Why use a layer when making photo adjustments?

Assuming you are using Photoshop, you want to create a better looking image than your camera settings have delivered, you can open this file and make adjustments without harming your photo and losing information captured in your original

Since many use the standard JPG format, a lossy configuration, they find that each time their image is altered, data is lost, meaning that accurate sensor information is gone forever. If your image file is nothing special then you have nothing to worry about. However if you are shooting to sell any of your images, or are particularly fond of your photo then following this brief tutorial will give you an advantage.

Open your JPG image in Photoshop. If you choose Image> Adjustments> then choose an option you'll be changing pixels within the original file. Not a good thing if you make a mistake and then save in original JPG format, because you have now forever altered the photo and lost data. You can of course avoid pixel damage by using a different approach, choosing the use of Layers and saving appropriately.

You can alter your image safely by using Layer> New Adjustment Layer> and perhaps Levels or Curves, for instance. The effect is easy to check by simply clicking on the eye icon next to the background layer. You will see that the effect you have created will show on the background layer.

You now have the choice to Save As (Control/Alt on a PC) create a name and save. Then when closing you will be asked if you want to Save changes to the original Photoshop document before closing, and here you can simply click on 'No'. Choosing the 'no' option allows for the original image to hold all of the original data for future use.