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Showing posts with label head. Show all posts
Showing posts with label head. Show all posts

Monday 7 March 2016

Picture Post Introduction The Forgotten.

This is the first in a new series. This is where the image has center stage and the writing takes a bit of a back seat. I may include some thoughts on the pictures but will be kept to a minimum.

  To give you an idea of what I mean:

This series of images were made in a church grave yard in a small village not far from me. A place I have visited a number of times over the years. It has a quiet air that encourages you to sit and contemplate for a moment or two. On this occasion I could not resist making a few images, it was the way the light was streaked across the ground catching the frost making it sparkle that set the camera to my eye.


After I had processed the negatives I scanned them to the computer to sort out the levels and tone of the pictures, a feeling of sadness came over me. As I studied each image that was worked on I had a strong sense that these were now the forgotten.









Technical data:

Nikon FM, lens 80-210 zoom with macro, film HP5, ISO 400, developed in ID11 for 14 mins.


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

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.