First images with the Mamiya

I'm not super-pleased with the first results I've gotten with the Mamiya C220. I don't think I'm being self-effacing when I say that the problem appears to reside with the photographer rather than the equipment. The images are too dark and the negs too flat to get an image I'm entirely happy with at first try. Here is an example of a B&W image I took with the camera:

First, let me say that this is a neg that I've scanned on my flatbed scanner using a piece of glass to hold it in place. Not ideal, but I don't have time to actually get in the darkroom today to make contact sheets and prints. The other problem with it is the fixer with hardener may be too old and appears to have left little "crystals" on the negative - some can be brushed off, some appear permanent (I spent a little time retouching in Photoshop but didn't want to do too much since I wouldn't print this from the computer anyhow). I used Rodinal developer with TMAX 400 film at a dilution of 1:50 for 10 mins. If I had a time base for TMAX 400 at 1:100, I would give that a shot since it might produce a better overall tonal range. I also need to get a better idea of exposure values using the Gossen light meter (something I'm not used to doing since I'm used to TTL metering).

It's not an awful shot, but I've got a long way to go to get a true understanding of the Mamiya. I'm hoping my color negs are more promising than this B&W roll. Lots more work to do.