light shaper~image maker

By jcwilson

Geek Blip Update

My bad. Carelessness on my part.

Non-geeks read no further, just know that unless your images have an an embedded sRGB color profile (or no profile) they will NOT render correctly on blipfoto.com.

My workflow is to shoot in raw format (except of course with the iPhone), open images in ACR (Adobe Camera Raw) to do most adjustments, then bring into Photoshop to do more creative stuff. (Since I'm a Mac user, I sometimes use Aperture 3 instead, because I've got NIK plug-ins for it, and Silver Effects 2 is great for B/W images.) Anyway, ACR is set to 16 bit mode, in order to work with the camera's full 14 bit data. A short while ago I realized that ACR should also be set to ProPhoto RGB color space for the same reason - it is the largest color space and will thus include all of the camera sensor's data. Thus, when the image is opened in Photoshop it comes in as a 16 bit, ProPhoto file. All these bits are important to have if you're going to make multiple levels and curves adjustments. Fewer undesirable artifacts will creep in when you have more data to work with. But when you're finished tweaking, unless you're making exacting, professional grade prints on a high end printer, all those extra bits do nothing for you other than create hugh, memory hogging files. Your display can't show the information and most printers can't print it. So you toss the superfluous data out by converting the image to 8 bits and sRGB color space. You can manually convert to 8 bits or automatically convert when you save as a jpeg file. However, in Photoshop, the color space conversion is only a manual operation. Dummy me, for several days now, failed to read Photoshop's explicit message when saving as a jpeg that the embedded color profile would be ProPhoto.

Which brings us to why yesterday's blip doesn't look right on blipfoto.com but does look right on my Apple Gallery. It looks right on my Gallery because Safari (Firefox and Explorer as well) are smart browsers, read the image's embedded profile and display the image correctly. Blipfofo.com on the other hand apparently does not honor the embedded profile. It either ignores or strips the embedded profile and applies a sRGB profile. How do I know this? Because, in Photoshop, if you APPLY (not CONVERT) a sRGB profile to a ProPhoto image you get exactly the same color shift as seen on blipfoto.com. Note, there's a big difference between APPLY and CONVERT a profile. A very lucid and complete explanation can be found HERE (click on: SEE COLORMANAGEMENT IN ACTION Color Management Web tutorial) and HERE.

Many folks use Adobe RGB as their working color space. If you do, it's important to understand that unless you CONVERT the image you're going to Blip to sRGB, it WILL NOT render correctly on blipfoto.com. The difference won't be as great as what I experienced with a sRGB profile applied to my ProPhoto image because the difference between Adobe RGB and sRGB isn't as great, however there will definitely be a difference.

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