Brightness Contrast tool, Gimp Tutorial
In a photo is really important choose the right exposure.
In this tutorial I'll tell you how to adjust brightness and contrast of a photo with Gimp.
The Brightness-Contrast Tool is the easier solution, and the worst one,
because generally the result will be a loss of detail in the high and low lights.
Brightness-Contrast Tool simply "cut off" the high and low lights. The contrast will be enhanced, but many details will be lost. This tool is suggested only in low contrast photos.
If you need more accuracy you should consider the histogram for adjusting illumination.
Anyway I think that the curves are the best tool for exposure and contrast enhance. If you want to choose the easier way, and you don't need the best quality, the Brightness/Contrast tool is the right decision.
As first thing, open your photo, then click Colors - Brightness-Contrast.
A window like the one above will appear. There is little to say, you have to change only two parameters.
The preview, reset and ok button should be quite explicative.
There are only a couple of things that i think are important to know:
When you increase the contrast, probably you will lose details on high and low lights, don't exaggerate.
When you increase the contrast, the image will be darker, generally I add brightness too for a better result.
Below you can see some screenshots with different settings of contrast and brightness. This photo has medium contrast, so the loss of details is acceptable with +30/+30.
As you can see, when you increase contrast, the photo looks more saturated, but there is a loss of details on the high and low lights. I think that the best result is on the third image (+30 +30). As I said before is better if you learn how to use curves for brightness and contrast regulations, the results will be more accurate and you will not lose details.