It makes good sense to work with a limited range of well-chosen films. You get to know their performance intimately 8211; what each can contribute to your particular style of picture, its response to different subject situations and, when necessary, just how far you can abuse the film before results become unacceptable. 8230;
Film is, very simply, a light-sensitive emulsion on a plastic base. An easy way to think of film is to compare it with bread and butter. Think of the bread as the base, the butter as the emulsion. When you hold this combination in your hand, what you feel and see is mostly bread, the base 8211; not butter, the emulsion. The base (bread) holds and supports the emulsion (butter), the active part of the film. 8230;
How sensitive a film is to light, that is, how much it reacts to a given quantity of light, is indicated by its film speed. The more sensitive-or faster-the film, the higher its number in the rating system. 8230;
Most people8217;s experience of colour film will be buying a colour negative daylight balanced film. This means the image goes onto the negative film and then is reversed into a positive colour image in the printing process. 8230;
is a panchromatic black-and-white reversal film intended for taking black-and-white
slides and/or for making movies. The nominal film speed is ISO 100/21o. Due to undercoated very effective silver antihalo layer the film features very good resolving power and high contour sharpness. This antihalo layer will be decolorised during processing. Film is produced on a cellulose triacetate safety film base of thickness 0,125 mm when high mechanical and dimensional stability and high life expectancy is required.
The Inverse square Jaw is the basis for flash exposure calculations. The farther the light travels, the more the light rays spread out and the dimmer the resulting illumination. …see full text
To Calculate your own Flash Exposure
To calculate your own flash exposure you need to know two things: the distance that the light travels to the subject and the guide number (a rating given by the manufacturer for the flash when used with a specific film speed) …see full text
Bounce Flash Travels an Extra Distance
If you are calculating a bounce flash exposure, measure the distance not from flash to subject but from flash to reflecting surface to subject. …see full text
Format refers to the size of film that you are using.
Medium format mostly refers to 120 film which will be 6cm wide but depending on the camera you are using can be 4.5,6, or 7cm long and even longer which would go on to a large format camera. Our cameras produce negative that are 6 X 6cm and 6 X 7cm. We would advice that you do not use 220 film as it doesn8217;t have a paper back and can rip and is difficult to load, also some of our cameras are not designed for this longer film, So please stick to 120 film.
We do have a Polaroid back for the Mamiya RS67 for this you need to buy Polaroid film.
Lots of older medium format cameras don8217;t have built in light meters and so you will most probably have to use an external light meter. Saying that we do have a metering hood and metering pentaprisim but we would advise you to use a hand held light meter.
Light Meters help to give an accurate light reading which will be converted into the appropriate shutter speeds and fno relative to the film speed ie ISO. When using a light meter first dial in the correct ISO, then set the mode to either ambient, flash non-cord or flash cord, dependant on your lighting. For a general reading point the meter at the subject from the position of the camera and take a reading.
For a brightness-range take a reading from the brightest part and the darkest part then split the difference. Using a grey-card measure the light reflected off it. For incident-light reading use the white plastic diffusing dome then meter the light that is fallin8217;g This methods will not take into account close-up work, filters on the camera or very long or very short exposures.
Most medium format cameras require you to both cock the lens and wind the film on as two separate actions unlike most compacts and 35mm cameras where both these actions are carried out simply by winding the film on.
Controlling the exposure. Both shutter speed and aperture affect the amount of light reaching the film. To get a correctly exposed negative, one that is neither too light nor too dark, you need to find a combination of shutter speed and aperture that will let in the right amount of light for a particular scene and film.