (you may wish to choose a different center):

RA 09h 57m 27s, Declination +69º 16' 52"

Whatever actual coordinate that you choose, you can save it to your "Favorites" list with a name of your choice, so you can use it again in the future to add images to your image stack.

Chen