Light box

[Octane (Humayun)]

All,

Inspired by Barry's wonderful light box, I went about making my own.

I have not built anything since high school woodwork/metalwork/electronics and building a serial cable to control my DSLR with my father, and, am quite proud of my progress thus far.

All of this has been done on the ultra cheap. I purchased foam core board from Eckersley's, an arts and craft store here in Canberra. Two Perspex sheets from ACT Plastics, and all my measuring, cutting, gluing instruments have been purchased from Bunnings and a can of matte black spray paint from Magnet Mart. I think, all up, I've spent about $100.

I will be receiving assistance off our Rocket Boy Andrew with the design and construction of the LEDs that will illuminate this box.

I have built my light box to accommodate my ED80 and also for a Celestron C9.25 or a GSO RC 10" (if I decide to go down either route).

Image 1: 300x300mm Perspex sheet, sandwiched between two lots of 300x300mm foam core board with a 275mm diameter hole cut out in the middle, all glued together. I have built two of these, as you can see. I have built these diffuser masks this way purely for rigidity of construction. To the left is my ED80 and the two little black squares are diffraction masks that I've built for my ED80 and ST80 for focus assistance with the DSI for guiding;

Image 2: You can see the sandwich referred to in the previous point/image;

Image 3: The base (or top) of my light box with markings set out for where the sandwiches are going to sit. You can also see points where I was going to hammer in some nails to set the diffusers. The masks will sit 50mm apart as this seemed to be the most optimal distance for an even illumination of the second mask;

Image 4: The base (or top) joined to one diffuser mask; these were held in place by my Led Zeppelin Complete Studio Recordings boxed set and my Kate Bush book, as I hammered them into position. Also, I don't own a hammer, so, I'm using the counterweight bar for my G-11 to hammer the nails in softly;

Image 5: Both diffusers joined to the base (or top);

Image 6: Correct way up!

This project has been built set to Klaus Schulze's 1977 masterpiece, Body Love 2 -- a must for any fans of pure electronica.

I'll post more to this thread as it nears completion.

Comments and critique or assistance, welcome!

Regards,
Humayun

[RobF (Rob)]

Nice Humayun. Hope it continues to come together well for you.

I found the a number of very handy diffuser layers in an old dead 17" LCD I had lying around - knew I kept it for something....! Your plastic looks perfect and much tougher too.

[Octane (Humayun)]

Hi Rob,

Thanks, mate!

It's coming together quite well. I'll post some more images later and a first light being illuminated by my 24" widescreen LCD.

I just realised yesterday that the plastics supplier sold me two differing types of Perspex. When I held one up to the window, I couldn't see anything, which is what I expected. I held the other one up, and I could see an orange sun which was blaring from behind the clouds. Dang!

Not to worry, I'll put the slightly transparent one closest to the LEDs and let the more opaque sheet do more of the diffusing.

Regards,
Humayun

Originally Posted by RobF

Nice Humayun. Hope it continues to come together well for you.

I found the a number of very handy diffuser layers in an old dead 17" LCD I had lying around - knew I kept it for something....! Your plastic looks perfect and much tougher too.

[RB (Andrew)]

Originally Posted by Octane

I will be receiving assistance off our Rocket Boy Andrew with the design and construction of the LEDs that will illuminate this box.
Regards,
Humayun

I'll make sure the LED's will blink and flash in tune with your favourite music Klaus Schulze's 1977 masterpiece, Body Love 2.

[Octane (Humayun)]

Andrew,

lolllll, Rick Roll! Cheeky bugger!

Regards,
Humayun

Originally Posted by RB

I'll make sure the LED's will blink and flash in tune with your favourite music Klaus Schulze's 1977 masterpiece, Body Love 2.

[Octane (Humayun)]

All,

Here is a single flat frame taken tonight with the camera attached to the ED80 and hand-held up against the light box which was being illuminated by my 24" widescreen LCD monitor. I created a new document (white background) in Photoshop, went into full screen mode, and set the 2000x2000 document to "actual size".

The image has not been touched in any way; it was a small sized JPG straight off the camera.

0.5 second exposure at ISO-100.

Regards,
Humayun

[RB (Andrew)]

Originally Posted by Octane

The image has not been touched in any way; it was a small sized JPG straight off the camera.

0.5 second exposure at ISO-100.

Regards,
Humayun

It seems overexposed at 0.5s.
Have a look at the histogram in PS and compare it to the one I attached here.
I just lowered the levels to bring the histogram back to half way.

Try shorter exposures.

[Octane (Humayun)]

Hi all,

My light box is pretty much complete. I have to say I'm rather pleased with myself considering I'm a gumby when it comes to electronics; I managed to wire everything up by myself and hook it up to a diode and light switch and battery terminal.

Image 1: the final wiring layout. I have used 8 7000 mcd white LEDs wired in parallel (4 x 1 resistor + 2 LEDs). I am sure, that with a bit more careful planning, I could have cut out precise lengths of wire to make it even neater. I have used Tarzan Grip to glue all the components and have placed masking tape over the bits and pieces until the glue dries. I might just leave the tape on for extra security. The diode is right in the middle;

Image 2: lights on! You may notice that I've positioned the LEDs at approximately 45 degrees to point towards the centre of the first diffuser mask;

Image 3: on the outside, the battery holder and switch;

Image 4: a wider view to show where the battery holder and light switch are positioned;

Image 5: the box will double-up as a modern furniture/lighting featurette. You can see how well the first and second diffuser work to stop light in its tracks;

Image 6: an evenly illuminated field!

Three things left to do:

1. Connect the LED panel correctly (much like the rest of the box -- with nails);
2. Create a front panel mask for my ED80;
3. Flock the exterior of the box with some kind of thick material so as to not blind star party goers or destroy their dark adaption.

I was going to spray paint the whole box in matte black, but, I kind of like the idea of having the box illuminate my bedsit at night -- it really is quite bright!

I am really tired right now, but, will hook up my ED80 to my camera tomorrow and take a series of flat fields and create a master flat field to see how this puppy performs.

I would love comments, criticism and/or ways to make this even better.

Thanks!

Regards,
Humayun

[RB (Andrew)]

Looks good H.
If you're going to use it next to your bedside at night, make sure you use rechargeable 9v batteries.

[GTB_an_Owl (Geoff)]

HEH! - where did you get them resistors "H"

sorry "H" - private joke - some of the pony club boy's will get it

geoff

[bloodhound31]

Great work Humayun, I'ts great to see people make better and better stuff each time!

Heres an image I took with mine, th show what a flat should approximately look like. (apologies for the image compression, but you get the idea.)

http://www.asignobservatory.com/Imag...e/Figure19.jpg


This guy here also has a great idea, using his monitor and a diffuser as a light box. Gee there are some clever people around!

http://images.google.com.au/imgres?i...GYr6kAXI-ZG6Dw

Baz.