A little disheartened to say the least

[brianw999]

Jid,

Well now, there's something new for me to try.
Must admit that when I overexposed in the past, using RAW, I'd bin the pic at the time of shooting on looking at the preview, before ever getting to the computer, thinking that I'd blown the whites.

Brian.

PS. Thanks for the PM.

[cja]

To add to what Jid has said.


· An image has three colour channels, Red, Green and Blue. In JPEG format if one channel is blown out all channels in the relevant pixel will default to white. In RAW only the colour channel that is blown will default to white which means that up to two colour channels remain. Photoshop can then use the remaining data to interpret how the pixel should actually be. Thus you have a chance of recovering highlight detail that might otherwise appear to be blown.

· More than half the image data in Raw is devoted to highlights, which again gives you a hand in recovering the detail. Very little data is devoted to shadows so by underexposing you create the problems shown in this image. The white paint on the Bus is nicely exposed but all else is well under exposed and there is no hope of recovering any of the detail in those Black engine intakes. So by setting exposure compensation to 0 or even over exposing as JID suggests you have the chance of getting the best of both worlds, (ie both shadow and highlight detail).

also

· When you shoot in RAW you are shooting a 16 bit image rather than the 8 bit image produced by JPEG. This means that the image contains about four times as much data (I think) as JPEG. This provides much greater latitude for editing purposes.