Louise - Paisley wrote in to tell us about a very cool project from Steve of PanoCamera:

In my day-to-day routine I often find myself having to do extensive photographic documentation of objects or locations, only there is often someone waiting to turn off the lights, or move objects, or any myriad of possible interruptions. This is one reason why using a camera tethered to a laptop can be a pain. The computer is a burden to travel with, takes five minutes to boot, the batteries run low, the ten minutes you had to get the job done just became five... It occurred to me that if I could somehow tether a DSLR to an instant-on device like an Arduino microcontroller I would have less weight to carry around and could get more work done. After mentally spec'ing out what I would need, I realized the solution was right in front of me - because I bring it with me for Mario Kart wireless races on long night jobs - (In the manner of John Lasseter's slow epiphany voice): "Use-the-Nintendo-D-S." Duh.

Check out the author's blog for more information: this will be available soon as a combined hardware/software package for about $100. Panocamera DSLR Control

The trick is to use a tripod to take a number of duplicate photos. Each photo should have some portion of the subject unobstructed, and if you take enough of them, you should have every portion of the subject represented in at least on of the files. If you use the same settings and frame all of the shots exactly alike (hence the tripod), it's then just a simple matter of stacking all of the versions on top of each other and cutting out the tourist portion of each layer. All that will remain is the intended subject, and assuming you were careful to capture enough images, there won't be any gaps left behind.

There are a lot of things that can make it easier to achieve good results with this method. Simply, the closer each of the images are to each other, the less visual artifacts you'll have to deal with in post processing. Using a tripod to keep the framing stable, enabling manual focus, fixing the exposure settings, and taking the photos as close to the same time of day as possible will go a long way in making your post-travel photo reconstruction efforts less of a chore.

Remove Tourists From Travel Photos

To obtain certain lighting effects, you sometimes need to attach things to your flash head, such as gel filters or bounce cards. Normally, this involves fussing around trying to strap things down with a rubber band or opting to gum up your equipment with sticky-backed velcro or tape. Instead you can create a cheap speed strap that's both easily removable and simple to attach things to.

There are commercial solutions for this that can be a bit pricey, but Jake O'Connell found a way to make one on the cheap for about $3. Velcro came out with something called a "Design Strap", which is basically a zip-tie with Velcro on one side. Put a rubber band around your flash and then wrap a couple Design Straps over that and you have an attachment system that stays put, comes off easy, and is simple to attach things to. Just add velcro to your gels, bounce cards or whatever and you can quickly affix them to the flash however you like.

DIY 3 Dollar 10 Second Speed Strap

With an empty Pringles can and some lens and body covers, Photocritic devised a way to make a reliable extension tube for taking macro photos. You can make the tube for a few bucks worth of materials - unless you have spares, in which case it's free. Once it's made, you just wrap a standard lens in fabric, shove it backwards in the tube, and slide it in and out of the tube to adjust focus, similar to how a bellows would function. The photo above, which he took of a match head, really illustrates how cool this is, especially when you consider the cost.

Extreme Macro Photography on a budget

Daniel Forsythe put together a walkthrough that shows you how to disassemble your iPhone (original or 3G) and adjust the lens for taking close-up photography. The image above is from his Flickr account, demonstrating the camera focused at about 4 inches - perfect for taking project photos. You can adjust the lens to focus anywhere from infinity (the default) to less than an inch, but you'll need to take apart your phone to adjust it. If you take a lot of close up photos of projects, notes, or bugs, now you can tweak your phone and find a setting that works well for your needs.

Close-focus your iPhone 3G [via Gadget Lab]

When you take pictures with the built-in flash on your digital camera, it's common to get a washed-out, deer-in-headlights result from your subject. This is particularly noticeable with portraits and close-range photography. To obtain a softer, more natural look from your photographs and eliminate the glare, you need a flash diffuser to help disperse and soften the light.

If you have an old white film canister and an x-acto knife, you can make a clever little flash diffuser that will slip over the flash on your typical SLR camera. Photojojo has a guide for making one. It should really take you about 5 minutes (assuming you have a canister on hand), so give it a shot. Your photographs—and your photo subjects—will thank you for it.

Make Your Own Flash Diffuser from an Old Film Container

Berlin hacker Julius von Bismarck invented and patented the Image Fulgurator, a device so awesome that it can remotely insert images into other people's photos.

You aim the device at the same subject that another person is photographing, and when they snap a photo the resulting image will be manipulated with a separate, overlayed photo. The person taking the photo will have no idea anything happened until they examine their photo.

The result is pure magic. Here's a clip of the first public "image fulguration".

The device uses a standard 35mm camera body and lens as a projector. Instead of undeveloped film, the camera is loaded with exposed, developed slide film. A flash is built into the back of the camera, sending light backwards through the body, past the the slide and out the telephoto lens. A light sensor is used to trigger the flash when another camera's flash goes off. Thus, when someone else takes a photo, the Fulgurator zaps its slide's image onto the object for a few milliseconds.

In you want to make something like this, you can use some of the techniques that folks typically use to photograph lightning. Below is a link to a simple Arduino project that will give your SLR a light activated shutter release.

While you're at it, take a crack at making your own Fulgurator with a bit more stealth factor. I'm pretty sure I'd get tazed walking around downtown waving this thing around.

It'd almost be worth it.

Image Fulgurator by Julius von Bismarck [via The Future is Awesome]
Lightning Trigger for a Camera

If you want to shoot time lapse movies with your DSLR, you need an intervalometer, a simple device which sends a signal to your camera to trigger the shutter at a timed interval. You can buy one for around $100, or you can write a few lines of basic and have your trusty TI calculator take timed photos for you, resulting in nifty movies like this:

Yonderknight has an Instructable for doing exactly this with a standard TI 83. You can connect a Canon EOS Rebel to the calculator with the standard 2.5mm data link socket, and the software just sends a 1 down the line once a second. Matt Coneybeare tool this a step further with his code for the TI-89, allowing the user to specify a duration and interval period.

Both howtos walk you through the whole process, including a couple of recommendations for importing and converting the image frames into a video. It should be pretty straightforward to adapt either of these methods to your specific TI platform and video needs.

Turn a TI-83 into an intervalometer
Time-lapse code for the TI-89

Lambert Smith has a great howto for converting a standard 50mm lens from an old SLR camera into a dedicated macro lens for your digital camera. By reversing the 50mm lens and using a number of extension tubes. The photo above is his conversion hack on a Canon Powershot G3, which has a non-interchangeable zoom lens. Custom adapters can be made by gluing filter rings back to back, so you can do this with a normal digital, a DSLR, or even a traditional film camera.

Once set up in this manner, your camera will have a fixed point of focus (unless you use a bellows). When taking a photo, you simply move the whole camera toward or away from the subject until it is in focus.

Reversed 50mm - A Dedicated Macro Lens

There's a technique called the Polaroid emulsion lift that allows you to transfer a Polaroid print to different materials, such as glass, rock, or watercolor paper. Essentially, you soak a completely dry photo (one that has set for at least 24 hours) in hot water and carefully peel the emulsion layer from the photo backing. The thin layer of film can then be carefully removed, spread over a new surface and allowed to dry.

The video above shows how the process works, and there's a link to more specific details below. This is supposed to work best with type 669 film due to it's really think emulsion layer. That said, people have had great results with other types of film, and a thinner emulsion layer will produce cool crinkly effects and tears, which can also be desirable.

Polaroid emulsion lifts
Emulsion lift example on YouTube

Jacob Seidelin figured out a way to obtain EXIF data from images in Javascript, allowing AJAX applications to pull information about the make and model of camera used, as well as any aperture, focal length, or description information that may have been tagged to an image by the camera or a photo editor.

The exif.js javascript library scans through all IMG tags in your HTML document, looking for the custom exif="true" parameter to be set. The DOM image object doesn't contain the necessary raw image data, so XMLHttpRequest is used to fetch the image data. In Safari and Firefox, the responseText property contains the binary image data. This isn't available in IE, however, but Jacob was able to put together a VBScript alternative that is still able to pull the data from the response.

From your code, pulling the EXIF data for an image becomes as simple as this:

var theimg = document.getElementById("imageid");

alert("Image Make: " + EXIF.getTag(theimg, "Make") + "\nImage Model: " + EXIF.getTag(theimg, "Model"));


How cool is that? I expect we'll see this in every ajax photo gallery soon.

Reading EXIF data with Javascript

Lifehacker's Adam Pash put together a nice overview for using CDHK, the firmware enhancement toolkit for consumer-grade Canon point and shoot cameras. With CHDK and a compatible Canon device, you can capture images in RAW format, display live RGB histograms while shooting, and even write custom UBASIC scripts to take time-lapse photos or capture lightning strikes. It does all this while running from an SDCard, so it doesn't require permanent modification to the camera's firmware.

Turn Your Point-and-Shoot into a Super-Camera
Canon Hacker's Development Kit WIki
UBASIC Script Programming

In 1970's Communist Czechoslovakia, the state-run magazine ABCs for Young Technicians and Natural Scientists published a cut-out paper camera called the Dirkon. Looking very much like an old Nikon, the little camera is essentially a simple pin hole design, dressed up to look like its SLR cousin.

Fast forward to 2000's Capitalist USA and you'll find the ReadyMech Cameras which were recently released by adver-warehouse Corbis. Retaining much of the Dirkon cool factor, but looking nothing like a contemporary SLR or digital, there are a number of bizarrely awesome models to choose from.

Whether you dig the ReadyMechs or the classic Dirkon, making the cameras is as simple as printing out a PDF on heavy-weight paper, and following some simple instructions to cut, fold and tape the camera together. To use the camera, you assemble the package around a standard roll of ISO200 35MM film, wind between shots, and pull a little tab aside to expose the film for 10 seconds or so, depending on how bright the lighting is. Getting a clear photo is all about holding still (or setting the camera on a solid surface during exposure).

The Dirkon Paper Camera
ReadyMech Cameras

I posted earlier this week about abrasion holography, a hologram technique that uses a network of simple arc shaped scratches to encode a visible, 3D hologram into a chunk of plastic. Carl was the first to comment on exactly what was on a number of peoples minds:

This is just crying out for someone to generate complex pictures using CNC.

Like many great ideas, someone has already worked this one out! William Beaty was kind enough to write back with a link:

The scratches need to be be almost perfectly smooth with no jaggies at all. Normal CNC doesn't work, but a couple months ago Evan at homeshopmachinist.net found that "drag engraving" does reduce the jaggies enough.

The photo above is Evan's cube, engraved on blackened copper. The top image is what you see in normal diffuse lighting. The bottom is one perspective of the hologram when viewed head-on under a point-source light. Evan writes:

The way this type of hologram is generated is to start with a 2d representation of the subject (the cube in this case). Then an arc is drawn using a point on the visible vertices and edges of the shape. A set of closely spaced points along all visible edges is then used to provide the anchor points for the radii of the arcs. The reason the image isn't perfect appearing is because of slight inaccuracies in the placement of the arcs (my fault) and some waviness in the copper plate which is only 26 gauge material.

There are a lot of creative possibilities with this one. First person to engrave a HACKS hologram on a copper business card wins a standing ovation.

Synthetic Holograms With a CNC Mill - Link
DIY Hand-Drawn Holograms - Link

Typically the creation of a hologram involves lasers and various other expensive equipment and materials. William J. Beaty figured out a low-tech way to create your own holograms using a simple abrasion technique that requires only a compass and a chunk of plastic. He came across the idea while walking through a parking lot, noticing strange hand prints that seemed to float above or deep inside the surface of polished car hoods.

The images were naturally-occurring holograms. The owner of the car had obviously polished the hood with a dirty mit, and the millions of particles of grit in the mit traced out millions of nearly-parallel scratches in the black paint. The particular hand motion had created a geometry of abrasion patterns which turn out to be nearly identical to the interference patterns which make up those embossed-foil Benton whitelight [holograms].

So how do you make one? All you need is a spanner (compass with 2 needles) and a chunk of hard plastic such as Lexan. For simple flat shapes, you just draw the reference shape below where you want the hologram to appear. Set the diameter of the spanner to an inch or two, put one of the points on the shape and score a small arc across the plastic. You then repeat this process for a bunch of other points on the shape, leaving a number of small arc shaped scratches. When you observe the scratches in the light, you'll see a hologram of the shape that appears to float beneath the surface of the plastic.

The image above, from William's site, is actually a stereo photo of one of his holograms. You can cross your eyes to see the effect. The cube that reflects from the scratches appears different based on the angle you view it.

The depth of the hologram is related to the width of the spanner, so you can actually create three dimensional holograms using the same technique. William's FAQs have more details on doing this, as well as hints for creating opaque shapes that have other objects hidden behind them which are only viewable from certain angles.

Abrasion Holography - Link

John Graham-Cumming posted an automated tool for detecting "Clone Tool" Photoshop forgeries. Photojournalism ethics issues (LInk, Link) aside, John had some ulterior motives:

I was motivated to work on this program by greed (or at least my never-ending love of having a little flutter on things). Best of the Best runs spot-the-ball competitions in airports to win very expensive cars. But they also run the same competition online. That meant I could get my hands on the actual image used... could I process it to discover where the ball had been removed? (In reality, this isn't the right way to win because the actual ball position is not governed by where it actually was, but where a judge thinks it was).

Would it be cheating if I could? Apparently not, the competition rules say I should use my skill and judgment in determining the ball position. Surely, skill covers my programming ability.

So, I went looking for tampering algorithms and eventually came across Detection of Copy-Move Forgery in Digital Images written by Jessica Fridrich at SUNY Binghamton. The paper describes an algorithm for detecting just the sort of changes I thought I was looking for.

Essentially the algorithm cuts the image into a bunch of 16x16 chunks and runs each chunk through a discrete cosine transform. The DCTed chunks are compressed and sorted, and the algorithm looks for multiple matching chunks that were shifted the same direction and distance, highlighting the source image if a large number of matches are found.

Another blogger, jjwiseman, released a speed optimization for John's code, which he successfully used on the infamous Adnan Hajj Reuters images. While the algorithm is able to detect this style of manipulation, it's noted that it has a habit of returning false positives in images with a blurry background.

That said, it'd be pretty interesting to run this through a big database of news photos and see what turns up.

Detection of Copy-Move Forgery in Digital Images - Link (PDF)
John Graham-Cumming's Clone Tool Detector - Link
Protecting Journalistic Integrity Algorithmically (jjwiseman's update) - Link

There's an easy way to make a UV pass filter for your camera. It just takes a $5 incandescent black light, a large bottle cap and some duct tape.

For years I've wanted to mess around with UV photography. Unfortunately, all the websites on DIY UV seem to assume an infinite amount of money and access to specialized equipment on my part. There are two things that I don't like, when someone tells me I HAVE to spend a lot of money (quartz lenses starting at $3000) or that i need specialized equipment (Wratten 18A filters, not cheap either).

So I set out to do it my way, and here's my $5 solution to UV wavelength photography.

It's not completely void of visual artifacts, especially at the edges of the photo, but that's what the crop tool is for. As long as you're creative, which you are, you can make it work for you and get really nice results. Save the 3000 bucks for that trip to Europe... you know, where you can exchange it for about 2000 Euro.

Photography in the Ultraviolet spectrum - Link

It's a real drag when you think you've taken a great picture, only to load it up in photoshop and discover that your hands weren't as steady as you thought they were. Depending on the magnitude of your error, chances are you can correct most small camera bumps or pans using a deconvolution filter. The particular technique used depends on which package you use, but they are all built around manipulating the image in the frequency domain to reduce the photo's linear blurring.

Nathan Willis dissected three applications for removing the effects of camera movement from your photos. Two of them, Refocus and Iterative Refocus, are open source Gimp plugins. The third, Unshake, is a closed source Java application that is capable of producing high-quality results with little user effort (though your CPU will be hurting for a minute or two).

If you watch the movies, you have probably seen the impossibly accurate "computer enhancement" hand-waving that turns a blurry mess into a crystal clear mug shot or license plate for the hero to chase. Real-world image enhancement is not that good, but you may still be surprised at the level of quality a good Fast Fourier Transform and deconvolution can produce.

All three of these applications produce admirable results. Refocus is the fastest, and subjectively Unshake produces the cleanest results. It is unfortunate that among the three alternatives, one is not free software and the other two lack active maintainership. But since the math is well understood, maybe someone will pick up where the other programmers left off, and bring even better refocusing technology to the image editors of tomorrow.

The above photo is from the Unshake site. It seems to work well for predominately straight-line blurs over the range of 8 pixels or less. I haven't tried the two Gimp plugins, but I have a feeling the Iterative Refocus package could produce the best results given enough tweaking of the setting.

It's all Fast Fourier Transforms and way over my head, but it works (and frankly, if it was good enough for the Hubble, it's good enough for me).

Unshaking and refocusing your photos - Link
Unshake - Link
Refocus - Link
Iterative Refocus - Link

Instructables user echo_anomie posted a nifty howto for creating a very simple portable laser projector. With a bright enough laser, you can project an image across long outdoor distances and there's never any need to adjust focus.

When it's all assembled, you just drop photo slides in the path of the beam and they are projected wherever you have the thing aimed. It'd be interesting to try this with some kind of LCD in place of the slide. This should let you project eerie green videos on skyscrapers around town.

Laser Image Projector - [via] Link

High Dynamic Range (HDR) photography is the process of taking several images at different shutter speeds and combining them into a single photo that contains no washed out or underexposed areas. The result is a surreal, almost too perfectly lit photograph that contains a high level of detail throughout the image.

Photoshop has a built-in HDR photo merging tool which produces some incredible results without too much effort. The image above, from Ryan McGinnis' excellent Photoshop HDR tutorial, is pretty surreal. It reminds me of a high-res rendering from a video game.

If you're using the GIMP, you can get similar results by carefully masking and merging layers, or you can download and use the exposure-blend plugin which will simplify the process a little. Below are links to both processes - you can see which works best for you.

Whatever package you use, the important thing is to use a solid tripod and only adjust the shutter speed between shots. For the best results, you'll also want to set your camera to RAW mode.

How to Create Professional HDR Images in Photoshop - Link
HDR photos with the GIMP - Link
Using the GIMP exposure-blend plugin - Link

Dave Nance used an ordinary door peephole fitted to a lens cap to produce some whimsical looking images like the one above. Depending on the optics used in the peephole (many are made of plastic) and whether you choose to use a tripod to compensate for the decreased amount of light, you can really end up with a lot of strange aberrations and large regions of the photo that are quite out of focus. Then again, that's sort of the point:

Still, there is something about the way these images look that speaks to me. Perhaps it has to do with the fact that my eyes are slowly going to hell. Without my glasses, the world that I see is no longer as sharp as it was when I was younger. Beyond that, the blurring, streaks, flares, and distorted textures, all create a kind of surreal feeling. When combined with the linear distortion caused by the "fisheye" effect of the lens, it can make these images seem like snapshots out of a dream.

You can experiment with this or other lens-glued-to-lenscap arrangements and see what you like. You'll just need to focus your camera as close as possible ("macro" mode), and then use the adjustments on the external lens to bring things into focus. Most of these setups are pretty touchy and let in very little light, so for best results you'll really want to use a tripod and a remote shutter.

Faux Fisheye With a Door Peephole - Link

WebDesignerWall has a big list of undocumented Photoshop shortcuts that you might find useful. Most notable are scroll wheel zooming by holding down Cmd+Opt, scroll wheel document panning by holding Cmd (or Cmd+Ctrl to toggle between left/right and up/down) and, my new favorite, moving a selection by holding the spacebar while dragging. The latter lets you reposition the top-left location of the marquee while you are still making it, which is about as useful as it comes when you are trying to select something to the exact pixel.

Photoshop Secret Shortcuts - Link

Using an old mouse and a 3/32" stereo jack, Dave Schlier hacked together a nice little shutter release for many Pentax and Canon cameras. One mouse button is used to trigger the half-pressed autofocus mode, and the other triggers the shutter to take a photo.

It will work on Pentax and some Cannon cameras that use a 2.5mm (3/32") stereo monopug that use the middle and inner pins as separate contacts and the outer (large) pin as common.

Supplies: 3/32" stereo jack (solder connections), 3 or 4 wire cable (I used phone wire), old 2-button mouse.

It's a fun way to make use of an old mouse. With the right connector and some slight adjustments, you should be able to adjust this to work with any camera that uses this type of remote shutter release.

Mouse remote shutter release - [via] Link

Daniel M. German found a way to automate perspective correction and projection adjustments for his wide angle photography. He does this by using a Wiimote to record the pitch and roll of the camera at the time a photo is taken. This information can then be fed directly into panotools, instead of manually entering control lines and processing the images to calculate these tilt values after the fact.

I modified an open source DarwiinRemote to record inclination. It happens that if you keep the WiiR in a stationary state, its three accelerometers can be used as two inclinometers. Fortunately most of the time, when one takes a handheld photo, one keeps the camera steady. Steady enough to read the inclination of the WiiR.

I also modified the driver to record the reading from the accelometers, the estimated inclinations, and the timestamp. I would then use the timestamp to match the images from the camera to the readings from the WiiR.

This is a cool idea. I would not be surprized to find high end cameras internally recording and stamping this information into photographs in the near future. A lot of consumer cameras already support panoramic stitching, so with digital accelerometers and tilt sensors being as cheap as they are, why not internally support adjustments like perspective correction or projection remapping?

Using the Wii Remote to correct perspective - Link

For those of you who didn't catch our previous post about seam carving, it's a smart image resizing algorithm, invented by Dr. Ariel Shamir and Dr. Shai Avidan. Where you would normally have to choose between cropping or squeezing/stretching an image to change its aspect ratio, the seam carving method will attempt to find horizontal or vertical paths within the image that can be removed without altering "important" parts of the image, such as people or other objects that would look funny if squished.

There are now a couple of open source Actionscript implementations as well as a GIMP plugin that enable you to "liquid rescale" your photos.

I'm thinking that with a few simple tweaks, you could hack one of the Flash versions load a user-specified JPG or PNG and provide an interface for adjusting the image. It'd just be a simple matter of doing a screen capture to pull the result back into the image editor of your choice.

There's also a Photoshop plugin that claims to do this, but it's closed source, unavailable for macs, and the test version doesn't work for images larger than 640x480. To that I say, "Phtfphpht," but I've included a link in case you are interested. To be fair, it's probably cool... I'm just more excited to see the open source versions surfacing.

References:
GIMP Liquid Rescale (lqr) plugin - Link
Content-aware image resizing in Actionscript (Joa Ebert's original source) - Link
Seam carving in Actionscript (Mario Klingemann's optimizations) - Link
Pictual: Photoshop plugin for smart resizing - Link
Seam carving: content-aware image resizing - Link

Ariel Shamir and Shai Avidan have presented the coolest digital image effect I have ever seen. "Seam carving" allows an image to be resized non-uniformly, so you can change the height to width ratio in the image without cropping, but also without distorting important features in the image (such as faces).

If I understood the demonstration correctly, the algorithm detects horizontal and vertical paths which span the whole image and have the least gradient magnitude along the span. When resizing an image, the pixels along these seams are stretched or removed, leaving the rest of the image untouched. Areas of an image that absolutely need to be preserved can be manually excluded, and the seam generating function will negotiate paths around those pixels.

You need to watch the video to really see this in action, but the technique can also be used to remove whole portions of an image without perceptible artifacts. Essentially, you could cut an Ex out of your old vacation photos and the rest of the image would distort itself, unnoticeably, to fill in the gap.

Seam Carving for Content-Aware Image Resizing - [via] Video: Link PDF: Link
High-res copy of the above video @ Dr. Ariel Shamir's site - Link

Most of these are shot from helmet cam, but there's something cool about the perspective from a fixed bike mount as well. The latter is really easy to do on the cheap, and there are a couple Instructables that'll show you how to build a secure mount for your video camera with just a buck or two or hardware.

Video Camera Mount for Bicycle - Link
Bicycle Camera Mount for under $1 - Link

Oh, and it costs under $5 to make, sets up quickly, and will easily fit in your camera bag.

String Tripod - Link.

How To Compile Gimp for Mac OS X -[via] Link.