PDA

View Full Version : Enlarging Color 4x5 Negative with 1:1 Ratio Troubleshooting



rshorosky
19-Oct-2011, 17:56
hey everyone,

i have recently been shooting 4x5 color film and after spending the past few years making c-prints from 6x7 and 35mm i wanted to start making c-prints from 4x5 negatives. the problem i have run into is that i am trying to print 4x5 negatives onto 11x14 paper with a 1:1 ratio and am unsure if this is possible with an enlarging lens or if i should just go right to contact printing? i have tried using 135mm and 150mm but i cannot get the lens to reduce the image to 4x5 in. and be able to fully focus the image with a grain focuser. the problem with contact printing is that i do not want the black borders around the image so my only thought would be to construct my own negative holder that would fit the 4x5 negative and cover the rest of the paper? i have never contact printed before so i am fairly new to the processes but am fairly familiar with the color darkroom so tips so any and all assistance would be greatly appreciated.

all the best,
ryan

Daniel Stone
19-Oct-2011, 18:19
...the problem with contact printing is that i do not want the black borders around the image ...

contact print, easy peasy japaneezy. TRIM the black borders off before mounting.

There ARE lenses designed for 1:1 "enlargements", but why "enlarge" it if you can just contact print it? It'll be sharper, that's for damn sure

-Dan

Bill Burk
19-Oct-2011, 18:20
Lift the enlarger head, rack out your lens as far as possible, then find the focus point by holding a sheet of paper under the lens.

I'm fortunate to have an Auxiliary Focusing Attachment for my D-II which lets me reduce 4x5 with a 135mm lens to 35%

ic-racer
19-Oct-2011, 18:36
At 1:1 lens coverage is double infinity coverage. Since enlarging lenses are not used at infinity, so its hard to know exact image circles. But I'd say that a 100mm to 80mm lens should cover 4x5 at 1:1. That way you will have enough bellows draw. You can use a 135mm lens but you will need 270mm bellows draw on your enlarger. If you use an 80mm lens then you will need only 160mm bellows draw.

When I do 1:1 (which I prefer over contact anyway) I just use a 150mm lens. But my enlarger can do 600mm or more bellows draw, so I don't have any problem.

ic-racer
19-Oct-2011, 18:39
Also, when focusing realize that every lens has two points of focus when put on an enlarger. One focal point is used for making an enlargement and the other is used for making a reduction. At 1:1 the two points are real close, so you will likely encounter a sharp image, then with continued focusing it will get blurry and then sharp again.
http://img.photobucket.com/albums/v670/ic-racer/enlarger2.jpg

rshorosky
20-Oct-2011, 09:55
thanks for the help everyone, i actually was able to do a few contact prints last night and used an easel cover with board to do cropped contact prints that looked pretty nicely focused. i am still having trouble getting an image focused at 1:1 using both 135mm and 150mm lens so i might just contact print for now unless using an enlarging lens can better focus the image over a contact print (which i don't think does?) the problem i encountered trying to "enlarge" 1:1 was that using a 150mm lens i had to extend the bellows fully down and then using the focusing knob i would only get the image partially focused (similar to the image on the right above). i tried dropping the actual tabletop which the paper lies on down about a foot to see if that would help but i still couldn't get a solid result.

Bob Salomon
20-Oct-2011, 11:14
A contact print made with the emulsion in full contact with the paper will always be sharper then a print that goes through an enlarging lens in an enlarger at 1:1. First there are no enlarging lenses made for 1:1. There are duplicating lenses made for that purpose like a 120mm Apo Rodagon-D but it was never designed for 4x5. Then there are issues of enlarger alignment between the film, the lens stage and the baseboard, then there is aperture issues. You must be within the optimal aperture range of the lens. Then there are film flatness issues. You must be using a glass carrier. Lastly you are going through a lens and that will always somewhat degrade the image, regardless of the quality of the lens, enlarger alignment, magnification, aperture and film flatness.

All you need to do 1:1 from a negative, or a slide is a piece of clean glass to hold the film flat on the paper.

And you can do more then one negative at a time if they all require the same exposure and color filtration or contrast (if black and white).

ic-racer
20-Oct-2011, 11:48
emulsion in full contact with the paper All you need to do 1:1 from a negative, or a slide is a piece of clean glass to hold the film flat on the paper.
Maybe not so easy with double weight paper and a glass less then 1/2" thick.


piece of clean glass
Again, easier said than done.
If one is using the enlarger with a lens for light source , the rays will be collimated and dust on 5 surfaces will show through clearly. (Top of glass, bottom of glass, top of negative, bottom of negative, top of paper). Every time you put a piece of paper under there for a test print, more dust can get in.

With a diffusion enlarger doing 1:1, dust on the carrier glass won't show.

Bob Salomon
20-Oct-2011, 11:55
Maybe not so easy with double weight paper and a glass less then 1/2" thick.


Again, easier said than done.
If one is using the enlarger with a lens for light source , the rays will be collimated and dust on 5 surfaces will show through clearly. (Top of glass, bottom of glass, top of negative, bottom of negative, top of paper). Every time you put a piece of paper under there for a test print, more dust can get in.

With a diffusion enlarger doing 1:1, dust on the carrier glass won't show.

There is no reason to have the light from an enlarger focused when making contact prints and, if you want, you could also put diffusion material in the enlargers filter holder above or below the lens. You could also put a diffusion or fog filter on the lens. You could also just remove the lens or get a contact printer.

ic-racer
20-Oct-2011, 12:11
There is no reason to have the light from an enlarger focused when making contact prints and, if you want, you could also put diffusion material in the enlargers filter holder above or below the lens. You could also put a diffusion or fog filter on the lens. You could also just remove the lens or get a contact printer.

Yes, good points. I acutally would put some diffusion material down. However there is also risk of loss of sharpness if the negative/paper sandwich is not very tight, once you diffuse the light for contact printing.

My own comparisons between contact and 1:1 'enlarging' were essentially identical. The paper resolution is the limiting step, and both methods, when done with skill, can yeild comparable results.

Process lenses for 1:1 are cheap and easily obtained.

Bob Salomon
20-Oct-2011, 12:17
Yes, good points. I acutally would put some diffusion material down. However there is also risk of loss of sharpness if the negative/paper sandwich is not very tight, once you diffuse the light for contact printing.

My own comparisons between contact and 1:1 'enlarging' were essentially identical. The paper resolution is the limiting step, and both methods, when done with skill, can yeild comparable results.

Process lenses for 1:1 are cheap and easily obtained.

The contact print is always superior, as long as the film and paper are in tight contact and the glass is clean. A lens will always degrade somewhat. It isn't rocket science to build a spring loaded glass plate with a plywood or aluminum back with a couple of springs to hold the back plate and the glass tightly together, Then all you need is a base to set it on with the glass side up, facing the light. Or buy an old contact printing frame. They are usually thrown away as junk today.

Greg Davis
27-Oct-2011, 07:00
I did what you are trying to do once. I contact printed the image, but to keep the borders white I used a sheet of Rubylith film. I cut out a hole in the sheet and used rubylith tape to tape the negative in the hole. This worked for black and white very well. If you are trying to do the same for color, I would get a large sheet of regular lithe film and fully expose and develop it and then use it the same way. Rubylith is a red acetate sheet available at art supply and drafting supply stores.