Digital BW, The Print

like many of you, i suspect, i store the photos i've worked on in photoshop format so i can 
retain layers, etc, and readjust them easily later. but this creates huge files. the worst 
discrepancy is for a jpeg that was taken as jpeg and not raw; the file often grows to 30MB 
or more for a 6MP image.

my intuition -- and i'll admit i haven't checked the numbers -- is that this is much more 
space than should be needed, even ignoring the effect of jpeg compression. hence my 
question: are there some tricks people use to reduce the file size? yes, i know storage is 
cheap, but using lots of unnecessary space has its costs (eg, in time spent backing up).

obviously, i don't want to lose information by reducing resolution. but i'm assuming that 
much of the growth is because photoshop is caching information that can be deleted. for 
example, if i have all my work in layers, i'm usually happy to clear the history, and 
presumably a long history takes a lot of space. are there other things like this?

i wonder whether maybe photoshop itself is not well designed in this regard? a curves 
layer, for example, shouldn't require more space to store than the amount of data entered 
when you design the curve -- a few bytes for a couple of points -- as it should be able to 
recompute the effect of the curve from its specification. it seems not to do this, however.

any thoughts?

/daniel

Daniel,
 
> 
> ... i store the photos i've worked on in photoshop format so i can
> retain layers, etc, and readjust them easily later. but this creates huge
> files. ...

> question: are there some tricks people use to reduce the file size?

I'm a contrarian here -- the fewer layers the better.  I always store the
files in un-compressed Tiff (or sometimes Photoshop) format, with the fewest
layers possible.  On the other hand, I'll have multiple older drafts and the
original scan available to go back to whenever I want.  The old draft may
have a few layers and masks that I can also pull when needed.  

To be sure the information is easily accessible from the older drafts, I
avoid re-cropping or re-sizing the image after the original scan, until I'm
ready to print.  This allows the clone tool to be easily aligned at (0,0)
(top left corner) with a 1 pixel brush size.  (It's even easier in Picture
Window than Photoshop.)  Also, masks can be pulled from the same-size older
drafts. 


Paul
www.PaulRoark.com

> From: daniel [mailto:dnj@...]
>
> like many of you, i suspect, i store the photos i've worked on in
> photoshop format so i can
> retain layers, etc, and readjust them easily later. but this
> creates huge files. the worst
> discrepancy is for a jpeg that was taken as jpeg and not raw; the
> file often grows to 30MB
> or more for a 6MP image.
>
> my intuition -- and i'll admit i haven't checked the numbers --
> is that this is much more
> space than should be needed, even ignoring the effect of jpeg
> compression. hence my
> question: are there some tricks people use to reduce the file
> size? yes, i know storage is
> cheap, but using lots of unnecessary space has its costs (eg, in
> time spent backing up).
>
> obviously, i don't want to lose information by reducing
> resolution. but i'm assuming that
> much of the growth is because photoshop is caching information
> that can be deleted. for
> example, if i have all my work in layers, i'm usually happy to
> clear the history, and
> presumably a long history takes a lot of space. are there other
> things like this?
>
> i wonder whether maybe photoshop itself is not well designed in
> this regard? a curves
> layer, for example, shouldn't require more space to store than
> the amount of data entered
> when you design the curve -- a few bytes for a couple of points
> -- as it should be able to
> recompute the effect of the curve from its specification. it
> seems not to do this, however.

If it's disk space you're worried about, just compress the files--they
should be highly compressible. In Windows, on an NTFS file system, you can
just set the compressed property of the file (under the Advanced button), or
of the folder that contains them.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...