Sony Alpha: The Star Eater

If you follow me on Instagram you’ll notice it is both the one place I rarely engage in politics and also one of my hobbies has increasingly become astrophotography. I sit out in the quiet of the night and take pictures of the stars, nebulas, and planets. The picture above is one I took of the Orion nebula with a Canon 70D attached to my telescope. I’m just starting out and have a lot to learn. One thing I have learned already is that the Sony alpha series of cameras has been badly screwed up by Sony.

I have a Sony a7rii. I had a Canon 70D and once I got comfortable I realized that you date your cameras and marry your lenses. I already have an expensive Sony E-mount lens for an FS7 video camera so I figured I would move over to Sony for photography. I have not been disappointed except in astrophotography. But the disappointment leads to a greater concern with Sony.

Back before digital, photographers used film. Film had negative prints that were then used to render photographs. Fiddling with the negatives in various ways could enhance the picture in various ways. The digital equivalent is the RAW file. A RAW file captures all the information a digital camera sensor records and that file can be manipulated to pull out color from shadows or tone down exposure. The RAW should serve as a digital negative, giving you exactly what the camera sees.

Unfortunately, Sony has updated their popular alpha series of cameras. The result is that stars get eaten.

Sony, through a firmware update, placed an algorithm in its cameras that registers sharp, bright, small stars as hot pixels and tries to erase them. That would not be a problem if Sony just did this with a jpeg image file. But Sony has sought to do this in the RAW files, altering the RAW image itself, which is unusual in digital photography. The result is that many crisp photos of the night sky are now muddied and diminished. Sony’s algorithm confuses stars for hot pixels and erases them from the night sky.

This had just been a problem on long exposures on the “bulb” setting, but more recently Sony has carried the algorithm over to any exposure from 4 seconds and above on any setting. It may yield some great day time shots, but it renders the camera unusable at night.

That is unfortunate. I really love the a7rii. I hope they release an a9 version with sLog and I will gladly upgrade. But I cannot use my Sony camera at night for long exposures. The details I might otherwise capture are lost to an algorithm Sony told no one about and for which they provide no way to turn off. That is disappointing.

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Erick Erickson

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