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Canon EOS 'R' for astro??


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There are one or two DPReview threads relating to "noise reduction" on the R5 and R6, from the work done by Bill Claff.  For example here:

https://www.dpreview.com/forums/post/64403868

The Fourier transform of the raw data certainly shows that internal camera processing of the raw data is taking place but it's impossible to say whether or not it is a deliberate attempt at noise reduction.  It's unusual to see such processing on short exposures.   I have seen some of these raw files and I've confirmed what Bill is seeing.   However, it is not possible to extrapolate from these results what would be the effect on astrophotography.  For that we would need to see some raw long exposure dark frames and some astro long exposure raws containing very tightly focused stars with no trailing.

Mark

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1 hour ago, Skipper Billy said:

Thanks Mark

I am slightly wary about something happening to supposedly RAW images that I have no control over and can't turn off.

I think I am leaning back towards the Canon 5D MkIV again !!!!

Thanks again.

A quick search seems to indicate it is not a problem in the real world - noise reduction is applied mostly on short exposures and up to ISO 640. I 've  no experience of the 'R' series, but these user reviews for astro seem don't seem to flag any issues.

dpreview

petapixel

 

Edit: It's only £30 more on Amazon that the cheapest available, so why not buy, try and return under distance selling regulations if you are not happy. You might have to pay return postage but it avoids an expensive mistake.

Edited by Shimrod
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1 hour ago, Shimrod said:

A quick search seems to indicate it is not a problem in the real world - noise reduction is applied mostly on short exposures and up to ISO 640. I 've  no experience of the 'R' series, but these user reviews for astro seem don't seem to flag any issues.

dpreview

petapixel

Sorry, I can't take those reviews seriously.  Marco Nero (DPReview) is shooting untracked JPG images.  Brent Hall (PetaPixel) is also shooting untracked and has star trails.   Those reviews don't help us understand if accurately tracked long exposure astrophotography with good quality optics will have problems similar to the well known Sony star eater issues.

Mark

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9 hours ago, sharkmelley said:

Sorry, I can't take those reviews seriously.  Marco Nero (DPReview) is shooting untracked JPG images.  Brent Hall (PetaPixel) is also shooting untracked and has star trails.   Those reviews don't help us understand if accurately tracked long exposure astrophotography with good quality optics will have problems similar to the well known Sony star eater issues.

Mark

My understanding of the Sony issue is that it is a hot pixel removal process rather than noise reduction which is removing stars.

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9 hours ago, Skipper Billy said:

Cheers @Shimrod I will have a proper read at those user reviews.

The other way of looking at it is to choose the camera that is the best fit for your main use - if it is predominantly going to be used for daytime photography, is the occasional AP usage going to be good enough?

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1 hour ago, Shimrod said:

My understanding of the Sony issue is that it is a hot pixel removal process rather than noise reduction which is removing stars.

It's a question of semantics.  The Sony issue is well understood because of detailed investigation and it only affects pixels with outlying values - which of course is a type of visible noise.  With these types of algorithm the problem comes when tightly focused stars are damaged along with the rest of the noise.  The problem is that we don't yet know the effect of the R5/R6 raw data filtering on stars.  From the reviews we know it probably doesn't affect untracked images with slightly trailed stars but the Sony raw data filtering didn't cause any issues for these types of images either.

Mark

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34 minutes ago, sharkmelley said:

It's a question of semantics.  The Sony issue is well understood because of detailed investigation and it only affects pixels with outlying values - which of course is a type of visible noise.  With these types of algorithm the problem comes when tightly focused stars are damaged along with the rest of the noise.  The problem is that we don't yet know the effect of the R5/R6 raw data filtering on stars.  From the reviews we know it probably doesn't affect untracked images with slightly trailed stars but the Sony raw data filtering didn't cause any issues for these types of images either.

Mark

My assumption here is that for Aurora and milky way widefield the shots will most likely be untracked - I could be mistaken though. If I was replacing my camera now I would go with the 'R' series  - however I am waiting for the 7d equivalent as the R5 is more than I would be willing to spend. Of course this is Skipper Billy's money we're spending which is why I suggested Amazon with their excellent returns policy so he could buy and try.

There are a few longer exposure shots on astrobin taken with an R5. I've dropped the links below.

astrobin1

astrobin2 - milkyway

Astrobin3 - orion nebula

Edited by Shimrod
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On 09/06/2021 at 22:43, Skipper Billy said:

Cheers @Shimrod I will have a proper read at those user reviews.

There is a review of the R6 in this month's Sky at Night Magazine. The review is by Chris Grimmer - the longest exposures in the review images appear to be 60s.

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3 hours ago, Shimrod said:

There is a review of the R6 in this month's Sky at Night Magazine. The review is by Chris Grimmer - the longest exposures in the review images appear to be 60s.

Great timing - thank you so much for letting me know. 

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  • 2 months later...
45 minutes ago, sharkmelley said:

Did you come to a decision on this?  I recently bought the Canon EOS R for astrophotography and I'm very pleased with the results.   I will certainly be using it in preference to my Sony A7S and Nikon Z6.

Hello Mark.

In the end I didn't upgrade and stuck with my 70D for now - mostly because I have been so busy at work I haven't had time to even think about it!

I will look forward  to seeing some of your images.

 

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1 hour ago, sharkmelley said:

Did you come to a decision on this?  I recently bought the Canon EOS R for astrophotography and I'm very pleased with the results.   I will certainly be using it in preference to my Sony A7S and Nikon Z6.

Mark

You seemed quite sceptical of the R series for long exposure photography earlier in the thread, what changed your mind? Or is it a specific difference between the older 'R' and the newer R5 & R6 which is the issue?

It's worth noting that Canon recently stopped producing the Ra (dedicated astro camera) so if anyone was interested in one of those, you might still be lucky to find one in stock.

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17 minutes ago, Shimrod said:

You seemed quite sceptical of the R series for long exposure photography earlier in the thread, what changed your mind? Or is it a specific difference between the older 'R' and the newer R5 & R6 which is the issue?

The issue is raw data filtering on the R5 and R6 that was noticed by Bill Claff's tests on the PhotonsToPhotos site.  The question is whether or not this filtering damages small tightly-focused stars.  From the evidence I've seen in long exposure dark frames, I doubt if stars are affected but it would be nice to know for sure.   The EOS R does not have this filtering.

Mark

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  • 7 months later...

Sorry I'm late to this, but the link came up while searching to see if anyone had modded an EOS R as the Ra is either impossible to find or just ridiculously expensive.

I have an EOS60Da and also the EOS R (unmodded) each has it's advantages. Overall I do like the EOS R as some have commented the EVF takes some getting used too (about a day) but now I wouldn't be without one.

On sensitivity the EOS R is on par with the EOS 5D MkIV it certainly is streets ahead of my old EOS 60Da in terms of noise and general sensitivity to low light, the EOS 60Da still edges out the R at the Ha end of the spectrum. I use the EOS R mainly with lenses as none of my scopes can deliver a FF imaging circle without serious vignetting and distortion at the edges so I end up cropping back to APS-C sizes anyway.

 

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