“Chimping” is the act of gazing at the back of your camera after taking a shot. It is easy to fall into the trap of concentrating on the screen and missing everything else that is going on around you, but instant feedback does have many advantages. Chimping allows you to immediately check the framing, focus, exposure and color balance so you can either confidently move on knowing that the shot is in the can or adjust and reshoot.
Here’s an interesting bit of information about the 645D. On most modern cameras, there is not much of a delay between taking a photo and the image appearing on the LCD screen. Not sure what the technical name for this time is but let’s call it Image Processing Time. The 645D, due to it’s 40 megapixel sensor, is dealing with huge files. What this means is that the Image Processing Time on the 645D is around 11 to 13 seconds. If you take a shot and immediately glance at the screen, you will be greeted by an hourglass.
For me this wait of a few seconds is not an issue, the image processing time on my Pentax 67 film camera was measured in days or weeks rather than seconds. However, if you normally use another model of DSLR and your technique involves a quick chimp after each shot then you’re going to find this a painfully slow wait.