Toggling Your Box Camera's ISO

Note: May not be a box camera.

 

I get it. 1 aperture and 1 shutter speed. Kind of limiting, I know. While it's definitely worthwhile getting familiar with the various EVs your box camera can shoot in without adjustments, it is undeniable that having a workaround for when the light doesn't suit your settings is a big plus. It makes the camera more versatile, increases your creative options, and removes a lot of the frustration:

 "If only I could take that shot, but it's just too bright!"

Well the good news is there are some tools and techniques that can help, so never again do you need to curse yourself for bringing your beloved box camera instead of your SLR.

Too Much Light

Box cameras have slow shutter speeds. Laughably slow by modern standards. Most people these days don't entertain shooting handheld at 1/30th of a second, or at least not without lenses with image stabilisation or cameras with vibration reduction. Lacking these features on our box cameras we have to resort to things like exhaling after the shot has been taken, or placing the camera on a flat surface. This works for the most part, but the slow shutter speed can cause headaches when there is a lot of light. Simply, they may cause the image to be overexposed. 

If my camera is loaded with ISO 200 film and I am shooting in very bright conditions, my pictures will be overexposed by maybe one or two stops. We can solve this "in camera" (as opposed to when we process the film), with the addition of a neutral density filter. 

If you're not familiar with neutral density filters, put simply they reduce the amount of light entering the lens, without a colour bias (at least the good ones). They come in various strengths, so depending on the one you use could reduce the light by 1 to 10 stops (and further if you have the bank balance of an oil tycoon). These have many creative purposes, such as allowing the deliberate use of slow shutter speeds to capture motion blur, (think dreamy waterfall shots), or allowing a wide open aperture to produce more shallow depth of field.

For our immediate purposes, we just want our shot to expose correctly. So if our light meter determines that we risk an image being 1 stop over exposed, we can place an ND2 filter in front of the lens and then take the shot as normal. If we risk 2 stops of over exposure, we do the same with an ND4 filter. If 3 stops, we use an ND8 filter. Simple. 

Too Little Light

I have a box camera loaded with Ilford Pan F 50 (or worse, Rollei RPX 25) and when I get to my location it has turned overcast, typical. This, and other low speed films like lots of light. So finding myself in lighting conditions such as EV12 or EV11, suddenly my famously slow shutter isn't slow enough thanks to the fixed f/11 aperture. Now, this workaround won't be appropriate for all subject matter, especially if it's moving, but the simple answer to this is to secure the camera so it is absolutely still and then take the shot more than once. Each click of the shutter lets in more light.

Take the photo twice to add one stop of light. Take it four times to add 2 stops of light. Eight times to add 3 stops of light etc.

This will work with mountains, but your dog won't sit there perfectly still while you click the shutter release four times, so choose your subjects carefully. 

Ful-Vue settings:

ND8 @ 1/30 = 3 stops less

ND4 @ 1/30 = 2 stops less

ND2 @ 1/30 = 1 stop less

1 shot = 1/30 of a second

2 shots = 1/15 of a second (1 stop extra)

4 shots =1/8 of a second (2 stops extra)

8 shots - 1/4 of a second (3 stops extra)

A handy way to get the ND range is a small cheap variable ND filter, which will be plenty reliable at these low settings.

There we go, we can now get +/- 3 stops on a box camera with only 1 extra filter in the gear bag. You can take it further, but pressing the shutter 16 times will get tiresome and the good high stop ND filters are pricey.

Development

Both of the approaches outlined so far to either increase or reduce the amount of light entering the lens are approaches that can be done on location, in the moment, in camera. However, there is another approach that can also help keep you snapping away without worry that the pictures will be under- or overexposed. This approach takes place during development, back home, once all the pictures are taken. Or, if you don't develop your own film, a lab will do this for you. Just make sure they know your requirements.

The processes are called push, and pull developing. Basically, you compensate for the under- or overexposed images by toggling their development times. If your images were overexposed, you want to pull the film. If your images were underexposed, you want to push the film. 

It is highly important to note that this only works for the whole roll, not individual shots.

Pulling Film

I've discussed pulling film here before, but to pull film you need to reduce the development time by about 10% for every stop pulled. My husband has a neat calculator for this on his own website, which can help you determine the correct development times. If you are loaded with ISO 100 film, and decide a reduction of 1 stop to ISO 50 would better suit the lighting conditions, then you pull by 1 stop. If you are loaded with ISO 200 film, then you'd need to pull by 2 stops etc. 

What this means on the actual shoot is that you just take your pictures as normal (no neutral density filters) resulting in a roll of overexposed images. The shorter development time then compensates for this and should result in developed images that look correct and not overexposed. 

Pushing Film

We do this for the opposite scenario. For example, you are loaded with ISO 50 film and an increase of 1 stop to ISO 100 would better suit the lighting conditions. In this instance you push 1 stop. If you need ISO 200, you push 2 stops and so on. Predictably, when pushing, you want to increase the development times. Use Nicky's clever calculator to work out the necessary timings for your own film development.

Again, during the shoot, just take the pictures as normal. No taking multiple exposures. You will end up with a roll of underexposed images and the push processing should correct this. I've got a few posts on this blog where I experiment with this method using Catlabs X Film 80, which produced some good results. By pulling and pushing I was able to treat it anywhere from ISO 50 to 640 without any problems. 

Pros of this Method

1) Nice and flexible. You can basically load up your film, make a mental note of the EV at your shooting location, then work out which ISO would have been best suited to those lighting conditions and push/pull accordingly.

2) Less limiting. You can still shoot your camera even if the box speed of your film isn't ideal and still get good results.

Cons of this Method

1) All or nothing. You can't push/pull just a few frames. It affects the whole roll.

2) Not all films are created equal. You can push and pull some no bother. Others within reason, and others should be left well alone. You'll have a lot more wiggle room with black and white film than colour. Make sure you do your research first.

3) Just like with digital photos, if you toggle the ISO this way you increase the noise. The more stops you push, the more grainy the images. The more stops you pull the more contrast you lose.

Things to Consider

1) Is the roll already part shot with correctly exposed images? Then you probably don't want to shoot the rest of the roll with a view to push/pull processing. You'll ruin the first images.

2) Are the lighting conditions really changeable? Then you probably want to correct the exposures in camera with filters or multiple exposures, or you will get inconsistent results.

3) Do you know that the lighting will stay consistently too high or too low? Then correcting the exposures in development is the best option if the camera is loaded, or the film cupboard was sparse.

Some Results

Catlabs X Film 80 pushed to 640

Catlabs X Film 80 pulled to 50

   

 

   

Getting to Grips with Light - Sunny F16 Rule

Photo by chuttersnap on Unsplash

The 'Sunny F16' rule is there to help you work out whether the shot you want to take will expose correctly when you don't have a light meter to hand. It's a simple rule that applies in clear, sunny conditions (EV15). It states that if you are taking a shot with the aperture set to F16, the shutter speed should roughly match that of your film. In other words, in high noon sun with no clouds (EV15), when shooting at F16 with an ISO of 100, the shutter speed should be about 1/100th of a second. Or, if the ISO is 25, the shutter speed should be about 1/25th of a second. Simple.

Now, of course, with box cameras we cannot adjust our settings, and most have wider apertures than F16, and more often than not the light conditions are overcast...Bear with me. The rule still has some use.

I've written before about exposure values in my post about film speeds, and the sunny F16 rule is another neat trick to make sure you have the right conditions, or the right camera for the job. There's a good argument for having more than one box camera loaded with different film speeds so you can grab the one set up correctly for the light conditions (particularly as they are so cheap on eBay). I have four Ful-Vue cameras, so in theory I could put a different film speed in each of them (actually that's a good idea, why haven't I done that yet?)

Anyway, back to the point. To illustrate we'll assume we're shooting with a Ful-Vue camera with an aperture of F11 and a shutter speed of 1/30th of a second. 

To keep things simple, we're going to assume that the camera and selected film are the only tools at our disposal (no neutral density filters, we'll get to that in another post), and for the purposes of this example we are not going to push or pull the film in development (again, we get to that later).

If, hypothetically speaking, we were shooting a subject at EV15, and the camera had an aperture of F16, then the correct film speed would be ISO 30 to match the fixed shutter speed. You can't buy ISO 30 film, so you're left with a choice of ISO 25 or 50. To be honest either would work fine. ISO 50 might overexpose a little, but film latitude is such that that shouldn't be an issue, similarly ISO 25 isn't going to be too far out at 1/30th  of a second either.

Let's assume we're loaded with ISO 50 film. The aperture size is F11, which is one stop of light greater than F16. This means that to correctly expose the film we now need to toggle one of the other variables. By increasing the stop to F11, we now technically need to decrease the shutter speed one stop to 1/60th of a second...but of course we can't do that. What we need to do instead is toggle the ISO, which is easy on a digital camera, harder on a film camera. Here you have four options:

1)Take the shot. It may be mildly overexposed. No big deal.
2)Find a different subject in weaker light that will expose correctly.
3)Use a different box camera loaded with ISO 25 film and the same shutter speed and aperture.
4)Use a different box camera with completely different settings to correctly expose the image.

Disclaimer: I am not suggesting you travel with 4 box cameras at all times to be ready for most light eventualities. Watch the forecast or look out the window. Choose the best bet, and take your chances, or, if your camera bag will take two cameras hedge your bets.

Here is an illustration. Let's assume I do load each of the four Ful-Vue cameras with a different film speed. They would then each be optimal for different exposure values:

Ful-Vue Exposure Values
F11 1/30th ISO 200 = EV11 (subjects in deep shade)
F11 1/30th ISO 100 = EV12 (subjects in open shade/heavy overcast)
F11 1/30th ISO 50 = EV13 (subjects in cloudy-bright light - no shadows)
F11 1/30th ISO 25 = EV14 (subjects in weak, hazy sun)

So, as you can see, none of these cameras is actually correctly set up for EV15, or sunny F16 conditions. I do have another box camera though with a bit more versatility, my Balda Baldixette, which has 2 apertures. You can see it's EV options here:


Baldixette Exposure Values
F9 1/60th ISO 200 = EV11 (subjects in deep shade)
F9 1/60th ISO 100 = EV12 (subjects in open shade/heavy overcast)
F9 1/60th ISO 50 = EV13 (subjects in cloudy-bright light - no shadows)
F9 1/60th ISO 25 = EV14 (subjects in weak, hazy sun)

F16 1/60 ISO 200 = EV13 (subjects in cloudy-bright light - no shadows)
F16 1/60 ISO 100 = EV14 (subjects in weak, hazy sun)
F16 1/60 ISO 50 = EV15 (subjects in bright or hazy sun - sunny F16 rule)
F16 1/60 ISO 25 = EV16 (subjects in bright daylight on sand or snow)

So, to get perfect shots at EV15, I should leave my Ful-Vue cameras at home, grab my Baldixette, load it with with ISO 50 film and shoot it at F16.

Disclaimer: I do not own four Baldixettes, I'd still have to pick a film speed, shoot with it, then reload.

Interestingly, if you look at the exposure values available when shooting at F9, they are identical to those offered by the Ful-Vue cameras. This is thanks to the Baldixette's faster shutter speed. So it would make the most sense for me to load the Baldixette with either ISO 50 or 25 to allow it to shoot at exposure values beyond the range of the Ful-Vues. This is handy to know as it means if I want to shoot in the snow in bright sun, I should choose the Baldixette at ISO 25.

What's the point of all this?

Again, this is a way of using knowledge of exposure values and a longstanding film photography rule to make good choices about exposures. Ask two questions:
What are the light conditions?
Is this the right camera for the job?

If you have only one box camera then you need to:

1. Be stricter about maybe not taking the shot.
2. Not get hung up about maybe overexposing a little. 
3. Get good at recognising light conditions, particularly the ones your camera is set up for.

If you want to play around with different camera settings to experiment with resulting exposure values, check out this site.

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.