Adapted lenses - Post your PHOTOS! - Part 5

Thursday early morning I had the first clear night sky in weeks in Tampa, FL, and managed to grab some images of Jupiter near opposition.

I wanted to see if my Meade ETX-125 Maksutov telescope was a good 'full-spectrum' infrared instrument, so I shot three ways on a SkyGuider Pro tracking mount:

- a full-spectrum converted Canon M200 APS-C camera with a Tiffen Hot mirror filter (passes visible + H-alpha and a little infrared up to about 700 nm)

- the full-spectrum converted Canon M200 camera with no filter

- a non-converted but otherwise identical Canon M200

All images taken with a 2x Kiron MC7 teleconverter which made the 1900mm f15 optics into roughly f30. The M200 is a Canon APS-C sensor but its 4k video is cropped, so the images are at the camera's pixel resolution (I did not downsample them, just cropped them). The Hot Mirror Filter I used is a Tiffen 49mm hotmirror filter, I removed the glass from the 49mm camera filter, and it just happens to fit nicely in the depression in the back of the Canon EF T-ring, where it mates to the teleconverter.

I shot 2 minutes of 4k video at 1/125s, Processed in PIPP, stacked the best 1200 images Autostakkert, and used exactly the same wavelet sharpening for all images in Registax. Final processing done in DxO Photolab. The 3 images had different white balances due to the different parts of the spectrum captured by each. I tried to bring them to somewhat similar white balance but matching them exactly wasn't really possible.

Interestingly the infrared images seem to show slightly better contrast and detail than the visible light image. Also Callisto is very dark in infrared (the full-spectrum image) meaning it must have a very low albedo in IR.

Even though the diffraction limit of the M200's sensor becomes obvious by f8 or f11, using specialized image processing by stacking 1200 images, and transform wavelet processing, can bring back some of the detail lost to diffraction, even at f30.