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Photoshop Tutorials For Beginners Lesson 15: Saving Images In Photoshop
When you have finished working on an image, either for good or for the time being, you are ready to save it. But what is the best way to save your photos? Well, it depends on what you want to do with them. You may have heard of the different file types: JPEG, PNG, TIFF, Photoshop PDF and PSD, but you might not know when they are best used. So in this tutorial, we will see why certain pictures need to be saved in certain ways, and how to do it. Let's get started...
Saving for printing, storing or web display
When we have a photo that we like, most of the time we either intend to print it, post it online, or keep it on our computer to re-visit later. Well, there are different files types that are suited for each of these different purposes. I will explain the options clearly and briefly below. But first we need to understand a simple concept: the difference between lossy and lossless compression.
Lossy vs lossless compression
When digital photos are saved, either on our memory cards or in our image editing software, they can either be compressed or uncompressed. The point of compressing a photo is to shrink it so that it takes up less space, on either our memory card or computer.
But how does compression work? Well, there are 2 ways: lossy and lossless. Lossy compression works by automatically discarding some information in the image to make it smaller. It's gone the moment the image is saved and you can't get it back. The information that is chosen to be discarded is in the least detailed areas of the picture, like a blue sky, as far as that is possible. All JPEG files have had lossy compression applied to them.
Lossless compression is still a way of reducing the size of the file, but the reduction of information is only temporary - you can get it all back. In a nutshell, lossless compression is a way of expressing information more efficiently. No repeat information is saved. For example, I could write the number 10,000,000,000,000,000,000, or I could 'compress' it by saying 10 with 18 0's. The zeros can be easily added later since, we know what 1 of them looks like. The same is true of colour and tone information.
Lots of files can be compressed losslessly, including Raw files, TIFF's, PSD's and Photoshop PDF's. The meaning of lossy and lossless is easy to remember, because information is lost with lossy compression, but none is lost with lossless!
Different file types for different image usage
Now on to the most important part: which of the major file types are best used for what? Let's see...
JPEG: We all know about JPEG's, because they are the standard file type for saving images in digital cameras. They are also the standard file type for displaying images on the web. JPEG's are by definition lossy compressed files. This is great because they are nice and small, but it's also not so great because there is a loss of quality. JPEG files cannot support 16 bits/channel, so should be left in the 8 bits/channel mode.
PNG: PNG files are, alongside JPEG, the other file type that are most common for web use. They actually use a lossless compression and are able to handle a greater colour gamut than JPEG's. But the chief reason I sometimes save to PNG is that they can support transparency, which JPEG's cannot. Transparancy in a Photoshop document remains transparent when saved as PNG, but is filled white when saved as JPEG.
TIFF: TIFF files are one of the standard file types used by the printing industry. They employ a lossless compression, so no information is lost when saving. It is also possible to preserve Photoshop layers in TIFF files. For these reasons, saving to TIFF can be a good idea when you a) want to save a photo on your computer for future editing, and/or b) want to save a photo on your computer for printing. TIFF files can be edited in either 8 bits/channel or 16 bits/channe mode. Some online printing companies specify that files must be sent to them in TIFF format.
Photoshop PDF: This is another file type that is fairly standard in the printing industry. When you save as Photoshop PDF, you are given the choice of either lossy or lossless compression. Obviously, it's best to save with lossless compression so that no information is lost. As with TIFF's, these files are good to use for storing images to re-visit later and for printing. The image will be stored at a compressed size, and will return to full size when opened.
Photoshop (PSD): PSD files are used to save images that are still being worked on. They are not the right file type to use for saving a finished image, ready for print or web. They are 'working' files. The great thing about PSD files is that they automatically preserve all layers used when editing pictures in Photoshop. So you retain the flexibility of layers even after an image is saved.
Lastly, a quick note on Raw files, which are an option that you will find in the shooting menu in your camera:
Raw: Raw files are created in-camera and can be saved as uncompressed, lossless compressed or lossy compressed. They are able to contain the maximum possible amount of colour depth and dynamic range in your photos. It's best to shoot in uncompressed or lossless compressed Raw, although even lossy compression with Raw files does not reduce quality that dramatically.
Raw files need to be converted with software (like Addobe Camera Raw) before they can be opened in the Photoshop workspace.
Adobe Camera Raw:
The massive amount of information in Raw files enables us to adjust colours and tone a great deal without causing problems like posterization. Uncompressed Raw files take up a lot of space on your computer, so I prefer to convert and save them as TIFF's or Photoshop PDF's, so that they can be stored and re-visited as lossless compressed files.
Saving files for the web
The actual process of saving files for web use in Photoshop is very simple. Go to File>Save For Web and Devices, and you'll see the dialogue box appear. Here you can select the file type: GIF (for graphics), JPEG or PNG. I always choose JPEG for photos.
Next choose the quality option, which ranges from Low to Maximum. The higher the quality setting, the larger the file size will be. You can check the file size at the bottom left of the image. Lower down the dialogue box you can set image size, in pixels. As you reduce the size of the image to fit your webpage, notice the file size decrease.
Most image sizes for web use will allow you to set a high quality setting and still have a file size of under 50 or 100k.
Saving files for printing
Saving your images for printing is equally straightforward. Go to File>Save As and choose either Photoshop PDF or TIFF. These files will preserve the full colour and tonal information for your print.
If you want to save as TIFF and preserve layers for future editing, make sure the Layers check box is selected. If you chose to save as TIFF, the dialogue box will give you the option to save with LZW, ZIP or JPEG compression, as well as no compression.
LZW and ZIP are both lossless forms of compression, so you can choose either. There is no overwhelming case for one or the other when saving photos, but I tend to use ZIP compression most of the time.
If you chose PDF you will see the dialogue box, with settings for General, Compression, Output, and Security. Under Compression you can select None, JPEG (lossy) or ZIP (lossless). Select ZIP to preserve the full information of your image, then hit Save PDF.
If you are saving files to send to a printing company, make sure you check which file types they accept first. Many companies require compressesd TIFF or PDF files, as these contain the full image information and provide the best results. But they also usually accept JPEG's, because that is the standard file format for saving images in digital cameras. If you're interested in the companies that I swear by, I've reviewed my favourite places for sending images to print here.
That's the end of this lesson on saving images in Photoshop. I hope you found it useful! You now know the difference between lossy and lossless compression, what advantages JPEG, PNG, TIFF, PDF and PSD files each offer, how to save images for web use, how to save images for storing and how to save images for printing.
For a beginner-friendly book with step-by-step Photoshop tutorials, I recommend "Photo Nuts and Post" by Neil Creek.