Working with Lightroom and Photoshop file size difference
DeneysParticipantMay 17, 2013 at 8:32 amPost count: 739
Has anyone else noticed the huge difference in file size when working in Lightroom & Photoshop compared to Photoshop only.
I open the Raw file (NEF D800) which opens first in Camera Raw 7.4. I do my basic changes, then click “open image”. It then opens in photoshop and asks to do a Colour space conversion. I convert it from Adobe RGB to working space Prophoto RGB. Once open I do a content-aware fill on a small aria (Bit of the soft box showing in photo) once done, I save the projects as a photoshop PSD file or Tiff.
File size of PSD file is 99MB
File size of TIFF file is 108MB
Lightroom and Photoshop
In lightroom I do my basic changes. I then right click on the photo and click on “edit in/Photoshop” it then opens in photoshop with out asking to do a colour space conversion (as LR is Prophoto RGB)
I do the content-aware fill on the small aria and save the projects as a photoshop PSD file or Tiff.
File size of PSD file is 216MB
File size of TIFF file is 216MB
Why the +- 100MB difference ?
DeneysParticipantMay 17, 2013 at 10:44 amPost count: 739
Ok I tried to see what would happen if I did it on a separate layer and saved it like that…… now I know they say its only zero’s and one’s but the file size once saved is 723MB.
Madness…. lets round that off to 1GB for a project that’s 128 projects and my terabyte is full.
Dave_ParticipantMay 17, 2013 at 1:44 pmPost count: 472
I have noticed a similar thing. Tiff files are bigger than PSD, not 100% sure why though. But when going from LR to Photoshop, I have learn’t to always “flatten” the image before saving back to LR. Otherwise the file size is huge.
The problem is worse when you edit in a plugin like Nik software, you just get a big tiff and no real way to reduce the size. Unless you edit in PS, use the plugin in PS, flatten the image and save back. However, the files are still huge (usually over 100MB).
I am not sure there is a fix, as I have searched before. The usual “solution” is that “HDD’s are so cheap today, just buy more!”. Not really what we are looking for.
HeinrichRParticipantMay 17, 2013 at 1:53 pmPost count: 630
Suggestion, What is the file size when you set ACR to pro photo ( on the bottom of the window is a blue link in ACR if I remember correctly dont have PS with me) and export it from ACR as prophoto and not as Adobe, could it loose data because you use adobe from the raw file and then convert to prophoto is CS?, where LRoom uses prophoto from the beginning (I dont know the difference between a ADOBE and PRO photo ‘s file size )
SteveGParticipantMay 17, 2013 at 7:15 pmPost count: 616
Putting out Adobe rather than ProPhoto from ACR will make no difference.
What’s happening is that from ACR you opened an 8-bit image and from LR you exported a 16-bit image.
8-bit gives you a file that’s 3x your MP count. 36×3= 108mb
16-bit it’s 6x your MP count.
The difference between the PSD and TIFF file sizes is down to lossless compression. The PSD probably has LZW or more likely ZIP compression in it while for the TIFF you have set no compression.
Also: if your working space is ProPhoto then just tell ACR to go directly to ProPhoto and save yourself the conversion step. You’ll also reduce the chance that you’ll clip colours that are in your capture, but don’t fall within AdobeRGB. Not many real world colours that do this, but there are some.
DeneysParticipantMay 20, 2013 at 7:10 amPost count: 739
Thanks Leo, Dave and Heinrich for your help.
Steve you are correct LR exports it as a 16bit ProPhoto and PS converts it to a 8bit ProPhoto. If I do what Heinrich suggested and change the settings in ACR to 16bit ProPhoto both files are the same size.
Just going to have to get some more HDD’s
Thanks again to all
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