Lamp alignment??

[pergorm]

Hello!

Can anyone direct me to a clear explanation of how you align the lamp in a condensor-housing??. I have searched the archives and the www without finding any usable explanation.
Or mabye someone can give me an explanation here??

Thanks
Per

[Drew Wiley]

You need to be more specific. Which brand and model of lightsource/enlarger are you
working with? Manuals are still often available for popular brands like Durst.

[pergorm]

Hello


Thanks for your answer.
I have a Durst L1200, but the manual is not very specific on this issue, A few lines about "checking for dark sections or hot spots". That is not a very usefull description on such a important matter. Should the negative area be in focus??. Should i focus on the lamp?? To my eye, even a very malaligned lamp wil not show visible "dark sections". So, i am looking for a general description.....

Regards
Per

[Drew Wiley]

Per - there are both low-tech and high-tech ways of checking for hot spots. The low
tech way is to set the focus and baseboard about where you would for a typical print,
whatever size is most important to you. Get the hardest grade print paper you can
find and expose a test strip to obtain a medium gray. Then develop a complete print
for as high a contrast as you can get. Make sure your tray technique itself gives as
even development as possible. If you don't have a densitometer, you can simply tear
off little areas of the print and overlay them on other areas to see if there is a difference in density. Ordinarily it will be very difficult to obtain complete eveness of field from center to edge unless you have an extremely efficient diffuser as well as a
longer than normal focal-length lens. But as the corners drift away from the center,
they should be equal density. You can dodge and burn eges and corners to make up the difference as long as it's predictable. Of course, first make sure your print is centered exactly below the lens and not off-center, and that the lensboard itself is properly aligned, before you make this test.

[pergorm]

Hello Drew!

I never thought of exposing a print for max. contrast as you describe it. In a way this "low tec" test is a very important test. After all it is the final print that decides if everything is OK!!
Thanks for leading me in that direction. I will try that a.s.a.p!!

Regards
Per