Lightintensity

[jappie]

Would like to know what is an acceptable difference of lightintensity from center to corners on the baseboard of my enlarger (durst M800).

Many thanks

jappie

 

[David A. Goldfarb]

I'd be concerned if it were more than 1/10 or 1/5 stop. You should be measuring with the lens focused and with the negative carrier in place.

If it is more than 1/5 stop, be sure you have the right condenser for the format (or for a larger format), that it is in the correct position, and that you have an appropriate focal length enlarging lens. If all that checks out, try stopping down the lens and seeing if things improve and take note of the widest aperture you can use without significant falloff.

 

[clogz]

I don't know the Durst 800 at all but - if applicable - adjusting the lamp will help.
So will stopping down the enlarger lens.