Hacking a Sigma lens to work with a Canon camera

sigma-lens-canon-camera

[Martin Melchior] wanted to use an older Sigma lens with his Canon camera. The problem in trying to do so is that the camera uses a different communications protocol than the lens is expecting. But if you don’t mind cracking it open and doing a little microcontroller work you’ll be using the lens in no time.

The hack uses an ATtiny24 chip, two resistors, and a capacitor. You won’t need to do any coding, but you do need to burn the firmware to the chip (you can use an Arduino if you don’t have a proper AVR programmer). There’s plenty of room for the add-on hardware inside the lens so after reassembling the enclosure you won’t even be able to tell that the unit was altered. Unfortunately it doesn’t look like [Martin] took any pictures of the lens with his added electronics, but the schematic he posted should be enough for you to get the job done yourself.

If you’re into these types of DSLR hacks you should try something extreme, like using view camera parts with your modern camera.

LiFePO4 batteries work much better in a camera than NiMH

SAMSUNG

We agree with [Zapmaker] that Canon cameras chew through nickel metal hydride batteries. But we’re not going to use Alkaline because we think it’s wasteful. His solution is to use a battery that has a higher voltage rating. What you see here is a single lithium iron phosphate cell paired with a dummy cell to increase life between charges.

The reason that NiMH batteries don’t last very long is that they’re only rated at 2.4V. It won’t take long for that voltage to drop below the camera’s cutoff threshold since they didn’t start very high to begin with. But a single LiFePO4 cell has the same form-factor but produces 3.2V and maintains voltage well through it’s discharge cycle.

The size is right, but using one cell won’t work by itself. He built a filler for the other slot which is just a wood dowel with a screw all the way through it. The point was ground down and a bit of foil added to ensure a proper connection. We’d be interested to hear back about how this performs over the long term.

Microcontroller gives you more control of your camera lens

Here’s one way to get more control of your camera lenses. [Vladimir] built an Arduino-based pass-through ring (translated) which intercepts automatic lens controls. It’s meant for use with the Canon EOS lenses which have their own electronics allowing control of things like focus and zoom.

It seems like part of the motivation here was to uses the lenses with other brands of cameras. But [Vladimir] does also talk about the possibility of improving on some of the sensors that don’t perform well in certain climate conditions (think of how crystal oscillators will drift as temperature changes).

The machine translation is a bit rough to follow, but it seems the adapter ring still uses the settings sent in from the camera but has the Arduino clone to translate them into a format that the lens is expecting. In addition to this there is a set of buttons on that small PCB beside the lens which allow for fine tuning the aperture.

This is a lengthy writeup, but there’s two more on the way that will help fill in the gaps of how this hack works with different lens models, and some more tips on how to use it.

[Thanks Vasily]

DSLR performance measured with audio editing software

[Jaroslav's] camera didn’t have a feature to measure the speed of its response in different modes so he figured out his own method. Using the microphone on his webcam he recorded the sound made by the mirror and shutter movements, then used Audacity to analyze the camera’s performance.

When you get right down to it, this is a fantastic idea. Audacity, the open source audio editing suite, has the ability to show each captured audio track next to each other. That makes it easy for you to precisely align the clips, and has in-build time measuring features with fantastic resolution.

He tested a whole bunch of different settings on a Canon EOS600D DSLR camera. In the image above you can see him comparing performance between different ISO settings. He also looks into different brands and sizes of SD storage cards, as well as the time difference when storing raw image data versus JPEG encoded data.

Exposing some fake electronics with too-good-to-be-true prices

[Giorgos Lazaridis] needed an AC adaptor for his Canon PowerShot camera. He hit eBay and was excited to find this branded adaptor for just five bucks! It works and, even though it would sometimes reboot his camera if the cord was twisted around in the jack, he was satisfied that it did what it was supposed to.

That is, until one day he observed some very peculiar behavior while taking pictures of a PIC circuit he was prototyping. When holding the camera and putting his other hand near the breadboard one of the status LEDs in his circuit began flashing sporadically. If he was using the camera with batteries instead of the adapter this didn’t happen.

His first instinct was to hook up the adapter to his oscilloscope and see what is happening on the power bus. The signal is incredibly noisy. Shockingly so. [Giorgos] cracked open the case to see what is going on with the power supply circuit inside. You simply must view the video after the break to see the horror-show he found. The board is poorly soldered, components are not properly seated in their footprints, and our favorite is when [Giorgos] points out a squiggly trace which takes the place of the smoothing inductors.

Have you documented your own fake electronic hardware finds? We’d love to hear about them. [Read more...]

Knockoff game controller makes a fine remote shutter release

remote-shutter-release

[Duncan Murdock] received a Canon DSLR camera for Christmas and wanted a remote shutter release to go along with it. Since nary a store was open on Christmas, he was pretty much out of luck. Scrounging around in his parts drawer, he found all sorts of goodies waiting to be reused, including a knockoff Wii nunchuck.

He pulled the original cable from the nunchuck and replaced it with an old telephone wire, attaching a 2.5mm plug to the end. The plug goes directly into his camera’s control port, allowing him to trigger the auto focus and shutter mechanisms with the push of a button.

We like the idea of a junk controller being recycled for use in a camera, though we think it has far more potential than being used as a simple wired trigger. If both the nunchuck and camera were fitted with some sort of wireless interface (Bluetooth, IR, etc), we think it would make a great addition to any hobby photographer’s kit.

Auto-Focus assist hack keeps improving

[Adrian Onsen] keeps making improvements on his auto-focus assist hack for DSLR cameras. The module seen above is version 3.0, which makes a few changes to the previous hardware and also presents a much more finished look.

With version 2 [Adrian] was using a defocused laser to illuminate dark subjects so the DSLR auto-focus could be used. It worked, but wasn’t really ideal. This time around he’s swapped out the laser diode for an autofocus assist lamp salvaged from a Canon 550EX he picked up ‘as is’ on eBay. It is mounted on the front of his project enclosure, using two alkaline batteries for power. It sounds like [Adrian] is struggling a bit with his circuit design. He want’s to make it work with either alkaline or rechargeable AA batteries (just two, down the from four AAAs used in version 2) but so far the rechargeable are a no-go. They power the circuit, but must not put out enough light for the sensor to work.

Future plans include getting rid of the external cords by adding a hot shoe connector.