Unexposed/dark edges to photos

Hello!

I have just received my first roll of 120 back from the developer and 4 of the 15 photos have dark/unexposed lefthand edges and I'm keen to know what went wrong! There also appear to be some odd colour casts. This was my first outing with my Mamiya 645 Pro TL. These were shot roughly at 1/500s f/4 80mm. I also seem to have missed focus in most of the photos...

Any guidance much appreciated!

Sorry if this in the wrong place...

Shutter issue.

Looks like shutter capping -- shutter moves left to right, I presume, and you turned the camera left side up for the vertical? This happens when the first curtain runs slow and the second curtain catches up and "caps" before the film frame is cleared. It's probably an adjustment on an electronic shutter, but it's an adjustment likely best done by an experienced expert.

The vertical color bars are exposure variations, caused by the same basic problem: changes in running speed of the shutter curtains. Pretty clear your camera body needs a CLA. If you bought it from KEH, recently enough, you might be able to get them to do it (or have it done) at little or no cost to you; otherwise, you're looking at some expense, but once done, your body ought to run perfectly for years.

Well that is very sad, but thanks for providing an explanation! I bought it on ebay so should be covered for returning. Hopefully.

If you otherwise like the camera, and got a decent deal, it might be worth sending off for a CLA. There might even be a shop local in Glasgow that can do that work (Steve O'nions on YouTube uses a shop in Liverpool, many major cities have one or two).

All depends how much you like the camera and what you paid...

Welcome to Photrio.
A couple of other things to investigate before you return the camera.
That also looks like what you get if something gets in the way of the light - a camera strap, a poorly sized lens hood, a dark slide that hasn't been fully removed or a light seal that has come loose (most likely at the dark slide slot). Having a dark blob at the end of the frame can also cause any automatic scanning software to become confused - thus the colour casts.
May we see a backlit photo of the negatives themselves - including the edges and the spaces between frames?