How did photographers touch up photographs before the invention of Adobe Photoshop?

Question

Photoshop is very popular for retouch pictures taken by photographers. But how did photographers touch up photographs before the invention of Adobe Photoshop?

Answer 1

In addition to Alexander's answer, you might be wondering about such touch up tasks as removing spots, cracks, and blemishes. Before digital photography, skilled 'retouchers' used very fine brushes and colored or black and white dyes to fill in areas on negatives and/or prints. Dust resting on the negative during the exposure of the photo paper would prevent exposure and create troublesome white spots. These were filled in with darker colored dyes. The tools and dyes are still available in well stocked photo supply stores. Troublesome spots may still be fixed this way on fine art digital prints. They occur due to dust on the paper when printed, or spots where ink has flaked off after printing, sometimes due to mishandling.

Answer 2

This could start as early as making the actual exposure - a simple predecessor to a graduated neutral density filter was covering an area for a part of the exposure, by putting a piece of cardboard in front of the lens, for example (or even simpler, your hand). A bright sky could be exposed less that way, rendering it darker.

The most commonly used technique was probably "dodging and burning" in the darkroom. Portions of the negative would be developed a little bit longer to lighten them (dodge), or a little shorter (burn) to darken them.

Partials of photos would be combined into a single new photo - like making a collage with scissors and tape.

As search for "retouching film photographs" should yield plenty more results. :-)