Re: Astro modded Canon cameras, future lenses...
Thomas A Anderson wrote:
Sounds like quite a mess that Canon wasn't anticipating with the Ra. As was pointed out elsewhere as well, the lens is older than I thought....shocked that Canon hasn't updated it since 2008. Anyway, that sucks. Maybe its just one of those things that has no solution and would take a team of scientists to figure out.
Canon didn't stop production due to a fault, they did so because these Modified cameras for astrophotography are a "Limited Edition/Special Edition" model. It's hard to believe it's been over a year and a half since release of the Ra. Most stores won't stock them since they have to pay for their stock in advance - so they call out to the Canon warehouse when customers request one (it's classified as a "special order" in most countries) and Canon lets them know how many are on hand. I believe Canon Australia was only issued between 5-10 units during the 2020 pandemic period. Canon's past Modified Cameras were only available for about a year before discontinuation and were released in 5 and 9 year intervals. So there's a lot of unhappy people out there right now who waited too long to obtain one. Admittedly, the high price was influential. If you can live without the 30x magnification (which is very, very useful), an EOS R or RP can be modified as a more affordable alternative.
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Past Canon Modified Digital cameras for Astrophotography were:
* EOS 20Da - [APS-C] - June 2005.
* EOS 60Da - [APS-C] - August 2010.
* EOS Ra - [Full Frame] - November 2019 (incorrectly listed here as Nov 2018)
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The two features the Ra has that are different to the regular EOS R camera are:
* 30x Magnification on the LCD.
* Factory Modified Infra Red Sensor.
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The two issues with the EOS Ra camera are:
* Odd vignetting with the EF 24mm f/1.4L II Lens (at least on mine).
* Flare at the surface layer of the sensor with bright subjects with wide apertures.
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Considering that many professional telescopes with custom built sensors (some of them in the many millions of dollars in price) produce far worse flare that is usually uncorrectable, I don't have an issue with this at all.
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The EF 24mm f/1.4L II USM lens is one of Canon's best Primes and was one of the first remodels of previous essential L-series lenses. Even today, Canon doesn't have anything that offers a suitable alternative and the image quality is simply gorgeous. I just went through my samples-folder (put together before buying this lens) and some of the images are breathtaking. It was also my favorite lens on the EOS M for this reason. Most 2008/2009+ lenses are considered pinnacle technology lenses. This particular one has Canon's UD glass and high precision GMo Aspheric elements for correcting CA. But it also has a unique defocus (specifically bokeh) effect due to the diaphragm design. Yet less distortion than Leica was offering. Though not specifically mentioned on the brochures (which is strange), this lens also has SWC (Sub-Wavelength Coatings) to better minimize ghosting. Diffraction spikes from this lens are great with smaller apertures and it's one of the few Full Frame lenses to perform nicely on APS-C cameras.
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Sigma immediately reverse-engineered it to offer up a cheaper version which had slightly more correction on coma but was plagued with AF problems that annoyed owners. But the Canon was suitably expensive for years and that's why so few enthusiasts and hobbyists bought it. It's mainly found in the kit of professionals for this reason alone. But the closeup ability and overall performance in the hands of journalists, landscapers and produce photographers (especially car enthusiasts) is what caught my attention.
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I believe that there's an RF 24mm version in the works but I'm torn between using that or adopting the upcoming RF 35mm lens (which may yet be an f/1.2L lens). These are both a little way off still and either would be very useful. But despite my efforts to identify the cause of the hard vignetting from this lens on the EOS Ra, I'm no closer to an answer. My best guess is that there's a unique aspect to this specific lens where just a millimeter or so in tolerance differences is enough to cause an imperfect image projection onto the sensor. Neither my lens not my camera have been subject to abuse.
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I think Canon knows that the 35mm focal length (on FF cameras) is highly desirable for journos, travelers etc so they'll likely earmark that one for release first. It probably won't vignette on the Ra but the new lens construction methods (ie coma reduction, syntheric fluorite UD elements, optical coatings and flange distance etc) ought to add some benefits for Astro work. For everyone else (that doesn't do astro), the RF 35mm ought to have BR optics technology to match the EF 35mm f/1.4L Mk II version, which is a magnificently sharp lens.
