zondag 9 maart 2008

Photo guide: DIY Gobo & Grid

(beware, compactcam pictures below.. my eyes still hurt :( )

We live in Holland. We want a light modifier that brings us specific light when attached to a flash head and that is very small. Specific in the sense that it makes the light very directional. This light modifier is called a grid in photographic terms, or sometimes a honeycomb grid (the one we'll make probably does not go by that term, since the holes are square, more on that later). The grid has a pre over a normal snoot in that it's even smaller (snoots sometimes need about 40cm to make the same tight beam that a grid does). What do we need to make such a grid? And where do we get it? All the ingredients are below in the first picture, but here is a textual list:
  • A sharp knife or other tool that can cut through plastic and cutting board. I had this already.
  • Karwei: Black tape (gaffer tape or something alike). 5 euro's.
  • Praxis: Velcro (both the vel and the cro ofcourse :D). 6 euro's for both.
  • Any store that has plastic car/plane/boat models: Plastic glue. I had this already, but I recon this would set you back about 2 euro or so.
  • Karwei: Plastic sheet laths to put on the ceiling. The side of these made perfect sense for a grid! Mine cost 5 euro for a single sheet. Normally these go for 40 euros for 4 sheets, which is way too great an amount. Find loose laths and bargain on it with the store people :-)
Here you can see the actual lath from the side. As you can see there are squarish holes in it and you can actually look through. These holes will be shot at from the side, so we want to stack multiple layers of this to make a grid that covers the whole flash head.

Here you see a few drawings on the top of the board. Note that my flash head has dimensions (SB-24) of 75mm x 41mm. Alas, no exact size is possible but you want a bit of overlay for using filters/gels on your flash head combined with this tool. So I made 2 longer ones of 8cm x 8cm to stick over the head (top layer and bottom layer) and 4 smaller ones of approx 8cm x 5 cm.
Use the knife to cut out the parts. This takes time and energy, and you need to trim the borders to make it look O.K..
Here are all the pieces together. 4 smaller ones and 2 bigger ones. Time to take out the glue!Before putting together the whole thing, put velcro (hooks side) on one of the big parts you cut.

Now put the pieces together. If the glue seems hard to stick, put books on the whole thing and let it dry for a few minutes. If you're done, start taping the outsides to stop light from spilling outside (and it makes the unit look more nice in my opinion). I've also taped the part that comes over the flash to prevent spill light from exiting the unit at the wrong end.

In the next picture you see the part where the flash head should enter the grid. Note: only one side has the velcro to connect to the top of the flash, this thing is light enough to stick on even with the flash hanging upside down ;)

As you can see in the next picture, the squares aren't actually completely squarish but they'll still work great. Note that I have 5 cm of length for the light rays to be straightened out. This is relatively long for a grid (there are 2 cm versions as well)! Also note you can best use this item at maximum zoom setting (for my flashes thats approximately 85mm) for minimum power loss/spill.
Because I had huge amounts of the laths left, I decided to make some light blocking devices as well. These are easy, 10x20cm devices you put on the side or top of your flash to block light in a singular direction (like stray light into your lens, or to prevent leakage unto ceilings/walls that is not wanted). In the next picture you see the device cut out. Putting some velcro on these things makes them sticky.

This is one side, but I made the other side covered in black tape again so this part will not reflect light (or a lot less!!).
In the next picture you can see both my newly made tools. I've also made some gobo's (the light blockers) out of foam and taped them with the same black tape (they are even smaller and lighter).
Enjoy this stuff! Soon I'll add some pictures of these things in actual use so you can see how these influence your lighting.