Professional Digital Photography - Why professional photographers shoot in 'RAW' image format.

 All images are shot exclusively in the camera 'RAW' image format, which require converting in PhotoShop before use. 
This requires additional time, which is why there is a charge for conversion.

The following information explains why.

RAW V's. JPEG 

The idea of a raw file is to preserve all of the sensor data captured by the camera. No conversion processing is done inside the camera; so all processing is deferred until the raw file is downloaded to a PC.

This is in great contrast to a camera JPEG where all the conversion processing is done inside the camera, including things such as white balance, tonal range, contrast, saturation and sharpening, etc.

This process is irreversible, so if the camera white balance was slightly out, it may be very tricky to amend in Photoshop, whereas, in most raw converters, changing the white balance is trivial.

Worse yet, the 12-bits per pixel of sensor data is truncated to 8-bits for the JPEG conversion. Also, JPEG uses 'lossy' compression to reduce file size, which means it discards some additional colour information as a trade-off for smaller files. Consequently, JPEG may produce some artifacts, such as halos around dark objects contrasted against a bright background or visible banding in graduated areas of an image.
These artifacts can be worsened later during post-processing such as sharpening.

Basically, shooting and capturing in JPEG is fine for the consumer or amature who does not want to “develop” his own film and is also used by some professionals such as news reporters and sports photographers, who's images are mainly for press, who are satisfied that JPEG suits their requirements.

However, professional photographers have traditionally always done their own processing and printing to get the absolute best results by having control over every step in the photography process, and do not allow the camera to do processing that they prefer to defer until later.
A rough comparison is Polaroid vs. regular film, or taking the film to the local drugstore instead of using a professional lab to process and print it.
It's just not professional.

 Finally...

I recommend that images are saved as TIFF's to preserve all information, however, even if images are finally saved as JPG's they will still be superior in quality to those processed internally by the camera!