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2bit Astrophotography with the Game Boy Camera
- jacquesm 9y agoThat's worthy of the term 'hack'. Very neat :) There should be some silly way of doing this with just a single photo diode and a speaker to provide one axis of motion and to let the Earth's rotation provide the other axis.
- anfractuosity 9y agoHeh that'd be very cool! Do it!
- rocky1138 9y agoCan you explain what you mean?
- jacquesm 9y agoTo make an image you need two axis, one horizontal, one vertical. Because the earth is already moving if you have a single photodiode looking at the stars you will scan a line if you wait a while. By adding a second axis of motion such as a speaker which you modulate with a saw-tooth curve you can add a second axis. If you then scan over time you can re-constitute the image by plotting the dots with the intensity captured by the diode taking into account the driving voltage of the speaker and the time that has passed.
- zkms 9y agoNow you're thinking with superresolution!
- jacquesm 9y agoOh, I just had an even nicer idea that I really will have to try. I won't say what it is yet to not spoil the surprise but I'm sure that it will work :)
- rocky1138 9y agoI get that. I guess I was just confused as to why your first thought was to use a speaker to move the photo diode as opposed to an Arduino with a stepper motor.
- monochromatic 9y agoIt's an exercise in simplicity. Adding an Arduino is a little against the spirit.
- rocky1138 9y agoCan you explain how a speaker with a square wave would move the diode? I'm so confused.
- jacquesm 9y agoSawtooth, not a square wave. Hook the speaker up to some kind of frame, glue a small hinge to the cone, hinge to an arm that's anchored relatively close to the speaker, diode at the far end of the arm in a tube so the light is directional, instant scanner :)
- orbital-decay 9y agoYou can do this even without any motion and possibly even with no focusing optics, just with a single sensor, diffraction grating and a lot of math. This is called single-pixel imaging and is an ongoing research topic in computational imaging.
- anfractuosity 9y agoCould you explain in laymans terms how that would work? If you're only obtaining a single value for a single pixel and there's no movement, how does the pixel value change even if there's a grating in front? Or do you mean the grating can still move?
- keithpeter 9y agoAnd noise? I used to do long exposure photos of interiors of buildings on film (~2h) but digital cameras seem challenged to me.
- anfractuosity 9y agoThat's very interesting re. film. I'd be curious why that is. I've only ever done exposures less up to around a couple of minutes with film & digital. Do you have any examples that you shot for 2hr out of curiosity. Was that with ISO 50 or less, or did you use a darkening filter too? Edit: I wonder if it is due to reciprocity failure with film - https://en.wikipedia.org/wiki/Reciprocity_(photography) https://en.wikipedia.org/wiki/Reciprocity_(photography) ?
- keithpeter 9y ago125 asa FP4 roll film (all monochrome and hand developed needless to say, I used a Rollieflex camera on a tripod when I was playing with this stuff decades ago). I found the correction chart below on t'web [1] just now. I recollect using 2.5x per stop over 1 second which gives slightly longer exposures than [1], but then I did tend to 'pull' the development a bit (contrast goes up), so a 2 minute metered exposure would be 2.5^7 seconds (10 minutes) instead of 2^7 seconds roughly. A 10 minute exposure on the meter corresponds to two hours and a very significant contrast hike - I recollect printing on grade 1 and grade half filter settings (multigrade paper). I only used extreme exposure times in old dark interiors e.g. churches in the UK in November or something. Inside so no need for any filters - not astro. I'll dig a few prints out and scan them over the weekend. Nowt astounding. See if you can find a book about Edwin Smith if you are near a library with a very good photography collection. I have a fantasy of using 10x8 film with a pinhole camera and just doing contact prints... but then I remember the darkroom days and the amount of water that got used up... [1] http://home.earthlink.net/~kitathome/LunarLight/moonlight_gallery/technique/reciprocity.htm http://home.earthlink.net/~kitathome/LunarLight/moonlight_ga...
- djhworld 9y agoReally fun read, thanks Next step, find the Gameboy Printer and print out your shots!
- tbabb 9y agoVery cool. I'd be very curious to see what happens if you do exposure stacking-- in principle, you could get a lot more bit depth!
- throwaway1572 9y agoCame here to say exactly this! In addition, you could stack and them once you have something that's at least 8 bits per pixel use Photoshop to clean things up. I guess instead of making an HDR image from SDR images you'd be making an SDR image from LDR images. :-)
- Jyaif 9y agoI doubt the CMOS is only 2 bits, otherwise we wouldn't have such nice dithering pattern. Somewhere in RAM there's probably at one point a representation of the image with at least 3 bits per pixel.
- Luc 9y agoThe camera outputs analog values. I don't know for sure but I bet the dithering is applied right after the analog pixel is converted to digital...
- objclxt 9y agoYep, here's the technical data sheet for the chip: https://people.ece.cornell.edu/land/courses/ece4760/FinalProjects/f2012/qs44_twc55/qs44_twc55/datasheets/MITSUB_image_sensor.pdf https://people.ece.cornell.edu/land/courses/ece4760/FinalPro...
- trevyn 9y ago"Artificial Retina LSI"... beautiful. :D
- joshumax 9y agoLooks like the maximum supported exposure time is ~1 second... That mixed with the fact that the fact that it has a fairly shallow well depth probably means that the CMOS would be best suited for LUCKY imaging. Also adding a cooler to the back of the Gameboy camera may help reduce amp glow. Anyone have the specs on the ADC chip?
- userbinator 9y agoThere is some reverse-engineered documentation here: https://github.com/AntonioND/gbcam-rev-engineer/tree/master/doc https://github.com/AntonioND/gbcam-rev-engineer/tree/master/... The ADC appears to be part of the ASIC which contains most of the circuitry to interface the sensor to the GB.
- 9y ago
- phpnode 9y agoIs this the most Hacker News title of the year so far?
- app4soft 9y agoCASIO WQV-1 is would be much better choice for 2-bit astrophotography.[1] [0] ftp://ftp.casio.co.jp/pub/watch/wc/WQVLink_Manual_K.pdf [1] http://www.3wheelers.com/elvis/body_wqv-1.html http://www.3wheelers.com/elvis/body_wqv-1.html
- app4soft 9y agohttps://youtube.com/watch?v=czXbhW_hT3A https://youtube.com/watch?v=czXbhW_hT3A
- ljf 9y agoMan I loved that watch - I still have it in my watch box somewhere, but it miss behaves now. I regret not buying the black plastic versions for spares when they were about £12 each. Ho hum!
- app4soft 9y agoIn 2007 my friend got working WQV-1. I tried it and for me it was something like "007" artifact. Think, if I could buy one sometime - I will buy it immediatly!
- ljf 9y agoThey still come up on ebay, but the prices are higher now. But still much less than the £200 it cost in 2001 or whenever I got it.
- serf 9y agodigital camera watch from the early 2000's : 6 months of battery life on a CR2032 coin battery. Current day smart watch (without a camera in most cases) : 24 hours to 1 week battery life using a lithium ion battery.
- zokier 9y agoThe images are remarkably good, considerning the general quality of GB camera images. I suppose this demonstrates that if you stuff enough glass in front of a camera, you can get half-decent images even from the worst of sensors.
- kregasaurusrex 9y agoNeat stuff! I wouldn't have thought that old of a digital sensor would have the sensitivity to see distant dim objects like this. And being able see the same thing in Stellarium by matching up the coordinate view with the actual photo is also cool.
- makmanalp 9y agoIn case anyone here knows - where can one buy an "old-school" low-res / monochrome / dithered camera module that produces images this one, for easy use with a raspberry pi or arduino or something? All I get is weird electronics company websites with "request more info" buttons - nothing that gives me pricing and a "buy" button. Or alternatively, what's a way to transform high-res images to look like that?
- Extigy 9y agoThere's an iOS app called Retrospecs that has some cool lo-fi filters.
- roywiggins 9y ago8Bit Photo Lab on Android is pretty good.
- mcpherrinm 9y agoDithering is something done in software; not in the camera (well, camera firmware could do it for you). I'd just get a modern camera and apply filters to get the aesthetic you want. You can take a look at the output of several dithering algorithms on the Wikipedia page: https://en.wikipedia.org/wiki/Dither#Algorithms https://en.wikipedia.org/wiki/Dither#Algorithms Floyd-Steinberg is a reasonable first choice if you want to implement one. There's pseudocode on its Wikipedia page too: https://en.wikipedia.org/wiki/Floyd%E2%80%93Steinberg_dithering https://en.wikipedia.org/wiki/Floyd%E2%80%93Steinberg_dither...
- joshvm 9y agoBin the image from a raspberry pi camera by a factor of.. 8 or so (maybe 16 if you need smaller)? Load the image as grayscale and divide the counts by 64 to get 2-bit values. Kinda difficult to buy crappy low resolution detectors these days because nobody makes them and you'd need to build the readout electronics yourself. You might as well just use a decent detector and make it look bad.
- anfractuosity 9y ago
- faragon 9y agoSuper-resolution [1] using the Game Boy Camera: any taker? [1] https://en.wikipedia.org/wiki/Super-resolution_imaging https://en.wikipedia.org/wiki/Super-resolution_imaging
- owobeid 9y agoIf you guys don't have the original Game Boy Camera and would like to try, I wrote an iPhone app a while ago to get a similar effect. Sorry for the shameless plug :P https://itunes.apple.com/us/app/pixl8r/id981531620 https://itunes.apple.com/us/app/pixl8r/id981531620