C812 Multiple Format Camera ( Prototype )

Central to the field camera user experience is the amount of weight you’re expected to pack- a camera system that is too heavy to carry will inevitably lead to compromises. How many holders, how much water, how much to shorten the handle of your toothbrush, these are all questions that stem from carrying a basic camera system in the field, and sometimes leads to the ultimate compromise of shooting within a small radius of the trunk of your car.

C812 carboncameras.com

C812 Features

The C series cameras are positioned firmly in the tradition of Large Format Photography but at a fraction of the weight, made possible only by the redesign of the film holder and camera back.

This camera does not use traditional film holders, the weight penalty is simply far too great. There is little point in designing a lightweight camera if it is going to be matched by the weight of eight or ten loaded sheets, or if the penalty for making the camera too light is a reduction in stiffness. Significant weight savings can be made by reducing the weight of the film holders; additionally, a lighter weight camera designed for multiple support points allows you to travel with a lighter weight tripod system.

The camera is designed to be completely intuitive in use, from setting it up to getting the shot.

Indexable screw focus operating on the rear standard will not alter perspective, and is much more precise and usable for close up work. The rotations of the focus spindle can be counted, meaning that the focusing scale can be dispensed with. Under the dark cloth, you can compose, focus near, focus far, count the revolutions, and multiply by two to compute the focus spread in millimetres. The feedback is instant. No need to come out to check distances off the scale. By the time you emerge, you can translate focus spread to the required f number using a simple chart, which you can even store in your head.

Quick focus- the back can be disengaged from the screw focus, by flipping a couple of levers, allowing instant coarse focus. Flipping the levers back engages the screw focus.

Front standard setting- the front standard slides out on its tracks, and track extension is set with a single lever. The whole camera sets up really quickly, from fixing to the tripod, to unfolding the back, to raising the front standard and extending the bellows takes seconds. There is a bubble level on the front extension base for rough levelling, more levels on the front standard top, and detents for perpendiculars on the front and back standards. The levels at the back of the camera are embedded in the focusing screen, so they can easily be checked while working.

The camera is lightweight, yet rigid- The camera has been designed around the principle that a lightweight camera should require a lightweight tripod- assisted if necessary by the use of some lightweight monopods at the rear, which can clip onto the rear shift mount using standard Arca dovetail clamps.

Physically large cameras are particularly vulnerable to vibration and the structure of a large camera and tripod can be represented by a column supporting a couple of long cantilevers- perhaps not the most rigid solution, and requiring large and heavy connections to be effective. A lightweight tripod and two lightweight monopods is a three column solution, and serves to dampen vibration much more effectively when necessary. There is also a mounting point under the front standard. For even more vibration damping, the front and rear standards can be connected via a pair of telescoping carbon fiber braces, further reinforcing the structure.

Maximum extension is determined by the physical size of the camera. On the C812, for example, the maximum standard extension is 650mm. This can be increased to 850mm by the addition of extension rods to the rear carrier arms for a weight penalty of only 100 grammes, and a few seconds to screw them in…

The camera has a full range of movements, with the exception of rear rise. The front standard has base tilt, rise, fall and shift and there is an additional plus or minus 15º of front tilt which can be dialled in remotely from behind the camera using an optional extension screw drive. Front swing can also be controlled remotely, using an optional pantograph device. Although seemingly overkill, front movements can often be problematic when using longer lenses, and some may appreciate the option. Keyword ‘option’, these devices are not essential to the operation of the camera.

Rear swing is quasi-asymmetrical- since the rear swing rotation axes are offset from the film plane there are minute variations in focus- 0.5mm focus shift for a 10º swing using a 300mm lens, for example. The results are clearly visible on the focusing screen and the deviation is virtually unnoticeable in normal operation when combined with simultaneous rear focusing.

The camera can shoot both horizontally and vertically- the back and bellows are unclipped, removed, and rotated 90º. The darkcloth is detached from the velcro tabs on the lifting lid, and reorientated for use in the vertical position.

The Camera Back and Film Holder System- Designing a lightweight camera system around a standard film holder seemed a pretty pointless exercise- what is the use in shaving grammes off the camera when a standard 8x10 film holder weighs in at 650 grammes. If a significant weight saving could be made, an holistic approach would be needed.

The idea of a bag magazine for large format film is not in itself now- but the particular design for this system for larger sheet film, combined with its dedicated back, focusing screen, integrated darkcloth, and lifting lid has not been done before in this way.

The design of the camera back was prototyped on the C1117 (pronounced C eleven-seventeen) and the system has worked very well, although the entire camera has been completely re-designed from the ground up.

Carbon C812 Prototype | Provisional Specification

5x12 | 6x12 | 8x10 | 8x12

Weight 2800g
Film Holder Weight 200g
Maximum/Minimum Bellows 650mm, or 850mm, using rear rail extension set. Minimum 90mm.
Front Rise (Landscape) 80mm
Front Rise (Portrait) 30mm - Extra indirect rise is available by tilting the base
Front Fall (Landscape) 80mm
Front Fall (Portrait) 150mm
Front Shift ±92mm
Front Base Tilt Forward 90º
Front Base Tilt Back 20º
Front Axis Tilt 15º Total - can be adjusted from behind camera
Front Swing 80º Total - can be adjusted from behind camera
Rear Shift (Landscape) ±80mm - can be increased 55mm by re-positioning rail
Rear Shift (Portrait) ±30mm - can be increased 55mm by re-positioning rail
Rear Tilt Forward 90º
Rear Tilt Back 25º
Rear Swing (Landscape) 60º Total
Rear Swing (Portrait) 20º Total
Rear Standard Focusing Indexed Trapezoidal Spindle - 2mm travel per revolution via Handle - Free Focusing via Flip Lock Disengagement
Levels Front Bullseye Level on front carriage - Torpedo Levels on top of front standard
Level Rear Levels embedded in Focusing Screen
Detents Front Standard Vertical - Rear Standard Vertical
Tripod Mounts 2 x ¼ - 20. Rear standard - Arca style dovetail rail - Front carriage- 1 x ¼ - 20 mounting point
Integral Darkcloth Repositionable for Portrait /Landscape
Lens Board Sinar Style
Focus Screen Cast Resin
Accessories Front Tilt Drive Shaft | Front Swing Pantograph and extension