why does photomatix pro 6.0 convert raw files

IMHO, unless you have a good reason to do otherwise, processing should be applied to the merged image. sharpening, which changes pixels along the edges) because they could be applied in different ways in the different images, and may result in artifacts later.

Returning to your question, processing RAW images before merging may change the merge result - the algorithms will work on different data - I'd be very careful also about those who alter some pixels only (i.e. The advantage of RAW is just you have the original camera data, so any improvement to the 'load' algorithms (demosacing, camera profiles, etc.) can be re-applied to the sensor original data, something you can't do if those are no longer available. Thereby, if after the merge the image is still in a 'large' enough format, it can be edited as if it was a RAW - how much depends on the merging algorithm and the resulting image. Manipulating a RAW file or a 16 bit ProPhoto RGB TIFF file is quite the same, especially since they will transformed into the same in-memory format. When you open it in Lightroom, IIRC the in-memory format is very similar to that used internally by DNG, in its variation of ProPhoto RGB color space.Īny image stored with enough bit-depth and large enough color space can be edited with ample space before too many data are lost, clipped, etc. In memory, the image will be some sort of 16-bit RGB image, hopefully in some large enough color space. 'RAW' means you have the data as read from the sensor, but most image processing applications need to transform them into a common format they can manipulate. When you load an image, it won't be in 'RAW' anymore - it will demosaiced, camera profile applied, etc.

Why does photomatix pro 6.0 convert raw files