Vignetting.. I think

[Old_school]

Hello, I just started printing 16x20 after doing smaller formats with no issue. I bought one of those Speed EzEl from ebay for this size. This print has the corners blown out but I can't figure why. I made 3 and they all look the same, just this one image. The negative looks fine as well as looking at the image on the easel with a white card before shooting it. I use under the lens filters and moving that around didn't change the corners. I haven't tried shooting this one smaller yet. Any ideas?
Thanks

 

[jim10219]

What size negative and what enlarging lens are you using?

 

[winger]

Well, basically there just isn't enough light reaching the corners of the paper. What size negative, what size enlarger lens, which enlarger, how is the condenser positioned if there is one?

 

[Old_school]

Well, basically there just isn't enough light reaching the corners of the paper. What size negative, what size enlarger lens, which enlarger, how is the condenser positioned if there is one?

Beseler 45mx Dichro 45s lighthead with 4x5 neg in a negaflat holder going though a 135 lens. Oddly, other prints I did were fine which is what threw me.

 

[Bill Burk]

Is it possible the negative has edge "overdevelopment" signs?

Since there is a similar blowout on the right edge, I think you might have a negative with some extra development on the outside... or maybe camera flare.

Otherwise it does look like a kind of vignetting while printing. Upper left looks good so you might not have the light centered over the film.

 

[btaylor]

Since it is a Beseler 45, are the bellows properly adjusted for 4x5? If they are adjusted for a smaller film format you will get vignetting.

 

[Rick A]

I may be wrong, but most of the lighter area is on the full length of the right side. Possibly a light leak in the film holder at the dark slide gate. There is the possibility the enlarging lens is causing it, but I doubt it. You say you didn't have this issue with any other negatives, I would definitely be suspicious of the film holder.

 

[koraks]

Insufficient coverage due to inappropriate enlarger setup, insufficient lens image circle and/or condenser configuration.

 

[Ian Grant]

You need to post a quick photo of the negative to rule out that it's at fault. It does look like vignetting but I'm not sure how that can happen.

A 135mm lens should be fine it's all I used for years with a cold cathode head on a 5x4 enlarger, and a dichroic head works similarly and is what I'm using now. My Durst enlarger has a lver to switch from using 35mm to 120 to adjust the light box, is there anything like that with your Beseler Dichro head ?

Ian

 

[M Carter]

Setup your enlarger as you would for that print. Pull the neg, remove any filters or go to white light with a color head. Insert the carrier, stick a sheet of white paper in the easel. Turn the lights off and let your eyes adjust, and inspect the bare light on the white paper. Check at your printing aperture and wide open. You should be able to see vignetting as severe as show on the print. You'll know in a minute.

 

[ic-racer]

Hello, I just started printing 16x20 after doing smaller formats with no issue.

You will see that the lens is much closer to the negative when making a 16x20, thus requiring a larger image circle for full coverage. Many 3 or 4 element lenses will falter under these conditions.
Also, with the lens closer to the negative the lens 'sees' the negative as bigger than the light source compared to you smaller enlargements. This means you light source needs to be perfectly centered over the negative and the lens.

Welcome to the fine art of making big enlargements! The details are important.

 

[grahamp]

Either the negative has edge and a second corner fogged - which is not that easy to do, the print was shaded partially during exposure. Or, which is my guess, the paper (it is 20x16) was not kept fully immersed on on edge and a corner - print development fault. It is not vignetting, which would affect the corners, not the middle of the long side.

 

[Old_school]

Thank you for all the feedback. Below is the negative. The right side middle flash on the print above was from the light in my darkroom reflecting but not on the print. The upper bellows is collapsed all the way since I use the 4x5 mixing box for everything. Not enough room for the condenser head in my basement.

I haven't moved the easel since.
With the lens wide open and no negative or filters; the lower corners are right on the edge of the circle just where the light falls off for an inch. Bingo. Critical, just wasn't aware how critical. The head is pretty high and the lower bellows is down good and not much wiggle room.

Learn by doing...

 

[MattKing]

While many 135mm enlarging lenses do cover 4x5, they are probably the ones designed specifically to do so.
135mm is a fair bit shorter than the diagonal of a 4x5 negative - approximately 150mm.

 

[Sirius Glass]

...
Not enough room for the condenser head in my basement.
...

Use a lower table so that you can add the condenser or a color head. I use a color head for both color and black & white.

 

[Bill Burk]

Good negative and glad the right side was a glare not a defect.

You probably will be able to center the next prints as you go forward.

You might want to look at “burning” the edges/corners anyway. Look into some of what Ansel Adams says about the edges and corners. To paraphrase badly, the eye wants to see darker edges and corners.

 

[Kilgallb]

Since it is a Beseler 45, are the bellows properly adjusted for 4x5? If they are adjusted for a smaller film format you will get vignetting.

Post a picture of the Enlarger showing the position of the top bellows.

I had the same issue with my 45mx. The top bellows for 4x5 needs to be as small as possible (totally compressed). You also have to be careful to center the carrier properly. There is a lot of slack in the negative centering.

The MX45 barely covers 4x5 so careful adjustment it required.

 

[Ian Grant]

While many 135mm enlarging lenses do cover 4x5, they are probably the ones designed specifically to do so.
135mm is a fair bit shorter than the diagonal of a 4x5 negative - approximately 150mm.

As far as I can remember all 135mm enlarger lenses are designed to cover 5x4, at least from the major manufacturers. There are also 120mm WA enlarger lenses for 5x4.

Many use a 240mm lens like a Componon S on their 10x8 enlargers as an alternative to a 300mm which needs so much more head height, this is the equivalent of a 120mm on a 5x4 enlarger. There was also the 270mm enlarger lenses which are the 135mm equivalent.

With a Dichroic colour head or a Cold cathode there's no issues using 135mm or 120mm enlarger lenses for 5x4, there could be issues with a 120mm and a condenser head as the condensers are designed for a "normal" focal length enlarger lens and would need adjustment or repositioning the light source for even illumination with the shorter lens. I never had an issue when switching from a 6" Dallmeyer to a Schneider 135mm Componon with my condenser enlarger.

Ian

 

[Old_school]

Post a picture of the Enlarger showing the position of the top bellows.

I had the same issue with my 45mx. The top bellows for 4x5 needs to be as small as possible (totally compressed). You also have to be careful to center the carrier properly. There is a lot of slack in the negative centering.

The MX45 barely covers 4x5 so careful adjustment it required.

I have a Beseler condenser head also but it's too tall and the light coming out of this thing is great, as long as I keep fixing it...