A comparison of a telescope image of the Moon with telephoto lens images with and without a tele-converter. My new 200 mm lens and tele-converter is intended for wider field of view shots than a telescope can give. This comparison shows the image detail that each resolves on the Moon.

Images are from today's waxing gibbous Moon taken with three lenses: the Questar 1400mm f15 telescope and a Vivitar Komine 200mm prime telephoto with and without a Vivitar 2x tele-converter. Vintage manual telephoto lenses are a great low cost source of high quality lenses for mirrorless cameras. The camera was my Sony a6300 APS-C mirrorless camera with 1.5 crop factor. Forty images were taken with each camera, the best 8 were chosen, stacked and processed with the same workflow.

It is surprising how much of the subtle detail of the Questar image comes through even when reduced to only 640 pixels wide. I was also surprised at the difference between the images with and without the tele-converter lens. I'd expected the magnified image to be just a bigger blurrier version of the image with the prime lens alone, but there is clearly additional detail. The Questar (1400 mm) original is 3645 pixels wide and the 200mm with 2X tele-converter image is 1134 pixels wide. They are linked to full size JPEGs of the original images.

The Questar image above was exposed for 1/30 sec at ISO 100, best 8 of 40 images stacked and deconvolved in Lynkeos, with final crop and exposure adjustment in Photoshop.

I also made another version of the Questar Moon image using the superior 8 parameter affine transform stacking in Nebulosity. For the comparison here I used the simpler Lynkeos stacking because the extra effort isn't worthwhile in the lower resolution camera lens images.

The image above was taken with the Vivitar 200 mm lens and the 2x tele-converter. Exposed for 1/60 sec at f8 and ISO 100, best 8 of 40 images stacked and deconvolved in Lynkeos, with final crop and exposure adjustment in Photoshop.

The image above was taken with the Vivitar 200 mm lens. Exposed for 1/125 sec at f8 and ISO 100, best 8 of 40 images stacked and deconvolved in Lynkeos, with final crop and exposure adjustment in Photoshop.

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These images are included in my note on Moon photography - a dozen ways to shoot the Moon

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