Originally Posted by wavecurrent 
I'm using the aperture for compensating the exposure with manual lenses, smaller when the image is overexposed and the other way when underexposed. This has worked since the days with the MX and LX, but now days you have the histogram as well for evaluation
I guess it is really a question of being lazy, and let's be honest, most of us are.
when I shot slides, I always under exposed a little to safegaurd the highlights. I did this by setting the ISO from 64 to 80.
When I bought my PZ-1 it had DX code reader, and exposure compensation, since it was a pain to override the DX system, it was easier to add exposure compensation, which achieved the same thing. exposure compensation was applied to all metering functions because some bright person figured youo always wanted to shoot the same way regardless of metering in autopmatic and manual.
With the *istD, I test each of my lenses and find some give constant over or under exposure, and again I find it useful to be able to set the EV compensation once, for that lens, and then go on and shoot without having to think during each shot, how much compensation I need to add. remember my premise at the onset, we are all lazy.
with the K10D, not having the ability to dial in EV compensation in manual is an issue, because it changes the way the camera works with a lnes combination between any of the program or auto modes and manual. I know some people say manual is manual, BUT on every other camera EV compensation works in Manual, the K10D is an exception. If the K10D metering worked better, in terms of errors with manual apature lenses, correct exposure for tele converters etc, it would not be such a big deal, but the exposure issues in the K10D make this a badly needed function. It's too bad that pentax will not go back and add this to the software.