Using Filters

There are so many filters out there this could be an incredibly long post.

However, some are considered more "essential" than others. For most photographers, instances where the polarising filter will come in useful will far outweigh the number of times they wished they had their trusty Cokin "Mirage" special effect filter handy.

Now, box cameras can take filters too. Usually the push-on type, although the Fulvueflex has a 37mm filter thread for screw-on types. Realistically, the filters that would be most useful for helping you achieve your creative vision would be the following:

Linear Polariser, neutral density, close-up, yellow, orange, red, and green.

Ensign Ful-Vue model 1 with its orange filter. This is a 25mm filter, but it's a little roomy, so a 24mm would be better.

Why a linear polariser? Because they are cheaper than circular polarisers. A circular polariser is made from a linear polariser with a randomiser stuck to the back of it which increases the cost. In any case, circular polarisers are only essential for cameras with through-the-lens metering or autofocus as the polarised light can cause them to give false readings, and our box cameras do neither. Polarisers filter out scattered light which can help produce darker, more dramatic skies; can reduce the shine on surfaces; and can remove the reflections from water. The only caveat is that the viewing lens and taking lens on box cameras are different so you'll have to hold the filter to your eye, rotate it until you achieve the desired effect on your subject, then attach it to the taking lens in that precise position.

The chances of finding tiny push-on neutral density filters are pretty slim, however they can still be used on box cameras. Firstly, they can be simply held in front of the lens. Secondly, if the lens mount has a filter thread, either buy the screw on filter to fit, or buy a step up adapter and use a larger filter. If it is a variable ND filter you'll have the same problem where you have to adjust it to just the right setting and then attach it to the taking lens in that precise position. However, it is well worth the hassle as the limitations of the box camera can put certain subjects in bright light conditions out of bounds, unless of course you have an ND filter. These filters can also give some excellent motion blur on moving water, to the point where waves on the sea look smooth and calm. This would be a nice creative use of the box camera's Time setting.

Depending on the box camera, it may already have a close-up feature. For those that don't a close up lens, or portrait attachment as they were commonly known can help. Many makers specify a particular attachment. The one intended for the Fulvueflex, for example, allowed the camera to focus as close as 3 feet. As a guide, since most box camera lenses are set to infinite focus, a +1 close-up lens will allow the camera to focus at 1 metre (40 inches), and a +2 close-up lens will focus at half a metre (20 inches).

When shooting in black and white, colour filters are useful tools to render certain grey shades lighter or darker. The yellow filter is probably the most commonly used to emphasise the contrast of clouds against a blue sky, but it also helps reduce blemishes in skin tones. The orange and red filters provide more dramatic results, with blue skies rendered very dark indeed with the red filter. Green filters are handy when shooting foliage as they lighten greens and therefore help retain detail in the darker leaves.

These filters will see the cameras through most situations, and will broaden the lighting conditions in which the cameras can shoot. The most useful when shooting box cameras is undoubtedly the neutral density filter. The increased scope for shooting when conditions are too bright for your film is very useful. The next most useful is probably the yellow filter (assuming you shoot black and white). Any additional filters in your toolkit will be all down to creative preferences. If you want multi-images for that abstract art look, or crazy rainbow effects around all light sources then by all means check out those creative filters.

Who wouldn't want this?

Additional filters that could be worth consideration are the R72 filter for infrared photography; the blue filter (when shooting black and white) for moody shots of fog; and a cross-screen filter for nice star patterns on street lamps etc.  

Filter Factors

In most cases you can't just apply filter and shoot. Colour filters, polarisers, and neutral density filters all darken the scene through the taking lens, so you need to adjust your exposure times to prevent your image from being underexposed. Now, adjusting shutter speed is easier said than done. At a standard speed of 1/30, adjusting by one stop would mean a speed of 1/15. 2 stops would be 1/8, and 3 stops would be 1/4. I don't know about you but my judgement of speed is not that precise. But we can't adjust the aperture either? No, but you can take the shot twice, or even 3 times.  Obviously this has implications for your subject matter. If it is stationary it's no big deal, but if it includes moving elements there may be some ghosts in your final image.

Many box cameras came with pale yellow filters built in, and these could be used at the standard shutter speed without issues. A deeper yellow filter may have a filter factor of 2. An orange filter typically has a filter factor of 4, and a red filter typically has a filter factor of 4-5. These figures are not exact as they vary from each maker, but as a very rough guideline: when using a yellow filter take the shot as normal; with an orange filter take the shot twice; with a red filter take the shot 2-3 times. Depending on the linear polariser you may need to take the shot twice. The strength of your neutral density filter will determine the number of shots needed. If the EV value of your subject is one stop too high, applying an ND2 filter will mean you only need to take the shot once. If you have an ND4 filter, you'll need to take the shot twice.

If you are shooting with an R72 filter, this has a filter factor of 16, which means 4 stops of compensation. For this I'd probably put the camera in Time setting and count half a second by saying "one and" and releasing on the "and". Or, take the picture four times and see which approach turns out best. The resulting images will show you which setting gives the best results so make sure you take notes.

Needless to say, when accounting for filter factor on a box camera, the camera either needs to be firmly secured on a tripod, or sitting firmly on an even surface.

Yes using filters would be a hell of a lot easier on a more versatile SLR that lets you look through the taking lens and then works out the filter factor itself with its metering system. The point of this post is just to show filters are still accessible to box cameras. They just need a different approach.

Ways to work out exposure settings with filters:


Divide the film ISO by the filter factor. The number gives you the modified ISO number by which to meter the scene. Eg: ISO 50 divided by a filter factor of 2 gives a new ISO of 25. Set your light meter to read for ISO 25 and apply its suggested settings. 


Another useful method that I found online in a forum, though it was a long time ago and I don't remember the source, is to count on your fingers using the following sequence: 2, 4, 8, 16, 32. If your filter has a factor of 4, that equals two fingers, which represents two stops of exposure compensation. 8 would be three stops etc.