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Pushing R5 Raw files

  
 
cameron12x
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p.1 #1 · p.1 #1 · Pushing R5 Raw files


Is it true that Adobe Camera Raw only allows one to "add" 3.00 stops of exposure?

And DPP only allows 5.0 stops?

I'm doing some astrophotography that requires my R5 raw files to be heavily over-exposed in post.

Thanks in advance!



Jun 25, 2022 at 10:43 AM
Jman13
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p.1 #2 · p.1 #2 · Pushing R5 Raw files


Well, if you're pushing beyond 5 stops you're going to end up with basically garbage files. The low end of the file has fewer bits of data, so massive pushes are going to result in extreme noise and loss of detail. What would require this level of pushing?

Lightroom allows a +5 stop push, btw. Pushing shadows +100 in camera raw as well is like a 3 stop push in the shadow range also, which gets you to around 8 in Lightroom. I don't know if I'd ever really want to use files like that, though.

Edited on Jun 25, 2022 at 10:56 AM · View previous versions



Jun 25, 2022 at 10:52 AM
cameron12x
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p.1 #3 · p.1 #3 · Pushing R5 Raw files


Getting data from distant galaxies...


Jun 25, 2022 at 10:55 AM
Jman13
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p.1 #4 · p.1 #4 · Pushing R5 Raw files


The problem is the data becomes just trash at giant pushes. You are MUCH better shooting at much higher ISOs for that sort of thing.

I did some quick tests...here's a shot at -7 stops exposure: (you can push the whole image +10 in lightroom if you do +5 then a mask that affects the whole image and another 5), and another by raising the ISO. Both taken at 1/125s, f/4...just one at ISO 100 and the other at ISO 12,800.

Here's the 7 stop push at ISO 100:






And one natively at ISO 12,800 (7 stop higher ISO):






And here's 100% crops of detail and shadow areas in the two images:








Jun 25, 2022 at 11:05 AM
dj63401
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p.1 #5 · p.1 #5 · Pushing R5 Raw files


cameron12x wrote:
Is it true that Adobe Camera Raw only allows one to "add" 3.00 stops of exposure?

And DPP only allows 5.0 stops?

I'm doing some astrophotography that requires my R5 raw files to be heavily over-exposed in post.

Thanks in advance!


With the latest lightroom update, you could go far enough to make screen all white. Edit in regular exposure +5, then you could paint a mask over entire screen, add up to +4 exposure, then if you needed more, the mask has a new amount slider you could turn to to 200%. It turned an under exposed shot of some green leaves to entire clear white screen.




Jun 25, 2022 at 11:08 AM
armd
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p.1 #6 · p.1 #6 · Pushing R5 Raw files


Not sure why you wouldn't want to do multiple shorter exposures, push less, and image average?


Jun 25, 2022 at 11:43 AM
AmbientMike
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p.1 #7 · p.1 #7 · Pushing R5 Raw files



cameron12x wrote:
Getting data from distant galaxies...


What stacking software? Have you downloaded Deep Sky Stacker?

Whirlpool galaxy might be doable now for one.



Jun 25, 2022 at 12:27 PM
armd
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p.1 #8 · p.1 #8 · Pushing R5 Raw files


Precisely. Why isn't he stacking?


Jun 25, 2022 at 12:35 PM
cameron12x
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p.1 #9 · p.1 #9 · Pushing R5 Raw files


This is a special use case. I normally do stacking using DSS.

I just got a new mount (CEM26) a couple of weeks ago and am learning its quirks and the ASIAir computer software.

This is a very short stack with a total integration time of about 8 minutes of the Whirlpool Galaxy (M51) in very bad seeing conditions.

Canon 5D4 body.
Canon 400mm f/4 DO II + 2X TC III.






Edited on Jun 25, 2022 at 01:33 PM · View previous versions



Jun 25, 2022 at 01:22 PM
gdanmitchell
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p.1 #10 · p.1 #10 · Pushing R5 Raw files


cameron12x wrote:
This is a special use case. I normally do stacking using DSS.


You refer to a special case, but perhaps it would be worthwhile to provide some description of what you are trying to do. There are folks here with enough photograph background that you might get some useful ideas regarding how to deal with your challenge that don't rely on such an extreme "push."

It is the nature of digital image files that pushing and expanding the very bottom fraction of the full luminosity range is also going to drastically increase the noise in the final image. For one thing, the SNR is already low; for another there are fewer bits available to record the luminosity differences accurately here. I suppose there might be some kind of specialized AI that could be applied to dealing with the noise, but that's not likely to be part of software designed for more typical image processing.

So, what is it that you are doing?

(If you are utterly certain that there is no alternative to a giant push in post, then you more or less have your answer already, I think. Otherwise... more context please!)

Dan



Jun 25, 2022 at 01:25 PM
 


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cameron12x
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p.1 #11 · p.1 #11 · Pushing R5 Raw files


gdanmitchell wrote:
You refer to a special case, but perhaps it would be worthwhile to provide some description of what you are trying to do. There are folks here with enough photograph background that you might get some useful ideas regarding how to deal with your challenge that don't rely on such an extreme "push."

So, what is it that you are doing?

(If you are utterly certain that there is no alternative to a giant push in post, then you more or less have your answer already, I think. Otherwise... more context please!)

Dan


Sorry, I've been pretty obtuse.

Instead of looking at the histogram on the R5, I instead looked at the "pushed' histogram on my cellphone (which gets its images from the ASIair computer. I should have realized the ASIair images were extremely pushed, and as a result the actual images recorded on the R5 SD card were highly underexposed.

So, this has become an unintended exercise to determine exactly how far I can push R5 images in post, and how the various software packages (Lightroom, Photoshop, ACR, et al) do it, and their limitations...



Jun 25, 2022 at 01:31 PM
Kameratrollet
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p.1 #12 · p.1 #12 · Pushing R5 Raw files


cameron12x wrote:
Sorry, I've been pretty obtuse.

Instead of looking at the histogram on the R5, I instead looked at the "pushed' histogram on my cellphone (which gets its images from the ASIair computer. I should have realized the ASIair images were extremely pushed, and as a result the actual images recorded on the R5 SD card were highly underexposed.

So, this has become an unintended exercise to determine exactly how far I can push R5 images in post, and how the various software packages (Lightroom, Photoshop, ACR, et al) do it, and their limitations...


18 EV pushing in darktable. At 14 EV there are no more pixels left that are not white.



Jun 25, 2022 at 04:20 PM
Imagemaster
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p.1 #13 · p.1 #13 · Pushing R5 Raw files


cameron12x wrote:
Getting data from distant galaxies...


WARNING: Do not attempt to photograph our galaxy, Earthling. We are watching you and you could face serious repercussions.

Sorry, could not resist.



Jun 25, 2022 at 04:38 PM
Milan Hutera
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p.1 #14 · p.1 #14 · Pushing R5 Raw files


I still don't understand what the "special case is".

For deep sky every camera has an optimal ISO setting. I guess for R5 it's ISO 1600 (guesstimating from the original R, which has an astro version Ra as well). Next, determine the optimal exposure length based on your target, light pollution levels and your mount/guiding capabilities. I wouldn't hesitate to shoot 2, 3 or 5 minute exposures if your light pollution allows it to saturate the dark portions of the frame. I get funky looking results on Astrophotography tool when it comes to previews too, that's why I check the test data in dedicated software such as Pixinsight instead. You can probably use Siril which should work just as well and it's free. I wouldn't generally worry about histogram. I was able to recover everything from the Orion nebula core with nothing but 3 minute exposures at base ISO (Gain 0 in case of my astrocam).







With so little integration time, reshooting this should be a non issue IMO.



Jun 26, 2022 at 07:30 AM
AmbientMike
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p.1 #15 · p.1 #15 · Pushing R5 Raw files


Interesting you already have whirlpool lately!!! The one I mentioned. I remember seeing a nice one of it using 200mm aperture f/4 orion IIRC, so 800mm FL cropped should be enough imo

I'm certainly no astro expert but if I needed to pick it up that much in pp I'd probably just use high iso to begin with. I don't have a drive so I used 6400 on aps one time. Looked pretty good.

12800 picked up 2 stops is 51200. Probably difficult to get good results 102400 anyway. Depends on the iso used, 1600 picked up 3 stops is 12800 on an iso less camera if one existed. So that might be possible.



Jun 26, 2022 at 12:26 PM
exdeejjjaaaa
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p.1 #16 · p.1 #16 · Pushing R5 Raw files


cameron12x wrote:
Is it true that Adobe Camera Raw only allows one to "add" 3.00 stops of exposure?



UI allows 5 "stops", however you can simply add whatever you want in a .dcp camera profile ("BaselineExposureOffset" tag) and combine that with UI to get whatever you want in any direction ( = "BaselineExposure" for a camera model / which might be a nominal ISO dependent - you can see what it is by converting CR* to DNG and checking the value of that tag / + "BaselineExposureOffset" in a .DCP camera profile you are using + UI slider in ACR/LR)

or you can plug some raw to dng converter like Iridient C-Transformer (or even Adobe's own DNG converter) before ACR and adjust "BaselineExposure" instead in DNG using for example exiftool w/ "-IFD0:BaselineExposure=..." that way you will also make sure there will be no hidden-from-you variable nominal-ISO-dependent adjustments performed by ACR/LR (or even plugged into DNG by raw to dng converter itself - because some do) - you control what it is (adjustment in .dcp profile, if present, is not variable, but constant)




Jun 26, 2022 at 05:29 PM
cameron12x
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p.1 #17 · p.1 #17 · Pushing R5 Raw files


Milan Hutera wrote:
I still don't understand what the "special case is".

For deep sky every camera has an optimal ISO setting. I guess for R5 it's ISO 1600 (guesstimating from the original R, which has an astro version Ra as well). Next, determine the optimal exposure length based on your target, light pollution levels and your mount/guiding capabilities. I wouldn't hesitate to shoot 2, 3 or 5 minute exposures if your light pollution allows it to saturate the dark portions of the frame. I get funky looking results on Astrophotography tool when it comes to previews too, that's why I check
...Show more

The special use case is that I'm trying to see if I can "steal" enough data from severely underexposed files. The answer, as I have come to determine in this case, is NO.

That's an excellent rendering of M42. I can even make out the Trapezium. Well done!




Jun 27, 2022 at 09:12 AM
cameron12x
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p.1 #18 · p.1 #18 · Pushing R5 Raw files


I am just getting started in this hobby...

Bortle 7/8 skies
Canon R5 (not modified)
Canon 400mm f/4 DO II (No filters)
CEM26 Mount
ASIair polar alignment
ISO 800
30 second subs (unguided)
70 minutes total integration
Stacking in DSS
Edits in Photoshop












Jun 27, 2022 at 09:20 AM
cameron12x
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p.1 #19 · p.1 #19 · Pushing R5 Raw files


Thanks to everyone who provided their insight in this thread. Much appreciated!


Jun 27, 2022 at 09:21 AM
Milan Hutera
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p.1 #20 · p.1 #20 · Pushing R5 Raw files


cameron12x wrote:
I am just getting started in this hobby...

Bortle 7/8 skies
Canon R5 (not modified)
Canon 400mm f/4 DO II (No filters)
CEM26 Mount
ASIair polar alignment
ISO 800
30 second subs (unguided)
70 minutes total integration
Stacking in DSS
Edits in Photoshop


Unfortunately, for bortle 7/8 skies, you have to use some sort of light pollution filter - like Optolong L-Pro for broadband targets and you will have to collect A LOT of data.

Last night I got surprisingly nice data on M20 - The Trifid Nebula, which is very low on our horizon and affected by the streetlights of nearby villages. Officially we are at Bortle 4, but I'd say we are getting close to 5. Definitely inbetween. I used Baader Neodymium Moon & Skyglow/IR cut filter, which is a bit cheaper equivalent to Optolong L-Pro. I shot 3-minute exposures and got roughly 80 minutes of data. The stacked photo was much nicer than expected. I'm aiming to get at least another 100 or so minutes. For your bortle 7/8 sky, you would have to get multiples of that dataset and there is a great chance it wouldn't look as good.

I would suggest exploring Cuiv The Lazy Geek videos, who shoots (or used to shoot, he's taking a hiatus for now) from Bortle 9 sky in Tokyo. Mostly narrowband data through very expensive filters though.



Jun 27, 2022 at 01:42 PM
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