A Very Unusual Camera That Emphasizes Time Over Space | Hacker News Reader

A Very Unusual Camera That Emphasizes Time Over Space

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402 pointsspathak58 comments

I built a camera like that out of wood a couple years ago. It uses gears on the inside to pull a regular roll of film through and expose it through a narrow vertical slit as you rotate the whole camera on its center axis. It's sort of a broad-stroke photo. http://nnife.com/d/?dimension=33

Here are a few shots that turned out decently: http://nnife.com/p/?dimension=20 These are just film scans. You can by the light bars see on the photos that it was very hard to rotate the camera at a constant rate.

You can also see that as I went with/against the traffic, cars were elongated or shortened. Really interesting phenomenon. I was working on this with a painting teacher at the school I go to, whose fascination with unconventional forms of photography got me interested as well. Unfortunately I was a woodworking noob when I made it so its success rate was too low for me to keep using it and I never took many more photos than that.

If I ever get around to building a better version I want to try an idea he had: mount the camera in a spot and expose it over the same piece of film at three different times of day using red, green, and blue filters. That would add another level to emphasizing time in a photograph.

The teacher I was working with is named Nicholas Evans-Cato. The experiment started off as just one to make a film panoramic camera. You can see why he'd be interested in that if you look at his work. http://www.georgebillis.com/artists/nicholas_evansCato.html

I'm sure it's been done before, but it was a really fun experiment. Changed the way I think a little bit.

Oh man, those "few shots" are beautiful. Do you have them in a higher resolution?

I recently discovered that you can get some interesting results by pointing the iOS6 panorama camera out the window of moving vehicles...

https://www.icloud.com/photostream/en-gb/#A25oqs3qSfZoE

You don't need an $85,000 camera to play around with slit scan photography. As with just about everything these days, there's an app for that: https://itunes.apple.com/us/app/slit-scan-camera/id419292360...

Note that this is slit-SCAN, which is a bit different in that it moves the "slit" across the face off the sensor, rather than capturing from a static slit over time (the same technique was used in Star Trek:TNG to show the Enterprise going into warp). Nonetheless, you can play with time similarly.

If you want to play with real hardware, scrap a $100 scanner.

Simplest/oldest: http://www.sentex.net/~mwandel/tech/scanner.html (The garage door picture continues to be awesome after so many years.)

More professional version: http://golembewski.awardspace.com/index.html (And weirdest - you really do not want to blink during one of these photos.)

There's also the (admittedly more expensive) wonderful Widelux camera and its various Russian knockoff models. Jeff Bridges uses it to wonderful effect to document on-scenes at most of his movies, and then present the staff with a book when shooting closes. http://www.jeffbridges.com/camera.html

You can just make a video, and select a column of pixels. Then place the different columns (color-wise) you get from each frame next to each other. The resulting image will have the same width as the number of frames you used and it will probably have a lot of artefacts considering the quality of today's (home) video technology. But it is essentially the same.

Just what came to my mind just now.

It's worth noting the the Slit-Scan Camera iPhone app is FREE: https://itunes.apple.com/us/app/slit-scan-camera/id419292360

Slit scan photography has been used artistically before: http://www.cabinetmagazine.org/issues/25/belden-adams.php (the picture of the runner and the cyclist is nicely mindbending)

And pretty much everyone here would be familiar with a couple of artistic uses of slit-scan photography - the opening credits of Doctor Who ( http://h2g2.com/approved_entry/A907544 ) and the ending of 2001: A Space Odyssey.

Is it possible the author hasn't seen a photo finish before? I was surprised he didn't mention races at all.

I thought that as well. I can't imagine anyone who reads athletics/cycling reports wouldn't have recognized those for what they were. He's not far wrong in the article, to be fair - just in suggesting that the artist invented the technique. But that suggests he did no research beyond a misleading gallery press release, since just googling the term brings up lots of interesting stuff.

I don't mean to denigrate the art though, because the pics are still striking and interesting.

I hadn't, so it certainly is possible.

Look at the photo from the article you linked... http://www.cabinetmagazine.org/issues/25/direction%20of%20ti...

The caption says... "the biker and runner crossed the finish line moving in opposite directions"

Wow!

They crossed the finish line in the same direction: past to future.

Face first is what matters here.

Right!

I was also reminded of that weird final scene in the Animatrix short about the runner when he has some kind of warp spasm before transcending and waking from the Matrix. That just gave me a renewed appreciation of animation.

It seems like it would be simple enough to convert a video into an image like these by isolating a single column of pixels from each frame and putting them together chronologically.

Yeah, that was fun:

  #starting at 467s and outputting the images of the next 3 seconds
  ffmpeg -ss 467 -t 3 -i video.mkv output.%04d.png
  # crop image to 1px slices 280 pixels from the left.
  gm mogrify -crop 1x+280+0 *.png
  # stitch them
  gm montage -border 0 -geometry +0+0 -tile x1 *.png image.jpg

Perfect example how easy and straightforward it is to use command line utilities.

Now someone just has to find movies with static camera scenes that have a lot of horizontal actor/object movement.

Random example showing Bill Bailey as a demon: http://i.imgur.com/AWWG8.jpg

Some static rallye car cameras from http://www.youtube.com/watch?v=D2QMuT04EOw -> http://i.imgur.com/GV3bY.jpg

Needs either higher framerate videos or longer scenes.

Corollory : One could produce a whole range of image0%d.png from vertical slices through the video, and stitch them together into a movie. Essentially rotating the movie abouts its y axis (in the x-t plane).

If we assume 50fps, then every 1000px wide video would become a 3-4 minute short. But movies would require a very wide screen...

I tried that with a Super Metroid run (hoping that the results would be easier to see with a video game):

http://i.imgur.com/8TOPA.gif

Nice! That's much neater than I thought it would be.

P.S. you can use "output.%03d.png" to zero pad the output to 011 (and %04d for 0011 etc.)

Yeah, just noticed that myself. Thanks. :)

Cool demo. The 'gm montage' step isn't working for me and I'm finding its options completely non-intuitive. I produced a series of 1979 PNGs from a 66-second video, and when I stitch them with:

  gm montage -borderwidth 0 -geometry +0+0 -tile x1 *.png image.jpg

I get an image that is 45, not 1979, pixels wide. In fact the number of PNGs used as input and the resulting width have a nonlinear relationship:

    # of 1-px wide PNGs     Resulting width (px)
    5                       3
    10                      4
    20                      5
    50                      8
    100                     10
    200                     15
    500                     23
    1000                    32
    1979                    45

Note that I made a couple changes: to speed things up I used "-vf crop=1:1080:280:0" with ffmpeg to skip the separate cropping step and output 1x1080 PNGs, and my version of gm didn't accept the -border option so I assumed you meant -borderwidth.

What's up with the crazy widths on the result? What is GraphicsMagick doing?

Cool hack! I learn something new today.

This is how goal line cameras work - there's one at every race course and sporting event around the world. I had a weekend job running one at a race course growing up.

Nowadays they are digital I guess, but the technology is the same - you record only a sliver (the goal line) - the analog version has the film running past the sliver on spools, with the speed being adjustable based on how fast objects you want to record.

Looking at those photos, I wonder if a "time algorithm" could reconstruct them into a "normal" photo?

Probably not, as the slit is kept looking at one plane. You could turn it into a video one pixel wide, though.

It might be interesting to see a video where each frame is one photo of this, and over time it goes through the different X-positions. Effectively swapping the horizontal and time axis in a video.

You would need multiple slits to be recorded at the same time, but that would just be separating a still frame from a video stream.

If you start with a video you can do this. You'd transform an X x Y x T dataset (X x Y dimensional frames shown over a period 0-T) into a T x Y x X dataset (T x Y dimensional frames shown over a period 0-X).

For a long video you'd get a very wide image that varies over a pretty short duration. A 1920x1080 video clip that's 80 seconds long @24 fps would come out right. It'll still be 1920x1080 and 80 seconds long after transformation.

This is how finish line cameras at races normally work. At least many of the bike races I've been in.

Here's a rather interesting article (from 2004) on how the Tour is managed... http://www.engadget.com/2004/07/19/counting-every-second-a-b...

Horse as well. Throw in a well positioned tall but narrow mirror on the opposite side of the track, and you get a full view of how the race finished in a single photograph.

Yes, all professional track meets (e.g. the Olympics) use these cameras to officially determine order of finish.

Rowing as well

As many others have mentioned, this is a well-explored field. Golan Levin maintains a very extensive list of slit-scan camera experiments, check it out for some awesome examples:

http://www.flong.com/texts/lists/slit_scan/

This pic [1] always used to bug me. Finally makes sense.

[1]: http://www.flong.com/storage/images/texts/slit_scan/lartigue...

Ah, no that's something else: shutter distortion.

This was made on a large format camera -- probably something like 4 x 5 inches -- with a focal plane shutter. The shutter has a huge distance to cover -- 4 inches -- and it takes a while for the slit to cross the whole film frame.

The camera panning on one direction caused the spectators in the background to be distorted in one direction, while the car was moving faster than the camera and is distorted in the other direction.

Its interesting to note that the distortion was mimicked in cartoons as a way to show speed.

Hacked up a quick JavaScript implementation of this for anyone to play with: http://jsfiddle.net/soulwire/xKCt4/embedded/result/

It uses Web RTC so you'll need a capable browser (such as Chrome) and will have to allow webcam access when prompted!

Daniel Crooks is an Australian artist who does similar work, but with video as well as still images. http://www.youtube.com/watch?v=nvUwud5r5Ug

Some of his work is projected onto huge displays which is am amazing immersive experience!

Ward Cunningham and I built something similar with an old Mac mini and an external firewire iSight camera when we both worked at AboutUs a few years back. We pointed it at the train tracks behind the office and got some cool images of trains as they passed by. I don't think we saved any of the images, though -- it was just a quick after-hour hack project.

On a related note, the new Panorama function in iOS 6 seems to turn the iPhone's camera into a slit scanner using the phone's accelerometer for the rotation rate to stitch together a pretty good panorama on the fly.

A similar volumetric slitscanning technique can be done using XBOX Kinect using 3D data points, here is a video result from an experimenter:

http://vimeo.com/51383370

"...this technique uses spatial + temporal data stored in a 4D Space-Time Continuum, and 3 dimensional temporal gradients (i.e. not just slitscanning on the depth/rgb images, but surface-scanning on the animated 3D point cloud)."

This is the kind of photo they use for getting a "photo-finish" shot - they have the vertical spacial dimension, and time running sideways.

I have a similar idea for one of the representations of where I'll be speaking:

http://www.solipsys.co.uk/new/TalksInSpaceTime.html

Here's the first place I saw this in video form: http://www.mutek.org/en/tv/191-biosphere-genkai-1

CINECHAMBER CHANNEL BIOSPHERE - GENKAI-1 Official video by Egbert Mittelstädt From the album N-Plants

It's performed in the cinechamber which is four huge video walls with I think an eight speaker array. The time distortion is amazing and you are totally immersed.

Does this remind anyone else of the Tralfamadorians analogy from Kurt Vonnegut's Slaughterhouse-Five? I can't find the relevant quote...

Yes. It's probably been 15 years since I read the book but that was still my first thought as soon as I read the headline.

This reminds me of something I saw a while back (it might have been on Boing Boing or something, and I'm sure it made its way across the web) of a guy who had a camera he'd made out of an old scanner. Basically, the scanner would move across the surface very slowly so it captured a slice of time. I wonder if that sort of technique is being used here.

Look up "The Fourth Dimension" movie by Zbigniew Rybczynski - at first sight it is hard to believe it was made in 1988 because it looks like a product of some heavy digital 3D processing. In fact it is each of the 625 horizontal scan lines shifted a bit in time relative to the previous one, an idea very similar to the one described in the article.

http://www.jaymarkjohnson.com/videos/

I did something similar once with a flatbed scanner. Put my hand/face/whatever on the bed and moved it parallel to the scan head. Made for really long creepy fingers or a smushed up face.

It reminds me "One year in one image":

http://eirikso.com/2011/01/04/one-year-in-one-image/

every time I see parts of human body like that, I have a flash backs from the very first time when I saw Aphex Twin's Rubber Johny. Worth watching, IMHO :)

http://www.youtube.com/watch?v=NmH1vidnQ1g

kind of similar work of zbig rybczynski way way back (using analogue gear). on a side-note, discussed this with sean of autechre on how to achieve the same effect in maxmsp/jitter by delaying each horizontal line :)

This technique was used in a slightly different way on NRO satellites. I think KH-7 was the first (GAMBIT http://www.thespacereview.com/article/1279/1 ). They would get the film moving at the same speed as the ground that they were covering. The constant momentum of the film moving was easier to counteract than the constant back and forth motion of a big shutter if they were capturing film "plates".

I was looking for this recently! There is a photo, either form this artist or someone else, that was taken at some sort of festival, a photo of all the people walking by.

It was featured in some website that made the rounds on reddit or slashdot or somewhere.

You can get the same effect with a flatbed scanner, which operates on the same principles but assumes a fixed subject, so the camera moves while scanning. I can't find a link now, but there is a fad of rolling your face on a scanner and sharing the result on a website.

Also, this is basically how a CMOS camera works, which is why you get a distortion effect (not jsut blur) when photographinc moving objects: https://www.google.com/search?q=apple+cmos+distortion

Reminds me a lot of "Dancing on the Timeline", a slitscan version of a classic scene from "Singing in the Rain"

http://www.youtube.com/watch?v=HmWljCI_4Ok

It seems excessive to invent a new type of cameras just to take pictures of taichi masters.

j/k

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