Film Speeds

So when taking a photo you need a camera, obviously, but you also need film and there are a lot of different makes and speeds out there. It can be hard to know where to start.This blog is about box camera photography, so we'll focus on medium format film here.

Your box camera may have come with its original instructions or it may have labels on the inside that recommend certain film types for that model. The chances are the recommended film isn't available anymore (some of these cameras are pretty old after all). Film gets discontinued, so don't worry if the camera says "for use with 'x' film". You can use other makes, and naturally these recommendations favoured the makers own-brand films to boost sales. Funnily enough Kodak recommended Kodak film while Ilford recommended Ilford film (see above). You can see a list of discontinued films here. For example, in my copy of How to Make Good Pictures, produced by Kodak (1951), for box cameras it says:

With a box camera and ordinary film, snapshots are best made in bright sunlight, though with Kodak 'Verichrome Film' [discontinued] satisfactory results can be obtained in the open or 'bright' shade and on days of hazy sunshine. In the early morning and late afternoon, the light tends to contain a higher proportion of red than it does in the middle of the day. The sun may appear to be bright, but its light is not strong at these hours as it is filtered through much of the earth's surface haze. 'Kodak' panchromatic films - 'Panatomic'-X [discontinued] and 'Super-XX' [discontinued] are of great help at such times because they are sensitive to red.

So, don't go looking for those Kodak films. One of my Ful-Vue cameras came with its original instructions. It very clearly states I should be using Ensign 120 film (Ensign Ultrachrome Film in fact), which of course is discontinued. Bear in mind also with some of the older cameras that manufacturers would have expected consumers to take black and white snapshots. We can still do that of course, but colour film is widely available now, so some more modern film guidelines are necessary.

Let's start with speed
When we talk about film speed we mean its sensitivity to light. Some are very sensitive, and some less so, making each type useful in different situations. Slow speeds require more exposure to light. Fast speeds require less exposure to light. Let's imagine some hypothetical photo subjects. First, a snowscape in really strong daylight. If your film is super sensitive to light then all that brightness will overexpose your image. A slow speed film will work better. Next, a dimly lit room. It will take an age to correctly expose with a slow speed film. A faster film is needed here. There is a trade off when using fast speeds however. They produce more noise. Noise is that snowy effect you sometimes get on the television. It makes the pictures a bit grainy, and becomes more noticeable if the picture is enlarged.

Film speeds are measured in ISO, though on older cameras it is more likely to be ASA (the terms are interchangeable).
Slow speeds: 200 ISO or lower
Medium Speed: 400 ISO
Fast Speed: 800 ISO or higher

Slow speeds capture details more effectively, making them ideal if you want to enlarge your images.
Use on very bright days and on subjects that aren't moving. The exception to this rule is night photography, where long exposures are taken with slow film to reduce noise. Generally these speeds are great for sunny landscapes and portrait photography, particularly when a shallow depth of field is required. 

 
The medium speed film will handle overcast conditions better and would be a better choice for pictures indoors.  This speed allows the use of faster shutter speeds, reducing motion blur.

Fast speed film is needed for poor light conditions, such as dimly lit interiors, particularly when using a zoom lens. It is also required for fast action shots and freezes moving subjects.

Ok, so that's a general overview of when different ISO types are used, but of course, not all shooting conditions are relevant to box cameras. They don't shoot very close up, and their slow shutter speeds make freezing fast movement impossible. You can't open up their apertures either, so forget about shallow depth of field. The focus of the lens is set in factory to make sure everything is sharp.

There are three elements that determine the correct exposure of a subject. The aperture, the shutter speed, and the ISO. Now, on a DSLR camera, you can toggle all three of these settings so the camera can be used in all kinds of situations. On a box camera you can't toggle any of them. Once the film is loaded you are stuck with that particular ISO until you load the next roll. The shutter speed is fixed at probably 1/30th of a second depending on the camera, and usually there is only one choice of aperture, likely F11. You might be lucky and have two apertures to play with. So, you can't adjust the camera to suit the conditions, at least not without some clever filters. Instead you have to adjust the conditions. This might mean moving to a sunnier spot, using artificial lighting to brighten your subject, asking the subject to stay still for a moment (unless it's a moving vehicle) or just admitting that the sun is too low and to take the shot another time.

One way to determine whether to take the shot or not is to work out the exposure value. This is a number that is attributed to the specific ISO, shutter speed, and aperture combination that you are using. As it is fixed on a box camera it is pretty easy to work out and remember while shooting. Our hypothetical camera has an aperture of F11 and a shutter speed of 1/30th of a second. Let's assume it has ISO 100 film in it. This would mean the lowest light conditions in which the camera could still shoot would be EV12. You can work this out using this fantastic Exposure Value Computer on Fred Parker's site. Read his whole article if you want to understand this topic better. EV12 corresponds with heavy overcast conditions. If the light is dimmer than this the picture will underexpose. At ISO 50, the camera could shoot at EV13, which corresponds with cloudy bright light. ISO 25 would let the camera shoot at EV 14, or in hazy sun. Funnily enough, EV12 and EV13 are the two settings available on my Kodak Brownie Cresta 3, so these were clearly the conditions considered optimal for that particular model.

Of course, the early literature recommended that these cameras be used in full sun, which seems to go against the guidelines above. Remember these guidelines were written 50, 60+ years ago and film reactivity has improved since then. ISO 50 and 100 were considered "fast" films, and it was presumed that consumers would be taking snapshots on ISO 25 or 50, hence they'd need to shoot in bright conditions.  You can still shoot in full sun with modern film. Film latitude is such that an overexposure of one or two stops will not ruin the picture. It'll be fine. Just take the shot.

Regarding medium speed film. At ISO 400 our hypothetical camera could potentially shoot at EV10, basically after sunset. However, unless you want to shoot all your pictures in those light conditions, you will find that your other daytime shots will be overexposed.

There is one factor that muddies all this clarity, however, and that is the 'Time' setting which is common on box cameras. This lets you do long exposures (with a tripod of course). This means you can use slower films in poorer light conditions. If you want to experiment with light painting, or even effects like star streak, you can use a slow film in your box camera after dark with this shutter setting.

What does it all mean then?
It means before you choose your film think about the likely subjects you will take with it. Box cameras can take portraits, candid shots, long exposures at night, landscapes, cityscapes, still life, and under the right condition they can shoot indoors. In fact, they can take moving subjects provided they are the correct distance away, but that's a post for another day.
 

It is unlikely that you will ever "need" fast film, though never say never. For the most part you will shoot between  EV12 and EV15, which means slow film, probably ISO 100, 50 or 25. Then again if, interiors with natural window lighting are your bag, medium speeds will be your film of choice.

Great, now which brand do I buy?
The best advice is to experiment. Check out the Box Camera Revolution group on Flickr. More often than not people mention the film they use in their photo descriptions. If you see a photo you like, make a note of the film it was taken with.

Common Film Brands

Black & White
Ilford
Fomapan 100 Classic
Kodak T-Max 100
Rollei
Catlabs X Film 80

Colour
Lomography
Kodak Ektar 100
Fuji Provia, Velvia, Acros,

620 Film
If you have one of the many Kodak Brownie box camera models out there then there's a good chance it takes 620 film. That said, so does the Ful-Vue Super. Though not as easy to get hold of as 120 film, you can find it at the following sources:
Analogue Wonderland 
Nik & Trick 

127 Film
Ok, so your box camera needs an obscure 127 film. Thankfully you can find it here:
Nik & Trick
Analogue Wonderland


I hope that clarifies the difference between film speeds and makes you feel more confident about loading your box camera and shooting photos with it. The best way to get to grips with this subject is to shoot film and learn from the results. Just remember to keep the camera still when you take the shot.