Photoshop Mystery!

[Elleth]

I just had something strange happen while working in Photoshop...
In the middle of working on a restoration the size of my document changed!?
It was originally 300 ppi and 6in x 8in.
when I opened the document today somehow it had been changed to 72 ppi and 30in x 40in.
I never changed the size and I'm at a loss as to how this happened????
The worst part is I had finished with the restoration and was about to print!
Any thoughts?

[T Paul]

Did you crop it at any point? You can set your crop to set sizes and resolutions to make cropping easier. The thing is that those settings remain until you change them, so it's easy to forget and go to crop an image without realizing that instead of a generic crop you are actually cropping to your previous settings.

[Elleth]

Nope...never croped the image, there was no need to.
I'm just baffled!

[T Paul]

Did you use the Save for Web feature? Using the Save for Web feature will change your resolution to 72 DPI.

[byRo]

I think T Paul probably is on the right track...

If not, you'll need some detective work:
- Was it just this file? Try others.
- Do you have an old copy (@300ppi) to open and see if this happens again?
- Did you do anything different? (Computer / Photoshop)

On the slightly bright side if you change the size back to the original you now have 360ppi.

Rô

[Elleth]

Hmmmm....
I did use the save for the web feature, however I changed the name of the file when I saved it, and I checke another file I was working on yesterday and the same thing happened!
I can understand the resolution being changed, but what about the dimensions?
The image went from 6 x 8 to 30 x 40?
So, if I bump the resolution up to 300 ppi and change it back to the original dimensions will I get the same quality in the final print or will I have to start over with this project?
I dont have access to a printer at the moment so I can t give it a try.

[T Paul]

When you used the SAVE FOR WEB feature it changed the resolution from 300 DPI to 72 DPI...by doing this it also changed you 6x8 file to 30 x 40.

I believe if you change the resolution back to 300 DPI and the original dimensions of 6x8 you shouldn't notice any loss in image quality.

However, if this is a jpeg file.....remember, once you save a file in a compressed format (i.e. jpeg), it will discard some of the image data, never to be seen again. The best course of action is to first save your file in an uncompressed format (TIF, BMP, PSD), and then after editing, save it in a compressed format. Furthermore, consider doing a "Save As" and save the new file under a new name in order to preserve your original file for backup. In other words, do not compress the image until you are finished working on it, because every time it is compressed the quality is diminished.

[Elleth]

Thanks for the advice Paul.
The file in question is the PSD file, I always save a copy of my working file, just in case...
I restored the PSD file back to it's orginal state, as long as I dont have to do the restoration all over again I'm a happy camper!
Thanks again.

[Doug Nelson]

I thought I had an answer for you until I did the math on your two versions. I've had PS randomly change resolutions on me before (or seemed random to me) but the actual number of pixels never changed (a 4x5 image at 300ppi can be the exact same image as an 8x10 at 150ppi, only the little data snippet in the file that specifies resolution has changed, none of the actual pixels need to). But your pixel count differs so some resampling had to take place.

[Elleth]

Here are the exact numbers
Original: 6.353 x 7.673 @ 300 ppi
Resized: 30.375 x 39.653 @ 72 ppi
That might change the equation.

[Doug Nelson]

Since 6.353 x 300 does not equal 30.375 x 72, resampling happened.

[Lasse]

Sounds strange that ps resamples an image without asking for it.. that it resamples the save for web file is one thing but the original..? that shouldnt happen. Im curius about what have casued this, i havent had the problem in ps 6 or cs.

/Lasse

[byRo]

Originally Posted by Elleth

Here are the exact numbers
Original: 6.353 x 7.673 @ 300 ppi
Resized: 30.375 x 39.653 @ 72 ppi
That might change the equation.

Yippee!!! Numbers!

The plot thickens....
These numbers mean that your photo got distorted!
The total pixel count on the short side went up by 14.7% but on the long side by 24.0%, which is an 8% distortion. So it's not so simple....and who said it was?
Rô

[T Paul]

Are the resized figures the same for your PSD and JPEG file?

[Elleth]

Don't you love a mystery!?

Yes, the jpg and psd file have the same numbers.
But I never changed the psd file. I suppose it's possible that I goofed and saved when I shouldn't have, but I don't think so.

Other then operator error, I'm mystified...