Bolex - The Technical Aspects of The Bolex

The Technical Aspects of The Bolex

For passing “The Bolex Test” or for general use of the Bolex camera, a better understanding of the controls is necessary.

For those individuals who take the visual learning approach when educating themselves, a good way to learn about the Bolex besides looking through one in person, would be looking at diagrams. A helpful site that depicts the Bolex inside and out is Controls on the Bolex. This site will go over the important controls of the Bolex, such as how to run the camera, where the footage counter is located and other important elements involved when using this piece of filming equipment.

Along with learning the different controls of the camera, as well as the proper way to load film, one must also understand the standard mechanics of the Bolex. When filming with a Bolex it is important to keep an eye on what the frame rate reads. For a standard motion picture film runs at 24 frames per second (fps), meaning the discs that makes up the camera shutter rotates 24 times per second. When filming at speeds faster that 24 fps a slow motion effect will be projected and when filming at speeds slower than 24 fps a fast-animated effect will be projected. An important point is to never run an empty Bolex at speeds higher than 24 fps, because this could damage the camera's motor.

An internal spring drive motor powers the Boelx. In order for this motor to run, one must turn the winding crank counter-clockwise. After winding the spring fully, the Bolex will shoot for 28 seconds.

While cleaning or loading the camera, the side cover must be removed.This is done by turning the "lid lock" catch. The camera's internal capacity was 100 ft. A 400 ft magazine (on the Rex 5 - or converted Rex 3 or 4) could be attached to the top of the camera. Just like with a still reflex camera, the Bolex has a viewfinder, which allows the filmmaker to view what he or she is filming. The Bolex has what's called a "reflex viewfinder." This specific viewfinder is made up of a reflex prism that deflects into the viewfinder about 20% of the light going through the lens.

The H16 Bolex usually has three lenses. Often,the camera was provided with a 16mm Switar or Yvar, a 25mm Switar or Yvar (and considered the "standard" lens) and the third lens was often a 75mm Yvar or 50mm Switar. It should be noted that only lenses with the designation "RX" in 25mm or less, can be used on the REX (Reflex) Bolexes. Lenses with desgnation "AR" were designed for the non reflex Bolex cameras. In the case of non reflex Bolex movie cameras, the taking lens could be swung into a high position and the image critically viewed/focused through a magnification tube. This provided accurate focusing but, of course, didn't offer the parallax accuracy inherent in a reflex camera. Many people, nonetheless prefer to use the non reflex Bolex with the side mounted viewfinder. The side viewfinder is parallax corrected and was surprisingly accurate. The fact that there wasn't light loss through the prism, enabled the non-reflex Bolex to perform slightly better in low light. An expensive optional lens is the 10mm Switar. This lens gives about the same angle of view as would a 30mm lens on a 35mm full frame still camera. The 10mm Switar is highly sought after. Some people had their H16 Bolex camera converted to "Super 16". This format was highly suited to telecine conversion, as Super 16 is close to the 16:9 electronic image format. Some conversions were more successful than others. Bolex (latterly) did offer a factory Super 16mm camera. This has the appropriate markings in the viewfinder and the film gate was machined and polished to professional standards. These cameras are fairly rare and always expensive to purchase. Sadly, most Switar and Yvar lenses that were below 50mm would vignette, to some extent, on the Super 16 format The 10mm lens will provide acceptable images, provided the iris is not stopped down to below F4. The 25mm Switar just abouts gets away with little vignetting. Photographers often didn't bother about this too much, regarding the subtle corner vignetting as a price worth paying and part of the character of such cinematography.

First generation Super 16, shot on (now defunct) Kodachrome was a visual treat. The image quality, sharpness, contrast and tonal range were superlative. Some movies were so excellent, that they were upscale printed to 35mm and used as full theatrical presentations. It is interesting to note that Bolex never used a registration pin (a registration pin jams into one or more sprocket holes, to stabilise the film during exposure). Many professionals regarded this as a failure - not accepting that simple friction could provide an image free of weave and chatter. Many professional cameras didn't have registration pins and provided very steady images but a well set up Bolex probably has the best steadiness of all 16mm non-registration pin cameras. Bolex did have a foray into purely professional cameras (Bolex Pro 16). Again, they decided against a registration pin and this (along with the fact that the gate couldn't be checked for hairs or other foreign bodies, whilst filming) this was probably the cause for the cameras to not be a commercial success. It just was introduced a few years too late and never gained traction in the market. This camera was only offered with 400 ft magazine capacity.