Trying out my low cost setup

[furrysocks2]

I 3D printed a replacement part for my Meade DS2000 mount and a simple clamp to hold my Datyson T7M (ASI120MM clone) and 50mm CCTV lens. I get a field of view roughly 5x4 degrees.

Last night was the first outing - I think I accidentally had the aperture closed down so I was struggling a bit with long exposure times, high gain, and binning, but the intention was to suss out the software.

I used Cartes Du Ciel and SharpCap 3.1, with an ASCOM hub and the Meade ASCOM driver, running over a USB-to-serial converter to the Autostar 497 handset.

Because SharpCap is limited to a 15 degree search area, I needed to roughly align the mount, sync it manually, then I could "solve and sync" in SharpCap.

Playing around slewing between the stars of Ursa Minor, I determined that my az/alt ratios were set incorrectly on the controller. A quick google and a false start getting them the wrong way round, I eventually managed to slew between the Perseus cluster and the Double cluster, with about 0.2 degrees error.

Imaging was a little problematic. I couldn't capture long exposures in SharpCap in MONO16, so had to revert to MONO8. SharpCap gives nice graphs during live stacking for drift/rotation. I was taking 120s exposures at one point, and it wasn't looking bad. But I've had good enough results stacking <2 second exposures with the same camera/lens in the past, so hopefully the lens aperture was just closed down.

I have another 5-40mm CCTV lens that I will give a go at some point, but the 50mm has a slightly lower f/ratio and FoV a little better for clusters.

 

Nevertheless, it's alive and working. I'll have another practice soon - hoping I can get MONO16 working with longer exposures in SharpCap, without it appearing to drop all frames.