I have read many opinions (both pro and con) about the ISO dial on the Fuji X-T1. Like many, I love that it is there, but it is hard to use… but why?
I used a Canon 7D for years and have not had any issues with the left-hand dial. Then it dawned on me. I don’t handle the left hand dial the same way. On my Canons, I use both hands to work the controls. Some are more easily accessed with the left hand and some with the right hand, and often, the right hand is in a hand strap (so I would naturally use the left hand to control the left hand dial).
When I moved to the Fuji X-T1, I would more often use my right hand to make changes and only occasionally controlling drive mode and aperture with my left. But when you hold the ISO release button with your right hand, it blocks the current setting on the dial and, with the camera body in the way, can only grip the dial from above.
Not so with the left hand which works much better. You can see the current setting and gripping is more natural.
Other people may have other issues with the dial. It is a little small to grip with fingers so those with bigger fingers probably have a more difficult time gripping it.
I have heard that people would like it NOT to have a lock, but from an old Canon 7D user, the left hand dial can be easily bumped and changed – often enough that Canon offers a replacement dial and (I believe) all newer models have a lock on the left hand dial.
The other complaint that I hear about is accidentally changing the drive mode. I, personally, have not had this problem, but I can see how this could happen. What I tend to do is change the drive mode, focus on getting the shot and then forgetting to change the drive mode back. Usually, the screen is different enough to clue me in, but occasionally, I will shoot continuous-high accidentally which is better than shooting single shot when you expected continuous.