A one-of-a-kind machine: the Logmar camera with matte box and external TFT viewfinder. You can still spot the 3D-printed parts.

Translation: Florian Cramer (Originalartikel hier.)

Tommy and Lasse are 63 and 30 years old. They are father and son, and they’ve always bonded over ambitious tech projects. Tommy is an expert mechanic, a crack on the lathe who knows everything about any kind of material. He can manufacture parts that he has in mind just so. Lasse’s expertise is even more microscopic than precision mechanics: He’s an engineer of bits and bytes. As a researcher and consultant, he develops complex micro controller applications, from chip design to full-fledged systems. Fifty years ago, Tommy became an amateur filmmaker, back then on Double 8mm with an Olympus Pen camera. Even today, long after the Olympus had been superseded by a Chinon Super 8 camera, he always keeps a fresh film cartridge in his refrigerator. Lasse has designed the hard- and software of highly complex micro controller systems for more than a decade. Motor control is his particular area of interest.

Tommy and Lasse are Logmar. The company was founded in 2009 in Lasse’s house in the Danish city Aalborg. Today, it houses a CNC lathe, a MakerBot 3D printer, an SMD assembly machine and even a reflow machine for the professional manufacturing of high component density controller boards. A big box with discarded control circuit board prototypes tells of the ceaseless and painstaking work done by father and son.

Speaking of the camera mechanics alone, we’ve thrown away our work and started from scratch five times. Or was it eight times? I stopped counting.

But what made them invent a new Super 8 camera, thirty years after the last regular model had been launched? It all started with a Krasnogorsk, the inexpensive and quirky Russian 16mm film camera. Tommy and Lasse once developed a drop-in replacement board for it. It was easy to build in and allowed every owner of the camera to completely replace its guts with a high precision electric motor drive, reliable exposure metering and a modern power supply. Although the project was ready for the market, it died a premature death since there were other third-party motor solutions, and the Krasnogorsk’s manufacturing quality was too uneven. Tommy and Lasse realized: Better start from scratch and get rid of all legacy technology.

First, Lasse wanted to build a better digital Ikonoskop camera. Today, he’s glad that he didn’t try since he had grossly underestimated the complexity of the task (like Ikonoskop’s developers did, too). There would have never been enough time to properly engineer the signal processing and a system for the vast amounts of data the camera would have to wrestle with. Logmar, after all, is a side project. Other players have more staying power. Every two weeks, there is a new digital film camera. It’s a highly competitive and well-served market. But Tommy and Lasse knew how many Super 8 cameras, Super 8 films and Super 8 filmmakers there were still out there. All of them still have to shoot with cameras that are at least 30 years old and have various deficiencies. This was enough motivation to build something different from everyone else: a new, analog camera, for the first time after a couple of decades.

Initially, Lasse wanted to create a 16mm camera because „16 simply is more than 8“. But the two men had a hunch that 8mm would be a better choice. Super 16 is dying out faster than Super 8. There are more Super 8 cameras, more Super 8 filmmakers, more projectors, and it’s more affordable.

Our whole family thinks we’re nuts. Well, everyone does, actually.

Lasse never shot Super 8 himself. His first camera was an NTSC video camera, with the usual inferior image quality. What both men found missing in Super 8 was some simple solution for high quality sound. So far, small gauge filmmakers only had the choice between either lousy quality or a high degree of complexity: On-reel sound has about the same fidelity as medium wave radio and can no longer be recorded live. Sync sound solutions are antiquated and prone to malfunctioning. Logmar’s modern solution is genuinely innovative.

The sound functions (more on them below) aren’t the only new feature. The film feeding mechanism and control unit are unique. Next to a real locking claw, the camera has its own, solid pressure plate and a combined film winding roll along with a bunch of technology that simply didn’t exist back in the times when Super 8 cameras were built.

Driven by inner motivation

Let’s start deep inside: with the camera motor. It’s amazing how quietly it runs, with a healthy hum. I realize, in utter surprise, that the frame rate can be adjusted in the camera menu with a precision of four (!) decimal places. As Lasse explains, the camera is driven by a Maxon D.C. motor, the same used in the Mars Rover – the best of the best. Other motors, such those of the manufacturer Faulhaber, didn’t meet the high standards of the two Danes. This motor is controlled by a completely autonomous circuit that runs independently from the rest of the camera’s electronics, thus ensuring highest precision. A PLL, clocked by a 100 MHz DDS, makes sure that the camera reaches its correct rotational speed within a few milliseconds. From the first to the last frame, the frame rate remains exactly constant. The error rate after ten seconds of the motor running is below 0.0003 fps. This means a tolerance of a single frame after 90 minutes of filming – which, however, will never occur thanks to PLL control.

Here, the rotary shutter generated three impulses per turn. With 25 fps, 25.000248 fps would be reached over the course of 10 seconds.

[alert type=“info“]A DDS (Direct Digital Synthesizer) is a component that can produce any frequency with absolute precision. Unlike a quartz, it doesn’t have an oscillation frequency of its own, but can be programmed in very small increments. The PLL (Phase Locked Loop) ensures, simply put, an exact coupling of the DSS’s input frequency with the camera’s selected frame rate. After fractions of a millimeter, the desired speed has been reached and will be perfectly kept from then on. Conventional quartz controllers often need several seconds until the control circuit has been locked in. The Logmar camera, however, keeps everything from the first to the last frame in lip sync.

[/alert]

The motor used is so powerful and precise that it could easily drive frame rates up to 100 fps. However, it’s not clear yet whether camera mechanics and film material would cope with this stress in continuous operation. For the time being, the Logmar camera will be limited to a maximum frame rate of 54 fps by firmware.

Loop former

The Logmar’s film transport is no less special than its motor drive. Like the ultra-rare Mekel high speed cameras, it includes a mechanism to push back the built-in pressure plate of the Super 8 cartridge and form a loop from the film that has been pulled out. This way, the film is transported just like in a classical cine camera. It eliminates the disadvantages of the Super 8 cartridge almost completely. Cartridge jams become a thing of the past, image steadiness couldn’t be better, even with stubborn and non-compliant film stock. There is an emergency shutdown at the lower film loop. If the loop disintegrates, for example at the end of a film reel or if blockage occurs, the camera motor will stop immediately.

Only Mekel built this before: a real sprocket in a Super 8 camera

Claw

The camera’s feeding mechanism is remarkable as well. The carrier is equipped with a built-in fixed pressure plate made from anodically oxidized aluminum. On top of that, it also has a real register pin. Its construction exceeds that of the drag lever used in the Nikon R10 for improving image steadiness. The Logmar’s register pin firmly locks the frame the whole time during which the shutter lets light onto the film. This ensures optimum image steadiness. The register pin, by the way, is dimensioned in such a way that it will exactly fit the film’s perforation and hold it free of play. Our test film shows how good this works: When projecting with a diagonal of two meters and dialing the frameline into the visible area, it doesn’t move a single bit. No 8mm camera ever reached this level of image steadiness, not even the best Swiss Double Super 8 (DS8) cameras. Similar to Max 8, the prototype camera shoots a wider-than-usual frame for Super 8 – „as wide as possible“, Tommy says. The corners are slightly rounded. It remains to be seen whether this feature will remain in the production cameras.

Viewfinder

The Logmar’s viewfinder system is no less unique. It resembles Beaulieu’s viewfinder but with only one shutter curtain. This way, one sees right through the camera lens without parallax displacement. At the same time, 100% of the light entering the lens ends up on film since there’s no viewfinder prism. Neither does the camera have swivel-in filters. This, once again, improves image quality. And unlike in practically all other Super 8 cameras, there’s nothing but air in between the lens and the film emulsion the moment the film gets exposed. This also means a large and bright viewfinder image good enough for pulling focus in dim light. The viewfinder image can have any size, since the optical viewfinder has been replaced with a small CCD camera rendering the viewfinder image on a monitor. For this purpose, the Logmar includes a camcorder-style side-mounted swivel LCD display. Since the video signal is routed to an external port, a field monitor can be mounted on top of the camera. Alternatively, a large (remote) monitor can be connected, or the signal can be recorded, but only in SD quality. For video buffs, it will be strange to see the viewfinder image flickering in the selected film frame rate during the recording, but seasoned Beaulieu shooters will feel right at home.

Unlike its first prototype, the camera no longer contains a dedicated monochrome LCD for its setup menu. All settings can now be conveniently adjusted via a button, a dial and an on-screen display. Through this display, all important settings such as frame rate and battery level always remain in sight. Of course, a frame counter is included. It shows both the exposed and the remaining frames of a cartridge. Since the camera automatically shuts off when a cartridge is full, no single frame will be wasted. Conversely, no shot will get lost on the „Exposed“ part of the film strip. As an alternative to the frame counter, exposed film meters can be displayed on the viewfinder, with single frame precision.

Metering

The camera still has a beam-splitting prism, but only behind the viewfinder mirror. It directs part of the light to a TTL metering photo diode. In the model tested, the meter wasn’t ready yet. Pros don’t mind using an external meter anyway. Ultimately, the camera will provide incident metering that honors the chosen frame rate. The camera currently has a 180 degree shutter, but this may be subject to change. Adjustable shutter angles will not be provided since it’s simply too complex to implement.

The brains

The heart of the new camera is an ARM Cortex M3 CPU, used as a micro controller – a very powerful and complex all-rounder. It’s the main reason for the camera’s flexibility and versatility. Users won’t take notice of what’s happening under the hood but enjoy the simply yet powerful functionality and future camera upgrades via firmware. The ARM micro controller coordinates a whole bunch of different specialty modules. It provides the camera’s On Screen Display menu, controls the frame rate unit, the USB port, wireless network connections, the audio section, exposure metering and more.

One of the main board’s many revisions: a WiFi chip, SD card reader, Scilab ARM mikro controller, JTAG port, DDS and PLL motor controllers, On-Screen-Display chip and Sanyo motor driver which unleashes a power of 24W without cooling.

Past Super 8 cameras came equipped with electronics, too, but a real micro controller architecture like the one used for the Logmar is a completely different beast. Since all relevant metering and control processes are implemented in software, firmware updates can not only fix bugs but also provide entirely new functionality. The camera is well equipped in this respect: USB and WiFi interface the Logmar with the rest of the world, its architecture is open for extensions.

Live sound

The Logmar’s core virtue and likely killer feature is its live sound recording. Sound capabilities by far exceed what Super 8 film offered in the past. For users, it couldn’t be simpler: All you need a run-of-the-mill SD card put into camera. It will record one self-contained, lip-synchronous audio file per take, with the exact date and time of the recording stamped into the file name. After shooting, the camera or the SD card can be connected to a computer, the audio files dragged underneath the digitized film tracks in a video editor (or concatenated for dubbing them onto the soundtrack of Super 8 reels) – that’s it.

This is another part of the camera where the job has been done properly. The heart of the sound engine is a 1063 chip of the Finnish manufacturer VLSI. This little circuit can not only play back audio files in all kinds of formats, but also record them in highest quality at 16 Bit and 48 kHz sampling rate. The VLSI chip is highly extensible, too, supporting DSP plug-ins, real-time audio analysis and different sampling rates. Thanks to wall-clock time, it offers high timing precision. Lasse still works on firmware changes that will let users adjust bass, treble and automatic gain control sensitivity. An optional, variable-attack audio compressor is being planned, too. Similar new functions will likely be provided via future firmware updates.

[alert type=“info“]The current camera prototype is still equipped with the older chip 1053 which can only create file in the Ogg Vorbis format. With the planned upgrade to its successor 1063, recording MP3 and uncompressed 16-bit WAV will be possible.[/alert]

For audio input, there’s a 3.5mm mini jack with automatic microphone or line level switching. Professionals will welcome the Neutric XLR/6.3 combination jack with 48V, short circuit-proof phantom power. Input selection is fully automatic, audio levels can be automatically or manually adjusted (with a knob dial, not with flimsy buttons). There’s a headphone jack for controlling the live sound. Audio meters (that also display clipping) can be directly viewed in the viewfinder’s on-screen display. In other words, there are no stumbling blocks for doing professional live sound recording in-camera.

Looking for contact: the camera’s still unlabeled connector and the externally mounted, easily swappable video battery

The camera still has one more sound goodie under its hood: In the future, there will be an option for recording continuous sound from the very moment that the camera has been switched on. There will still be one audio file per take, but gapless sound recording will obsolete the use of additional field recorders. A camera operator shooting only ten minutes of footage during a live concert will still obtain a high quality sound recording of the entire event, with lip-sync sound.

Power supply

The Logmar will run on stock 7.2V video camera batteries. They are inexpensive, easily available, charge fast and can be bought in different sizes for optional use as counterweights to long lenses. Surprisingly, one such battery does suffice for creating the five different voltages the camera needs: 1.8V, 3.3V and 5V for the different electronic circuits, two times 48V for the phantom power on the microphone jack, between 7 and 30V at 24 Watts for the camera motor running with optimum performance at each fps speed. This kind of perfectionism has no precursor in any Super 8 camera built before.

A large battery pack helps balancing long lenses

Special features

The Logmar’s unique viewfinder system makes the camera behave in ways that will be unfamiliar to filmmakers accustomed to their 8mm Nizos, Canons or Bauers. First of all, changing cartridges is a bit more complex since a film loop needs to be manually pulled out and threaded. And, fortunately, the Logmar disregards the Super 8 cartridge’s ASA notching. It’s left to the operator to correctly set exposure and, if necessary, use conversion filters. In order not to damage the registration pin, one can only remove a film cartridge after the camera has „parked“. In the current prototype, the operator needs to manually trigger parking of the registration pin un the camera menu, or the film will be stuck. For the production version of the camera, the plan is to have the pin automatically go into parking position every time the film chamber is being opened.

Thanks to its unique motor control, the camera works without a mechanical brake at the rotating shutter. Therefore, the last picture of each take can optionally be overexposed for an additional few fractions of a second. This makes sense when shooting negative stocks and using flash frames as clearly visible markers between single takes while editing. People shooting and projecting reversal stock can turn off this feature.

Searching connection

On top of its various sound connectors, this Super 8 camera boasts unparalleled connectivity. In the mechanical department, a c-mount thread for cine lenses serves as the lens mount. A PL mount would have been possible but has been skipped as a cost-saving measure. On top of the camera is a hot shoe for microphones or lights, on the bottom a tripod socket leaving enough room for mounting a hand grip with a camera trigger. The camera’s most distinctive visual feature is its large top handle for convenient and well-controlled camera movement.

In the electrical department, the camera is connective as well. On its top, there’s a socket for the viewfinder’s video signal along with a WiFi antenna. The camera can be remote-controlled via WiFi. Tommy and Lasse plan to openly release a simple yet powerful protocol that will allow everyone to program their own custom applications for controlling the camera. Next to classical remote control, intervalometers and triggering camera takes with motion, audio and light sensors should be doable. The plan is to make all camera settings remote configurable. This should include exact frame rates, single frame shutter time and DSP options.

Finally, a USB port provides wired connectivity for firmware updates and transfer of audio recordings from the SD card. Developers interested in the camera’s open protocol can use the USB port to read out debug information.

Helping the camera see the light of the day

How soon will the camera be for sale? If everything goes fine, around April 2014. The prototype is nearly feature complete, with beta testing starting these days. Ten preorders will be the first step towards the final product. They will allow Logmar to manufacture the moulds and tools for all the camera parts that currently only exist as 3D-printed prototypes. Then, volume production may begin. The introductory price for preordering customers will most probably be between 2,000 and 2,500 Euro ($2,700-$3,400). After an investment of more than 300,000 Danish Crowns ($55,000), more than one hundred manually assembled parts per camera and four years of continuous unpaid labor, that’s a very fair offer. As a special treat, the first brave ten buyers may, if they wish, choose blue or red instead of black for the color for the anodized aluminum camera body.

With exact 100 cN, the Logmar neatly winds the film around the cartridge’s take-up core.

The prototype with a 10mm Cooke lens and screw-on top handle. The camera body is only slightly wider than top-of-the-range Super 8 cameras from the 1970s.

A field test of the camera will follow soon – Filmkorn will provide you with extensive coverage!