Skip to main content
S
SNteach
Participant
March 31, 2018
Answered

Camera Raw Image Size

  • March 31, 2018
  • 1 reply
  • 1120 views

I am an Photo Elements instructor and one of my students sent me the following question about opening RAW images in Elements 2018.  Hopefully someone may have the answer.

"I have a conundrum.  I'm now using PE 18.  My Nikon DSLR camera is set to RAW images, which are almost 23 M.  I import these into the PE18 Organizer, where they are still 23 M raw images. Then I open one up in the Editor (expert).  Basically I am opening the image up in the Editor as Camera Raw.  Then, in the Editor I see the size of the image is now almost 69 M (68.7). 

How can this be? 

If I now save it as a TIFF, it's still almost 69 M.  (I save TIFF more often than PSD.)  These are images I may want to come back to later for more editing.

If I don't close this image and crop the image even a little and now save it as a 5" x 7" JPEG (Settings = Maximum, 12), it ends up as only around 3 M in size.   It used to be that when I saved an image as a 5" x 7" JPEG after cropping, it was maybe 8 to 12 M in size, even if I cropped a lot. I'm saving the images to JPEG with the same settings I always used to use in Photoshop Elements 14.  I save to JPEG when I'm all done editing that image and just want to save a final product on my hard drive.

Has something weird happened in PE 18?  Do you have this happening to your images in PE 16?  It's really strange to see a 23 M image blow up somehow to almost 69 M and then compress down to 3 M."

    This topic has been closed for replies.
    Correct answer John Waller

    I thought the camera RAW image was not compressed at all

    To be precise, there is no Raw image. Just data recorded to memory card when you take a picture. There are three options when storing Raw data files:

    • Uncompressed
    • Lossy Compressed (some image data discarded)
    • Lossless Compressed (no image data discarded)

    Lossless compressed is ideal since you can fit more "data" (=photos) on your memory card with no loss in data. Entry level Nikon cameras give you minimal options to change the Raw file saving method. High end Nikons offer all three.

    See https://photographylife.com/compressed-vs-uncompressed-vs-lossless-compressed-raw

    Which model Nikon camera do you have?

    When you open a compressed Raw data file, the Camera Raw plugin decompresses the Raw data file (there is no "image" at this stage - just mathematical data) and converts it to an RGB image to view on your monitor. The conversion process is complex but my simplistic understanding is that the Raw data is overlaid by a Bayer filter. Both Raw data+Bayer are used by Camera Raw to create the RGB pixels. So each 1MB of Raw data (with the Bayer filter added) converts to roughly 3MB on the hard drive (1 Red channel value, 1 Green channel, 1 Blue channel).

    So your 23MB lossless compressed Raw file on the memory card becomes roughly 69MB (file on hard drive) after conversion to RGB (including metadata) in Adobe Camera Raw and output as an image to Photoshop Elements.

    1 reply

    Jeff Arola
    Community Expert
    Jeff ArolaCommunity Expert
    Community Expert
    April 5, 2018

    The 69 M in size you see in the Editor is the size it would be on disk if you saved the image as an uncompressed TIFF.

    It's just an estimate and not always exact, but usually pretty close. PSD files retain the same info as tiffs, but are usually smaller in disk size because it uses more efficient lossless compression than the most popular LZW TIFF compression.

    What operating system are you using?

    Margaret Zabor
    Margaret Zabor
    Participating Frequently
    April 6, 2018

    (This is the student) I am using WIndows 10 on an HP Envy Laptop.  There were 2 questions: how/why did an almost-23 M camera RAW image end up as an almost 69 M image when I opened it in the Editor, and why were the saved JPEGs only about 3 M after minimal cropping and using the same settings as I had used with Photoshop Elements 14?   I'm still confused.  I thought the camera RAW image was not compressed at all, so why would it expand when opened in the Editor? I had a Chat with an Adobe representative who remotely accessed my laptop and had the same results.  Thank you.  Marge

    John Waller
    Community Expert
    John WallerCommunity ExpertCorrect answer
    Community Expert
    April 7, 2018

    I thought the camera RAW image was not compressed at all

    To be precise, there is no Raw image. Just data recorded to memory card when you take a picture. There are three options when storing Raw data files:

    • Uncompressed
    • Lossy Compressed (some image data discarded)
    • Lossless Compressed (no image data discarded)

    Lossless compressed is ideal since you can fit more "data" (=photos) on your memory card with no loss in data. Entry level Nikon cameras give you minimal options to change the Raw file saving method. High end Nikons offer all three.

    See https://photographylife.com/compressed-vs-uncompressed-vs-lossless-compressed-raw

    Which model Nikon camera do you have?

    When you open a compressed Raw data file, the Camera Raw plugin decompresses the Raw data file (there is no "image" at this stage - just mathematical data) and converts it to an RGB image to view on your monitor. The conversion process is complex but my simplistic understanding is that the Raw data is overlaid by a Bayer filter. Both Raw data+Bayer are used by Camera Raw to create the RGB pixels. So each 1MB of Raw data (with the Bayer filter added) converts to roughly 3MB on the hard drive (1 Red channel value, 1 Green channel, 1 Blue channel).

    So your 23MB lossless compressed Raw file on the memory card becomes roughly 69MB (file on hard drive) after conversion to RGB (including metadata) in Adobe Camera Raw and output as an image to Photoshop Elements.

    Terms & ConditionsAccessibility statement
    Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices