Mars & Jupiter: First light with new camera

I picked up a monochrome QHY-5M-II CMOS planetary/guide camera at NEAF, intending it for lunar and solar work. The tiny camera, the size of a small eyepiece and weighing much less, has 74% quantum efficiency in the green part of the spectrum, and a respectable 50% QE at the red Ha line. I took it out last night for "first light" using my Orion Apex 127mm Maksutov on an iOptron Minitower mount. Seeing is never great on my suburban Larchmont street, but Jupiter and Mars, the latter still low in the sky (33 degrees) but at maximum diameter for this apparition (15.1 arc-sec), were inviting targets. Although there is a learning curve for the acquisition software (Torsten Edelmann's FireCapture 2.1, a free program), it worked well enough without any study and I captured some avi's without problems. I quickly processed two of them before going to bed, stacking in Autostakkaert2, applying wavelets in Registax 6 and doing some final contrast control in Photoshop. The results are rough because I'm still untutored in planetary imaging, but the outcome was very satisfying. It's the first time I've ever imaged the Martian surface.

I imaged Mars, which was only about 31 degrees elevation, through a 2x Barlow, giving f/24.2, and an orange filter. The North Polar Cap is just visible at about 2 o'clock on the right edge of the disc. Lying inwards towards the center of the planet is the dark area Mare Acidalium, with the plain of Tharsis the light area below. On the left side, the dark southern area is composed of the Sinus Meridani and Mare Erythraeum, separated from Mare Acidalium by the light band of Chryse.



The Jupiter image is a wider-field shot without a Barlow or filter, at an exposure chosen to try to show the two innermost moons, Europa, at 10 o'clock 3 planet diameters distant, and Io, at about 4 o'clock 2½ diameters away, as well as the planet. These may be hard to see on your monitor, but they are definitely on the image. If you try to make them reasonably bright either during capture or processing, the planet gets overexposed. The Red Spot (grayscale with this monochrome camera) is almost on the meridian.

These are pretty rough images but were easy to make. I need to learn a lot more about the capture software and processing techniques.


Larry Faltz