As I developed a passion for sketching deep sky objects, it became inevitable that I would start thinking about more practical ways to do so than with a clipboard and red LEDs that were always too bright or too dim and shining all over the show except on the circle where the action was supposed to happen.
I tried a number of tricks but all were unsatisfactory. Eventually I started thinking of a hands-free, fully adjustable red LED lightbox.
My husband was ecstatic when I showed him the plan because it gave him an excuse to buy a new Weller soldering station. Our old soldering gun would have done the job just as well.
For the next few days I played the dutiful wife as I have not mastered the art of TIG welding and needed my husband to construct a lightweight A4 sized aluminum casing. I’m sure there are other ways of constructing the casing. The main thing is to keep it as light as possible.
The bottom looks like a baking tin. The inside has been sprayed white to help with reflection. The top is framed red perspex.
I have used two red wide-angle LEDs each attached to its own battery pack housing two AA batteries. The lights can be switched on individually. Using one LED at a time will give sufficient lighting most of the time, the second is mainly for backup.
The LEDS have been glued to the “baking tin” with hot glue. The LEDs need to be lifted off the bottom slightly otherwise they cause bright red spots. A thick blob of hot glue will do the trick but before fixing permanently experiment with prestik.
The lightbox is attached to a fully adjustable tripod by means of a quick release bracket which will make transporting easy.
Since designing my light box I have made a few very necessary adjustments:
- With just the one sheet of red perspex, the LEDS were far too bright when I became dark adapted. I covered the LEDS with an extra red plastic lid with a strip of aluminum foil lining the inside rim. This helped to contain the light to almost the size of my sketching circle and toned down the brightness considerably
- I have cut a circle (size of my sketching circle ) in a piece of cardboard (size of the lightbox frame) and put this in place before replacing the red perspex cover. I did not like the whole frame being lit up.
- As most papers have fibres which become visible when using up-lighting, I sketch on firm tracing paper which is nice and smooth and diffuses the light as well.
- An adapter to clamp an external red LED to the lightbox comes in handy for when I log my obs before sketching.
- I have added a removable tray to the tripod for pencils, erasers, eyepieces and spectacles.