Raw to tiff??

Discussion in 'Digital Discussion & Q&A' started by domromer, Feb 1, 2008.

  1. domromer

    domromer TPF Noob!

    Joined:
    Aug 11, 2007
    Messages:
    878
    Likes Received:
    0
    Location:
    Eugene, Oregon
    Can others edit my Photos:
    Photos NOT OK to edit
    For the past few days I've been organizing my pics in lightroom. I'm still trying to figure out my workflow. I've been shooting a ton or raws lately and can't decide whether to save them as raws. Then only save a tiff if I end up tweaking them, then finally make a jpeg out of the tiff if I need one.

    So today I started to convert raws to tiffs. My raw files are around 6-8megs each. Where the converted tiffs are around 20 megs. How is this? I though a raw was an unprocessed jpeg. Why are the tiffs so much bigger?
     
  2. Alex_B

    Alex_B No longer a newbie, moving up!

    Joined:
    Aug 30, 2006
    Messages:
    14,491
    Likes Received:
    206
    Location:
    Europe 67.51°N
    Can others edit my Photos:
    Photos NOT OK to edit
    they are 16 bits, which already makes some difference as RAW data is either 12 or 14 bits usually.

    also, depending on the RAW format there is lossless compression of data.
     
  3. domromer

    domromer TPF Noob!

    Joined:
    Aug 11, 2007
    Messages:
    878
    Likes Received:
    0
    Location:
    Eugene, Oregon
    Can others edit my Photos:
    Photos NOT OK to edit
    That being said, why do more people seems to convert raws to tiffs for storage rather than save the raws?
     
  4. Alex_B

    Alex_B No longer a newbie, moving up!

    Joined:
    Aug 30, 2006
    Messages:
    14,491
    Likes Received:
    206
    Location:
    Europe 67.51°N
    Can others edit my Photos:
    Photos NOT OK to edit
    - because there is a standard for TIFF, but not for RAW. All RAW formats are totally different. If you dig your archives in 10 years time, you might be happy to have the TIFFs ;)

    nevertheless, one should archive the RAW data as well, since you might want to reprocess them with different settings one day.
     
  5. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

    Joined:
    Dec 16, 2003
    Messages:
    33,822
    Likes Received:
    1,811
    Location:
    Edmonton
    Can others edit my Photos:
    Photos NOT OK to edit
    As far as I know...you don't or can't save RAW files. A RAW file is just the data from the camera (with an embedded JPEG so that you can see it). So once you open/convert the RAW file...it must be saved as something (JPEG, TIFF, PSD etc).

    Now with Lightroom...it's a different story. Lightroom is a non-destructive workflow, so when you open a RAW file and make adjustments...it doesn't actually make changes to the image. What it does is to save the changes/adjustments that you made.

    I'm not sure if Lightroom embeds this info into the file or if it saves a separate file but the point is that anything you do in Lightroom, won't damage the integrity of the image because you aren't actually making changes to the file.

    When you do save (output) the image...then lightroom applies the changes to the image. So, as I understand it, you don't need to save the file in an image format until you have a reason to do so. If you plan to work on the image again later, just keep it in Lightroom (save the changes) and then when you open it again, you will only be editing the changes.

    As for why TIFF files are so big (PSD files as well)....I'm not sure. I think it's because they are actual image files, which need to have a lot more information...RAW files are just the gibberish that comes out of the camera.
     
  6. kittymaguire

    kittymaguire TPF Noob!

    Joined:
    Sep 24, 2007
    Messages:
    73
    Likes Received:
    0
    Location:
    Amsterdam
    Can others edit my Photos:
    Photos NOT OK to edit
    In Lightroom you have two choices when you import images, the first is to keep the raw format, any changes made to the image will then be stored in a separate file, the 2nd is too import as dng which is Adobe's digital negative format. Changes made to the image by Lightroom will be written to the dng file but in such a way that Lightroom will be able to revert to the original as shot image.

    The tiff is bigger because it is an agreed standard were as the raw format varies between cameras which means that the camera manufacturers can take short cuts when writing the image data.

    If you are using Lightroom to manage your work flow then don't keep to store your images as tiffs. You can export the tiff or jpg only when you need to use them.
     
  7. EOS_JD

    EOS_JD TPF Noob!

    Joined:
    Feb 15, 2007
    Messages:
    1,698
    Likes Received:
    0
    Can others edit my Photos:
    Photos OK to edit
    One thing that has not been mentioned here is that RAWs are actually Compressed files. it has nothing to do with tif being an agreed standard or that they are actual image files... they both just hold digital information. So this is the reason file sizes are smaller than for the tifs you export. All manufacturers RAW images are different sizes and I think this is down to how each compresses their files.

    Also your converter will normally create an uncompressed (24-bit) TIFF files, so they'll be larger. A 24 bit RGB file has three 8 bit colour channels - 3 channels x 8 bits = 24bit image.

    Do you export your tifs as compressed files? You normally have the option of LZW compression which is a lossless way of compressing the tif image and reducing your file size.

    What bit depth do you export as? 8bit or 16bit? By exporting a 16 bit image, this will create a 48-bit TIFF(16 x 3 channels - RGB) file that retains the full dynamic range of the raw file.

    These files will be double the size of the 24 bit files.
     
  8. Alex_B

    Alex_B No longer a newbie, moving up!

    Joined:
    Aug 30, 2006
    Messages:
    14,491
    Likes Received:
    206
    Location:
    Europe 67.51°N
    Can others edit my Photos:
    Photos NOT OK to edit
    Has been mentioned, first reply ;)
     
  9. EOS_JD

    EOS_JD TPF Noob!

    Joined:
    Feb 15, 2007
    Messages:
    1,698
    Likes Received:
    0
    Can others edit my Photos:
    Photos OK to edit
    Also to add.... Everyone should keep their RAW files. To delete them is crazy. I don't believe many do though.

    I keep the RAWs and convert to jpg. Do my edits then save only once. It's rare that I need a tif unless I need to save and come back to a file. JPGs generally work fine for me though - Even with a little loss (which is never noticed).

    I've got to the stage that unless I edit in photoshop, I don't save the jpg or tif and keep only the RAWs. Lightroom is used more now than photoshop in my workflow.
     
  10. EOS_JD

    EOS_JD TPF Noob!

    Joined:
    Feb 15, 2007
    Messages:
    1,698
    Likes Received:
    0
    Can others edit my Photos:
    Photos OK to edit
    Sorry Alex. Must have read it differently in my eagerness to respond! :)
     
  11. Alex_B

    Alex_B No longer a newbie, moving up!

    Joined:
    Aug 30, 2006
    Messages:
    14,491
    Likes Received:
    206
    Location:
    Europe 67.51°N
    Can others edit my Photos:
    Photos NOT OK to edit
    np :)
     
  12. Helen B

    Helen B TPF Noob!

    Joined:
    Sep 16, 2007
    Messages:
    3,296
    Likes Received:
    465
    Location:
    Hell's Kitchen, New York
    Can others edit my Photos:
    Photos NOT OK to edit
    I don't think this has been mentioned in detail before in this thread, though Big Mike has touched on it, so here goes: Raw files from a normal Bayer-pattern sensor have only one channel per pixel. Each pixel has only luminance data - the colour data are added and interpolated during the conversion.

    The Raw files can be uncompressed, losslessly compressed or slightly lossily compressed depending on the camera and the options available.

    Best,
    Helen
     

Share This Page

Search tags for this page

aw versus tiff

,

create a 48-bit rgb

,

lightroom tiff too big