I really would like to use the Magic Lantern firmware, especially for increased bracketing available for HDR shooting. I looked at the Rebels, but I think I would miss my extra little wheel.
I'm looking for a good low shutter count 50D, would it be a good upgrade for what I need?
From my reading, the Magic Lantern port for the 50D is less stable than it is for the 60D and rebels. You may want to consider the 60D for Magic Lantern use.
I'd skip the 50D if I was you. I had one for a while, but I was getting better images with my 40d. The 50D and the T1i share a sensor, and it was a fairly short lived sensor for a reason. The 18mp sensor in the 7D, 60D, t2i, t3i seems quite a bit better.
Bought the 50D and sold the 40D...after about six months bought another 40D...once we did the firmware update,found my wife and I were each wanting to use the 50D more then the 40D...so sold the second 40D and bought another 50D so we each have one...
In AV or TV Mode you can get up to four stops either way...set the AEB to the function button,turn the main dial behind the shutter button to the four stop setting,take the first of the AEB three shots ,press the function button again and using the back quick control wheel to adjust the EC two stops for next three AEB shots and so forth....doing this to get 6-12 AEB shots.
Although I normally shoot M, you can use Av because in M in order to vary the shutter speed you have to use the the top dial which is not as easy and smooth moving as the back dial. I get a six shot spread by doing the following:
In C.Fn. change dial increments to 1/2 stop.
Set AEB to +/- 2.
Continuous drive.
First shot at 0 EC.
Two clicks of the back dial to +1 EC. Second shot.
This gives -2, -1, 0, +1, +2, +3.
Using a remote release in one hand and the second hand on the back dial, it takes not much more than a second.
You can set the AEB to the function button and have quick access to adjust the exposure compensation.By doing this you can take 6-12 bracketed shots.For more in depth on this read the link below and the folow up comments.
I know the 1d bodies will do 7 in one sequence, at +/- 3 EV.