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Loxley vs DS Colour Labs

Discussion in 'Digital Image Editing & Printing' started by EightBitTony, Apr 27, 2018.

  1. GlennH

    GlennH Well-Known Member

    My understanding has always been that lab software cannot, in general, read profiles, and assumes everything to be sRGB. Thus, nothing is converted to sRGB at the front end. Files are converted to the printer profile on that basis. If the printer profile happens to contain colours outside of sRGB, as they often seem to do, these colours get clipped unless the lab sends the file to the printer with "no conversions". This service seems relatively rare (I'd ask DSCL about this if I were going to bother). One reason labs might ask you to "edit in sRGB" is so you can't preview/soft proof colours in the printer profile that are later clipped.

    Buried on DryCreek somewhere is a sentence (a few years old) that says "many versions of the Fuji Frontier PIC driver crash when given files with profiles embedded", but presumably labs would alert customers to such a problem.
     
  2. Waypoint Charlie

    Waypoint Charlie Active Member

    I think different labs handle things in different ways. I do have a technical background in imaging, but more on the display side, so don't claim to be an expert in printing. It's simply based on various things I've read and from the results of various tests I've made. From what I've observed so far (and I may be wrong)...

    Loxley accept sRGB and somehow do the necessary conversion at their end. It seems to work.

    Sim Lab request sRGB but this is not ideal for their print process. In other words, it's not colour managed. You might get better results by converting files you send them to the generic DP II Fujifilm profile for Frontier Print sRGB (not PD Mode), provided you don't embed the profile in the files (as this might prompt the uploader to convert to sRGB, which defeats the object).

    https://www.fujifilm.eu/eu/support/photofinishing/color-management

    DS request that the files are supplied converted to the correct paper profile to their print process. In other words, the colour management is down to you. This is good advice and their custom profiles aren't bad. They could probably be a little better, but for the money it seems very churlish to complain. The only issue I've found personally is with the web uploader converting the files to sRGB, but you can prevent this by not embedding the profile. If you send them sRGB files (as I'm sure many customers do) you'll get prints looking similar to what you'd get back from Sim Lab.

    From what I understand (and again I may be wrong) the Fujifilm Frontier machines can be configured to operate in PD or sRGB modes. PD stands for 'Print Direct' and provides access to the full native printing gamut. sRGB mode seems to attempt to restrict the gamut to sRGB colour space. However, and this is important, it does not mean that the printer behaves like a device conforming to the standard sRGB IEC61966-2.1 profile for every paper type. If it did, they'd be no reason for Fuji to supply their own profiles for the sRGB mode.

    My suspicion is Sim Lab and DS operate their machines in sRGB mode. If they were configured to PD mode I'd expect some of the printed colours to look more saturated. I wonder if there's some misunderstanding at Sim Lab into thinking that the sRGB mode on the printer conforms to the standard sRGB IEC61966-2.1 profile. My guess is they do know but they are not setup to perform the conversion on all the sRGB files they receive. And why should they bother, if customers don't notice or don't care?

    I found this article informative. It's quite old (I think updated in 2012) but much of it seems applicable today. Note the Fuji test image in the middle. That's how that it looks if I send an sRGB profiled file of that image to Sim Lab or DS. Standard sRGB is simply not the correct profile to use.

    http://pehache.free.fr/FOTECH/FRONTIER1/index_en.html

    I'm sure all this is far beyond the comprehension of the vast majority of customers (including many at my local photo club) who simply want to get their sRGB files printed. They want to concentrate on the creative side and leave the printing technicalities to the professionals, which is perfectly understandable. If that's you, go Loxley.
     
  3. GlennH

    GlennH Well-Known Member

    Almost no labs are colour-managed, including Loxley. If they were, you'd be able to send them Adobe RGB or ProPhoto RGB files and they wouldn't insist on sRGB or deny you the possibility of converting to the printer profile. It's not even colour management, strictly speaking, if you convert to the printer profile and the lab sends the file straight to the printer, but it is a pure process that amounts to the same thing (you've done all the CM before sending the file and only require that the profile accurately represents the output). Only a very small percentage of photographers would bother unravelling this stuff, but labs that offer the service for reasons other than gimmickry may as well get their advice straight. Sticking to sRGB is less of a headache as long as it works.
     
  4. Waypoint Charlie

    Waypoint Charlie Active Member

    I'm afraid I've looked into this in far more depth than is healthy for my sanity!

    Actually, Loxley do colour manage. I believe they operate their machines in Fuji sRGB mode, as do DS and Sim Lab, but if you supply Loxley an sRGB file they definitely do not print directly to the machines in Fuji sRGB mode but perform conversion of the data. Loxley also claim to be able to accept files in Adobe RGB and ProPhoto RGB, although I've not tried it. I don't know whether this is performed at Loxley or by the company they enlist for their web interface. In any case, it would be counterproductive to supply them JPEGs in a wider gamut than sRGB, given they print in Fuji sRGB mode.

    DS and Sim Lab can probably accept files in Adobe RGB and ProPhoto RGB too (although again this would be counterproductive), but this is because LiveLink (the company who provide their web upload service) convert all files to sRGB. File conversion won't be physically performed at DS or Sim Lab.

    As I understand it, the Fuji Frontier machines can be operated in two modes. In PD (Printer Direct) mode it provides access to the full printer gamut, which in some areas exceeds sRGB. In sRGB mode the gamut is restricted to sRGB. It's this mode the labs use as, in theory, they can print an sRGB file without any colour management.

    However, there are some sRGB colours the Frontier printer cannot reproduce. e.g. saturated greens. Fuji therefore apply a rendering intent which aggressively attempts to maintain 'punch', at the expense of colour accuracy. This is probably to meet the expectations of the consumer mini lab market. I think the contrast is increased slightly, crushing shadows and highlights at bit, and the colour space is significantly warped in some areas in an attempt to maintain saturation. For instance, saturated greens are shifted towards yellow, because yellow is a colour that the printer is more able to reproduce with saturation. To avoid having two colour values printing the same physical colour (which would cause tonal flattening) they make space for the shifted greens by shifting yellows towards orange and oranges towards red. So you can end up in the situation of having a colour which is in gamut (e.g. a yellow rape field) being altered to make way for a colour which is out of gamut!

    Sending sRGB data to a Fuji sRGB printer is clearly fine for many people as they don't seem to complain. However, for those wanting better colour accuracy, it's possible to adjust the colour values before sending to the printer, either manually or automating using a profile. Loxley do this at their end with their profile, so you simply send them an sRGB file and let them get on with it. With DS you perform the conversion at your end using their supplied profile (this is similar to the generic Fuji Frontier sRGB profile but every lab will operate their machines with slightly different calibrations). The profile attempts to maintain the correct hue, even if this means desaturating the colour to the point where it becomes printable. Sim Lab don't provide profiles and they don't profile at their end. If you send Sim Lab an sRGB file, they print it as Fuji sRGB.

    Some people may not like the washed out look they'll get on some colours (e.g. saturated greens) when adjusting using a profile. I'll soft proof to the profile in Photoshop and use the gamut warning feature to detect any out of gamut colours. I'll then make adjustments to my image to pull all the colours into gamut, as I want them. This might mean tweaking the hue of out of gamut colours to increase saturation, but at least it's in my control and I don't have to alter the hue of colours that are in gamut. If you send out of gamut colours to a printer it's like giving them a blank cheque to do as they please!

    Below is an example. On the left is the original sRGB image. In the middle is how you could expect it to look if you send it directly to a Fuji sRGB printer (this is how it would look sending sRGB to DS or Sim lab). On the right is how it would look by performing profile conversion before sending to the printer (this is how it would look sending sRGB to Loxley or a profiled image to DS).

    Incidentally, you can soft proof in Photoshop how your sRGB image might look printed on a Fuji sRGB printer. Enter the Fuji_Frontier5-sRGB_CA-DPII_V3a profile as the 'Device to Simulate' and tick 'Preserve RGB Numbers'. The Fuji profile is available here (Crystal Archive Digital Paper Type DPII)

    https://www.fujifilm.eu/eu/support/photofinishing/color-management


    Profiling.jpg
     
    Last edited: Dec 21, 2018
    Bazarchie likes this.
  5. GlennH

    GlennH Well-Known Member

    Surely you wouldn't want to tick "Preserve RGB Numbers" in softproofing? Doing that is like applying the wrong profile under "Assign Profile". It causes a colour shift and effectively ditches colour management. Provided the lab is performing an sRGB>printer profile conversion, this is not what you'll see in the end result. Obviously you need to match the rendering intent to Loxley's as well.
     
  6. Waypoint Charlie

    Waypoint Charlie Active Member

    Perhaps in my long ramblings I didn't make it clear, in the case of DS and Sim Lab they do not perform an sRGB>printer profile conversion. As far as I can tell, they simply send the image file data directly to their Fuji Frontier machines, which they operate in Fuji's sRGB mode. If there's any colour management it will have been performed by LiveLink (the company handling the web uploads), and they will have converted to sRGB (if they've detected files are not already sRGB). LiveLink do not convert to the printer profile.

    Therefore, if you have the profile for the lab's machines (which will be similar to the generic Fuji Frontier sRGB profile), you can get a pretty good idea of how your sRGB files are going to look in print by soft proofing to that profile and ticking "Preserve RGB Numbers". Yes, that's like using "Assign Profile". Yes, what you're doing is seeing what happens when you apply sRGB profiled data to a device with a different profile.
     
  7. GlennH

    GlennH Well-Known Member

    My understanding has always been that there is a conversion in sRGB mode and that "no conversion" is only possible in PD mode--ironically more desirable but rarer. Your "Preserve Numbers" suggestion is supported at the bottom of this thread on Luminous Landscape as a way of previewing the apparently aggressive colour conversion. That seems to work in terms of producing a very saturated proof image with my old Loxley profile, but I'm not sure how the shoehorned colour minus any rendering intent works as a means of proofing if a conversion (with rendering intent) takes place. AFAIK most Frontier labs perform a blind sRGB>printer profile conversion in sRGB mode on the fly, but secondhand knowledge has its limitations.
     

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