TIFF files enlarge after saving

[robgo2]

I have noticed that my TIFF files balloon in size whenever I save them.  For instance, a particular file may be 185MB when open with layers in CS6, but it increases to 317MB when I save it as a TIFF.  If I use ZIP compression, it may be reduced to 285MB.  Is this normal behavior?

Thanks,
Rob

[Schewe]

How many channels/layers? The size when open is assuming a flattened pixel dimension, but adding layers and channels increases the final saved file on disk.

[xpatUSA]

I have noticed that my TIFF files balloon in size whenever I save them.  For instance, a particular file may be 185MB when open with layers in CS6, but it increases to 317MB when I save it as a TIFF.  If I use ZIP compression, it may be reduced to 285MB.  Is this normal behavior?

Sorry, I didn't quite get whether the file 'when open' was a TIFF or not, before "saving as"?

My own humble experience is that a 3.86MB X3F file opened today in DCraw saved as a 9.81MB TIFF uncompressed. A growth ratio of 2.54 for that particular file.

[robgo2]

The files opened in Photoshop are unflattened TIFFs.  The file size that I quoted for them includes all open layers and channels.  Why would the size increase when the file is saved?  FWIW, the original raw files start at roughly 25MB.

Rob

[xpatUSA]

The files opened in Photoshop are unflattened TIFFs.  The file size that I quoted for them includes all open layers and channels.  Why would the size increase when the file is saved?  FWIW, the original raw files start at roughly 25MB.

Sorry Rob, I've never used layered TIFF's, so I don't know enough to answer the question.

[tar4heel2]

Some clarification is needed here; are you opening RAW files and saving to TIF?  I assume that's what you're doing.

There are potentially two scenarios at work here:

1) Saving to 16-bit TIF will increase your file size due to the increase bit depth.
2) As mentioned before, saving multiple layers will increase your file size tremendously.  Your Photoshop should be warning you the file size is larger when saving as TIF with multiple layers open.  If you're not getting this warning, it's definitely the difference in 16 bit TIF.

[Dave (Isle of Skye)]

I have noticed that my TIFF files balloon in size whenever I save them.  For instance, a particular file may be 185MB when open with layers in CS6, but it increases to 317MB when I save it as a TIFF.  If I use ZIP compression, it may be reduced to 285MB.  Is this normal behaviour?

Thanks,
Rob

Hi Rob,

I think this may be the same thing that I noticed on my own files a while back and wondered as you do, what was causing the ballooning file size problem.

The solution I found was to make sure that you have all the layers flattened to a 'Background' layer at the end of your processing and before you commit to a file save. Just merging layers down or using the short cut keys Ctrl+E or Ctrl+Shift+E etc, does indeed appear to flatten the layers into a single layer, but it does not flatten them into a 'Background' layer and there is a huge size difference as a result if you don't do this.

Why a 'Background' layer should be so much smaller than a flattened single layer I do not know (and perhaps someone here does and would like to tell us?), as it contains no more or no less information, but it just does.

Or if you want to save your files with the layers still in tact, then just make sure that the bottom layer of your stack is a 'Background' layer. You can do this by highlighting the bottom layer of the stack, then selecting the 'layers' menu and 'New Background from Layer' through the layers menu drop down list.

Dave