Originally Posted by MattKing
It's the same concern.
Is the bright part of the bulb where the rest of the optics of the enlarger expect it to be?
There are tests you can do that check how even the light is, and whether all the corners of your negatives are properly illuminated. Printing a slightly fogged piece of film is one of them.
Some times you can add extra diffusion to even things out, but that changes the character of the illumination, which is one of the strengths of Durst enlargers.
Thanks, Matt, I'll keep on eye on that and check around for the best tests to do to determine if the smaller bulb is causing any problems.