. . . and the tadpole starts complaining to the uninterested spider and fly about his sensor tilt problems.
The Tadpoles, Spider, and Fly Nebulas. IC 410, IC 417, and NGC 1931 respectively.
Narrowband with RGB stars. Total integration time is 40 hrs.
Scope/camera: Esprit 100 and QHY268M
RGB stars were combined with a starless narrowband RGB image using the PixelMath screen expression: combine(starless_narrowband, broadband_RGB, op_screen()). I saw Adam Block use this expression in one of his recent videos. It is an excellent method of adding RGB stars to a narrowband image. I've tried many other techniques and none of them have come close to the results I achieved with the screen combine expression.
I initially had issues with the corner stars when I started using the QHY268M with the Esprit. I assumed the problem was with the scope, and I ordered a TOA130 out of frustration.
While waiting for the TOA to arrive, I tried to improve the corner star performance of the Esprit by adjusting the tilt set screws on the 268. I reflected a laser off of the sensor through the front of the OTA and rotated the camera with a NiteCrawler focuser. I adjusted the set screws until I had virtually no movement of the laser's reflection at a distance of 6 to 8 feet away.
After adjusting the tilt plate on the camera, the corner stars with the Esprit improved substantially. Instead of having severely elongated corner stars going different directions, I had only a minor hint of symmetrical elongation in the far corners. I think some more work on backfocus could have further helped.
In any case, the integrated images had satisfactory round corner stars, and I would not have ordered the TOA had I known I could achieve such good results with the Esprit.
Edited by Shannon Foye, 24 June 2022 - 12:46 AM.