Condenser dark spots

[ParkerSmithPhoto]

So I have a new Beseler 45V, which came without a light source. I borrowed a friend's old blue 45 condenser head, popped it in, focused a 6x6 negative, removed the negative, and I'm seeing a dark semi-circular spot in the middle of the projection. I did adjust the height on the condenser head with the top bellows.

I've never seen this before. Am I missing a lens? There are two in the head.

I am also seeing vignetting at the edges of a 6x9 frame, so I wonder if this isn't one problem with two symptoms. The dark, purplish semicircle in the central area of the frame gets even worse when the head is at zero settings, ie. for a 4x5 neg.

Any ideas?

Thanks for the help.

 

[ic-racer]

Check the bulb

 

[Gerald C Koch]

Any condenser head needs to be matched to the focal length of the lens used. You can't just swap things around without adjustments. Read the instructions for the enlarger. There should be some online. I would invest in the correct head.

 

[ParkerSmithPhoto]

I think I may have solved the problem. The condenser head has both the lenses installed flat side down, rather than convex to convex. Funny thing is, it looks like this older head was made that way, as there is heat absorbing glass under the top lens, and I can't see any way to install convex down.

Got a much newer head on they way from another APUGer... We shall see.

 

[MattKing]

Any condenser head needs to be matched to the focal length of the lens used. You can't just swap things around without adjustments. Read the instructions for the enlarger. There should be some online. I would invest in the correct head.

On the Beseler website the OP's enlarger is stated to be compatible with all Beseler 45 series light sources.

I wonder if that compatibility requires a particular fitting, or if the adjustment guide on the head he tried is only accurate for the M series enlargers.

Beseler can apparently be difficult to contact, but I would definitely try emails and telephone calls to them.

In case you don't have it: http://www.beselerphoto.com/contact-us/

 

[Hatchetman]

Perhaps too obvious, but there are different slots for the lenses depending on the film size (I think). are they in the right slots?

 

[John Koehrer]

There should be a spacing collar between the condensers. Could be incorrectly installed?
The heat glass has to be on top of the top condenser.

FWIW I've never seen(sheltered life?) a condenser head that didn't have the convex sides facing each other. The hot spot's probably the result.

 

[ParkerSmithPhoto]

There should be a spacing collar between the condensers. Could be incorrectly installed?
The heat glass has to be on top of the top condenser.

FWIW I've never seen(sheltered life?) a condenser head that didn't have the convex sides facing each other. The hot spot's probably the result.

Hey John, It was your email that cued me in and that solved the mystery. Not only was the top condenser upside down, but the heat absorbing glass was between the two. My friend found his manual with the exploded view diagram and we put it back in order. Works perfectly. Thanks.