Pinhole Trailer #3- Construction

Making the Trailer Light Safe

After researching a number of different options, including building our own trailer from the ground up, the students decided to purchase a trailer. Purchasing a trailer increases the safety (we don’t have to worry about it flying off of the frame when it is traveling) and allows the students to focus on the modifications needed to turn it into a camera. The trailer is 6 feet wide, 6 feet 3 inches tall, and 10 feet long, much larger than our original 5 foot, by 5 foot, by 8 foot design. Once the trailer was delivered, the first task was to paint the interior and caulk any light leaks with black silicone sealant.

Lighting

Once the interior of the trailer was light tight, the students needed to find a set of lights they could use so that paper could be developed without getting exposed. They also needed to find a power supply to run the lights, so they would not have to be run off of a car battery. The students decided to use LED strip lights. They determined that the light from the red LEDs did not fog the photographic paper by placing the LEDs a distance of two feet away from the paper and running the lights for 20 minutes. In addition to testing the lights they also had to test the battery packs. We purchased two 12 V, 3000 mAh lithium ion battery packs. The students calculated, based on the reported current draw of the LED strips, that one battery pack could power two ten foot LED strips for three hours. Testing indicated the battery pack could power the strips for two hours and thirty minutes which is more than a sufficient amount of time to develop photos. In addition, the strips can also be set to white light, to allow students to clean up under easy to see conditions. Once the testing was completed, the students mounted the lights in the trailer.

The Aperture

Once the trailer was light safe, and the lighting had been installed, it was time to create an aperture hole. This hole will be larger than the aperture we are planning on using and will allow us to attach a lens board or a waterhouse stop to the trailer. It will also allow us to attach a simple shutter. A three inch in diameter hole saw was used to drill the aperture hole in the side of the trailer. With the aperture hole drilled, a simple cardstock waterhouse stop and shutter can be used to test the trailer.

Next week we will test the trailer’s camera functionality!

Pinhole Trailer #2

After converting the room into a pinhole camera, students were given the task of designing a pinhole camera using a unique object, (i.e. something that is not a simple box). In order to do this our students had complete a number of tasks.

Students had to drill a pinhole ranging from 0.1 mm up to a maximum of 0.3 mm using a CNC router into a small sheet of copper metal. The router was used because the drill bits were extremely fine and fragile. Drilling by hand resulted in the breakage of a number of drill bits.

Next, the pinhole was scanned and the image was imported into Photoshop (images below).

Using Photoshop, the students measured the diameter of the pinhole in pixels. Using the number of pixels per inch, students used dimensional analysis to convert the diameter into units of mm.

Once the pinhole diameter was known, students could calculate the focal length, the viewing angle, and the image diameter at the focal length for their pinhole. This helped them decide on an object that had a size large enough for the image they were trying to capture. They used this information to design their pinhole camera. An example of one of the student’s designs is shown below.

After they constructed their camera, they had to test it and modify it in order to get a negative that they could print in the dark room. In addition to making a physical print of the negative, they also created a digital print of the negative using Lightroom. The top image below is a camera made from an old medicine bottle. The second image is the negative made with the pinhole camera. And the bottom two images are the physical and digital prints of the image.

In the gallery below, we will be adding images of the students negatives and prints.

Pinhole Trailer

This week we started our pinhole trailer project. A pinhole trailer is a trailer that can be used as a pinhole camera and as a mobile development lab. Once the trailer is completed, we hope to take the trailer to elementary schools to have our high school students teach the younger students about photography. The younger students will get to sit inside the trailer and see the image from the pinhole form on the wall opposite of them. Our students will explain how this works, the younger students will build pinhole cameras of their own, take pictures with them, and develop them in the trailer.

The students came up with a design for the trailer.

Next, they researched commercial options, and we purchased a trailer this week.

In addition, our students learned about pinhole cameras. A pinhole camera, or any camera, has four parts: a light tight body, an aperture (opening), a shutter, and a film plane.

When the shutter is lifted, allowing light to enter the body through the aperture, an inverse image of the scene is formed on the film plane. To help students visualize how this works, we had the students convert the classroom into a very large pinhole camera.

All of the windows were blacked out, except for one small paper sized square (middle image above). Different sized paper apertures were placed over the square (above left), which turned the room into a large pinhole camera. A piece of foam board was used as the film plane (above right), and the film plane was moved back and forth until the image was in focus. Students repeated this process with various aperture sizes to explore the relationships between aperture size, depth of field, image sharpness, and image brightness (which relates to exposure time.) They also used lens with the different apertures to see how the image quality was affected. Next week, students will be building their own pinhole camera.

Capturing the Spark (Part 2)

This week our students captured the spark of Wint-O-Green LifeSavers on color film. Working in complete darkness each student captured the spark of three different lifesavers. The first image was their control.

The image shown above, is one of our students control images. The oil of wintergreen in the candy fluoresces blue. For their next two images, students painted the surface of their candies with fluorescent dyes. These dyes absorb the UV radiation that is produced and re-emit it in a different portion of the visible spectrum changing the normal blue color to yellow, green, pink, or orange depending on the dye or dyes used. The two images below show the effect that the fluorescent dyes have on the color of the spark.

By the end of the week, all of our students had captured the spark multiple times. Their images are in the gallery below. Next project… Thermal Imaging.

Triboluminscence – Capturing the Spark of a Wint-O-Green LifeSaver(TM)

Today we started our unit on Triboluminescence. Triboluminescence is the formation of light caused by mechanical action, such as rubbing, breaking, or crushing. There are many different materials that exhibit this type of behavior: quartz, scotch tape, computer labels, duct tape, and Wint-O-Green LifeSavers.

When, for example a LifeSavers candy is broken, chemical bonds in the candy break resulting in an unequal distribution of charge on the pieces. This creates a large voltage difference between the pieces. As a result of this difference, electricity flows, symbolized by the lightning bolts, between the pieces in the diagram below. The electricity excites the electrons in the nitrogen molecules in the air, the purple spheres, surrounding the candy. Air is approximately 78% nitrogen. The nitrogen molecules emit ultraviolet light, light purple squiggles, which is absorbed by electrons in the oil of wintergreen molecules in the LifeSaver candy. The molecules lose some energy to vibration before the electrons relax back down to their ground state. Because some of the energy is lost to vibration, when the electrons relax back down to their ground state, the energy that is emitted is lower than the energy that excited the molecule and the wavelength is shifted from the UV portion of the spectrum, which we cannot see, into the visible portion of the spectrum in the form of blue light, which is the spark we see.

In other words, the triboluminscence causes the oil of wintergreen in the candy to fluoresce. Fluorescence occurs when electrons in a molecule absorb energy with a shorter wavelength and then re-emit it at a lower energy longer wavelength. In commercial products, fluorescent dyes are used to make objects appear brighter than their surroundings. The dyes absorb UV radiation which we cannot see, lose some of the energy to vibration and re-emit the light in the visible portion of the spectrum. The figure below shows different dyes under room light and fluorescing under UV light.

Materials with common fluorescent dyes in them under normal light (above) and black light (below). From left to right: Rhodamine B, laundry detergent, Mr. Clean, invisible ink.

Ultraviolet light having an energy equal to the difference between the first and the fourth energy levels is absorbed by the electron. The electron is promoted to the fourth energy level, this is a high energy state or excited state. The electron loses some energy to vibration. When the electron relaxes back down to its ground state, it has less energy than it absorbed. So the light that is emitted has a longer wavelength, and is now in the visible portion of the spectrum, which we can see. This is an over simplification but conveys the general idea of what is happening.

We introduced the concept of triboluminescence by having the students observe this process in a variety of different materials such as alluvial quartz, computer labels, scotch tape, LifeSavers candy, and duct tape. We posed a question to our students: can you capture the triboluminescene using your cell phone? The students experimented for an entire period before realizing that it was very difficult to capture the light created by this process.

Next, the students investigated different highlighter markers to determine if they contained fluorescent dyes. Then, they used the fluorescent highlighters on the lifesavers to see if they could shift the color that the lifesaver produced under UV light.

Next week, the students will try to capture the spark and shift the color on film.

Long Exposure Pinholes

This week our students built a simple pinhole camera to track the sun’s movement across the sky, and to observe how the sun’s path increases in height across the sky increases from the winter solstice to the summer solstice. As the sun rotates around the Earth, from winter to the summer, the angle of the sun goes from low to high. As a result, the sun traces higher and higher paths across the sun, reaching its maximum height at the Summer Solstice.

The image below shows the suns path from March 12th to May 20th. Gaps between the solar bands are caused by cloudy days, and gaps within a single band are caused by clouds passing over the sun.

To make the images, a piece of photographic paper is placed into a soda can that has a pinhole in it. The light from the sun exposes the paper and the path of the sun is recorded. The can is left outside for 1-2 months. After two months, it is taken inside and and the paper is scanned. The interesting fact about this type of image is that it is not developed. When its taken out, it is still light sensitive, so it has to be quickly scanned before the image degrades.

Building the Solar Pinhole Cameras

To build the camera, each student had to cut an aluminum can in half. Next, the used a hole punch to make a large hole in the side of the can. Then, they painted the inside of the can gray or black to reduce reflections, and painted the outside of the can gray. They used a needle to put a small hole in a piece of copper flashing and the hole was taped over the larger hole in the can. The photographic paper was loaded in the darkroom, and the can was closed using electrical tape and duct tape. Then, an identification label was placed onto the can. Finally the cans were collected and placed around the school facing the sun. They will be left outside until May 20th. The slide show below displays images of our students constructing the cans.

Update May 23rd: The slide show below displays a number of our students long exposure pinhole images. For each pair of images, the first image is the paper as it looks when it is taken out of the can and the second image is the paper scanned and inverted. Next year, we plan on having our students construct a wedge so that the entire path of the sun across the sky is visible. That is something we did not consider when placing the cans outside.

NHSTE Student Showcase

November 27, 2018

Select students participated in this year’s 32ND Annual Christa McAuliffe Transforming, Teaching, & Technology Conference Student Showcase. We arrived at the conference with display boards, students work and photographic technology to demonstrate. Our students worked to set up their display and highlight what they have been working on.

We answered questions about our process, and demonstrated the technology we have been exploring, both old and new! This was a great experience for both us two as teachers and for our students. They were also given the opportunity to answer questions at the Radically STEAM session. They answered from a student point of view and gave insight on STEAM curriculum, instruction and assessment.

Polarized Light Exploration

November 21, 2018

To continue polarized light exploration, our students were given polarized light filters, and were asked to search the room for plastic objects created under stress. After experimenting heavily, they started taking photos.  At first they tried only two polarizing filters, and it was very tricky to focus the phone cameras like that. Then, as a class they discovered that their phones work really well as different colored backgrounds and have 1/4 polarized screens. They played with shades of red and blue, and of course white light. The cellphones added a multicolored, and patterned texture to everything we photographed.

To start the unit, everyone found some different items including para-film, a stretchy plastic wrap made from paraffin wax. It showed different types of stress from where we pulled, to the area that was stretched in the middle. After the first round of photographs, we learned that other objects, like water beads and bubble wrap added a mirroring affect to the light below. It took a simple bubble or two and turned them into a half-sphere of gorgeous, rainbow colored light. Also, when photographed, the water beads looked as if there were small, frog faces on each one! We presented these images to the class, and more questions arose. For example, what would happen if we took photos of the water beads mid- growing? Turns out that they look extremely compelling when photographed. The water beads got bigger, and even more interesting visually.

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Introduction to Macro Photography

November 14, 2018

Macro photography is a type of photography that involves getting very close to  photography very small subjects. Typical uses of macro photography are photographing insects, teeth (for dentistry), chemical reactions, and circuits. The image below shows two Dental-Eye macro cameras we have in our classroom. Dentists used to use these to take extreme close-up images of teeth.

Dental_Eye.JPG

To introduce the students to macro photography, we had the students use their cell phone cameras with a macro attachment to photograph pennies. The image below shows the macro attachment the students used with their phone. The image on the lower left was taken by a cell phone without the macro attachment. If the phone camera had been moved any closer to the penny, the image would be blurry. The image on the right was taken with the macro attachment. You can get much closer with the macro attachment, notice the the initials “LS” underneath the banner. We also introduced the concept of depth of field to the students. Depth of field is the area in front of and behind the subject that remains in focus. Images in which only the objects immediately in front of and behind the image are in focus are said to have a narrow depth of field. In macro photography, the depth of field is very narrow. You can see this effect in the picture to the left below that was taken with the macro attachment. As you move further away from the “LS” the image loses focus.

Macrosetup

In order to make photographing pennies interesting, our students used a series of chemical reactions first, to zinc coat the penny making it silver colored, and then second, to form the alloy brass on the surface of the penny turning it gold colored. We discussed chemical reactions and alloys with our students and discussed the differences between an interstitial alloy and a substitutional alloy. Brass is a substitutional alloy that forms when zinc atoms mix with copper atoms on the surface of the penny.

Students took a macro image of the penny at each stage of the process: after cleaning, after coating it with zinc (silver color), and after mixing the copper and the zinc (gold color). Then, they used the App PicsArt to create a collage of the three images. Because the depth of field is so narrow in a macro photograph, and because this was our students first experience with macro photography, some of the images in their collage were blurry. But this was a good introduction and prepared them for our next unit on polarized light macro photography. The following image is an example of one of the students collages.

Penny_Roth

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