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A conversation (and question) about the raw processing...


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So I've found that the raw processing in Affinity Photo (for images that require a large amount of exposure compensation) has me questioning how good it is. The Photos app seems to produce better results with almost no effort. Affinity seems to show up some ugly red blotches (I can add images if someone is curious) that leave a lot to be desired. This is with some Fuji RAF files, but I'd be interested to know if someone else has seen something similar. The blotches in the dark areas are more obvious when the assistant is on, applying a tone curve, but even with it off it's easy to see they're there from the beginning. The results remind of what I'd get from Aperture. Lightroom and Photoshop would handle the extreme adjustments much better due to what I can only image is better raw processing.

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What do you mean by a large amount of exposure compensation?  It is common in many cameras for the red channel to blow out first so if you then reduce exposure you will reveal detail in the other channels but get uniform red patches because there is no detail to recover.

 

Is this what you are experiencing or is it something different?

 

I think I read somewhere that Lightroom/ACR try to reconstruct individual blown channels from the detail that remains in the other colours which might explain why you aren't seeing blotches in those raw convertors.  However, I wouldn't say that is because ACR is a superior convertor to Aperture (people like Guy Gowan would claim the opposite) but because it is manufacturing detail that isn't really there.

 

More detail and some example might help us to understand what you are experiencing.

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Thanks photog. The details adjustment shouldn't really need to be used to save poor RAW processing.

 

Coranda, I'll post an example tomorrow. Photog's post explains it pretty well (it could be a Fuji thing- I must test that) but I don't think it's a a channel being blown out. What I mean by large amounts of exposure compensation is that it's an image that's very dark and it was shot at a decently high ISO. So, when trying to recover the dark areas you're really pushing things. But, it's not just in ACR that things look right. As mentioned Apple's Photos app also does a solid job.

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I haven't used the RAW convertor in AP much so I can't really comment on it's quality but there is something that you need to bear in mind when comparing it to other convertors.  There is no such thing as a correct default conversion as raw files need to be interpreted to some degree so they can be viewed.  Different convertors pre apply various adjustments by default.  Lightroom/ACR for example, and much to many people's annoyance, applies some degree of recovery to images.  The amount varies from image to image but it won't tell you how much or give you an easy way to remove it.

 

What might, or might not, be relevant in your case is that AP defaults to zero colour noise reduction but ACR starts out with 25% to reduce colour blotchiness in the shadows.  Have you tried adjusting that in AP or turning it down to 0 in ACR?

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Yep, I am aware that there is no correct default conversion. I'm mostly talking about things from an aesthetic point of view. I have tried playing with the colour noise reduction, and to match what you get out of Photos.app or ACR, you have to push it to the Extreme level, which obviously isn't great for the colour in the rest of the image. I'll try and get you a really obvious example. The raw conversion process in AP just seems to leave red hotspots, that are really evident in Fuji RAF files.

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Actually, here you go. Here's a great example image to play with (terrible image, but with a good example of the issue :)) Take a look at the red dots across the black bumper of the front van. If you load it into any other raw converter you don't get those red dots. Even if you disable the AP assistant's tone curve adjustment, you can still see those red dots are a part of the fundamental way AP decides to handle raw conversion.

 

https://www.dropbox.com/s/393vq0263nb26fx/DSCF3559.RAF?dl=0

(the link's good for 7 days)

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Thanks, I'll try to have a look at it later.  I've seen a few critical comments about AP's raw conversion so I was planning to do some testing myself to  try to determine how much of the criticism is the result of default conversion parameters and how much on the quality of conversion algorithms themselves.   I'll incorporate your image into the testing and see if I can isolate what's going on with the red spots.

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he raw conversion process in AP just seems to leave red hotspots, that are really evident in Fuji RAF files.

 

Same here, no matter what I adjust. See also: https://forum.affinity.serif.com/index.php?/topic/11084-ap-fuji-raf/

 

Considering my overall experience about 10 days after purchase I would say AP is still in beta. Great potential but the roll out to the market came to early (e.g. no rotation tool in developer, macro persona has been removed, poor raw conversion and so on ...)

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r10k,

 

I've had look at your file in some detail.  I had originally though it might just be hot pixels.  I know that ACR has a default algorithm to deal with hot pixels and I thought perhaps that AP didn't.  However, in this case at least, that doesn't seem to be the issue.

 

I won't try to explain what I've found in this post, because inserting images is a bit too tedious, but I've produced a short pdf to explain my thoughts.  I don't have any particular knowledge of the algorithms used in either AP or LR so I stress that what I have written is my best guess.  It also doesn't offer any definitive solutions but hopefully it will be of some value along the way.  I'd be particularly interested if one of the Serif devs whose worked on raw conversion could shed some light on this.

 

https://dl.dropboxusercontent.com/u/7568628/Fuji%20X100%20Noise.pdf

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I'm super happy to have paid for it because of what it can do, but it does have lots of room for improvement. Hopefully this discussion about the RAW process will lead to that!

 

I've said this before but I think it's worth repeating.  I'm a retiree on a very limited income but I bought AP because I want to encourage the developers to keep going.  It's already the best PS alternative around and I intend to use it where I can and fall back to CS6 when I need to.

 

I also have Illustrator CS6.  I've never used it but I bought AD because I think anyone willing to take on the arrogant Adobe monopoly deserves encouragement.

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r10k,

 

I read the Loewald article you posted and, to be honest, I don't think it's really fair.  It's primarily comparing default processing which really is an apples and oranges situation.  Nonetheless, I do feel that AP has some way to go with it's raw processor.  I think I read somewhere that, when they started this project, they were expecting AP to complement Aperture in the same way that PS does with Lightroom/ACR.  Perhaps when Apple canned Aperture they felt they had to incorporate an ACR equivalent and it really just isn't there yet.

 

I'm not saying the Develop persona is bad but Serif have as good as acknowledged on these forums that it needs improvement and they're working on it.  As for that maze pattern in your file: it is a common consequence of fine detail but cameras most modern cameras have anti-aliasing filters that should blur it out.   I also tried processing it with a convertor (Raw Therapee) that offers ten different demosaicing algorithms but not one of the ten produced that pattern.  I'd love to know how AP is demosaicing.

 

But, it really is early days (PS is at something like V16 and ACR at V9).  I remain confident that this software is going to become something very special.

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I didn't find the article unfair personally because even without default processing it's obvious things aren't brilliant (if I understand what you mean by default processing). But, I completely agree things will improve with AP. That's why I'm more than happy to have paid for it. For the money it's pretty amazing, and the devs have been amazing so far with AP and AD :) I would still love to hear Serif's perspective on the raw side of things though...

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I mean, for example, it criticises AP for not using white balance metadata.  That's not true.  All he's really saying is that the default process doesn't apply white balance but that's just a matter of turning it on or creating a preset with white balance on.  In my experience, counter to his assertion, a camera's auto white balance data is often questionable and I frequently end up making my own adjustments so, that's not a fair criticism.  When he turns white balance on it isn't identical to his preferred convertor so he unilaterally declares that AP must be wrong without feeling the need to provide any evidence to support that contention.  No photographs of colour or grey scale charts.  That's neither fair nor intelligent analysis.  He might be right in his conclusions but he hasn't provided any evidence to support his argument and so, from a rational empiricist perspective, his assertions alone contributes nothing to the debate.

 

He also compares a Photos default process, which uses noise reduction, with the AP process which does not.  How can that be a fair comparison?  You can turn noise reduction on in AP and get a much less noisy image than that article presents.  Whether or not it's equivalent or inferior is an open question but that's not something he bothers to explore.

 

He declares that AP, "somehow manages to create both chrome (sic) and tonal noise even for well-exposed images...".  What's the evidence for this?  Having looked at images in AP and prior to demosaicing I haven't seen anything to particularly support this, but then he doesn't seem to have done any experimental analysis at all.  Opening an image in one processor with noise reduction on by default and another where it is, by default, disabled is a meaningless comparison with regard to noise levels.  The reality, as far as I can tell, is that AP doesn't create noise it's just that, by default, it doesn't do anything to reduce it.  To be honest, his suggestion that it creates the noise just makes me question whether he really has any understanding of the raw conversion process.

 

Yes, as I've said, there are still real issues with AP's Develop persona that I'm sure could be isolated with genuine empirical analysis.  However, so much of the criticism in that article is very shallow and could be placated with a different AP default preset.  To be blunt, I think there are many valid grounds on which the Develop persona can be justifiably criticised but there is nothing in that article that makes me think this guy is even close to being competent to assess a raw convertor.

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The article linked above regarding Affinity Photo's suitability for raw conversion is simply factually inaccurate. I have no intimate knowledge of the coding algorithm used in the raw converter in AP, but all one needs to do is conduct a couple of simple experiments to demonstrate that the author of the above article is either ignoring reality or ignorant of how raw conversion works. Most cameras permit setting white balance with camera presets ("Sunny" or "Flash" or "Cloudy, etc.), setting the WB explicitly in degrees Kelvin, or setting a custom WB based on an image (of a neutral target, for example).

 

I used my Canon 5DIII and shot the same scene in slightly overcast daylight from a window and rolled through all of the WB presets, as well as AUTO and the minimum (2500 °K) and maximum (10000 °K) color temp settings. When each raw file was imported into AP, the Develop persona opens with the White Balance section unchecked (not activated) but with a default conversion that preserves the look of the in-camera WB - the white balance that was set in camera - usually referred to in most raw converters as the "As Shot" white balance. This appears to be the AP default. It does not ignore the WB metadata, as the author of the blog post states - it reads the WB metadata and defaults to that as the default WB for the conversion. I do not know the basis for the blog author's assertion that AP ignores WB data. It is commonly known that White Balance values are interpreted differently across all raw converters and it is not uncommon to see color temperature readouts (in Kelvin) that vary across raw converters for the same image. For example, the image shot at a specified (by the camera controls) WB of 2500 °K is reported as 2362 °K in AP and 2459°K in Photos and 2550 °K in ACR; similarly, the image shot with 10000 °K WB is reported as 8892 °K in AP, 9550 °K in Photos and 9900 °K in ACR. ACR and AP permit the user to select a patch of gray with the dropper to set WB (i.e., spatial average) - it does not appear to be possible in Photos, so clicking multiple spots might be useful to establish click-WB in Photos. I do not use Photos, so there may be a way to overcome this limitation.

 

The author of the article also makes a statement about noise and, as discussed above, does not appear to differentiate between a raw converter that applies NR by default versus no NR by default (AP). The author also make the statement:

 

Incidentally, Affinity Photo’s noise reduction filter appears to have little or no effect. An image with noise reduction maxed out using Affinity Photo is far noisier than the same image processed without noise reduction using any decent program or Apple’s RAW importer’s noise reduction.

Again, there is no basis for this in the article - I suspect the author of the blog does not understand how to extend the effect of AP NR, by checking the "Extreme" check box. It appears that the AP NR slider gives you fine control in its default setting to target just the right amount of noise without hamhandedly overdoing it, but gives you the "Extreme" option to target excessively noisy images, like the OP's image of the vans in the alley, an excessively underexposed image with obvious chroma noise. If the RAF raw file linked above is opened in AP and ACR and NR is disabled, the images have similar noise characteristics and noise can be addressed in either raw conversion with the converter's NR tools. Incidentally, NR in Photos is off by default, at least when I opened the OP's image in Photos. I would like to understand how the blog author has determined that:

 

Affinity Photo’s RAW processing is terrible. It somehow manages to create both chrome and tonal noise even for well-exposed images shot in bright daylight

 

The noise is inherent in the image data - in some instances, the demosaic algorithm can create artifact, but I suspect this is not what the blog author is describing. In order to reduce noise inherent in image data, you actually have to use noise reduction. If NR is not enabled by default, you must enable and use it.

 

I posted simply to point out that the blog article linked above is inaccurate - one can simply prove that to one's self with a few simple test shots and comparisons with other raw converters, where the settings in each conversion are made as identical as practicable. The blog's author appears to misunderstand raw conversion, in general, and how AP works, specifically.

 

Here is a link to a composite image of Photos and AP-Develop with the 2500 °K image I shot, with the images opened at their default values.

 

https://kirkt.smugmug.com/Photography/Link-Share/i-Sc62g5k/0/O/comp1.jpg

 

kirk

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In Develop Assistant I can check 'Apply tone curve'. Which tone curve ?

 

Is using of presets (Exposure, White Balance, ...) provided in Develop Assistant ? The German tuturial here is more than nebulous.

- Oryk (MBpro 12" Retina)

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Kirkt, whether or not the blog author understands what's happening or is correctly describing things or not, there is a point to be made that the end result (even with extreme levels of noise reduction applied) doesn't look anywhere near as good as what someone would get from Lightroom/PS or Photos.

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That may be the case in some instances, but my point was that the author of the blog, whose main point is not to use AP for raw conversion, makes his point based on inaccurate statements and an inability to use the software.  I processed your image and got similar results using all three raw processors - each one required various adjustments to get the images to look similar in tonal distribution and color, and these were not simply based on boosting exposure and applying noise reduction.  I would not necessarily rank AP as the best conversion based on my expectations for raw conversion, but it is not as hopelessly awful as the blog author would make it seem - especially based on the conversion of your extreme underexposure case study.  To make a fair comparison, one must know how to identify issues in each conversion and overcome them, if possible, with the tools afforded to the user by the particular application.  If you cannot do this, then making a comparison is biased and will result in the kind of description offered in the blog post.  For example,  if you simply opened your RAF file in Photos and did nothing to it except boosting exposure and brightness, the image is a total mess and no amount of noise reduction will make it salvageable.  I leave the exercise to you to salvage it in Photos.

 

Considering Photos and ACR/LR are mature raw converters, I think AP has room to improve for sure.  Whatever point the blog author had, hyperbole aside, their basis appears subjective and is no doubt inaccurate.  Why don't you post a comparison here of a conversion of your file in Photos, ACR and AP (or any other raw converters) so we can benefit from your experience with these converters?  It might be helpful for the developers for you to explain what you see as the deficiencies of the Develop persona so that they can improve.  

 

kirk

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So, I still don't agree with you. And, this thread is about the quality of AP's RAW conversion. Not about that blog post, specifically. I posted that because it showed clearly the results I was getting. (meaning it wasn't limited to my exact setup) I didn't post any images because it's annoying to do that in a forum. That's why I submitted an original photo so you could see the results for yourself. Or more importantly, so the developers could see them.

 

I don't think this whole thing has much to do with noise reduction at all. And your statement that if I opened my RAF file in Photos and boosted some stuff it would look like a mess that no noise reduction would fix, is 100% false. The photo I adjusted in Photos (and ACR) looked remarkably good, after boosting things. (mostly though, for best results I adjusted the black point) Have a look for yourself. But let's keep this on topic to what is happening in AP- what's coming from the Develop RAW conversion process is producing remarkably different (and I would say undesired) results compared to the majority of popular RAW processors out there.

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