Skip navigation
This discussion is archived
Currently Being Moderated

Can I reduce a RAW file size for email?

Apr 13, 2012 10:59 AM

Tags: #camera_raw

How can I reduce a 64 Mb. ACR file to about 1 Mb. to email to students for an exercise?

 
Replies
  • Currently Being Moderated
    Apr 13, 2012 12:04 PM   in reply to grprt

    You can't.

     
    |
    Mark as:
  • Currently Being Moderated
    Apr 13, 2012 2:39 PM   in reply to grprt

    Actually in LR4 and Camera Raw 7 in Photoshop CS, you CAN create a downsampled DNG by using the Lossy Compression method of converting to DNG. In the LR 4 Export, select DNG then you have the ability to specify long dimensions or the size in Megapixels. Note, a Lossy DNG isn't un-demosiaced, it's been demosiaced but is still stored in Linear Gamma, so it's like a partially baked file, not a true unbaked raw file.

     

    Note, in Camera Raw 7 when you set up your save dlog, it's a bit different. You select Lossy DNG and then have a dropdown for size presets...

     

    Couple of things about the Lossy DNG, you SHOULD name it to distinguish between the downsampled DNG and your original DNG...you don't want to get into the situation where you overwrite your original. Also note that some things won't work totally as expected. For example, sharpening and noise reduction will be working but on a downsampled file. While the numbers will correlate, the actual effects will be a bit different because it's a downsampled file and more prone to potentially over sharpening. It all works, and the controls will work fine if you work at 100% zoom, but don't expect the high resolution your original file had.

     
    |
    Mark as:
  • Currently Being Moderated
    Apr 13, 2012 3:42 PM   in reply to grprt

    I suggest putting the file(s) on a webserver instead, and send your students a link.

     

    If you don't have your own web server, you can borrow one from you-send-it, etc...

     
    |
    Mark as:
  • Currently Being Moderated
    Apr 13, 2012 4:39 PM   in reply to grprt

    64MB is big. What's it from?

     
    |
    Mark as:
  • Noel Carboni
    23,469 posts
    Dec 23, 2006
    Currently Being Moderated
    Apr 13, 2012 7:21 PM   in reply to grprt

    Upload it to a web site and send them the link.

     

    Oops, I see Rob's already suggested this.  +1 to that!

     

    -Noel

     
    |
    Mark as:
  • Currently Being Moderated
    Apr 13, 2012 7:32 PM   in reply to grprt

    Even with Jeff Schewe's brilliant workaround, you just can't get from 64 MB to 1 MB and still retain a semblance of raw capture quality.

     

    Yes, 64 MB is one huge raw file.  The raw files from my MF Pentax 645d are around 40 MB.

     

    Other posters have already mentioned free services like yousendit.com.  You may also want to look into Dropbox.

     
    |
    Mark as:
  • Noel Carboni
    23,469 posts
    Dec 23, 2006
    Currently Being Moderated
    Apr 13, 2012 7:41 PM   in reply to station_one

    I wouldn't try to eMail even a 1 MB file to a whole list of people, by the way, especially not if it's important. That's not as outrageous a size as it used to be, but it's still possible it will overload someone's setup or simply be lost or corrupted in transit.

     

     

    Someone with students may be part of an organization that already has a web server.  Even an individual can easily afford the paltry fee to get a domain and the $3 a month it costs to rent services from a web server company with essentially unlimited storage.

     

    -Noel

     
    |
    Mark as:
  • Currently Being Moderated
    Apr 13, 2012 7:41 PM   in reply to Noel Carboni

    There are a few free services out there, MediaFire is one example, more than enough storage for a project like this all you need to do is ignore the adverts. I quoted one, but there are others a quick search on Google will give more alternatives.

     
    |
    Mark as:
  • Currently Being Moderated
    Apr 13, 2012 8:13 PM   in reply to station_one

    station_one wrote:

     

    Even with Jeff Schewe's brilliant workaround, you just can't get from 64 MB to 1 MB and still retain a semblance of raw capture quality.

     

    Actually, you can.

     

    Have you tested Lossy Compressed DNG? It's very interesting....the one thing you obviously loose is resolution if you downsample, but all the other raw processing controls work as exected.

     

    And note it's not my "brilliant workaround", it's a new feature designed by Thomas Knoll and the ACR team. You would be suprised at how well the lossy compression works even if you don't downsample and maintain full resolution. APhase One P-65+ 60 MP capture as a regular DNG is about 68-69 MBs. When the full size rez is saved as a lossy compressed DNG it drops down to 22 MBs. A downsampled 20 MP lossy DNG is down to 7.3 MBs and a 10 MP lossy DNG is further lowered to 3.8 MBs. And that's a DNG from a 60 MP camera that still retains ACR editing (and can allow exchanging .xmp editing metadata with the original). You can do a lot with 10MP capture size. Yes, it's not down under 1 MBs...but at 3.8 MBs, it's easily emailable...

     
    |
    Mark as:
  • Currently Being Moderated
    Apr 14, 2012 5:45 PM   in reply to Jeff Schewe

    Thanks for elaborating.

     
    |
    Mark as:

More Like This

  • Retrieving data ...

Bookmarked By (0)

Answers + Points = Status

  • 10 points awarded for Correct Answers
  • 5 points awarded for Helpful Answers
  • 10,000+ points
  • 1,001-10,000 points
  • 501-1,000 points
  • 5-500 points