Beseler 45mxt full frame vignetting

[chuck94022]

I got frustrated with my Beseler 4x5 glassless negative carrier. It crops just a bit too much at the edge of my negative.

I bought a couple of pieces of glass (from a framing store) and went about building a full frame (edge to edge) 4x5 carrier.

My Beseler 45mxt has a Dichro 45s color head with a 4x5 mixing chamber.

I was disappointed to discover that the 4x5 head and mixing chamber do not quite cover the negative edge to edge. There is a slight, intrusive vignette in each corner of the projected image. It actually intrudes slightly into the image. I guess now I know why the Beseler carrier crops as it does. It must crop right to the edge of this light circle.

Has anyone else seen this with a Beseler?

(While cooking up this plan, I was in the photo shop looking at a very nice Durst negative carrier, with built-in, moveable masks. But that negative carrier cost more than my entire enlarging system, so I decided to pass on upgrading! )

[Thomassauerwein]

I use a 45mxt Have not had any vignetting for either 4x5 or 6x12. I do not use a color head however but can't see this as the source of your problem. unless the head is off center. The light circle is tight but I can get black borders, so there is some margin for error. Have you compressed the light bellows all the way?

[chuck94022]

I've attached an example. Yes, the bellows are fully compressed. I'm wondering if, for this type of print, I'll need to change my light source.

The attached is a Tmax 4x5, printed on Ilford MGIV RC at grade 2. Note the corners.

[chuck94022]

Here is an image using my Beseler 4x5 carrier. I focused inside the blades to show the natural edge of the carrier and the amount of crop relative to the edge to edge negative.

(If you are using the Firefox browser, open each image in a new tab, then tab between them to see the differences.)

[kwmullet]

The Beseler4x5 I have has an adjustable condenser and I have to crank that up or down to whatever format I'm in, 35mm, 6x6, 4x5, etc. Is there such an adjustment on yours?

My enlarger is wrapped up at a previous house, but I'll be moving it in the next few days. If the mystery isn't resolved by then, I could shoot some quick digital pics of the adjustment I'm talking about & post them.

-KwM-

[ann]

which lens are you using? 135 or 150.

I have that enlarger, and use a filed out carrier at times, or a negatron, or glass carrier, and do not have an problems. However, i am using a 150.

[chuck94022]

KwM: Yes, it has an adjustment for various formats, and I have it adjusted for 4x5. In this setting the vignetting is minimized but not absent.

Ann, good question. I'm using a 135. I have a 150, I'll try it.

[Claire Senft]

Do you have a mixing box for a smaller format inserted? If you do this could be the cause of your problem.

[chuck94022]

Do you have a mixing box for a smaller format inserted? If you do this could be the cause of your problem.

Unfortunately, no, I checked that. It is definitely the 4x5 mixing chamber.

[chuck94022]

I just tried the 150mm lens. Same problem. It is definitely the light source clipping against the negative.

For the moment I'll just have to live with cropped images in 4x5, and use this for 6x6 and 35mm only.

Some day I might try a different light source, but in the mean time I'll just have to live with contact printing 4x5 if I want an edge to edge print.