DIY for Photography

This is the project home page of the SmaTrig 2.1, the improved version of the the SmaTrig 2. On this site you will find complete instructions how to use and build the versatile 15-in-1 camera trigger SmaTrig 2.1. Everything needed to build the device is provided including the PCB design, firmware, drill plans, etc. The SmaTrig 2.1 is based on an AVR microcontroller, and is equipped with sensor circuitry for detecting sound and light pulses for capturing lightnings or high-speed photography. The 15 functions can be divided into four groups: bulb mode bracketing programs for HDR photography, interval and timer modes, sensor modes and other functions like manual camera triggering or configuration. Many of the modes have some hidden advanced options, but I paid great attention not to obscure their usability. Ritual instruction manual spurners can use the SmaTrig just using their intuition.

Many people stil think that Linux is monochrome and you can't even display an image. On the fist glance the image processing potential under Linux may seem a little limited compared to those of Windows. But when it comes to automised image processing, things look totally different and the command line is a mercy. You just have to know the commands and options...
In the following I've put together some useful commands for image processing that I used again and again in the last few years. They might be interesting for the technically oriented, ambitioned DSLR user working under Linux.

This article describes a uC based delay circuit for photographic applications like drop or high speed photography. It can be used to control the trigger lag of cameras or flash units. The input and output of the circuit use standard 3.5 mm jack connectors, so the delay element can be looped into your existing trigger circuitry like the SmaTrig for example.
As simplicity and budget components were important design goals, there is no text display or any sophisticated analog input stage. The circuit allows three delay ranges which are indicated by LEDs.

On this site you will find a complete instruction how to build a versatile 15-in-1 camera trigger, the SmaTrig 2. Everything needed to build the device is provided including the PCB design, firmware, drill plans etc. The SmaTrig 2 is the second improved version of the multi-purpose 15-in-1 smart camera and flash trigger SmaTrig (1). Compared to the old version, it boasts some completely new features. The existent one have been optimised for better usability. The enclosure hasn't changed, so the trigger is still very compact having the size of a match box.

This article explains how to build the second improved version of the HDR-Jack. In contrast to the original circuit this version is powered from a lithium coin battery. This results in compatibility with cameras not supported by the first version, because of the focus wire issue. The circuit can be easily embedded in the enclosure of a cable remote controller as shown in the pictures below. The original function of the cable release is preserved.

Most DSLR and SLR cameras can be triggered remotely using a release cable. Unfortunately the connectors used for the external release have rather exotic shapes. Below you will find the pinouts for the common camera types. The standard solution consists of three wires: ground, focus and shutter. To focus the camera the focus wire has to be connected to ground. To release the camera both wires have to be connected to ground.

In the following the inner workings of a no-name Canon EOS 350D/400D battery grip will be shown. My motivation to disassemble the grip came from the idea to gain control of the camera buttons and wheels without opening the camera body. By connecting a microcontroller to the dial wheel and the shutter button in the battery grip, functions not included in (or intentionally excluded from) the camera firmware, such as unlimited exposure bracketing, can be implemented.

This article explains how to build an ultra-compact AVR controlled multipurpose trigger for Canon EOS cameras with a remote control jack connector (e.g. EOS 350D, EOS 400D, EOS 450D, EOS 1000D). The trigger features an interval function (intervalometer) for time lapse photography, a HDR trigger mode for shooting exposure bracketing image series, a bulb mode for astronomy or high-speed photography and a delayed trigger option for long exposure photography. The complete circuit is accommodated in the 2.5 mm jack plug needed to access the remote trigger connector. It's so small you can use it as a key fob.

Experiments with the external trigger function in my EOS 400D inspired me to develop a simple do-it-yourself sound trigger. The circuit detects sound pulses that exceed a certain pressure level.
The sensitivity of the trigger is limited, but high enough to detect popping champagne bottles, bursting balloons or eggs hitting the floor. It can trigger cameras as well as flashes, as both are activated by the same mechanism of short-circuiting two wires.

After triggering a camera (mechanically or electrically) it takes a certain time until the shutter opens and the exposure can begin. This delay is called the shutter lag. The values vary strongly depending on the camera model. The focusing time is not considered in this test. In all test images the focus was adjusted manually for fastest response times.
There are several ways to determine the shutter lag of a camera such as photographing falling objects, rotating discs or an electronic counter. I chose the digital method, due to a simple implementation and good readability of the results...

The EOS series of cameras from Canon offer a nice feature which is of particular interest for DIYers and technically oriented photographers. It is possible to trigger these cameras externally using an electrical signal. To the hobbyist's delight Canon used a customary jack plug instead of an exotic system connector. There is no special protocol needed to trigger the camera - you just have to short-circuit two wires. Knowing this, building a homebrew Canon RS-60E3 wired remote control is a snap! Or maybe an interval trigger, or a microcontroller based...

This article describes how the Canon RC-1 infrared remote control communicates with the camera. To figure out the protocol I used an IR photo-diode first. Because of the bad signal quality I decided then to disassemble the RC-1 and measure the IR-LED voltage directly. I used the occasion and took some pics of the circuit...

This article describes how to build a DIY low-budget AVR-based infrared remote control for Canon cameras. The reverse-engineered communication protocol of the RC-1 is described here. The RC-1 lets you trigger the camera instantly or with a delay of 2 seconds from a distance of up to 5 meters (~16 ft). It comes in very handy when taking long exposure pictures or for HDR photography. The presented circuit can be used as part of DIY interval triggers for smaller Canon cameras without the external trigger connector. In bracketing mode the RC-1 lets the camera shoot a whole series of images at once...

The SmaTrig is a compact, microcontroller based multi-function camera or flash trigger. Its 15 modes of operation make it come in handy in many situations. It is equipped with sensors for light and sound for capturing short-duration events. The only connection with the camera is the external trigger plug. There is no need to modify the camera in any way. The circuit is powered by an integrated coin cell...

The diagrams below depict the exposure level for different exposure times and aperture numbers for the Canon EOS 400D + EF-S 18-55 and constant light conditions. On the x-axis of the diagram the exposure time is plotted. A log-scale was chosen for more convenient visualisation. The y-axis represents the aperture number as chosen in the camera (linear scale). The isolines depict the mean exposure level of the images averaged over all pixels. The images have been converted from RGB to greyscale before averaging...

When photographing drops, the first problem to overcome is to build an apparatus which emits drops with a stable interval. This article describes how to build a very simple yet elegant drip apparatus (also called a dripper, emitter or just drop generator). The construction is rather trivial. The setup is show in the picture below. The materials you need are...