Hi everyone,
I've just started printing and I'm having a hard time with 6x6 negatives- an exposure of 5 seconds (f/16, 50mm lens, ilford multigrade 5x7 paper cut to 5x5...) resulted in a slightly dark print. I guess this is because there's a lot of light going into that 5x5 bit of paper.
Hi Eugene,
Not many people print medium format this small, but when done right, the prints can have a jewel-like quality to them. The resolution will look as good as large-format contact prints to most experienced eyes, as I am sure you have noticed by now!.
Are you sure you are using a 50mm lens for those 6x6cm negatives? That's extreme wide-angle, I did not know a 50mm enlarging lens existed that could cover 6x6cm, unless you are cropping a small area out of those negatives.
Secondly, your lens will be jamed right up to the paper. As everybody else here says, you should try a longer lens (for reasons other than just your overexposure!)
Most moderately modern enlargers (especially colour ones) I have ever used have a built-in neutral density filter, usually a switch or lever marked "Low --- High" or something like that.
Otherwise, for 5x7in prints, you could print at f/90 and the diffraction probably wouldn't show up on a small print like that, so this would be another reason to get a lens that stops down further than your current one. When I print that small from medium format, I used my LF enlarging lens (EL-Nikor 135mm), and that stops down to f/45 or so. Diffraction will never shop up on such a small print, so don't be afraid to stop down.
I would be hesitant to follow the advice of getting a dimmer light bulb, unless you don't mind swapping them out. A bright light source is useful for large prints!
Trivia: The widest angle enlarging lens I use (and have ever used) is a Schneider WA-Componon 80mm that covers 6x9cm - I use it for larger prints form 6x7cm negatives. I know Schneider made an exotic and rare Biogon-based enlarging lens, a 25mm capable of huge 35mm prints provided the negatives can stand up to it.