Difference between RAW converters

There is one big advantage of pictures taken in jpeg format compared to RAW: you have a fairly good idea what they will look like.

With RAW pictures, be it CR2 or NEF or any other version, it is just the raw data from the camera, and each RAW converter may interpret it in their own way. One converter may handle noise better than another. One converter may interpret the white balance or luminosity in one way, and another converter may have another idea of how things should work.

Here is an example where compensation for distortion is radically different. The pictures are taken with a Canon S90 camera.

The first picture is a CR2 file processed with Canon's own Digital Photo Professional. The lines and the tiles are pretty straight.



The next picture is the same CR2 file, processed by Picasa 3.6.1. Note the very bent lines. In the corners of the photos, there is actually more information than there is in the straight picture.



What likely is happening here is that DPP has information about how much the lens bends the picture. DPP corrects for it, and the tiles look like they should do. Picasa, however, probably takes pixel for pixel from the sensor of the camera, and the result is the bent aspect.

It is very possible that Picasa will update its converter for CR2 files from S90 in the future, so they will look closer to reality and further from the pixel data.

Note that converting to DNG is not a solution. If you convert to DNG, that does not remove the distortion, and Picasa displays the DNG as distorted as the CR2 file.