Post-Processing - The Basics

[TimIngmire]

This thread is for users to post useful info for new photographers or those looking into this area for the first time. Feel free to add any relevant information, tips, links that you feel would of help.

Tim

[KenByrne]

Most underwater photographs lack contrast just because of the medium we are in. The first thing I always do is look at the levels in photoshop.

The histogram for this one is as near perfect as I can get. There's data from a full black on the left to a full white on the right. Even so I'd probably be tempted to shift the black in a little to give it a bit more punch.



This is much more common for an underwater photograph. There is no data at either end of the graph but there is a reasonable bell curve distrubution where the data does exist. You can see the pointers where I'd shift the black and white points to improve contrast.



This was drummed into me when I was doing chemical prints in a dark room, except in very exceptional circumstances, you need to cover the full range from black to white.

[KenByrne]

If you have the option to have your files in 16 bit format use it. TIF files can be 16 bit and RAW files can usually be processed as 16 bit.

All output devices (screens, printers) are 8 bit so you won't see a difference but when you start processing the file adjusting levels or colours you can create gaps in the data. Processing in 8 bit there is nothing you can do about it. If you are processing in 16 bit there is more data available to start with so the loss is less and if you convert to 8 bit before printing or saving as a JPG (which can only be 8 bit) then the gaps in the data are filled when converting down.

Ken