Shooting in RAW

[rongwei82]

Hi, i was just wondering if from RAW convert to JPEG, will the file be compressed and will the photo quality drop? (eg. Not as sharp and clear)

Is there any way to retain the sharp and clear images even thou after convertion?

[zac08]

Originally Posted by rongwei82 Hi, i was just wondering if from RAW convert to JPEG, will the file be compressed and will the photo quality drop? (eg. Not as sharp and clear) Is there any way to retain the sharp and clear images even thou after convertion?

USM. (UnSharp Mask)

There are a few methods used. Google and see which you would prefer.

[calebk]

Definitely - JPG is compressed while RAW is not.

That said, most people cannot even tell the difference after conversion. If your photo has plenty of detail to begin with, even a JPG will still have much of that detail.

[David Kwok]

Originally Posted by calebk Definitely - JPG is compressed while RAW is not. That said, most people cannot even tell the difference after conversion. If your photo has plenty of detail to begin with, even a JPG will still have much of that detail.

RAW can be compressed too. lossless or lossy, available in Nikon cameras. Not sure if all, but at least I found in D300, D700 and D3.

[lennyl]

Originally Posted by rongwei82 Hi, i was just wondering if from RAW convert to JPEG, will the file be compressed and will the photo quality drop? (eg. Not as sharp and clear) Is there any way to retain the sharp and clear images even thou after convertion?

1. RAW can be compressed. For Canon the compression is lossless. I don't know about Nikon personally.

2. JPEG, even with lossy compression, can be sharp and clear, if you start with a sharp and clear image obviously. It is multiple editings and savings that lead to degradation. If you need to continuously open a JPEG, edit and save it back, don't use JPEG. Use it only for the final save.

3. You have a number of choices for lossless image format. You can save as TIFF, in PNG, in lossless JPEG (this is different from JPEG with maximum quality setting), or one of the proprietary format of your editor (e.g. PSD if you're using Photoshop).

My suggestion : always keep the RAW, but have a JPEG version for ease of use.

BTW the keyword here is lossless vs. lossy, not compression.

[windwaver]

Originally Posted by rongwei82 Hi, i was just wondering if from RAW convert to JPEG, will the file be compressed and will the photo quality drop? (eg. Not as sharp and clear) Is there any way to retain the sharp and clear images even thou after convertion?

It wouldn't be that bad after conversion unless you set the compression for JPG too high (e.g. 80% compression vs 20%).

[calebk]

Originally Posted by David Kwok RAW can be compressed too. lossless or lossy, available in Nikon cameras. Not sure if all, but at least I found in D300, D700 and D3.

Originally Posted by lennyl 1. RAW can be compressed. For Canon the compression is lossless. I don't know about Nikon personally. 2. JPEG, even with lossy compression, can be sharp and clear, if you start with a sharp and clear image obviously. It is multiple editings and savings that lead to degradation. If you need to continuously open a JPEG, edit and save it back, don't use JPEG. Use it only for the final save. 3. You have a number of choices for lossless image format. You can save as TIFF, in PNG, in lossless JPEG (this is different from JPEG with maximum quality setting), or one of the proprietary format of your editor (e.g. PSD if you're using Photoshop). My suggestion : always keep the RAW, but have a JPEG version for ease of use. BTW the keyword here is lossless vs. lossy, not compression.

I see. So sRAW is lossless compression. Am I right to say this?

In any case, you will have to finally save as a JPG for web upload, for distribution, for emailing out to people for common viewing. I wouldn't expect everyone to have a RAW viewer.

[Lucian]

sRAW means small RAW, ie. a smaller-sized RAW file. Nothing to do with whether it is lossy/lossless.

[lennyl]

Originally Posted by calebk So sRAW is lossless compression. Am I right to say this?

I don't have the exact details of sRAW. Most people seem to agree that for earlier cameras, 4 GRGB pixels are combined to form one RGB pixels in a sRAW file. That would explain why it has 1/4 the pixels but around 1/2 the size. The subsequent compression is lossless. I haven't figured out how the 50D's sRAW1 with 1/2 the pixels is created.