How does Affinity Photo work internally?

[Dynamic Range]

Hi,

 

I am looking at Affinity Photo as a replacement to Photoshop. I use prophoto RGB in Photoshop so I keen to understand a little about Affinity photo please.

 

1. The web site states Affinity Photo uses an unbounded linear colour space. Does this mean there is no internal color rendering intents that clip the color space to say Adobe RGB? I would be looking to export from Lightroom so keen to understand if I can use proPhoto RGB color space end-to-end for editing.
2. Does Affinity Photo have a Lab color space with l, a and b channels?
3. Does Affintiy Photo have a means for macros / actions and if so does it have simple programmable logic like if .. then .. else?

 

Many thanks

 

 

[R C-R]

I think you might be confusing color spaces, gamma, & rendering intent a bit. This article may be helpful in understanding the relationship among these three aspects of a color space. I suspect "unbounded linear colour space" refers to the PCS (profile connection space) Affinity uses internally, but that is just a guess.

 

Affinity supports both RGB & Lab color spaces, as well as the CMYK process color model. In Affinity, you can assign or convert among color spaces like proPhoto RGB, a.k.a. ROMM RGB (Reference Output Medium Metric); Adobe RGB; sRGB; or any other CMM (Color Management Module) your system supports that is usable in the chosen color space. In Affinity color spaces may be referred to generically as "color formats" or "color models" & CMM's referred to as "color profiles."

 

All four rendering intents mentioned in the article are supported, but this can only be set in Affinity's preferences (along with the various profile defaults used when opening new or un-profiled documents) so it is not something you can change on-the-fly in an already opened file. If a file has a color profile, it is used by default.

 

Affinity Photo currently has a very limited macros function. There is (as yet) no support for conditional or branching logic, & programmable variables are not supported, other than for a few parameters that can optionally be set in a dialog that requires user interaction when the macro runs. The developers have said that at some point in the future they hope to add scripting support of some kind, probably via Javascript, but there is no ETA for that.

[Dynamic Range]

Thanks for the info.

 

I was treading carefully about the internal color space question. I know of two popular raw editors that only use Adobe RGB internally. At least one of them allows export to ProPhoto RGB but no colors beyond Adobe RGB are ever saved into the exported file.

 

If you are going to print the final result I think it is worth using ProPhoto RGB so you can print to the full gamut of the paper. Just wondered if Affinity Photo would preserve the full gamut captured by the camera or if it is like some other raw converters and clips then down to Adobe RGB.

 

Good to hear there is a Lab color space, I use that for specific color corrections.

 

Fingers crossed for a better macro facility in a later release.

[R C-R]

If you are going to print the final result I think it is worth using ProPhoto RGB so you can print to the full gamut of the paper.

It isn't quite that simple. To begin with, the print is limited to the printer's gamut (for whatever paper or other print media is being printed). And gamut is spread over a three dimensional color space, so the typical slice through it at the 50% luminance level (or whatever other 'z axis' reference is used) does not tell the whole story. There are also times a wide gamut is not desirable, for example when the colors of an image are limited to a small part of the color space.

 

Another Cambridge in Colour article discusses this briefly.

[James Ritson]

Thanks for the info.

 

I was treading carefully about the internal color space question. I know of two popular raw editors that only use Adobe RGB internally. At least one of them allows export to ProPhoto RGB but no colors beyond Adobe RGB are ever saved into the exported file.

 

If you are going to print the final result I think it is worth using ProPhoto RGB so you can print to the full gamut of the paper. Just wondered if Affinity Photo would preserve the full gamut captured by the camera or if it is like some other raw converters and clips then down to Adobe RGB.

 

Good to hear there is a Lab color space, I use that for specific color corrections.

 

Fingers crossed for a better macro facility in a later release.

 

Hi, just some additional info that might help you:

 

If you begin developing a raw file (and thus are in the Develop Persona), most of the processing is done in 32-bit unbounded with a linear colour space. Some of the colour operations are performed in ROMM RGB, which will allow you to saturate and intensify difficult colour tones (like artificial blue and red light) without clipping them.

 

When you develop the raw file, by default the output is clipped to 16-bit integer and the colour profile is converted to sRGB. If you wish to remain in ProPhoto or work in another space, you can either:

• Check the Outputs option in Develop and choose an output colour profile.

Or

• In Preferences>Colour, change RGB Profile to whatever you wish (e.g. ProPhoto) and by default all developed raw files will be converted to that profile. Just bear in mind that if you choose this option, any images you open without an embedded profile will have the chosen profile assigned. So, for example, if you open a JPEG with no ICC profile embedded, and you have ProPhoto set as your RGB profile, that JPEG will have the ProPhoto profile assigned to it and will look different. Just something to be aware of!

 

 

But to summarise, yes, you can achieve end-to-end colour management in Photo, particularly if you're coming from raw. If you're pre-processing your images in other software I recommend exporting from that software as a 16-bit TIFF with ProPhoto (or another wide gamut profile) for optimum quality.

 

Hope that helps!

[Bart_van_der_Wolf]

Hi, just some additional info that might help you:

 

If you begin developing a raw file (and thus are in the Develop Persona), most of the processing is done in 32-bit unbounded with a linear colour space. Some of the colour operations are performed in ROMM RGB, which will allow you to saturate and intensify difficult colour tones (like artificial blue and red light) without clipping them.

 

When you develop the raw file, by default the output is clipped to 16-bit integer and the colour profile is converted to sRGB. If you wish to remain in ProPhoto or work in another space, you can either:

• Check the Outputs option in Develop and choose an output colour profile.

Or

• In Preferences>Colour, change RGB Profile to whatever you wish (e.g. ProPhoto) and by default all developed raw files will be converted to that profile. Just bear in mind that if you choose this option, any images you open without an embedded profile will have the chosen profile assigned. So, for example, if you open a JPEG with no ICC profile embedded, and you have ProPhoto set as your RGB profile, that JPEG will have the ProPhoto profile assigned to it and will look different. Just something to be aware of!

 

 

But to summarise, yes, you can achieve end-to-end colour management in Photo, particularly if you're coming from raw. If you're pre-processing your images in other software I recommend exporting from that software as a 16-bit TIFF with ProPhoto (or another wide gamut profile) for optimum quality.

 

Hope that helps!

Hi,

 

Yes, that's correct, but I think that the OP's worry is that internally there is a potential gamut limiting operation like e.g. in DxO Optics Pro, which internally restricts gamut to Adobe RGB primaries, even when converted to a larger gamut colorspace like ProPhoto RGB (with lots of empty gamut space). It would help if one of the Moderators could confirm if anything like that, which I do not think it does, happens in AP/AD.

 

Otherwise, we'd have to test with a very saturated image in a larger gamut output space, and compare (e.g. with ColorThink or similar 3D gamut visualization tools) with various known large gamut spaces to see if clipping/compression (depending on rendering intent) occurs.

 

Cheers,

Bart

[Dynamic Range]

Bart is correct,

 

A while back I used to use Adobe Bridge and I realised that I needed a DAM tool / raw converter that not only worked well with keywords but was also Adobe Photoshop friendly. Currently nearly all my photos are finished in Photoshop.

 

I had a deep, close look at both Lightroom and DxO Optics Pro. The latter would not provide any information on the internal color space (in fact were very evasive on answering my query) so I did some testing and was indeed able to confirm DxO was clipping colors, exporting as Adobe RGB or Prophoto RGB for further editing in Photoshop meant colors were lost, colors that I could print on certain papers. I spent a lot of time with ColorThink etc to do my testing.

 

I am interested in alternatives to Photoshop but the editor must be able to preserve the colors captured in camera as I do final soft proofing based on output destination. It would be great if somebody from Affinity could confirm either way if there are any internal color gamut restrictions.

 

If no internal color clipping and Affinity Photo were to add a HSB color model that would be a game changer for me.