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M.Chapman

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About M.Chapman

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Alamy

  • Alamy URL
    https://www.alamy.com/contrib-browse.asp?cid={72CEF26C-BD33-43B9-830D-8FE28CE464C7}&name=Mark+Chapman
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    4369
  • Joined Alamy
    12 Jan 2010

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  1. I've also been looking at doing some tests. I tried comparing sRGB versus aRGB versions of one of my Passport colour checker images on my monitor and printed out. I could see subtle differences on my monitor (calibrated HP23xi), but not in my printouts... (I've only got a Canon IP4200 with 5 inks CMY, Black and PhotoBlack). I thought I'd try a more severe test by creating a Granger Chart (takes 30sec in PS) which contains a very wide gamut. This has been much more illuminating and reveals there's so much mis-information out there. Many of the tests people describe are flawed and simply show what happens when you apply an aRGB or ProPhotoRGB profile to an image without converting the image data first. The differences between correctly rendered sRGB, aRGB and ProPhotoRGB are relatively small. But many tests take sRGB data and (incorrectly) render it as aRGB or ProPhotoRGB and then say "Wow - look at how much more colourful the results are" and therefore assume the differences are much more significant. It also needs to be remembered that soft proofing is just a "simulation" so may not represent actual results. I've just sent an email challenging one of the "expert's" comparison test results. If he comes back and confirms my observations I'll post some correctly produced Passport Colour Checker and Granger chart files saved as sRGB, aRGB and ProPhotoRGB image files so folks can draw their own conclusions on their hardware.. Mark
  2. +1 I recently bought a couple of my own images (to test whether Alamy supplies aRGB or sRGB) for personal use for £9.99. I was offered a full range of different resolutions all for the same price. It makes no sense to me.
  3. Another reason is; It will give you fewer images to keyword. Mark
  4. When was the last re-rank? I haven't seen any movement for ages, even though my CTR has been all over the place. Mark
  5. Wayback machine shows the following Alamy submission guidelines for contributors in 2008 here https://web.archive.org/web/20081222011649/http://www.alamy.com:80/contributors/stock-photography-technical-criteria.asp RGB files The issue of colour management for digital images is complex. To simplify things, Alamy asks contributors to submit images in RGB format. This is because the CMYK format has a smaller colour space, and so contains fewer colours. Unless you have reason to do otherwise, set your RGB "Color Settings" to "Adobe RGB (1998)" on both a Macintosh and a PC - this has become the defacto standard for most imaging professionals. By 2010 that advice changed and no longer appears to mention aRGB, for example see here https://web.archive.org/web/20101119110707/http://alamy.com/contributor/help/prepare-images.asp I couldn't spot any web-pages that stated contributors must use aRGB or that it was a QC requirement. However it's possible different advice was floating around on the forum or in emails at that time. Certainly I gained the impression when I joined Alamy that aRGB was required. So that's what I was submitting until recently. Personally I think it's a mistake to ship images without a profile. Although many systems will assume sRGB if there's no profile, Photoshop may not. If PS is set to use aRGB working space it will (depending on the colour preference settings) open sRGB images with missing profiles as if they are aRGB with no warning message. The customer then gets an incorrectly rendered (more saturated) image. It gets even worse if the customer is using ProPhotoRGB working space. Anyway it's good that current situation is now clear - thanks James. Please let us know if Alamy change their workflow. Mark
  6. Absolutely they are. IMHO the images I get from my Sony RX100 Mk III with 1" sensor have better IQ than my Lumix G& which has a Micro 4/3 sensor. Another factor that Alamy don't mention is the design of the sensor and micro-lens assembly. In general back side illuminated sensors (BSI) are better than front side as the sensor interconnections don't obscure the sensor elements. The micro-lens assembly is also important in focusing light onto each sensing element. As Alamy say, their guide is only a "rough guide". Another critical factor is how many pixels the sensor has. Too many pixels crammed into a small sensor will give more noise problems than a lower pixel count sensor of the same size. Mark
  7. Yes, I'm sure they asked for aRGB when I joined in 2010. So something doesn't quite add up, especially given their fairly recent comment "This is totally up to you and your own workflow, but we work with Adobe RGB and ignore any embedded ICC profiles when we process your images so before sending we recommend saving all images as Adobe RGB (1998)." Anyway the evidence is there, the images Alamy supply now are definitely sRGB with no profile and we have conformation from James Allsworth (Head of content). That's interesting. I wonder how I can test the effect it has on my home setup? A side by side comparison of 2 separate prints never really works for me, unless perhaps I chopped them up, but even then the joins get in the way. I wonder if I set PS to aRGB workspace and then create an image with a decent colour range from RAW. Then save a copy as sRGB, then reimport it as a new layer over the top of the original aRGB and then erase strips or areas in the sRGB top layer to reveal the aRGB underneath and then print it out to give a perfect integrated comparison. Would that work? I suppose the sRGB will be converted back to aRGB when I import as a new layer above an aRGB original, but the process of converting to sRGB, saving and then converting back to aRGB on import should cause loss of colour info. Mark
  8. Or at least corrected the early posting in this thread where Alamy are quoted as saying. "This is totally up to you and your own workflow, but we work with Adobe RGB and ignore any embedded ICC profiles when we process your images so before sending we recommend saving all images as Adobe RGB (1998)." That would have saved me buying two of my own images to check what was going on. I did at least get the commission though. 🙂 Mark
  9. I sought further clarification from Alamy as to whether the conversion from sRGB occurs when they receive our images, or only when they are supplied for download or display. I also asked why the profiles are stripped. This is the reply I have received. We convert on submission, we don’t store any aRGB profiles. We’ve always worked in this way and there has been no customer demand for an aRGB file. In the past, it may have been preferable to process using aRGB but in reality, as a contributor it’s down to your preference. The images will be displayed on Alamy as sRGB. We provide the images to the end user with the profile stripped because this is the most compatible and efficient way to do so. Software that supports colour profiles will assume that images without an embedded profile are in the sRGB profile. Software that doesn't support colour profiles will use monitor's profile, which is most likely to be sRGB as well in most cases. I queried this reply, as I felt sure that when I first joined Alamy (in 2010) Alamy asked for AdobeRGB format submissions and the SizeChecker application (NB. not an Alamy application) also gives a profile warning if the profile isn't AdobeRGB. I've just had a phonecall from James Allsworth at Alamy who confirmed that the answer in blue above is correct and has been at least since 2005 when he joined Alamy. So there's the definitive answer which James said he was happy for me to post here. (Thanks James) Mark
  10. Do a search in the forum for discoverability, there's lots of Q&A about it. Basically ignore discoverability, just add appropriate tags and supertags. Mark
  11. It's amazing how fast Alamy is approaching the end of the current sequence of 6 digit reference numbers that start with a letter. I wonder what will come next? 6 digit references starting with a number instead of a letter? 7 digit reference numbers? Hopefully Alamy's systems can handle an extra digit... Brings back memories of the Y2K software concerns. There's also the LR plugin. The total number of images doesn't seem to be going up at the same rate as the reference numbers are being used. This suggests a lot of deletions. I suppose that gives another possibility, that reference numbers of deleted images could be re-used? Mark
  12. I no longer use LR in my workflow (I hate having to import images into a LR catalogue which doesn't automatically update when I move files using file manager or any other app). The change in histogram is also a pain (carefully adjust tonal range in LR only to find it shifts when exporting to aRGB or sRGB). But I do use PS CC with inbuilt ACR. You're right about pixel editing, but in reality I very rarely revisit an image, and if I do I often find it's one I did a while ago and my standards have changed or improved so it's worth starting from scratch again. I may move away from PS CC before too long as I don't like the Adobe subscription model and other tools are almost good enough to do what I need (Affinity, On1, Acdsee, Pictorial and RawPower are all improving steadily). I'd swap back to PSE if it had auto CA removal. So keeping the RAWs and a default sRGB workflow work best for me at the moment. Mark
  13. I swapped to sRGB earlier this year because I find it simplifies my workflow Consistent colour rendering throughout Consistent histograms throughout End result (a single sRGB jpg file) is suitable for multiple libraries and matches what I saw on screen during editing without needing to "proof" With the web-based libraries I use I don't believe that aRGB would give more sales because the difference between correctly rendered aRGB and sRGB images on screen is very small and if clients aren't using a colour managed browser/viewer then sRGB will render better/more accurately. But I DO keep the RAWs so I can generate any format I want in future, or if a client requests. If I wasn't keeping the RAWs I'd be working in aRGB or higher and saving as 16 bit TIFFs. Mark
  14. Indeed, but that was presumably over 10 years ago, and Alamy are recently quoted as saying the following. To my mind there's no logic in requesting an aRGB file and then converting (downgrading) it to sRGB. Unless maybe Alamy believe they can do a better job of converting from aRGB to sRGB than anyone else? So I felt it was worth clarifying the latest position with Alamy, and I have now received this response (in blue) from Contributor Services. Here are some interesting articles on Adobe RGB vs sRGB: https://digital-photography-school.com/adobe-rgb-versus-srgb-color-space/ https://kenrockwell.com/tech/adobe-rgb.htm Our take on this is that pretty much everything on the internet uses sRGB - when we display images on our website we have to convert to sRGB. And to keep a consistent customer experience from viewing thumbnails and previews to buying and downloading the sales file we stick with sRGB. From the articles above there are no clear cut advantages in Adobe RGB when viewing on the web or printing. We accept that contributors will have their own preferred workflows and therefore for convenience will accept images using Adobe RGB and convert them sRGB. So assuming this latest statement is correct, the answer as to whether to submit AdobeRGB or sRGB to Alamy is that contributors should submit whatever is most convenient for them and Alamy will convert images to sRGB and then strip the profile. I hope that's helpful. I will ask Alamy to clarify whether this conversion happens on submission i.e. their database of our images contains only sRGB versions. If so they have no way of delivering (genuine) aRGB to clients even if they ask for them. Alternatively it's possible they store whatever we submit (sRGB and aRGB with complete with their profiles) and the conversion happens at the point of display or download. Mark
  15. OK I've just sent an email to Alamy Contributor Services explaining my findings. 1) Downloaded images have no embedded color profiles (that’s not good practice) 2) The aRGB image I uploaded appears to have been converted to sRGB before the profile was stripped. I included details of the tests I've carried out and copies of the original files I uploaded to Alamy. I'll let you know their response. Mark
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