[Henrique] wrote in to tell us about his time-lapse photography hack. Triggering of the camera is done via CHDK, or Canon Hack Development kit. This experimental kit allows Canon Powershot cameras to run scripts as well as other neat features without permanently changing anything. User scripts for this hack and others can be found here.

Once the Camera was set up to take pictures in a predetermined amount of time, a LDR (light dependent resistor) is used to detect when a picture is actually taken. A LED on the camera flashes every time an image is stored in the camera, so this provided an easy way to sense when this happens.

Once this signal is received, a PIC 16f84 processor and the associated circuitry then causes the stepper to step once per shot. The results of this experiment are very impressive, so be sure to check out the results after the break.

For another interesting camera trigger hack, check out this trigger mechanism made from an air freshener!

One thing we can all probably agree on is that Tesla coils are one part high-voltage electricity and two parts pure awesome. [Rob Flickenger] thinks so too, and he built a pretty nice one in his workshop some time ago. He took a bunch of pictures showing off the coil’s capabilities, but he thought that one photo taken from a single angle didn’t do much to relay just how fantastic it is to watch a Tesla coil in action.

Taking a cue from the Matrix movies, he bought a stack of Canon point and shoot cameras and constructed a bullet time rig in his workshop. In order to get the pictures just right, he flashed each camera with a customized version of the CHDK firmware that allowed him to trigger all ten shutters with a single button press. A few scripts help facilitate collecting all of the images for processing, after which he identifies the good shots and stitches them together. You can see the awesome results in the video below.

[via LaughingSquid]

Popped balloons or bullets fired into apples, anyone can photograph with a quick sound based camera rig. Lasers have been used forever in motion detection. And even door bell chimes have been used before for remote camera shutter releases. No, [SaskView] wanted to go further and created his Laser Triggered High-Speed Photography setup, to photograph (of all things) milk splashes. We liked the simplicity of the project however;  requiring no programmed microchips or overly complicated circuitry – rather he took a quick trip to the local dollar shop, used the amazing CHDK firmware, and he produced perfect results every time.

[Update: CHDK, not CHKD firmware. My mind must be elsewhere. Thanks jbot and agent smith]

Ever wanted to be able to launch a balloon into space, track its location via GPS, take some photographs of the curvature of the earth, and recover the balloon, all for the low low cost of $150? [Oliver Yeh] sent in his teams project, Icarus, which does just that. The group of MIT students found that they could use a weather balloon filled with helium to reach heights of around 20 miles above the earth;  their particular balloon achieved 93,000 feet (17.5 miles). Then, utilizing only off the shelf components with no soldering, conjured up a GPS tracker using a Motorola i290 Prepaid Cellphone. They then used a Canon A470 loaded with the chdk open source firmware to take pictures. After seeing the results of their launch, the team hopes that this could rejuvenate interests in science and the arts.

[Trammell] has released a new firmware for the Canon 5D Mark II DSLR geared toward film makers. The stock firmware was very limited on the audio side. This firmware adds features such as live VU meters, reduced audio noise, and crop marks for filming in different formats. The firmware is written in a manner that it can be extended fairly easily. Hopefully this will turn out to be as helpful as CHDK has been for point and shoot cameras.

[Adam] made a remote camera trigger that uses a laser. He had to install CHDK on his camera, which we’ve featured in a how-to, in order for it to work. CHDK allowed for a remote shutter trigger through the USB port. The laser bounces off a mirror and onto the photoresisitor hooked up to an Arduino. When the beam is broken, the Arduino sets off the trigger. He also plans to use the trigger to tweet over ethernet. Embedded is a video demonstrating its functionality.

[Related Control your camera remotely with your DS]

[via adafruit]

[Daniel] sent us his entry to the Epilog laser cutter challenge on instructables. He made a book scanner, mainly out of found parts. The bulk of the project was salvaged from dumpsters, though if you’re not comfortable with that, the free section of craigslist might be able to do the job. The cameras are loaded with CHDK, using StereoData maker, and custom software to compile the images into PDFs. They did a fantastic job of documenting every step of the construction, including helpful tips for some of the more complicated parts. There are several videos in the instructable, so be sure to check them out. We’re particularly amused by the extra step of making the photo captions visually interesting. At 79 steps, it’s a long read, but well worth it.

[Tim] photographs insects for bugguide.net. As you can imagine, macro photography is a must. He was very frustrated with his camera’s stock ability to capture the insects. You can see in the example on his site that the image is blurry and has some color issues. He did some research and hacked together a method of getting fantastic macro images for relatively cheap. He used the reversed lens method to get his macro lens set up. He then modded his camera with CHDK for more control. He found that his focal distance was too small to get the entire bug in focus, so he took 15 images at different distances and combined them to make the final image. We’re curious how the pringles can macro lens would compare to this. Thanks for the submission [sp'ange]. Lets see some more tips.

Both Canon and Nikon recently released DSLR cameras that now include a feature that most consumer level digital cameras have had for sometime: the ability to record movies. What makes movie recording especially appealing on a DSLR is the wide selection of lenses available to get the look you’re after. If you’re an owner of Canon’s 40D you may want to follow [DataGhost]‘s progress on the CHDK forum as he is currently working on bringing this function to the 40D.

While [DataGhost] has a working proof of concept he notes that there are still some issues pertaining to the camera powering down while recording a video, autofocusing, and writing to the memory card. Aside from this, [DataGhost] has made considerable progress and is considering adding custom user settings via the mode dial to really give some creative control. We’re excited about this hack and can’t wait for its release to the general public.

[via CHDK forum]

A camera called Pet’s Eye View hangs from your pet’s collar and takes photos in your choice of 1, 5, and 15 minute intervals. While the concept is good, the execution is poor: it can only take up to 35 images at 640 x 480px with no other resolution options available, and it has no expandable media slot. We also dislike the lack of GPS tracking, but wouldn’t really expect that for the $45 price.

For GPS pet tracking, Garmin has recently introduced their Astro System, which consists of a collar with a GPS and a tracking unit. Like most Garmin GPS product, this one is functional, full featured, and a great match of function and technology. We like live pet location tracking, we just don’t have $600 to spend on keeping tabs on the dog.

A homemade solution we like a lot more than the two commercial ones is [J. Perthold]‘s CatCam. Starting with a $20 keychain camera with a 1.3 megapixel resolution and an SD card slot, [Perthold] removed the casing and connected the board to an Attiny2313 microcontroller programmed to trigger the camera periodically. He built a small lightweight case for his modded camera and strapped it to his cat, [Mr. Lee]. This works out to essentially the same product as the Pet’s Eye View camera, but at least twice as good by almost every applicable metric.

One thing we love about the CatCam is the fact that it uses SD media. If you were to use an Eye-Fi instead of regular media, you could have a camera that is superior to the Pet’s Eye View and does geotagging all in one package. It’s not as useful as true live GPS, but at least you’ll know exactly where your pet went when you collect the photos. In addition, if the dog is still within your home network’s range, you should be able to see images as they stream in. If building an Eye-Fi enabled CatCam is too much work, consider using and Eye-Fi with CHDK in a Canon camera. This will give you the timed photography and the geotagging in an easy to build package. Hopefully you pick a small camera unless your pet has a strong neck. You could use some of time-lapse photography techniques we posted earlier to time whatever device you end up using.

The first step in getting SDM to work is installing the software on your SD card. You’ll need to find the correct version for you camera; a list is available on the main SDM page. If you are running Windows XP or Vista, run the installer in the zip file. Otherwise, load the files on the SD card and run the installer directly from the camera. Then decide whether this will be the right or left camera and repeat the steps for your second camera.

Next, you’ll need to prepare a switch unit, essentially a set of synchronized USB remotes. There are many ready made commercial units available, but building one on your own shouldn’t be much trouble, and a few ideas are provided on the SDM instruction page.

You’re basically ready to start shooting stereo images, just take a few test shots to get used to it and to customize the configuration on the cameras.

As anyone who has lusted over the technical specifications for Canon’s new Digital Rebel XSi knows, the capabilities of the average point and shoot camera are severely limited. Using the CHDK firmware hack, the features of Canon point and shoot cameras can be significantly expanded, allowing for ultra-high speed photography, very long exposures, time lapse photography, and RAW capture. This How-To provides a guide to our experiences using the CHDK firmware, and shows just how easy it is to get more out of a point and shoot than ever thought possible.

Installing CHDK

The first step is to install the CHDK software. Our friends at Lifehacker recently ran an article covering exactly that, so we won’t bother repeating the instructions. Be sure to install the Allbest build, it has all of the nice features.

After installing, you’ll want to have the firmware autoload when you boot up your camera. To do so, open up the main CHDK menu by pressing your ALT button, then the MENU button. Scroll down to “Debug parameters”, then click on “Make card bootable…” After it is done, turn off your camera, remove the SD card, and toggle the write protect switch. When this switch is toggled, the camera will automatically boot into CHDK (you’ll still be writing to it).

Taking long exposures

Long exposure photography is appreciated for its soft, sometimes surreal images of (usually) night scenes. Many point and shoot cameras only allow exposures of 15 seconds, but with CHDK, you can take photos at up to 64 seconds.

Navigate to CHDK’s main menu and find Extra Photo Operations. In Extra Photo Operations, change the Override Shutter Speed value to the shutter speed you wish to shoot at, such as 64 seconds. Scroll down and change the Value Factor from OFF to 1.

Though the camera will not indicate the modified shutter speed, the changes will take place. Just take a picture as you normally would. Be sure to have your camera set to manual mode. Taking photos of moving things works best for long exposures: try subjects like the ocean, windy trees, and traffic. Additionally, using neutral density filters, you can even take long exposures in the day time!

Taking ultra-fast exposures

Just as you can override the shutter speed for long exposures, you can take ultra-fast exposures as well, at up to 1/100,000 of a second with some cameras. Flash will sync at up to 1/60,000 of a second, and you’ll need flash with such short exposures. We were unsure how useful or easy this would be to use, but the results surprised us: in just a few minutes we were able to capture nice looking water droplets, without a hint of motion blur.

Navigate to CHDK’s main menu and find Extra Photo Operations. In Extra Photo Operations, change the Override Shutter Speed value to the shutter speed you wish to shoot at, such as 1/16,000 of a second. Scroll down and change the Value Factor from OFF to 1. Be sure to have your camera set to manual mode.

Note that the minimum shutter speed is restricted by the aperture value you have selected in the camera’s manual settings. The wide end (lower numbers), can usually only shoot at down to 1/8000 of a second, while the narrower end (higher numbers) can shoot for the full range.

Prefocus before taking the picture, either by using manual focus mode, or by holding the shutter button halfway down. Though the camera will not indicate the modified shutter speed, it will use the short shutter speed. There are many different things that can be done with high speed photography: capture water droplets, capture explosions, or even capture a bullet leaving a gun. All of these are possible with CHDK.

Running scripts

The real power in CHDK comes from running user made scripts. The first script we will look at is an intervalometer, which allows you to take many photos over a period of time. We used it to easily create a time-lapse video.

Copy and paste this script into a new document, and save as ult_intrvl.bas to your computer. Then, plug in your camera’s SD card, and copy ult_intrvl.bas to /CHDK/SCRIPTS/.

To use the intervalometer, navigate to the main CHDK menu, find “Scripting parameters”, and click “Load script from file”. Find ult_intrvl.bas, and press set. Then, scroll down and adjust the script parameters: the delay until the first shot is taken, the number of shots you wish to take, the interval between each shot, and whether or not you want it to take an “endless” number of photos. Then, exit the menu, but leave your camera in ALT mode, and press the shutter button to start the script.

The video above was created by taking approximately 700 shots at 15 second intervals over 2 hours and 45 minutes. Just set your camera on a tripod or another steady surface, and start the intervalometer. Using QuickTime Pro, go to File>Open Image Sequence to convert the hundreds of separate images into a movie. For space and processing considerations, we recommend setting your camera to a low-resolution mode before starting the intervalometer.

Exposure bracketing

Exposure bracketing allows you to take many pictures at slightly different exposures nearly simultaneously. You can use this to correct errors in the camera’s autoexposure, or merge exposures for HDR photography. Many higher end Canon PowerShot’s have exposure bracketing built in, but for those that don’t, CHDK has the answer.

Like with the intervalometer script, simply copy and paste this script into a new text file. Name it bracketing.bas, and place it in the /CHDK/SCRIPTS/ folder of your SD card.

Then navigate to the main CHDK menu, find “Scripting parameters”, and click “Load script from file”. Find bracketing.bas, and press set. Then, scroll down and adjust the script parameters. The step size is the difference between each image taken, in 1/3 EV steps, the correction is the EV of the middle image taken. The only slightly tricky part here is that first parameter is the (number of images – 1)/2. This means that if you want three pictures, it must be 1, five is 2, seven is 3, and so on. To run the script, exit the menu, leave the camera in alt mode, and press the shutter button.

With these different exposures, you can create HDR tone-mapped images, that show very bright and very dark regions exposed properly. For example, taking the seven different images of the lighthouse above into an HDR program such as Photomatix, optimizing settings for realism, produces this result:

You can also use HDR to produce more dramatic photos, such as this train. It is all in how you process the images.

There is a lot that can be done with HDR, from extremely vibrant photos, to the scarily surreal, such as this one below from Till Krech.

..

For more information on HDR photography, Stuck In Customs has an excellent tutorial.

Taking RAW photos

RAW photos can be extremely useful to digital photographer. They enable you to extract more information from bright highlights in an image, and RAW gives the you complete control over white balance. For example, in the above photo the JPG had an incorrect white balance, which was easily corrected using the RAW image. While DSLRs offer 12 bits of data in RAWs, most point and shoot cameras can only provide 10, meaning that even with CHDK, you won’t be able to extract as much information from highlights as you could with a DSLR. Still, RAWs are very useful for having precise white balance control.

In the Raw Parameters menu, enable “Save RAW”, and adjust the other parameters as shown. Now, you can take photos as normal, and a RAW will be automatically saved with your JPG. The RAW file will take quite a bit a more space than the standard JPG, so your camera will not be able to correctly display remaining space on the SD card.

Processing RAW photos

To process your RAW photos, you’ll need to convert them to the Digital Negative format, DNG. The DNG4PS-2 software can do this for these cameras: A610, A620, A630, A640, A710 IS, S2 IS, S3 IS, A700, G7, A560, A570 IS, IXUS 700, IXUS 70, IXUS 800, A720 IS, S5 IS, IXUS 950, A650 IS, A460, SD800 IS, A530, A540. You can also process the files using UFRaw or dcraw, though that is much more difficult.

Open DNG4PS-2, then go to settings. Adjust the model settings based on how many megapixels your camera is. Next, press OK, and find the path to RAW files option. This is not the location of the file that you wish to convert, but the folder that contains the files. When you have selected the correct folder, press “Convert”.

The DNGs will be in a folder marked with today’s date, and from there, you can process them in Lightroom, Aperture, Photoshop, or whichever RAW processing software you prefer.

Adding a battery meter

Tired of have the low battery warning sneak up on you? CHDK can add a battery meter to your camera, though the configuration depends on what type of camera you have.

To enable it, go to OSD parameters in the main menu, then to Battery. Edit the parameters so that they are as they appear above, if you have a camera with 4 AA rechargeable batteries. Cameras with 2 AA rechargeable batteries should be about half of that. For other power sources, experiment to find the best value.

Writing your own scripts

CHDK uses a very simple BASIC-like language called UBASIC. It has all of the features that one would expect from any language, but there are many camera specific features.

Input/output

Each script begins with a special header, that provides information and control to the user.

@title Intervalometer

In this header, the title of the script is declared, as are two user adjustable parameters. The syntax is simple: @title declares a title, @param par declares the name and label of a parameter, and @default [par] declares the default value of a parameter. Scripts can only receive input through the header, at the beginning of their execution.

To output information to the user, the print command is used: print "Num shots: ", a will print the number of shots, as inputted in the script header. Note the use of the comma to seperate text from variables. The print command is limited to 25 characters of text. To clear what has been printed, use the cls command.

Standard program flow

let a = 2

next x

:display

rem print even numbers

if x % a = 0 then print x

return

This block of code demonstrates many of the logic features of the UBASIC language. To assign values to variables, use the let command. You can also see a for loop and a subroutine. Note the use of the rem command to insert comments, and the single line if statement. UBASIC supports most standard mathematical comparisons, including +, -, *, /, %, <, >, =, <=, >=, <> (not equal to), &, |, ^ (xor).

Camera control

The meat of UBASIC is in its many commands for controlling the camera:

shoot

Takes a photo

click/press/release "button"

Clicks (press and release), presses, or releases on the cameras buttons. The following are available: up, down, left, right, set, shoot_half (depresses the shutter halfway), shoot_full, zoom_in, zoom_out, menu, display, print, erase, iso, flash, mf (manual focus), macro, video, timer.

wait_click timeout

Waits for a button to be pressed, then continues. The timeout value is optional.

is_key x "button"

Immediately follows a wait_click command. If the last button pressed is "button", then the variable x is set with the value of 1. If wait_click timed out, then "no_key" is used as the button name.

set_tv val

Sets the shutter speed to val. Note that val is not “1/1000″ or something similar, but rather an integer value. Each increase in the integer value corresponds to a 1/3 EV increase. The absolute mapping between integer values and shutter speeds varies between cameras, but tables are available here. This, and all following commands must be used with the camera in manual mode.

set_tv_rel val

Sets the shutter speed relative to the current shutter speed. Example: set_tv_rel 0-1 increases the shutter speed by 1/3 EV.

get_tv target

Sets target equal to the current shutter speed.

set_av val, set_av_rel val, get_av target

With the same syntax as shutter speed commands, these adjust aperture settings.

set_zoom val, set_zoom_rel val, get_zoom target

Just like set_tv/set_tv_rel commands. In set_zoom_rel, val is +/- the relative change. Zoom values range from 0 to 8 or 14 for A-series cameras, and 0 to 128 for S-series cameras.

set_zoom_speed x

S-series only. Sets the zoom speed, at x% of maximum speed. x may vary between 5 and 100.

set_focus x, get_focus target

x/target is distance in millimeters.

set iso x, get iso target

x/target is one of the following values: 0 (Auto ISO), 1 (50/80), 2 (100), 3 (200), 4 (400), 5 (800), -1 (High ISO).

Where to go from here

Try checking out the CHDK wiki, for more features then are even printed here. Finally, take photos! The most important thing that you can do to improve your photography skills is to take lots of photos.