We have an old Bogen enlarger with a 75mm lens. Why do 6x6 negatives produce an image on the baseboard in the shape of a circle?? 35mm images are fine and 6x6 negatives in our Durst are ok also.

What's going on?:confused:

It sounds like the enlarger either cannot project 6x6, or the head is not adjusted for that size negative. What model is it?

- Randy

My guess would be the condensors are not proper for 6x6.

Bogen Super 66 color. The carrier is adjustable to hold a 6x6 negative.

I am unfamilar with your enlarger. The fact that the carrier fits 6x6cm does NOT mean that the condensers do. There are 2 usual approachs used by manufacturers. A varaiable condenser that allows for a variety of spacing for the same 2 condensers. A different condenser set for different negative sizes.

If one has condensers that cover the largest negative and they are used with smaller negatives they will work fine but the exposure times will increase. The longer enlarging lens can be used with smaller negative sizes but with reduced optical quality and a reduced maximum print size.

If you drop by my house twixt 1 and 3 pm CST tomorrow I will show you.

I've had an old bogen 6x6 that had different condensors for 35mm and for 6x6. Sounds like you have the 35mm set installed.

I agree. If you have an enlarger with condensors for 6x6, they can usually be used for 35mm, but not the other way around.