If you are a hardcore Holga fan or have already taken the time to look up some sites featuring Holga mods and hacks (or to take apart your camera for that matter), you will know that the Holga, despite sporting a switch for two different aperture settings for sunny and cloudy conditions, only features one aperture. This is due to the fact that switching from cloudy to sunny causes an arm to slide in front of the lens opening, the area of the hole on that arm (which is supposed to allow less light in) is larger than that of the aperture; i.e. the amount of light remains the same.
In this entry I will demonstrate how I modified my Holga to obtain two different aperture settings of f/10 and f/17 for cloudy and sunny conditions respectively.
So, I’ve been meaning to write about how I’ve modified my Holga for quite some now; but every time I set out to do it, I was put off by my desire to cite (at least) the (most important) sources I used and the ensuing chore of having to look them up again – so, here they are 1, 2, 3, and 4.
The links I’ve given above supply sufficient and more in-depth discussions of that as well as details of how to disassemble the Holga, other possible modifications of the camera, information about the f-number, and further links on the subject. In this post, I merely wish to demonstrate my modification: I opted to remove the plastic ring in the inner diameter of which originally gives the Holga aperture diameter of roughly 4.5 mm; popping it out gave me a maximum aperture (for cloudy conditions) of a 6.2 mm diameter, equivalent to approximately f/10 (the exact figure is f/9.677) – the focal length of the Holga lens is given by 60 mm. Next, I proceeded to reduce the aperture for sunny conditions by gluing a piece of black plastic (originally a packaging for a pair of earrings) over the hole on the switch arm and drilling a 3.55 mm-diameter hole into it, giving me a minimum aperture of approximately f/17 (the exact figure is f/16.901).
I’ve thus obtained two aperture settings 1.5 stops apart; the photos below show the difference for roughly the same exposure: I think most strikingly is the much stronger vignetting when using the larger aperture.