50mm CCTV lens on a guide cam

[furrysocks2]

Received a 50mm f/1.4 c mount lens in the post today, to go on my Datyson T7M (ASI120MM clone).

Set to 0.1s exposure, gain somewhere in the middle, 2x2 binning, hand-held live stacking in Sharpcap, quick crop and contrast stretch in Gimp, no darks or anything.

Not bad for a not-quite-dark sky, 10fps and handheld. Down to mag 10 if I'm really lucky. Interesting to see what happens at full res, low gain, few second exposures. A little over 5.5x4 degrees, 32.7 "/px binned.

Need to concoct a way of putting it on a tripod, or as a digital finder on my dob.

[RichLD]

Result!

[furrysocks2]

Here's a full frame of M45 - capture settings 3.9s, gain at 32, 16 frames stacked.

Definitely some mag 12 stars in there.

Size:    5.82 x 4.37 deg
Pixel scale:    16.4 arcsec/pixel

 

Live stacking is ok I guess but a rectangular array of pixels perhaps doesn't actually tolerate field rotation too well. I ran an unsharp mask on this and stretched a bit. A simple barn-door mount might be fun to try, or I could stick it on the EQ3 and finish the goto drive. If it was tracking, might try a 25mm lens too.

Not sure if I want a screen anywhere near the 12" dob, so perhaps not an electronic finder. The tinkerer in me says live-solve and display RA/Dec on a 7seg display at the scope.

[furrysocks2]

I don't know how this is going to look, because the screen I processed it on ends up giving me images that never look good on the other, but here's my effort in the double cluster...

50 x 2.5s, gain 75, average of 20 darks subtracted by SharpCap. Stacked in DSS, cropped in GIMP

[furrysocks2]

[furrysocks2]

Have to try again on M31... this is hinting at dust lanes but need better data. Left live-stacking running too long, lost the bottom of the galaxy.