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Showing posts with label type. Show all posts
Showing posts with label type. Show all posts

Sunday 29 January 2012

Choosing an enlarger.


This is the most important tool in the darkroom after the enlarging lens. With this in mind you need to consider the following: 

1.   The number of negative sizes you may wish to print. It is a good idea to get a multi format enlarger even if you are only going to use 35mm.
2.   The most appropriate lens size and quality.
3.   What type of negative illumination. Diffuser or Condenser.
4.   The maximum size of print you are likely to make.
5.   Whether you may want to do colour at a later date. Colour headed enlargers can be used with multigrade papers. 

As mentioned in “3” the type of negative illumination you choose is worth  a lot of consideration -  there are positive and negative points to both. Here are some of the pros and cons: 

Diffuser enlarger: 
Diffuser light box
This type of enlarger design is used with colour and multigrade heads. The light travels through a mixing box and semitransparent screen above the negative. To counteract the drop off in light, these enlargers use a powerful quartz-iodide bulb.  This multi directional light passes through the negative and down to the paper. The affect of this will produce a gentler, softer quality to the  light, producing a less contrasty grade for grade photograph. As a result damaged and flawed negatives lose or soften some of their faults. 
There are tonal differences between diffuser and condenser produced photographs because of the way light passes around the silver particle's. This is negated when using Chromogenic monochrome and colour films as they rely on dyes to capture the light. 
Condenser enlarger: 

Condenser light box
Uses a plano-convex lens which spreads a bright hard illumination  evenly across the negative. Supplied from a opal tungsten lamp. The harshness of this light produces a contrast enhancement that appears to make  fine detail more exaggerated. This crisp appearance to the photograph has the negative affect of bringing into sharp focus the grain, any scratches, flaws and dust from the negative, meaning more time spent on retouching. These enlargers are subject to the Callier affect this is where the highlights in the negative scatter the light more than the shadow areas creating the increase  in contrast.


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.

Glass-less 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.