• Adding color: With tools such as Hue/Saturation, Levels, Curves etc you can manipulate pixels, and improve the contrast, brightness and colors of the image dramatically. By using color balance you can adjust the natural colors of the image effectively and get greater clarity in the image. You can even opt for complete black and white shots from color photos.
  • Cloning techniques: Old damaged photos can be brought to life by cloning and healing tools of Photoshop. With these tools you can repair an old photo, remove odd objects like wire, antenna, etc from background.
  • Special effects: You can merge photos together, partially hide or reveal parts of images, add filter effects like glow, wind effects, stained glass, charcoal effects etc. In other words you can create complex artworks out of your Photos.

To sum it up it is best to use Photoshop or other image editing software to edit and correct images but if you do extensive effects on it then the photo may appear fake.