The first films were made of silver-halide layers which were only sensitive to blue light then along came Orthochromatic Films where the sensitivity was extended to green and yellow, and finally to Panchromatic Film which is also sensitive to red and is the most common type of Black and White film available today. Early film emulsion was carried on a Nitrocellulose strip which was highly flammable and led to many fatalities, the Dromcollogher fire of 1926 was one very tragic incident, Nitrocellulose was quickly changed to cellulose acetate a much safer material.

Orthochromatic  Films (ortho for short):

Are not sensitive to red, which can be a problem in many photographic situations except when photographing foliage. One advantage with  Orthochromatic film is that it can be processed by inspection under a red safelight, which means you can also load it into developing tanks etc., under the same safelight. Orthochromatic films can be either of high contrast or continuous tones and their resolving power is often higher than regular Panchromatic films. But continuous tone Ortho films are usually more expensive than Panchromatic films, the alternative is to use filters with Panchromatic film.

Panchromatic Film (or Pan for short):

Nearly all current black and white films are Panchromatic as it is sensitive to all wavelengths except Infrared, you can modify the effects of Panchromatic film by adding a filter discussed in other notes.

Infrared Film:

Designed specifically to be sensitive to one or more of the infrared wavelengths, most lenses designed for film have a little red R next to the infinity setting as you have to adjust their focusing point for the shorter wavelength.

Black & White Reversal Film:

For making B & W slides, you can buy this film and develop it yourself or with the appropriate developer you can turn a standard B & W film into a reversal one if you wish.

Lith Film :

A type of Orthographic film made mostly for high contrast and continuous tone results, usually used in industrial processes e.g. for copying it can be used for other purposes such as Cyanotype, Vandyke, Kallitype etc and enlarged negatives, it can home developed with the appropriate chemicals.

Colour Negative Film:

Used for making prints, it is basically a three layer emulsion recording light in the complimentary colours of the three colour Red, Green and Blue wavelengths which are again reversed in the printing process, originally each layer had to be developed separately but this complicated process was solved by Agfa in 1936 and a single chemical developer  process known as C41 is now used along with fixers etc. for both industrial and home development.

Colour Reversal Film:

Used for making transparencies, it scans better than colour negative film but does not have its dynamic range, ISO speeds are also generally lower, it can be home processed using the three bath E6 process.

Introduction

Welcome to Our Second Newsletter bringing you both current news, news of events  to come and thoughts on some aspects of photography.

Club Meeting On the 6th April

Ian Willey gave an impressive account of his trip to the Galápagos Islands in 2013. His introduction covered the creation of these 21 volcanic islands which erupted from the ocean floor over a period of millions of years some 900Km off the coast of Ecuador. The
islands were discovered by chance in 1535, not all are inhabited but those that are support individual life forms unique to each island which formed the basis of Charles Darwin’s “On the Origin of Species” which caused uproar when it was first published in 1859. Ian’s photographs showed a wide variety of both land and sea creatures, the bright plumage of most of the birds was fascinating as was the way in which tortoises had modified their shells from one island to the next. A most enjoyable evening and many thanks to Ian.

Club Outing to Fermoyle Thursday 20th April

There will be an outing to Fermoyle this coming Thursday, weather permitting of  course, those wishing to take part should arrange to be at Fermoyle by 19.30 to maximise  daylight. If the weather is poor there will be a presentation by Paul Keeling in the Abbey Tavern at 20.00 hours as usual.

The New (But Old) Competition Rules

As we now have a Club Constitution and a Committee it was thought that, like all other Photography Clubs, we had better formalise and publish a set of rules governing our Club Photo Competitions. Basically they are the same as those unwritten rules we have been using for years but with some added clarifications, like what exactly is the difference between Black and White and Monochrome, to whom the entries should be sent and by what time etc. The Committee has decided that having those members with less experience in Photography compete with more experienced members for the same prize (if any) is unfair, so the current thinking is to split a competition into two groups. We are still undecided as to how we will arrange this so nobody feels they are in the wrong group.