Testing The Flexure Solutions
Tonight I was able to test the new tandem setup to see if the efforts to minimize flexure were successful.
In my case, the flexure shows up as drift over the course of the entire shot, but that really doesn't matter to me. The clincher is when it shows up in individual subs. Historically, my 5 minute subs show little to no drift due to flexure problems, but longer subs do.
I shot M13 for an hour to see what the drift was over time. Starting with the reference frame of 0.00 the Dec axis drifted 4.84 pixels over the hour and the RA axis drifted 3.53. Those are by far the lowest numbers I've ever seen in my system.
For long subs, I've been taking 10 minute H-alpha subs because I can't do 20's due to severe elongation in the stars with subs that long. In the gallery is a section of a 20 minute sub I shot last night. In this orientation, RA is vertical and DEC is horizontal. You can see that the stars are not *perfectly* round, but they are substantially better then what I've seen in the past. This is 100% view as well where I normally end up reducing the image size to 50% or so. This is definitely within the acceptable realm for me.
My guiding was better as well. Less flex in the guide scope brought my typical average of .30 RMS down to .16. I was thrilled to see that! The screenshot in the gallery is 30 minutes into my 60 minutes of subs.
In the gallery is also the image taken. The moon was 98% full this night, so it's a good target to shoot even under a full moon.
I included a 200% version as well to pixel peep the stars.
M13 - Globular Cluster
Scope: Vixen ED103S with WO Flat 2 0.8x FR/FF
Mount: Orion Sirius EQ-G with GoTo
Guiding: Meade DSI Pro and PHD Guiding
Guide Scope: William Optics ZenithStar 66 SD
Camera: Canon EOS 1000D (Modified)
Special Settings: None
ISO: 800 RGB
Exposure: 1 hours (12 x 300s)
Processing Software: Acquired in Nebulosity, Calibration, Stacking Deep Sky Stacker, Levels, Curves, Astronomy Tools and Noise Ninja in Photoshop
Support Files: 40 flats, 40 flat darks, 40 bias, 60 darks
See Gallery Below For Image