Unless my eyes deceive me I can see quite a difference in sharpness between an image saved by the camera as a JPEG and the same subject converted from RAW taken at the same time. Perhaps someone could tell me whether this is possible or are my eyes being deceived by some other difference between the two images.

Norman

I forgot to say that the JPEG is sharper than the RAW conversion.

Norman

Hi norman,

It certainly is possible -- I assume your jpeg is the blurry one, and both pictures were taken with a tripod so no chance of accidental blur -- then it's a matter of what quality you have it set to - on my camera it needs to be Fine or better.; For RAW, that kind of option is irrelevant and meaningless, you always get exactly the pixels the camera saw.

HTH

On Mon, Mar 31, 2008 at 12:38 AM, norman wrote:

Unless my eyes deceive me I can see quite a difference in sharpness between an image saved by the camera as a JPEG and the same subject converted from RAW taken at the same time. Perhaps someone could tell me whether this is possible or are my eyes being deceived by some other difference between the two images.

Norman

Okay, in that case I have no idea what is happening there.

On Mon, Mar 31, 2008 at 12:47 AM, norman wrote:

I forgot to say that the JPEG is sharper than the RAW conversion.

Norman

If it is a common case, not some particular image, the difference is obvious: in-camera image processing includes noise reduction (blurring) and sharpening. The resulting image look and feel is a result of combination of NR and sharpening, acting in contrary directions. If you use UFRaw for RAW conversion, it has noise reduction (disabled by defaults) and has no sharpening.

David Gowers wrote:

Okay, in that case I have no idea what is happening there.

On Mon, Mar 31, 2008 at 12:47 AM, norman wrote:

I forgot to say that the JPEG is sharper than the RAW conversion.

Norman

Could it be that your camera sharpened the JPEG quite aggressively and you did not sharpen the result of the RAW conversion?

That could very well be the reason. I had forgotten that there is sharpening going in the camera with JPEG which, of course, does not happen with RAW.

Norman

Hi,

On Sun, 2008-03-30 at 15:17 +0100, norman wrote:

I forgot to say that the JPEG is sharper than the RAW conversion.

Most cameras do some sort of pre-processing which usually involves sharpening the image. One of the main points of using raw images is that no such pre-processing is done.

Sven

On Mon, Mar 31, 2008 at 1:49 AM, Sven Neumann wrote:

Hi,

On Sun, 2008-03-30 at 15:17 +0100, norman wrote: > I forgot to say that the JPEG is sharper than the RAW conversion.

Most cameras do some sort of pre-processing which usually involves sharpening the image. One of the main points of using raw images is that no such pre-processing is done.

Actually, yes. Norman, i now recall that it's a fairly standard thing for serious digital photography, to run the final result through 'unsharp mask'.

for example, here: http://www.aim-dtp.net/aim/techniques/linear_raw/index.htm unsharp mask is used (in Photoshop) with r= 5, a=500, t=0. (I think a=500 in Photoshop terms is 0.5 in GIMP terms)

Hope that helps.