Ambitious plans for the Moon

WARNING! 16 megapixels of the Moon!

 

Ambitions were high. I planned to make a panoramic assembly of almost full lunar disk @4750 mm of effective focal length. But I quickly ran out of fuel disk space and went astray at the same time. So to get some result, I have reduced EFR 2,5 times (falling down to 1500 mm) and made this one - ~16 megapixels of the Moon and a bit of cold void around, built of 21 GB of raw data in 32 panels :)

 

Aquisition time (start of the session) : JD2456851,36642361 (13.07.2014 00:47:39 MSK).

Image orientation: almost real

Equipment:

QHY5L-II monochrome CMOS camera via 2x Barlow lens Celestron OMNI XLT 150 mm Newtonian riding Skywatcher NEQ-6 Pro SynScan mount.

Aperture 150 mm

Native focal length 750 mm

Effective focal length 1500 mm

Tv = 1 ms

Av = f/10

ISO NA

Gain 47/1000

Software: FireCapture

Exposures: 300/600 x32

Processing: movies was processed in Autostakkert!2. Resulting images ware were stitched in Microsoft ICE. Resulting panorama was sliced in four 2500x2500 pix panels. AstraImage has troubles handling BIG images. So panels were separately subjected to Richardson-Lucy deconvolution in AstraImage 3.0 (Gaussian type PSF, size 1,6 units, 7 iterations) and deconvolved images were stictched back in ICE.

Of course, final touches were made in PS and involved some contrast stretching and tone curve adjustment.

 

Notes on QHY5L-IIm CMOS camera:

Most appealing features were eye-piece design (with dustcap on it looks like a 35 mm film canister for me :), 30 fps at full resolution of 1280x960 pixels, high QE and every-pixel-worthy monochrome sensor. Build-in guide port would come handy one day also.

 

Of course it fits nicely into PST's eye-piece port and gets the focus instantly without need of cumbersome adapters. Barlow lens can be used also. One just needs hi-class luxury lens with compression ring not to scar the camera housing with fixing screws (my Bresser 5x SA Barlow is of that class :).

Unfortunately, in combination with PST it appears to be vulnerable to Newton ring's pattern that originates somewhere inside the telescope. Interesting - where is this "somewhere"? The only way to get rid of it is to let the Sun drift across the field of view, so any steady patterns are lost in stacking, while moving details are preserved. It's a PST-Sun exclusive issue.

Of course it's neglectable size and miniscule weight make it easy to balance the setup but adds a need of having a computer nearby the telescope and thus some extra cables. Well, foldable table, a chair and mount's remote controller make the session rather comfortable.

Design and usability: cool!

 

Speed... Surprise! Some capturing softwares, like EZPlanetary (QHY's own) and FireCapture, support .RAW readout, that results in 16-bit .ser files. Really nice. Of course the speed is limited to about 6 fps in this mode. In normal mode - 8 bit monochrome - with some tweaking, including adjusting disk write buffer size (FireCapture provides a tool for determining optimum) and choosing proper port I was able to get 15 fps, which can be turned into 30+ by specifing region of interest say 800x600 pix. But still it's not promissed 30 @full resolution. A problem to be solved.

Speed and performance: satisfactory+ :)

 

Sensor's performance... 1 ms shutter speed and 47/1000 gain at f/10 with the Moon as the target. And no Baeyr's pattern that reduce the effective resolution twofold. I like it!

But! Nonetheless I'm still unable to capture solar prominances along with surface features. Needs to try couple more times.

Sensor: good!

 

Sorry for apparent wordiness :)

Done