Presales question: disabling demosaic, sharpening, lens crop-factor detecting precion

[Wumpus]

Hi. Was able to try out Affinity Photo (latest revision over the holidays) for two days before my trial ended.

It seems my lenses were not detected, but I think that may be because of the crop factor precion: one camera of mine is crop factor 1.5, whereas the closest database matches were 1.52 or 1.53. Does it need to be an exact match (2nd decimal matching)?

Also, the qualities of the program seemed excellent, except I couldn't find where to disable all demosaicing and zero the sharpening. It appeared like both were always being applied to some extent. 

Would love an additional 5 days test armed with how to do that: if I can, consider this a conditional sale. 

Thanks! 

[Steps]

Yeah, the trial has consecutive days.

You can only trial each version once. So you can trial again with release of 1.7. This is to prevent abuse.

You can however trial again on another computer if you have.

The last option is to buy it and refund it if you don't like it. They have a 14 day money back guarantee.

See here: https://store.serif.com/en-gb/help/

[Wumpus]

Thanks for the excellently detailed post: very quick & thoughtful. Nice to know for the future that each revision allows a re-trial. Now I just need to find where to disable those two settings. Exposure and colour correction were surprisingly quick to arrive at what I wanted, but everything was all dithered to bits with some harsher edges. I know that other apps can produce output without those side effects from the same raw files, but I want to switch to something quicker. This could be what I'm looking for, but image quality will sadly have to trump my convenience.  Thanks again! 

[walt.farrell]

It's been my impression that demosaic is a fundamental part of processing a raw file to get a displayable image. See, for example, https://affinityspotlight.com/article/raw-actually/

I doubt you can disable it.

As for sharpening, if your lens isn't recognized I don't think any would be applied, but you can disable some of the automatic raw processing in the Develop Persona's Assistant Manager.

 

[firstdefence]

 

and 

 

 

[Wumpus]

Thanks very much. Yes, I verified that all cameras and lenses were on the supported list before I downloaded the trial. The only questionable aspect was that beside the lenses in the list were crop factors (which would understandably affect vignetting and distortion): in some cases it listed 1.52x or 1.53x beside my lenses, but not my sensor's 1.5x crop. That's one of the topics I was wondering about in my OP.

Demosaicing is often included automatically in many raw processing engines, but as far as I understand, it doesn't need to be, just as with default minimum sharpening. Some sensors don't use blur filters (eg Nikon D8xx), and some people prefer to apply a method of their choice for demosaicing that best suits their scene, or in a few cases, certain sensors don't even require dithering their images. I just want to disable it altogether. 

My Affinity images look great, but they're all kind of stochastically dithered and sharpened when viewed up close. It's not noise, either. I'm happy with the app's functionality, but want to fix these auto quality settings. The lens autodetection issue isn't a biggie for me: I'm sure I can learn how to create and apply a template - hopefully based on aperture and zoom, too.

Thanks again. What a considerate forum!

[R C-R]

21 hours ago, Wumpus said:

Demosaicing is often included automatically in many raw processing engines, but as far as I understand, it doesn't need to be, just as with default minimum sharpening. Some sensors don't use blur filters (eg Nikon D8xx), and some people prefer to apply a method of their choice for demosaicing that best suits their scene, or in a few cases, certain sensors don't even require dithering their images. I just want to disable it altogether. 

From what I have read about this, all Nikon D8xx series camera sensors use the Bayer filter method of recording color information. As explained in the Raw Actually Spotlight article, a Bayer filter itself does not blur anything; it is just a matrix of tiny color filters that allow each of the sensor's photoreceptors to be sensitive to only one color of light. The image data from the sensor is basically just an ordered list of the brightness value of each photoreceptor, so without the demosaicing step, you would just get a greyscale image devoid of any color information.

[Wumpus]

As far as I understand, most digital cameras use two techniques together: a CFA (colour filter array), which you described well, and an anti-alias ("blur") filter, so they are actually separate topics. The Nikon D8xx series (I believe) still uses the stock Bayer CFA incorporating the popular Nikon emerald green, but they do away with the blur filter, to really help with fine details like fabric or other patterns. It is the decision to use a CFA in the first place that creates the need for a blur filter, because each sensor site might see different brightness levels, yet will have colours (truly or falsely) applied to those brightness levels according to the filter that happens to reside at that grid location. To try to 'average' the colours into bigger discrete blocks, a resin blob gets applied typically over at least four CFA sensor sites in a rectangle, effectively distributing the light level to adjacent colour sites, and results in an accumulated overall RGB value (but at a quarter resolution than the number of sensor sites). Having the blur filter removed while still using a CFA grid can lead to aliasing artefacts, but generally results in far crisper, punchier images. The advances in DSPs in digital cameras now works miracles interpolating and sharpening the data back into something that is usually extremely similar to the original scene. It really blows me away how well they function.

Using just three colours in the CFA can somewhat restrict the potential range of colours detected and represented, so some vendors have tweaked the colours used, or even added additional colours or different patterns than the Bayer RGRGRGR... GBGBGB... grid, to try to improve the representation of subtle hues and details. Doing so usually creates some amount of grief downstream with support from RAW processors, as they need to do special treatment to handle those. But supporting different methods of reconstructing images from the mosaiced patterns lets different methods be applied, which depending on the scene, can do better or worse than a single defaut demosaicing method. And it lets you use other camera sensors.

My cameras don't use CFA or blur filters, so I was stoked to see mine in the supported cameras list, and  sure enough, my lenses were supported too. Affinity has a lot of power, and ease of use, so if I can switch from my current cumbersome headache of a workflow to Affinity, I'd really like that, but I need to find out how to disable the demosaicing and any default sharpening to preserve what I've got. I'm hoping one of their employees reads these forums. Even if I bought thenproduct to find out, I'd still need to know how to do that. Hoping I find out soon, because I want to decide upon a new method and stick with that for the next few years.

Thanks again!

[R C-R]

4 hours ago, Wumpus said:

My cameras don't use CFA or blur filters ...

What cameras would those be that do not use a CFA?

[lepr]

.

[lepr]

.

[Patrick Connor]

38 minutes ago, >|< said:

Monochrome digital cameras

Wow they're expensive (and news to me)

[v_kyr]

8 minutes ago, Patrick Connor said:

Wow they're expensive (and news to me) 

It's an elite club, that's the reason why expensive. Though you can also try to DIY with cheaper equipment.

[R C-R]

34 minutes ago, >|< said:

Why are you laughing?

Because it seemed like an obvious tongue-in-cheek remark about cameras for which a color filter array would have no purpose. Also, because I have a weird sense of humor.

5 minutes ago, Patrick Connor said:

Wow they're expensive (and news to me)

There is of course (for now) still the 'old school' approach to monochrome photography. I still have my nearly indestructible stainless tank & spools for 35mm film negative development & at least one old Nikon film camera  around somewhere. I would be happy to sell them to an interested party at a lot less than $2000. 

[Wumpus]

Great comments and a good chuckle (and true!).

Also don't forget the Foveons up to, but not including the Quattros, which do deliver per-pixel resolution (like a monochrome camera) and blue channel, but do a sort of in-DSP demosaicing for the green and red channels, which don't have a blur filter, but get 'binned' so that they act almost as if they had a blur filter to the adjacent sensor sites.

And I believe some video cameras that had per-primary sensors (using mirrors) could do stills too.

And ancient digital cameras used to do high-res by doing sequential monochrome shots through a rotating filter wheel, but had such long time gaps per colour capture that they could only be used for indoor stills. There used to be tons of articles and how-to's for removing CFA filters and removing blur filters, so I assume it still happens, but haven't investigated it: I recall some Canon models being more popular for that.

I've been using Foveons for over a decade, after sadly parting with my Nikons  (I was no longer doing professional work) . The Nikons were definitely more 'professional' in that they were dependable, quick, removed a lot of low-value efforts, and were compatible with a heckuva lot of related stuff. The Foveons are the opposite, but I like to think of them like 'Artisan' cameras: slow, featureless, short battery life, incompatible with much (although increasingly dependable), but at around base ISO and with painstaking exposure and focus attention, and tolerance for workflows that sometimes feel almost multi-generational, the results can be breathtaking, and remind us of why we got into photography in the first place. No idiot-modes or tarted-up HDR or pray and spray techniques can be used, almost like when you had to make shots count with conventional (and costly) pro film.

That's why I'm possibly being such a stubborn jerk about not losing that hard-won image quality, if that helps.

[Wumpus]

Does anyone have any recommendations for how to get the attention of the Serif support people, to confirm Walt's reading on my situation? Often pre-sales questions get a higher priority than post-sales support questions, so this might not bode well for my ever finding out for sure.

Thanks!

[v_kyr]

The Serif support people will usually recognize this, since they too read over the threads here in the forum.

BTW and in case you didn't tried, RawTherapee does support Monochrome Cams...

Quote

Monochrome Cameras

A monochrome camera has the same light filter in front of all pixels, that is you get a black-and-white image and no demosaicing is required. Some of these cameras have no infrared filter and are thus sensitive to infrared light, which can be used for creative black and white photography.

RawTherapee supports monochrome cameras, but the user interface is not adapted for it so when you load a monochrome file all color tools will still be enabled (they won't do anything meaningful of course). You will have to live with that, monochrome cameras are rare so we won't put any major effort into making the user interface morph into reduced monochrome-only version.

There are a few additional factors to consider when working with monochrome files: some monochrome cameras report that they have only a single monochrome channel and a neutral color matrix, like Leica M Monochrom, while others report RGB channels in a bayer configuration (like Phase One IQ260 Achromatic, or IR-modified cameras). If the camera reports only one channel, RawTherapee recognizes this and won't perform any demosaicing (the demosaicer selection is still enabled but does not do anything), and everything works normally. However, if the camera reports as an RGB bayer camera, demosaicing will be performed and a color matrix will be applied. To disable this, you should select the "Mono" demosaicing option, and select "No profile" as input profile in the Color Management panel.

See the Demosaicing page on RawPedia for further infos.

[Wumpus]

Thanks! Yes, if I recall, it was something about how the RAW data was stored, linearly or in a log format. I experienced that 'effect' (black images), but it was very easy to correct. I'm also evaluating Raw Therapee too, and have ruled out On1 already (but they had great support). Your third paragraph was completely new to me, and very interesting! Thank you - I appreciate that.

[walt.farrell]

10 hours ago, Wumpus said:

Does anyone have any recommendations for how to get the attention of the Serif support people, to confirm Walt's reading on my situation

@Patrick Connor, who posted above, is one of the Serif staff.

By the way, my guess would be that if you're camera is supported, and if indeed it does not need the demosaic process, that it wouldn't be performed. But that's purely a guess. 

 

[Callum]

On 1/15/2019 at 3:54 PM, Wumpus said:

Hi. Was able to try out Affinity Photo (latest revision over the holidays) for two days before my trial ended.

It seems my lenses were not detected, but I think that may be because of the crop factor precion: one camera of mine is crop factor 1.5, whereas the closest database matches were 1.52 or 1.53. Does it need to be an exact match (2nd decimal matching)?

Also, the qualities of the program seemed excellent, except I couldn't find where to disable all demosaicing and zero the sharpening. It appeared like both were always being applied to some extent. 

Would love an additional 5 days test armed with how to do that: if I can, consider this a conditional sale. 

Thanks! 

Hi Wumpus,

I'm sorry to hear your lenses aren't being picked up by Affinity what is the model of the camera you are using? I'm not sure if you can disable the de mosaic feature and sharpening but I will look into it and reply to this thread with my findings  

Thanks

Callum

[Wumpus]

Super kind and appreciated, for you to check what's happening with the demosaicing. 

The model I'm most concerned about is the SD1M (aka Merrill), which has a 1.5x crop factor. Of my four lenses, the two I tested with Affinity were zooms: the Sigma 50-150 2.8 EX DC II, and the 18-50 2.8 EX DC.

Thanks very much!

[v_kyr]

Those Sigma lenses should usually be recognized by the lensfun database, but you have to look if for all applicable ("dist/TCA/vign") or not here. - See:

• Supported Lenses for SerifLabs RAW engine (1.6.x)

• Supported Raw Cameras (1.6.x)

[Wumpus]

Think I might try purchasing the product to see if I can get me some of that pre-sales support.     I would like to make a decision on a new raw development workflow sooner than later. Thanks for letting me know that I can get a refund within 14 few days. Hopefully I can figure out for myself where that gets applied (or disabled), or if it's in a config file or the Windows registry.

Everyone has been quite kind, so that was a nice initial experience. Thanks very much, all. I'll post back with findings.

[walt.farrell]

3 hours ago, Wumpus said:

Thanks for letting me know that I can get a refund within 14 few days.

Note that you should purchase directly from the Serif Affinity Store, not from the Mac or Windows Store, if you want to be sure of that return policy.

[Wumpus]

I did (thanks for that, Walt) but it never helped one iota in terms of getting any support, so pre-sales or post-sales seems to make no difference with this product. Fortunately, for an entirely user-group supported product, it appears to have a great community.