Expert: LizaL - 2/15/2005

Question
I share some photos with a friend and use the tiff format because I was told you could open, manipulate and save time and time again without getting degraded compared to jpeg. Now when I save it to either tiff or jpeg do you mean that there is no way they can go back and see what the original photo was like or what I did to enhance it once it was saved in one ot those formats?
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Followup To
Question -
From my understanding Photoshop will keep all the photo manuplating and adjusting that you do to a photo in the photo's file. This has got to take more memory so is there a way to get rid of all that and just keep the actual finished photo to save memoey?
Answer -
Hi Gail,

You're right, Photoshop will retain all the manipulating you do, providing you save your file. It doesn't record your keystrokes, though; but if you work in layers, and save your file as a pure Photoshop file -- which has a .PSD extension -- you'll be able to go back and edit those layers and make further adjustments.


Here are some saving options, all of which will reduce your file size:

1. If you want to keep the file as a Photoshop document, but not keep the layers, you can merge the layers and save the file as a Photoshop document. With your file open, and your Layers palette open, click on and hold the little fly-out arrow on the right side of the Layers palette, at the top. The best choice here is Merge Visible; Flatten Image can sometimes apply too much compression. Here's a screen shot:

http://little-works.com/all_experts/merge.png

As you can see, you can also Merge Down, which lets you merge your layers one at a time.

Then you can go to the File pulldown menu, select Save As... and choose Photoshop from the pop-up menu of file formats.


2. Saving as a JPEG or a GIF will automatically flatten your layers, thus preventing you from going back and editing the original file, unless you've saved a copy beforehand. But both these file formats use file compression routines, and will reduce your file size. I'm sure you already know that JPEG is best for photos, and GIF is best for line drawings and artwork with big, solid areas of flat color.


3. If you're saving your image for the Web, you can go to the File pulldown menu and select Save For Web, and then save your file as a GIF, JPEG, WBMP, or PNG, according to the file's content. This will greatly reduce the file size. However, once you do that, your layers will merge and you can't go back and do any editing unless you have a copy of the original PSD file.


Long story short, you do have some options when it comes to saving, and reducing file size. One thing I can't stress enough though -- if you want to ever be able to go back and edit your original Photoshop document (the one with layers), save it with a different file name, and possibly in a different location, so you'll have an intact copy.

Hope this helps! And please post back if you need any more help, or if I need to clarify anything.

Lisa


Answer
Hi again Gail,

Yes, that's pretty much it. If you have a Photoshop file that has layers, and you made changes to that file, then saved the file as a JPEG, the JPEG compression flattens those layers so that you can't go back and have those layers available to you for editing. So that's right, your friends can't go back and see the original file, or what was done to it. They'll open the file and see one layer.

Does that make sense? Check this out and maybe it will make things clearer:

http://little-works.com/all_experts/example.mov
(might take a minute to load)

1. There are three objects in the file: a picture of a cat, a text layer that says "Cat," and a third layer with a green box.

2. When I save the file as a Photoshop file, all layers are saved intact. I save it to my desktop as a .PSD file. If I were to open that file again, all the layers would be there, and I could edit any and/or all of them. If I saved the file as a Photoshop file at that point, the changes would be saved, and the layers would remain intact.

3. Then when I save the same file as a JPEG, it becomes a flattened file. I close the .PSD (the Photoshop file), then navigate to my desktop and open the JPEG. As you can see, the JPEG file has no layers. They've been compressed. So if I wanted to go back and make the word "Cat" say "Dog," I'd have to create a new layer. I couldn't edit the old layer because it no longer exists.

4. I navigate back to my desktop, open the .PSD version of the file (the Photoshop file), and there are my layers. So if I want to make a change to a layer, I can.


Similarly, by viewing the layers I can see what changes I have made. If I go in to the .PSD file and change the word "Cat" to "Dog" and save the file as a Photoshop document, I can go back to that file and see the change I made, and the layer I made it on, and I can change it further. But if I save it as a JPEG or a GIF and flatten the file, the layers are no longer visible.

So to answer your question, no, your friends can't see the original file once you've made changes to it -- unless you've saved a copy of the original. That's why I always stress saving a copy of the original, just in case you want to go back and edit.


Please don't hesitate to post back if I need to clarify this, or if you need any more information! I hope it helps, but this can be confusing, so please do ask if you need further clarification.

Lisa