Interval Long Exposure Camera

Written by: admin@makezilla

There's a real beauty in long exposure photography.  Hours and days and weeks and months and even years can be condensed onto a single frame, and that frame will catalog the constants in our fast paced and forever changing lives.  However, the issue is that these photos can be difficult to capture using modern cameras.  Most fancy DSLRs have a maximum exposure time of 30 seconds, and then to get any longer than that you have to use the archaic "bulb" function that'll kill your camera's battery in only a few hours.  So what's the next option for long exposure photography?  Build the camera yourself!

First, a little science.  Anyone who has taken a basic photo course knows at least the basics behind film processing.  The light reacts with the paper, and then chemicals alter the products of these reactions so that an image can be seen.  Now throw that idea out the window.  Funny thing about RC photo paper is that it reacts noticeably to light regardless of any chemistry you may add after the exposure.  Its something to do with the silver ions and electrons and other things that bald guys who carry around calculators for fun would be able to explain.  But what does that mean for you if you're not bald and don't carry around a calculator for fun?  It's the key to your long exposures.  If the paper is exposed much much much longer than any exposure time that would work with darkroom chemistry, a discernible image will fry itself into the paper.  You can capture entire days this way: the sun can be seen in a trail across the sky and only objects that remained stationary for long periods of time will appear.  This image can then be taken to a flatbed scanner and scanned onto the computer.

So all you gotta do now is build your own camera to put the paper in.  Your camera can range from a basic shoebox with a pinhole to something with shutters and SLR lenses and all kinds of crazy things.  For this instructable, I'm going to show you how to go crazy with it.  Cool things can be captured by just opening up a lens and continuously letting light in, but what if you want an Arduino- controlled shutter that allows you to control when the paper is exposing and when it isn't?  That's what I'm going to show here.

Step 1: Materials

This project is very VERY open ended, and some of the components really depend on what you can get your hands on, so keep that in mind.  However, all of these things are very easily attainable.

First, the building materials:

3/8 inch wood
black caulk
wood glue
black paint
flat head screws and matching wing nuts (relatively small and about an inch long)
1/4 nut
any SLR lens with rear cap (it is imperative you have this cap)
50mm SLR lens with cap (yes, my design uses two different lenses)
black felt
donor 35mm SLR camera
Arduino Uno
9 Volt battery
actuator (I got mine from the steering mechanism of a radio controlled car I got from the thrift store)
paper clips
wooden dowel
RC photo paper

And tools:
Hack saw
Some kind of miter saw or miter brace
Hole saw
Drill press
screw driver
hot glue

**** depending on the route you take with this, you may need additional tools to take your donor camera apart.  a hammer always helps!

Other various workshop tools are always handy too.  There is no right or wrong way to build something.  And again, I stress that these are more along the lines of guidelines to an idea than instructions to building a refined product.  Go crazy with your design! 

Step 2: Step 1: Harvesting your shutter

For this project, you'll need a shutter mechanism, and the best way to get that is from an old camera.  Most 35mm SLRs have a similar construction, so I'll draw out some diagrams on where to make your cuts.  Basically, the goal of this is to get the shutter system out of the camera so that it's still functioning with as few extra parts and pieces attached to it as possible.  Old SLRs are really easy to find, so check around the garage or the attic, and they're always at thrift stores, flea markets and garage sales.

I find the best approach to taking things apart is if you see a screw, it probably needs to be removed.  Sometimes on these cameras, the fake leather trim has to be peeled back for the screws to be accessed.  Other times, screws can be so elusive that your best option is to just break out the hammer and take a few good whacks. 

Use your best judgment on this step.  If a component doesn't appear to be necessary to the shutter's function, remove it.  There is a lot of clockwork inside of a camera, and almost none of it is necessary to the basic opening and closing of the shutter.  Once you've taken absolutely everything you can off of the camera (with the exception of the shutter mechanism which is built into the body). cut away the aluminum body as close to the shutter as you can with the hack saw.  The bodies are almost always made of aluminum, so any blade for non-ferrous materials will be fine.  You'll want to brace the camera in a miter box so that you can get a clean cut.

When the shutter is out, you should have only the screens on the shutter and a few pins on the side of the housing that control the actuation of the screens.  I've pictured the shutter once I got it out of the camera.  Yours should look similar.  Play with the mechanical parts on the side of the shutter and figure out what piece you need to move to get the shutter to open and close.  There should be a small pin that meshes with the mechanical system of the camera when the shutter was still attached.  Make note of the location of this pin.

Step 3: Step 2: Choosing an actuator

I got my actuator out of a toy car.  It was the steering mechanism, and it moves a little arm from side to side.  This side to side motion is idea for this project.  Mind had about half an inch of travel. I'd recommend choosing something similar.

Step 4: Step 3: Build a Box

Using the wood, build a box.  You can be as creative or as basic as you'd like with this box, but it has a few requirements:

1.  Light tight.  After the box is constructed, seal the edges with the black caulk.  Light leaks will ruin your photos, so it's important to make sure the box is light tight.
2.  One side opens.  Make sure one side of the box opens.  This opening side still needs to be light tight when it is closed, so felt can be used to make a gasket (see pic).
3.  A 1 inch hole needs to be cut on opposite sides of the box.  These holes should line up relatively well so you can see through the box. 

So what size do you need?My box had about 2.5x2.5x2.5 inches of internal space.  It needs to accommodate the shutter mechanism, so if that size seems a bit too small to put your shutter into, feel free to make it a bit bigger.  

In addition to being sealed from light, the inside of the box needs to be painted black to absorb any stray light. 

Step 5: Step 4

Drill a 1 inch hole in the rear cap of each lens, and then align the hole in the cap with the hole in the box and glue it on the outside.  Put a cap on both holes in the box.  This will allow you to remove and interchange the lenses on your camera.

Step 6: Step 5

Build a film carrier/viewfinder.  This camera construction allows for composition before the shot using a frosted piece of plexiglass.  Cut a 2x2 inch piece of plexiglass and sand it down.  Then cut another piece, and paint it black.  The film will be taped to this black piece.  The sanded piece will be used during image composition.  I'll explain where these go in the camera in the next step.

Step 7: Step 6 insert components inside of the camera.

Picture of Step 6 insert components inside of the camera.7.jpg

Mount the shutter on the inside of one of the holes in the box.  The pins in the shutter mechanism should be positioned so they point towards the inside of the box.  The open area of the shutter should also align with the hole.  See the pic below.  Then cut four pieces of the dowel at a length equal to the height of the box.  Glue them in the box so that the piece of plexiglass can slide freely between them.  See the diagram below.

Step 8: Step 7: Mount the Battery, arduino and tripod thread

The most successful way to get good long exposure shots is to use a tripod, so you'll need to attach a mount on the bottom of your camera.  To do this, just take the 1/4 nut and superglue it to the bottom of the camera. 

Find a place to attach the arduino and the 9v battery on the outside of the camera and secure them in place.  I attached both on the same side.  Hot glue works wonders.



Step 9: Step 8: connect the actuator

Straighten out one of the paper clips and drill a hole in the box near the top of the shutter mechanism.  Insert the paperclip into the hole and bend the end so it's mounted around the pin that opens and closes the shutter on the shutter mechanism.

Glue the actuator to the outside of the box and connect the other end of the paper clip (the end not attached to the shutter) to the actuator.  Adjust things so that when the actuator fires, it moves the paper clip the proper distance so that the shutter will open and close.

Connect the button and the battery to the actuator so that when the button is pressed, the shutter opens.  The arduino can also be programed to be used as a timer when the leads are moved from the switch to the arduino unit. 


Step 10: Go shoot!

Attach your lenses to the camera.  The 50mm lens should go on the side of the camera without the shutter.  This lens is used as a focusing objective.  With the frosted piece of plexiglass in place, you should be able to look through this lens and see the image coming from the other lens when the shutter is opened.  Set the camera up, and with the plexiglass in the camera, compose your shot.  Then under a lightproof bag, swap out the the frosted plexi for the the black one with the film mounted on it.  Open the shutter and let your image start appearing!  You can open and close the shutter periodically or set it to open and close periodically depending on what you want in your image.  After a few hours, you can take the paper out of the camera in a dimly lit room and see your image.  Throw it on a flat bed scanner and scan it, and you have a digital time lapse image!

Again, no idea how this works, but you can set up the exposures for any time from a few minutes to years.  There are so many possibilities!  I'll post some pics when I finally get them.  Patience is key for these photographs, and the best part is that you can set it up before you go to work in the morning, and when you come back at night your image will be ready to go!