Enlargment of Negatives Using a Digital Process

Nathan Bess and Thomas Stimpson

Introduction

The goal of our project is to make enlarged digital negatives for photographic printing. The alternative photgraphic processes used in this project require an image to be contact printed. Ordinary 35mm negatives are too small to produce a good print. We wanted to make enlarged negatives using Adobe Photoshop and Dan Burkholder's book(GLOSSARY, Making Digital Negative for Contact Printing, Dan Burkholder, TR 267 .B87 1999) as a guide. Without Burkholder's book, this project and the idea behind it would not exist. Do not attempt to do this without his book or guideance from a similar reference.

Background

Traditionaly, to make contact prints one must have a negative as big as the desired print. This requires the use of complicated and very expensive cameras that very few people have access to. Dan Burkholder wanted to be able to utilize contact printing processes without having to use expensive equipment. In his book, he provides very detailed information on how to sucessfully make negatives at home. We also used Blake Shell's old project to guide us in the right direction of what works and what doesn't.

Procedure

This is our origional image that we scaned into the computer using photoshop.

1. Scan image into computer

2. Adjust the image size to desired dimentions (Image->Image Size)

3. Apply grayscale to image (Image->Mode->Grayscale)

4. Adjust levels of image to black 95% and highlights to 5% black (Image->Adjust->Levels->double click on white and black droppers, set C,M,Y to 0, and set K to 5 for white, and K to 95 for black.)

5. Apply the Unsharp Mask to image (Filter->Sharpen->Unsharp Mask) This is one of Burholder's recommedndations that may not make sense, but trust him, he seems to know what he's talking about.

6. Invert image so that final is a negative, not a positive. (Image->Mode-Invert)

This was our final inverted greyscale image that we printed out as our negative. We added a stepcurve supplied by Burkholder on the CD-ROM that accompanies his book.

7. Apply one of Burkholder's curves to image. The curves that he has are on the CD-ROM that comes with the book. Each curve is labeled for the intended printing process. It is very important to apply the curve so that the final negative has the correct contrast. Do not adjust the contrast of your image using the contrast feature of Photoshop! Below is our image with a Platinum curve applied on the left, and the image without a curve on the right. It is normal for your image to look bad with the curve applied.

8. Print image onto transparency using either an inkjet or laserjet printer. There are advantages to both types of printers. The first thing you shold know is that a normal transparency cannot be put through either printer. Specific transparencies are required for each type of printer. The problem with a laser jet printer is that the quality and detail of the image is very poor. This is why a photo quality inkjet printer is desired. The problem is that ink doesn't adhere well to the transparencies. To prevent ink from pooling up on the transparency, one must print the image at a low resolution. 240ppi is the desired resolution.

9. The new enlarged negative is now ready to be used in printing. We would recommend making a black and white print in the darkroom in order to evaluate the quality of your negative. Cyanotype and Van Dyke prints may not show the detail desired from the negative. One problem with these digital negatives is that they lack the density of traditional silver gelatin negatives. To solve this problem, Burkholder reccomends several solutions. The easiest one would be to print multiple transparencies and carfully stack them on top of each other. This will give a negative with multiple layers of ink which will help to duplicate the density achieved by a silver gelatin negative. The final negative we produced is pictured above with the step table.

10. The final print. We choose to make a cyanotype, but a Black and white print would be the first print one would want to make if duplicating our process.

The origional image compared with the final print made from our digital negative.

Observations and Data

The final cyanotype print we produced shows a good deal of deatil. The overall image is not as sharp or clear as we had desired. One of the reasons for this is that we made a cyanotype. Some of the graininess of the image may be noraml. A true test of the image deatil could be conducted by evaluating a Black and White print. We would also recommend using an inkjet printer. The detail and resolution are musch better than that of a laser jet printer. Many of the observations we made were discussed in the procedure.

Conclusions

We successfully made an enlarged digital negative. Our final print shows a good amount of detail, but it is a bit too light. Burkholder supplies enough information to work on this project for years. We only had a two week crash course on the subject. This is a very inexpensive way to access photographic proccesses only previosly available to those with access to expensive equipment.

Links

http://www.danburkholder.com

Acknowledgements

Making Digital Negative for Contact Printing, Dan Burkholder, TR 267 .B87 1999