Using the Cokin Filter System with a Holga
by Andy Smale
I have done it again. I have bought another Holga. Thats two I have now, one of the original 120S versions and now one of the new GN versions. This new one has a glass lens (thats what the G stands for), a bulb mode and a tripod mount. I also have a remote release cable for it.
Recently I modded my 120S Holga so that the aperture is now f10 (approx) rather than f13 which is standard (see the aperture mod article). Only 2/3rds of a stop but at least it makes the maths easier. The standard setting of f11 is only a third of a stop away. As the latitude of the film will allow for that third of a stop over exposure, its a bit of a winner. The picture shown below was taken with the aperture modded Holga.
If I can assume that I'm using f10 as my aperture, then I can use ISO 100 film and apply the sunny f16 rule. This states that on a sunny day, using ISO 100 film and f16 as the aperture then the shutter speed will be 1 over the film speed or 1/100th of a second. So using f10 as my aperture I can add an orange Cokin filter, this stops 1, 1/3 stops of light and so on an f16 day, I get the correct exposure, plus the orange filter will improve the contrast.
If I use ISO 400 film and a shutter speed of 1/100th second I get an effective aperture of f5.6. So adding a Red filter, that soaks up 3 stops of light, I can get the correct f16 exposure on a sunny day. Adding a green filter will give me an effective f11, using ISO 400 film and using an orange filter will give me an effective f8. Keeping with the orange filter and pushing the ISO 400 film one stop to ISO 800, with Ilford ID11, will give me an effective f5.6 and pushing the film two stops to ISO 1600, again with Ilford ID11, will give me an effective f4.
The Cokin filters I already have in my camera bag and I discovered that a 52mm A series adapter ring fits over the Holga lens beautifully. So after carrying out the mod and adding Cokin filters I have an effective range of f4-f16 using Ilford HP5 Plus which is an ISO 400 film and get pretty much spot on exposures. Development in Ilford ID11 will ensure a fine grain result, though I prefer the grittier look of Agfa Rodinal, which seems to accentuate the grain.
You will need:
- Cokin 52mm A series Adapter
- Cokin A series filter holder
- Holga
Method:
To attach a Cokin filter to a Holga slip the 52mm A series adapter over the end of the Holga lens as shown below. The Lens cap is 52mm and so the Cokin adapter will fit straight on without any problems, but is an interference fit so may be tight. Next add the Cokin filter holder. Finally add the Cokin filter of your choice.
Step 1
Step 2
Step 3
Step 4
Step 5
Things to remember when using filters:
All filters absorb some light so it’s better to use faster film, say ISO 400 and use filters to stop light entering the camera. Cokin publish the absorption values for their filters so these will give you a guide. Different colour filters will cause an individual effect on the final frame, and are most useful for changing contrast in black & white photography. Experiment to see what suits your style.
Note: using colour filters with colour film will result in your picture being the colour of the filter. If you are using colour filters, it may be best to stick with black & white film.
