I attended a workshop on the use of Adobe Photoshop that was conducted by Mr. George Reis of Imaging Forensics. The workshop was coordinated by our lab's Latent Fingerprint/Criminalists Supervisor who contracted with Mr. Reis to instruct about a dozen of the bench analysts, in-house, at our lab.
This workshop by Mr. Reis was quite informative and Mr. Reis is very knowledgeable on the application of Adobe Photoshop to forensic casework imaging.
If you wish to get the most out of your expensive digital imaging software I would
highly recommend that either you attend one of Mr. Reis' regional seminars or have Mr. Reis come to your lab and do a seminar at your place.
A link to the training offered by Imaging Forensics appears below:
http://www.imagingforensics.com/training.htm