sRGB and AdobeRGB

<p>One of our staff has been lucky enough to attract the interest of Corbis. On reading through the submission guidlines he has noticed that images need to be submitted as 50Mb tiff files using AdobeRGB colourspace.<br>

The question has been posed as to whether in setting up the picture controls in his D300, should be select AdobeRGB in-camera at that point of the workflow, or use sRGB in camera and convert later in Lightroom or CS5 before submission, given that not all his shots will be sent to Corbis?<br>

Anyone got some wise advice on this?</p>

<p>If he's shooting RAW then in-camera settings don't matter, and should be converted to aRGB in ACR or PS.</p>

<p>Ok...<br>

I think he's shooting Jpeg-large with zero sharpening, standard colour saturation and auto WB, as thats what the other agencies want. He doesn't want to spend more time on the computer than shooting.<br>

He's only just got LR3. Before, he just sucked the images into Breeze Browser, tweaked a minor amount and sent them off. Now he is looking a massaging the images into exactly the settings in Photoshop that Corbis designates and its very time consuming. But I see it from Corbis standpoint. They also don't want to spend a lot of time in post-processing either.<br>

Its a contrast to Reuters who just want your image at 300dpi, and jpeg as it comes out of the camera. They don't want any post by the photographer. They want to do it themselves. <br>

In reading a lot of the posts, it seems that sRGB is the most adopted colourspace, but Corbis say that their internal workflow software needs aRGB. Fair enough. He spoke to a couple of his colleagues who said that Corbis image requirements are more onerous that say Getty or Reuters.</p>

<p>Better to set the camera for Adobe RGB for the JPEGs, you can always convert to sRGB if the need arises. You can move from a larger to smaller gamut color space, not the other way. <br>

This may help:<br>

http://www.adobe.com/digitalimag/pdfs/phscs2ip_colspace.pdf</p>

<p>Why is he shooting jpegs when Corbis want Tiffs? Far better to shoot in raw and export from Lightroom in a colourspace/image type to meet Corbis' standards. Typically I've chosen to resize (via bicubic smoother) in PS. Just set the camera to make raws. </p>

<p>As far as i'm aware ( and I have contracts with both Getty and Corbis) the requirements for selected images are at the very least similar. Reuters are different- not really a stock agency in the true sense and are much, much closer to the final application/usage than Getty or Corbis. So sure, they will gear up to fit the image to the application themselves, as will most of Getty and Corbis' customers. But the stock agencies set out to provide their customers with the opportunity to buy a uniform product of high technical quality. The fact that most of the usages to which the images are put when sold do not demand a size anywhere near that which they ask their contributors to provide is irrelevent. As a contributor your colleague needs to meet their criteria or face having submissions rejected.</p>

<p>I guess it gives them flexility, starting off with a large tiff file...gives them the chance to downsize for a customer.<br>

Yes, a news agency wants the files as fast as possible, so large jpegs are easy straight out of the camera.</p>

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<p>- images need to be submitted as 50Mb tiff files using AdobeRGB colourspace.</p>

<p>- he is looking at massaging the images into exactly the settings in Photoshop that Corbis designates and its very time consuming</p>

 

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<p>What other settings do they require? Are you sure these are not something that can be set using the Export dialogue box in Lightroom? I would be surprised if the settings required could not be set as a Preset in Lightroom and as many images as required converted in one click without going into Photoshop. </p>

<p>For maximum flexibility he should be shooting in raw - the only downside then is the size of the files out of the camera. He should not set his camera to sRGB and then convert to Adobe RGB - as mentioned in an earlier post, there is no point in converting to sRGB in camera, and then to Adobe RGB later because sRGB is a narrower colour space than Adobe RGB. It is just as easy to convert from raw to Tiff than from jpeg to tiff. </p>

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<p>As per the Corbis guidelines.............</p>

 

 

 

<p>Digital Camera File Size Requirements

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<p> The recommended image capture file size is 50 MB, 8 bit RGB TIFF in Adobe RGB (1998)-Color Space (16.7 MB 8 bit gray scale Color Space "Dot gain 20%".) Maximum file size is 120 MB. Images should be fully processed. If the original capture is not 50 MB then the file will need to be non-destructively interpolated to 50 MB (please see 2.6. Interpolation / page 8). The best results for interpolation are obtained from professional cameras with a minimum capture size of 11 megapixels (approximately 33 megabytes). <br>

 

<p>File Format Requirements </p>

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TIFF in Adobe RGB (1998) Color Space (Grayscale Color Space "Dot Gain 20%) Image Compression should be set to: None Byte Order should be set to: Macintosh <br>

 

<p>Preview File Requirements (low res digital files for Editing of larger submissions) </p>

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<p>Preview files should be 1280 pixels on the largest dimension Preview files must be saved as a JPEG with a compression setting of 9 or higher </p>

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<p>IMO, set the camera to Adobe rgb. Take RAW photos, as even with jpgs they will need to be converted, so stick with RAW only to simplify the process. Taking RAW&jpg can confuse things a little. Lightroom can handle either format easily and it can be setup to export the photos into the file types and sizes they need. You have the tools to do the task with minimal effort once you learn how to use them.</p>

<p>Shadforth, I worked for Corbis until last year. They should still have a Photoshop Preflight plugin that you can get and run your images through from their site. It will tell you if it finds any faults otherwise they should be good to go. 50mb TIFF in Adobe RGB is all you need to worry about.<br>

<a href="http://studioplus.corbis.com/home/foyer.aspx">Corbis Studio Plus</a> has all the info you should need.</p>

<p>Isn't aRGB a larger color space than sRGB? If so, then shooting in sRGB and then converting to aRGB seems illogical as it completely misses the advantages of color capture in the larger space. </p>

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<p>Isn't aRGB a larger color space than sRGB?</p>

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<p>Yes it is. Converting from sRGB to Adobe RGB buys nothing and just adds time and data loss to the proposition. </p>

<p>Thanks Dave,<br>

Combining shooting Raw and setting up an Corbis export profile in LR is the answer.<br>

I had a read through their technical guidelines now too, and my eyes were bleeding by the end. Peter told me that they set all these parameters so that they have a technically consistent library.</p>

<p>I've had a look at the <a href="http://studioplus.corbis.com/DownloadableDocuments/Corbis_Technical_Guidelines_CommEd_v7_3.pdf"><em>Corbis Technical Guidelines: Commercial and Editorial Photography</em></a> (v7.3) and came across a strange instruction in point 2.4 "Over Sharpening" on page 7 -- <em>Do not sharpen your images in software. If overdone, sharpening introduces damaging artifacts.</em> -- while that's true, without any sharpening whatsoever, even really sharp images may look unacceptably soft.<br /> <br />Actually, I wanted to ask you guys something else: from the quality of the final print perspective, is it better to upsize an image to keep higher dpi at a given size, or stick to the native resolution and lower the dpi. I know this question is too general, so specifically:</p>

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<li>I was thinking about Corbis-recommended <a href="http://studioplus.corbis.com/DownloadableDocuments/Interpolation_Guidelines_v5.pdf">ACR interpolation</a> (takes place during RAW development)</li>

<li>The native resolution of my RAW files is 5184 x 3456 = 17.916 Mega pixels</li>

<li>ACR can produce files with pixel dimensions of 6144 x 4096 = 25.166 Mega pixels, ~40% increase</li>

<li>If I were to print 30" x 20" high gloss or metallic Durst Lambda, would I be better of interpolating during the RAW conversion so that I could print @ 200 dpi, or sticking with the native and printing @ 170 dpi ...or would there be no difference whatsoever even when scrutinized from up-close?</li>

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