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Wednesday, 23 November 2011

Types of Enlarger Negative carriers


There are two main types of negative carrier, with and without glass. There are arguments for and against each type. Lets be honest there are three types, the adjustable.

Glassless carriers avoid the Newton rings effect (a post for a later date) but also have the disadvantage of allowing the negative to buckle when they warm up, this is more pronounced with 6x6 negatives. To minimize this you should be very careful when focusing and use a smaller aperture to increase the sharpness across the negative.

Another disadvantage of a glass carrier is dust; to be honest it is not the big deal that everyone makes it out to be. It is just a case of being methodical in your approach. The main advantage of glass carriers is that they keep the negative flat. Another plus is that you can experiment with unusual effects by using various materials such as flower petals, salt crystals and soap suds etc in the carrier.


There are adjustable carriers also, which are very handy as they allow you to mask out badly illuminated edges without having to increase the magnification, or you can adjust them to include the rebate of the negative.

Enlarging Lenses



Enlarging lens mounted in lens saver.
When choosing your enlarging lens you should choose one that reflects the quality of the lenses you use on your camera. If you do not, that quality will not transfer to the final print. Of course there are other factors in play when making these decisions namely your own financial position; it maybe better to wait a little longer and purchase what you need instead of what fits your pocket at the time.

I cannot repeat this often enough that high quality camera lenses need high quality enlarging lenses, likewise reasonable quality camera lenses need reasonable quality enlarging lens. In other words like for like.

Enlarging bulbs


lamps in enlarges are usually opal this gives a diffused light which plays an essential part in providing even light over the whole negative this keeps the contrast to a reasonable level and has the further effect of reducing the intensity of any marks or dust you might have on the negative.

Lamp wattage is from 75 to 150 w. Their working life is about 100 hours, so it is a good idea to have a spare bulb. For those who have to move the enlarger after use because it is a temporary darkroom should allow the lamp to cool before moving, this may increase the life of the filament. It is far easier to damage/ break when warm or hot.

Enlarger


An enlarger consists of:

Enlarger for 35mmm negs
only. with out multigrade
head. Condenser type.

A baseboard on which enlargements are made; a column, which serves as a slide for the support arm, that holds the enlarging head, which consists of the lamp housing that contains the bulb; a single or double condenser; negative carrier, a place to fix the lens; a means of focusing and lastly a red filter that swings in front of the lens.

The lamp contained in the light housing is of the opal type and has a power output of 75, 100 or 150 watts. The pearlescents of the bulb with the help of a condenser distributes the light evenly across the negative. The lens focuses and projects the negative image on to the baseboard or rather an easel with paper on it. The higher the enlarging head is from the baseboard the closer the lens is to the negative the greater the magnification. The closer the head is to the baseboard the greater the distance the negative is from the lens the smaller the magnification of the picture. The typical focal length of lens for 35mm negative is 50mm and for a medium format (6x6) is about 75mm.
A multi format Enlarger with multi grade head.
Diffuser type.

The negative is clamped in the carrier which incorporates a mask that is the same size or format as the film and then placed in the light box. It is not a good idea to cut the negatives into single frames, it is better to leave them in strips to make it easier to line the frame up with the mask in the carrier, this also means you are less likely to scratched them.


Focusing is usually done manually, although there are enlargers available with automatic focus, these are usually more expensive.