Response to Enlarger misalignment

Omar, as you see from the responses, there are a number of things that can cause uneven focus. Most common is misalignment between the lens board and film holder. However, film bending is also a possiblity that occurs often with condenser enlargers. Lens softness is the third most common. The thing you need is a good reference negative. It is possible to buy film or glass ruled gratings which will project a sharp and square set of lines on the paper/holder. They cost lots. You can make your own for a lot less. Get a few sheets of drafting paper, ruled for millimeter (ten to the centimeter) and make a high contrast image on film. When copying, be very sure that the film plane and the paper are exactly parallel. This is critical. Using fine grain transparency film, you can make positives (dark lines on bright field) or use b&w film for negatives. Both is best. When enlarged, you will see the sharp lines on the easel, and if they go out of focus it will be obvious. To make it even better, use clear balsam cement to mount the slide or negative on a thin piece of glass, such as a glass slide mount cover (anti- Newton ring is best). This will prevent any bending of the negative. Balsam cement is usually available at most optical supply houses, especially those who provide materials for microscopes. This cement is used to mound covers on slides. Also, do not use the cheap quarter inch ruled paper you can buy at school supply stores. The lines are not as sharp as on drafting paper, and you won't be able to get as sharp an image. With this in the enlarger, you will be able to see the real sharpness and linearity of your system, and the effects of any changes you make. I hope this helps solve your problem. Good luck.

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