The 138S requires you to change out the condensers depending on your film format. With 5x7 they recommend 2 - #240 sized condensers. When I placed those condensers into the enlarger slots I was not getting a big enough evenly lit image circle. The corners of my negative that was projected onto the baseboard was vignetted.
I played around with the light source position, that did not work, then I tried a variety of condensers, still no luck. It then occurred to me that I could try flipping the 240s. I flipped the top 240 so it was upside down and left the second 240 in the normal upright position, and it worked! My light circle became a bit bigger and there was no corner vignetting of the negative. Not sure why it worked but it did work, that's all I need to know about that.
For those of you out there in the internet world facing the same problem, give the flipped #240 condenser a try.
I played around with the light source position, that did not work, then I tried a variety of condensers, still no luck. It then occurred to me that I could try flipping the 240s. I flipped the top 240 so it was upside down and left the second 240 in the normal upright position, and it worked! My light circle became a bit bigger and there was no corner vignetting of the negative. Not sure why it worked but it did work, that's all I need to know about that.
For those of you out there in the internet world facing the same problem, give the flipped #240 condenser a try.
