Results 1 to 9 of 9

Thread: Shooting in RAW

  1. #1
    Member rongwei82's Avatar
    Join Date
    Oct 2006
    Location
    Singapore
    Posts
    151

    Default Shooting in RAW

    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?


  2. #2
    Senior Member zac08's Avatar
    Join Date
    Feb 2005
    Location
    East
    Posts
    11,755

    Default Re: Shooting in RAW

    Quote Originally Posted by rongwei82 View Post
    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.
    Michael Lim
    My Flickr Site

  3. #3
    Senior Member
    Join Date
    Jul 2006
    Location
    Clementi
    Posts
    10,596

    Default Re: Shooting in RAW

    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.

  4. #4

    Default Re: Shooting in RAW

    Quote Originally Posted by calebk View Post
    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.
    D3S|N70-200|N24-70|N24-85|N50f1.4|N35f2|SB800|SB900|Yashica GS|S95
    www.flickr.com/photos/davidktw

  5. #5
    Member lennyl's Avatar
    Join Date
    Mar 2008
    Location
    Northern California
    Posts
    1,520

    Default Re: Shooting in RAW

    Quote Originally Posted by rongwei82 View Post
    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.
    Last edited by lennyl; 25th September 2008 at 04:56 AM.

  6. #6

    Default Re: Shooting in RAW

    Quote Originally Posted by rongwei82 View Post
    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%).

  7. #7
    Senior Member
    Join Date
    Jul 2006
    Location
    Clementi
    Posts
    10,596

    Default Re: Shooting in RAW

    Quote Originally Posted by David Kwok View Post
    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.
    Quote Originally Posted by lennyl View Post
    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.

  8. #8

    Default Re: Shooting in RAW

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

  9. #9
    Member lennyl's Avatar
    Join Date
    Mar 2008
    Location
    Northern California
    Posts
    1,520

    Default Re: Shooting in RAW

    Quote Originally Posted by calebk View Post
    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.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •