A7rIII Star Eater - Orion nebula and North America nebula region on a dark night

Started Dec 12, 2017 | Discussions thread
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Magnar W
Magnar W Senior Member • Posts: 3,730
A7rIII Star Eater - Orion nebula and North America nebula region on a dark night

This will be my last post with real world test photographs of the night sky taken with the Sony A7rIII. These are taken a dark night with no moon, and should tell pretty well what the Star Eater is about: Smooting out very faint stars, making this camera less attractive for serious astrophotography but just fine for everybody else.

Or is there more to it? This camera has poor Hydrogen alpha response, so the A7rIII would not likely be chosen by serious astrophotogrphers anyway. The North America nebula does barely show up, and the Orion nebula doesn't sparkle with bright red Hydrogen alpha areas. Since these data is not recorded, they can not be pulled from the raw files.

This time I captured the night sky with uncompressed raw files and no in-camera long exposure noise reduction. The files were processed Capture One, to low contrast, and no noise reduction at all at post processing. I also kept the sky background pretty bright, for easier inspection of the darker areas.

The pictures were stackted with Photoshop and the Statisitcs function to avoid loss of colors, which might be a problem with RegiStar. The merging mode is Mean, wivh I also used for my previous night sky photos that were stacked with RegiStar.

The camera was put on a AstroTrac platform that was aligned to the Polar star, to ensure nice and round stars. Manual focus with the A7rIII works like a breeze, som I am sure focus is as good as possible with the Zeiss Loxia 85 mm f:2.4 wide open.

I intended to take some tracked night sky photos with the Loxia 21 mm f:2.8 lens too, but the front element got covered with dew that frose to ice when I took some pictures of a weak polar light arch, so I had to put this lens away when I started my final night sky/Star Eater test.

Well, here are the merged files, and single files as well. Note that all posted files are all 100% crop:

North America nebula region. The bright star at lower right is Deneb. All are 100% crop.

 Magnar W's gear list:Magnar W's gear list
Sony a7 Sony a7R III Sony FE 90mm F2.8 macro Zeiss Loxia 21mm F2.8 Zeiss Loxia 35 +2 more
Sony a7R III Zeiss Loxia 21mm F2.8 Zeiss Loxia 85mm F2.4
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