Trying out the 12 inch for lunar imaging

[timh]

At Dave (turfpit's) prompting, with Robin's recent moon/ planetary live stacking additions to SharpCap and with me finally having bought a planetary camera time I finally turned the 12 inch VX12 Newtonian toward the moon and to see if it can live up to the promise of its theoretical 0.5 arcsec or so resolution? It was enjoyable to explore and start seeing the familiar lunar seas and craters so close up.

The first night I tried it - the 6th April - the skies looked clear but were actually turbulent -- I couldn't find good focus or get anything very good -- but the 7th was much better and here are some images of the Copernicus and Plato areas on that night. I've turned the colour up to provide minerological information -- but rather unrealistically so of course.

Equipment was a VX12 300 mm Newtonian F 4 on a CEM70 mount with a ZWO ASI 715 MC camera (which has tiny 1.45 uM pixels) with a 2X Barlow and Baader UV/IR cut off filter.

The image scale was therefore 0.125 arcsec/ pixel giving a sampling of ~ 4X versus a Raleigh limit of ~ 0.5 arcsec.

The ROI was varied between full (3864 x 2192) down to ~ 1200 x 600 pixels at gain 100 using fast mode at RAW 8 with the ADC set at 10 bit depth to maximise FPS. SER files of between 1 and 2 minutes duration were saved - comprising 150 to 5000 frames depending on the scale of the ROI and then subsequently processed to TIFF files just using the Sharpcap live capture option and taking advantage of its sharpening and frame selection options (I am not sure whether anything much different could have been achieved using Autostakkert and Registax?). Final adjustments were made in Affinity photo.

It was interesting to me to note that - looking carefully at the close in at the rather limb-elongated image of Plato - it is possible to - just about - spot even the smallest its craterlets at only 0.6-0.7 mile across - see https://www.cloudynights.com/topic/3484 ... raterlets/. For arcsin 0.6/250000 that puts the resolution down close to the theoretical maximum at ~ 0.5 arcsec.

It was also interesting to try and understand the effect of the light upon the image of Copernicus and trace the shadows behind the brighter illuminated peaks.