Karlos, a couple of articles you may find of interest - I hope they help
http://www.luminous-landscape.com/tutorials/expose-right.shtml![]()
http://www.visual-vacations.com …e_metering_strategies.htm![]()
If you were shooting at around f4 with the 18-55, it looks like you might be able to get another 3 stops of exposure out of your 50mm under the same lighting conditions. That's going to give you a much better signal to noise ratio (which is a good thing even if you are looking for that noisy, grainy effect, as it helps to prevent some very ugly posterisations that you'll get in your image otherwise).
Then, even if the image comes out lighter than the mood you're trying to achieve, you'll have enough detail in the image to safely throw a lot of it back into shadow safe in the knowledge that the subtle gradations in tone will be rendered smoothly.
I'm sure this has already occurred to you, but if you want some sensor noise in there, you could try throwing your ISO setting right up to its max value 
Finally, if you are shooting B+W in-camera, you might get more favourable results by shooting in colour and then performing your B+W conversion in PP. I know you said that PP is a process you don't particurlarly wish to go through (at least that's how I translated what you said), but PP is a simple fact of photography and has been since it's earliest days (Ansel Adams was once quoted as saying “The negative is the equivalent of the composer's score… and the print is the equivalent of the conductor's performance”) . It might be a chore, but if you want to get the best images possible, it will involve a degree of digital darkroom work.





