EOS Ra: A great Full Frame Astrophotography mirrorless camera...

zero214 wrote:

Great review Nero, I see that you also have an RP, any chance RP with a bigger pixel size could be more better in low light than R?

You know, I bought the RP for my wife. The 50mm lens I was using is one that I bought for her a few years ago and I had to borrow it for the evening. We usually borrow and share the lenses but rarely the bodies. I'm annoyed because her DSLR is sitting on a shelf covered in cat hair and dust right now and yet borrowing her camera gear requires a lot of assurances from me. I may have to try the RP although it's not sensor-modified like the EOS Ra is. So whilst the R will capture 400% more of the Ha frequency light at 656nm level, the RP won't be able to do that... hence the suggestion from others to buy an RP for astro and get it modded for this purpose (which is cheaper than an EOS Ra). I've not noticed any issues with the RP but the sensor it uses produces a bit more noise grain than the R, so I'm waiting for the next RP alternative to come around before buying one for myself. Canon says that the larger number of megapixels on the R means the signal noise is "averaged out" and visibly reduced.
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5.36 microns = EOS R
5.75 microns = EOS RP
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Yes, there's slightly more (0.39 microns) size to the sensor cells - but at that level it's going to be a subtle difference. The answer to "more light" is definitely going to be resolved with using a tracking mount to increase exposure times and lower the ISO being used. This ought to reveal more detail and color in some instances and I will be able to use narrower apertures to reduce CA and eliminate Coma and Vignette. I seem to remember reading a few years ago that you should never be afraid to increase your ISO beyond what it comfortable for you because higher ISO can often capture detail that might otherwise be lost with shorter exposures (or something to that effect). This is why I experimented with ISO 4000 the other night and it was reasonably smooth.
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A very TIGHTLY CROPPED image looking back at my car parked in the dark in the National Park (parked between two other vehicles). The Very bright green glow from inside the camper van was not visible at all to my eyes. It was pitch black darkness. The light on the exterior of these vehicles is coming from the sky. I'm guessing the green light is from a sensor inside the camper. .Another theory is that this is a curtain between the front seats that was illuminated from behind by a green LED from perhaps a microwave or a bedside clock.

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INFRA RED
The EOS R has had the IR filter layer removed from the sensor so the question earlier about whether or not this camera can be used for IR Photography via an IR threaded filter might be answered by an image I took the other night. This has been tremendously cropped and was taken in the direction of my car at night in the National Park.
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I attempted to fire an IR Remote at the camera with no sign of light visible (which is actually a little odd). I just aimed the camera (in a dark room) at an IR security sensor and it did not show any light. I also used it with a large plasma sphere that I know produces some UV and IR light but saw nothing unusual. In fact, the color accuracy was better than any other camera I've used for this same object.
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I have an IR filter but it's 58mm and that means I need to location my 100mm lens with the MA-67 mount on it that accepts a 58mm filter. It's about 320km away at another address right now. But I will get around to testing it. Presumably it will work with the right filter. Canon do not recommend using their cameras for IR photography due to the IR filter on the sensor. I first inquired about this in 2004 and the last camera that allowed some practical IR photography was the PowerShot G1X. There was still a mild "hot spot" in the middle of most shots but it was correctable in most cases during PP.
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I also ran a test with two very large museum-display plasma balls that I knew emitted IR light. They produced too much visible light to make this test viable - but I did detect some subtle additional glow in the plasma that was not visible to the human eye. There was an additional glow that the camera detected. Both plasma spheres displayed additional captured light with the EOS Ra.

Keep digital cameras away from the EMF surrounding neon and plasma lighting.  It will also interfere with the touch-screen and the AF of the camera.  Especially signage with large neon transformers..
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Regards,
Marco Nero.