Why have a light box in the first place?
Between my identical twin brother and I, we have shared countless hours out among the stars with our 700mm Reflector telescope and soon realised that a light box among other things would be a good addition to our tool set. Having that eye piece fall of the telescope stand one more time and trying to find it for the next 25minutes turns out to be a motivator.
So here is a quick introduction to how we made our light box take shape and the final product that looked like this while in use:
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| The "Twin"-Ligh box design - Chris and Rudolph Lombaard |
Well, if you are like me and you have some basic wood working tools around with some offcuts left over from another finished project, why not make something useful with it and impress your friends at the next star party.
Light box material list:
- Wood, preferably painted white all round to reflect as much light as possible.
- Chipboard and two pieces of 1.5''x3'' timber offcuts
- 1x 220VAC 40W, Light bulb, Colour Red.
- 1x Power switch to easily turn the light box on and off.
- Power cord long enough to reach your viewing site. 15meters was enough to the nearest power outlet of my house.
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| "Let there be a cauldron of red light" |
Have you noticed how your eyes have to adjust to the dark surroundings over a period of about 10-30minutes. Depending on how bright the light inside your home is before exiting into the dark, your eyes have to perform what it called dark adjustment by allowing faint light to enter a widening pupil through the retina and hit the back of the eye where light receptors transform the light into a signal that the brain can interpret. Because of the anatomy of the eye being so wonderfully made, it can recognise "normal" bright light during daylight hours as well as VERY faint light at night using specially made light receptors that are perfect for the job. There are many a books and articles [1] written about this phenomenon so I will just put it to you this way: "Your eyes will LOVE the red light when you are trying to watch the stars and fiddle around with equipment such as cameras and telescopes with knobs, buttons and writing (usually white on black in fine print that is difficult to read and cause you to make mistakes in pressing the OK button to delete all photos instead of the CANCEL button to go back to main menu options and survive to tell the story)". I think I have proven my point that you want to see what your doing while still maintaining your dark adapted vision.
Come on, how important could design really be?
When designing your own light box, think about some of the following things:
- Will the light box be hand held, or stationary?
- On a pedestal free-standing from the floor or hanging from a branch or other anchor?
- Where and when would you most likely require the use of the light box?
My first and foremost design consideration was to allow light only to shine in one direction and allow as much of the red light to go in that direction. There was many reasons why this was a good design consideration. The most obvious perhaps if compared to a flash light, is not to irritate and blind your next door neighbours and send the local security company knocking at your door or to bother other potential start gazers in the same vicinity with accidental flashes. Star gazing etiquette is the right subject for another day. Some nights while capturing the perfect light frames using your film or digital camera with long time exposure. Ruing a few 15minute light frames is not fun, ask me!
Final considerations to optimise the design I ended up with were:
- Have just enough of the light in one direction
- Hand held or anchor-able from telescope stand and lightweight
- One finger operation to be able to turn the light on and off easily
- Box to remain visible if left on ground turned off to avoid other family members from tripping over it and taking you and your new telescope down for the count. Sorry mom.
- Operable for long periods of time spanning potentially a full 7 hour night vigil left on the ON position all the time.
With the design out of the way and scavenge all the required materials from my dads home workshop (see my note below on back in the day), it was time to start the build by measuring, cutting, drilling, bashing, tapping and finally painting it a nice egg white. The only item on the list we had to buy was the red light bulb from the closest hardware store. Thanks dad!
Final product:
A view perspective shots of the light box to give you an idea of the final product:
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| "Front perspective with power switch" |
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| "Power cord into back of the box for light socket" |
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| "Top down approach with light socket visible and some dimensioning of the box itself" |
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| "Just another angle to show better depth" |
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| "Without you my friend, this project would not have been possible" |
Last notes:
Now, remember that this light box was built almost 14y ago by now, so if I could do it over again I would probably chose a combination of super bright right LED lights that have become so easy to source. A battery pack on top of that build in and USB chargeable would probably add welcome comfort instead of dragging around a power cord.
Please let me know if you have any other ideas in the comments below or DIY projects you completed and what the results were.
References:
[1] - Night vision - Wikipedia.org
