D-2 Vignetting Problem

[dfloeter]

I have installed a Zone VI cold light in my ancient but solid Omega D-2 and found slight vignetting on 4x5 negs. Burning the edges cures the problem but I would rather not. Has anyone else had this a problem and is there a solution such as using a longer lens? I currently have a 135 Rodagon 5.6.

Thanks

 

[Huram]

You are using a cone with your 135mm lense, right?

 

[dfloeter]

The cone is about 2 5/8" long.

 

[Ronald Moravec]

Make sure the tubes in the head travel across the 5" dimension of the neg.

The tubes might be getting old and you get less light from the bends.

Check if there is something between the tubes and diffuser. Buy a new diffuser if you can`t prove it is the original.

 

[Bobby Ctkr]

Probably the diffuser

I had the same problem with my B8. Rigged the diffuser and now, no vignetting. I actually put the diffuser/piece of round, snowy plastic, between the negative carrier and the "cone" that rests on the carrier. Light leaks, but works for me for now.

 

[Claire Senft]

There was a review about 15-20 years ago in Darkroom magazine of the Zone VI coldlite head. I believe that the review was written by Ctein. He noted that the head vignetted with the use of a 135mm lens in printing 4x5 negatives.

Zone VI was started by a gentleman by the name of Fred Picker. He was capable of being quite 'crusty'. outspoken and combative. He was also a skilled photgrapher.

He wrote a letter to Darkroom magazine stating that the fault was entirely due to the 135mm lens being used. He stated that using a 150mm lens would have coImpletely eliminated this problem. He was more than generous in offering the opinion that anyone but an idiot would know that a 135mm focal length enlarging lens is too short to properly cover a 4x5 negative. Please understand that I am paraphrasing based upon a article read long ago. The remarks about a 135mm lens not being able to cover a 4x5 negative is NOT a position I support.

However, since the Mr Picker was certainly in a good position to know his product's capabilities I would strongly recommend that you try a 150mm enlarging lens and see if the problem disappears.