Doing Interval Photography with a Sigma SD14

Figure 1: Homemade “DIY” power adapter for Sigma SD14

I really have come to appreciate the Sigma SD14 camera that I’ve been using for over a month or so, applying it for IR photography.  It really shines there, due to the Foveon class sensor that outdistances most competitors in terms of IR sensitivity.  I have captured time-lapse photos that I believe contain as low as 1.5 microns (high mid-infrared) wavelength light.  This is ordinarily not possible with the standard Bayer sensor in most camera brands, based on the info (veracity unknown) – that I’ve come across in my internet meanderings.

The thing with time-lapse photography on the SD14 is that it is hard on batteries.  You are holding the shutter open for long periods of time to capture the weaker end of the IR sensitivity window of the sensor (near the 1.5 micron mark) – and this is measured in minutes, not seconds.  Then, if you’re doing the stuff I’m doing, your running an interval timer to repeatedly take these time-lapse IR photos over periods of many hours.  The SD14 had (powerful for the time it was introduced) dual Analog Devices 600 MHz processors to allow the camera to do image processing.  It kinda eats batteries tho 🙂

The batteries that came with my SD-14 (although I don’t think they are the original OEM brand) – are only lasting a half hour each, tops.  I needed an AC adapter, but those are nearly unobtainium products on the new or used markets.  The adapter, when available, was about 80 bucks if I recollect correctly.  Since it’s unobtainium, it doesn’t matter much what the price was, because I’m forced to work up a home-brew unit to replace it.  I needed to track down the plug size (of the plug that goes into the camera), the needed DC voltage and current requirements, a source of DC voltage, other plugs that are necessary for the DC power provider, and (handily) a case to house the DIY adapter.

So, I found the following items:

  • 1 Aluminum minibox (125mm x 45mm x 55mm)
  • 1 DC-DC converter (credit card dimensions, plus 3/4 inch height).
  • 1 Canon RS-60E3 interval timer
  • 1 EIAJ-03 1.7mmId, 4.75mm OD 9.5mm length DC plug for camera
  • 2 Standard 5.5mm DC power plugs
  • 2 Standard 5.5mm DC power sockets
  • 1 Two amp fuse.

The DC-DC converter is a small unit that fits pretty easily into the 55mm wide minibox.  It can take from 4 to 35 volts DC as input, and can output from 2 to 34 volts DC.  It is capable of providing 8 amps, and has a potentiometer control with which to set the voltage as is needed.   The voltage needed for the SD14 is 7.4 volts DC.  I set the little DC-DC converter to provide 7.45 volts to allow for a little drop across the power cord.  It seems to work very well, and after running all day is not even slightly warm.  I packaged this up in the minibox after adding sockets to the box for 12 volt DC input from a 12 volt DC power supply on one side, and a socket for the converter-to-camera cable on the other side:

12 DC supply -> DC-DC (convert to 7.4 volts) -> camera DC “in” jack

The EIAJ-03 is available from Mouser as part number 171-3220-EX and cost $1.08.  It is a little different from most power plugs, so I’m glad that Mouser had it.  It plugs into the DC in port of the panel on the camera that is next to the HDMI port.

I made darn sure that I didn’t connect the output of the little DIY supply directly to the camera until the voltage coming from the DC-DC converter had been trimmed down to 7.45 volts!  As they come, these DC-DC converters can be set to *anything* out of the box, and maybe to a voltage high enough to fry the camera til it smokes!   No more than 7.45 volts should go into the camera jack (that EIAJ-003 plug).  Also, I put a 2 amp fuse in the DC-DC converter line.

The OEM adapter, when available, was rated at 3 amps.  However, the camera does not draw that much current.  The particular DC-DC converter that I selected for the project just loafs along at (whatever) the camera is drawing, which maybe is only 1.5 amps.

The Canon RS-60E3 interval timer is pretty handy, and as a double benefit it also works fine on my Pentax K5 camera.

Note:  None of this project is advise to others to duplicate.  I’m only a hobbyists, and so this is the work of same …

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The Sigma SD14 is a product of Sigma Corporation.  Sigma and Foveon are their trademarks.  This author and site has no affiliation with Sigma.  The Pentax K5 is a product of Ricoh Imaging Corporation, and is not affiliated with this author or site.

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