Post processing is now a mandatory part in digital photography. Digital camera inherits some problems from CMOS sensor. Digital images contain a whitish overly layer which reduce the color vibrancy in a camera image. Only way to overcome this problem is post processing. I am telling you, post processing can change you from a normal phototaker to a professional photographer. You can create an amazing vibrant image from a very simple and boring looking photo. You can give a dramatic look in a picture as you imagine. Most of the photographers use fancy software like photoshop. I have to agree, this is the best for post processing. However I am not shy to say that I am a poor graduate student. Spending ~600$ for a software ohoo is too much for me. Using crack photoshop latest version is too much pain in the ass. And personally I don't like to still those genius peoples work for nothing. So I would like believe myself as a opensource free software guy. Believe me though they are not as good as Photoshop but they can do most of the work you will need most of the time. Software like Gimp is a good solution to meet your photoshop need. Even Picasa or Windows Live Photo is sometime enough to give the dramatic look you want in your photo. Plus the are very easy and fast to use. You really don't need to be a nerd to work with those. Here are some example. All those photo have been post processed using Picasa or Windows Live Photo gallary. I believe those are not that bad. Isn't it.....
