Monday, October 16, 2006

Free and So Easy: DIY Grid Spots for Your Flash

This is so cool.

I would love to take credit for this idea, but the props go to Strobist reader Gut Mann, who posted a note in the Flickr Strobist threads a ways back.

It sat on my list of (about 20,000) things to do until I saw a piece of thick, corrugated cardboard yesterday. Making these little grid spots really could not be easier. (Heck, the top picture pretty much explains it.) And can be done with things you are likely to already have around the house.

I made a few grid spots for my speedlights. Here's what I used:
• Some corrugated cardboard - the thicker the internal cavity the better, and you won't need much. Just keep your eye out for a biggish box designed to hold something heavy. That tends to be the thick stuff.

• A ruler.

• A box cutter or razor knife.

• Some glue

• A rubber band.

First a little theory.

The grids will give you a very tight spot of light - tighter than a snoot - with nice edge gradients.

The beam width is a function of the thickness of the grid vs the size of the internal spaces of the corrugation. I made a half-inch and a one-inch thick grid for each of my flashes, and they work great.

There are two things you should know about these grids.

One, they will eat some light. But that is not an issue, since they are used with direct flash and generally in pretty close quarters.

Two, they will warm the light up somewhat. This is actually a bennie as far as I am concerned, as they tend to get used to light people and the warm light on skin is quite pleasing.

That said, they are, uh, free, which compares favorably to the ridiculously expensive extruded aluminum models.


Time to Make the Grids

The instructions are to make one grid of each size (1/2 inch an one inch) for a speedlight. Adjust to your needs accordingly.

1) Cut a 1/2-inch wide strip of cardboard about 16 inches long. Cut longer if your cardboard is not the thick, corrugated type.

2) Your strip should be cut so when you look at the long side, you look through the little corrugation tunnels. Be careful not to crush the tunnels when you cut. Use a sharp knife, and not on a surface you can damage.

3) Repeat, making a one-inch wide strip in the same fashion.



4) Cut the long strips into sections a tad wider than your flash head.

5) Stack them without glue to make sure they are wide enough to cover the flash head when stacked.


6) Apply glue to them as shown. The last section will not need to have glue applied, as it will be held by the glue on the next-to-last section.

7) Spread the glue with a finger or piece of paper to get complete coverage on one side of each piece. You do not need to use a ton of glue.


8) Assemble them as shown.

9) While the glue is still wet, align them with a flat surface so they will rest properly on your flash. As long as one side of the stack is straight and even, they will work fine.

10) Let them dry. You can "clamp" them with a rubber band as they dry if you wish. Be careful not to crush the layers.


Attaching And Using Them

You're good to go. Attach to your flash as shown in the top photo. Use a neutral or warm-colored rubber band. You can get fancier with the mount, but this way works fine.

They will give a very tight beam spread. Mine grids approximate about a 300mm lens.


The fall-off is quite smooth, with a nice, hot-spot in the center.

You can put a nice cardboard border on them, like Gut Mann did. But it really isn't necessary to get the job done.

And there is no law saying you need to use cardboard, either. You could use corrugated plastic. But you'll want to use a dark, neutral color (black would be ideal) to keep the light from bleeding out of the edges.

White is going to have a very soft - maybe too soft - gradient at the edges. And a colored version, say red, is going to change the color temperature of the light. The cardboard works in this case because the color shoft is actually beneficial for skin.

I am planning to use these for some assignments soon and will post the results as an On Assignment piece or two. The effect will be similar to that of a snoot, but tighter and with more control. They will also take up less space in your gear bag. Both tools have their own uses, and give slightly different looks.

I wanted to show you what I was playing with so you could try it out for yourself in the interim.

Give it a try. We'll compare results later.

And if you just stumbled onto this place from Makezine or another blog, you see what we are all about here.

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21 Comments:

Blogger David said...

That's awesome! What a great idea.

October 16, 2006 10:21 PM  
Blogger Jon Thornton said...

If you wanted the light to be less modified in colour, you could use corrugated white plastic instead.

Corrugated white plastic would probably eat fewer stops than corrugated cardboard.

October 16, 2006 10:57 PM  
Anonymous steven Noreyko said...

An additional tip - Use plastic corrugated material instead of cardboard.

Cloroplast is a material often used for outdoor signs - it's basically corrugated plastic.

I used this stuff to make a few grids for my Vivitars and SB-800s a couple years ago. Works great.

October 17, 2006 12:03 AM  
Anonymous Marty said...

Great idea! You could also use the corrugated plastic sign material like they use for political lawn signs, etc. It has the added benefit of being waterproof. Also, it is available in different colors, including black and white, so you could make a color-cast-free one if you wanted.

You should even be able to create a pattern with the light, by varying the depth (away from the flash) of the layers, as the shorter layers would allow a wider beamspread and the deeper ones would create a tighter pattern.

I love this site, and have told many friends about it! Keep up the great work!

October 17, 2006 1:07 AM  
Anonymous Gareth said...

I saw this one http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00CRWX&tag=

a little while back and gave it a try, it seems to work pretty well!

October 17, 2006 8:00 AM  
Anonymous Anonymous said...

What? No pictures of the effect? hehehe Nice idea. I'm gonna try the plastic and cardboard versions.
Thanks for the idea.

October 17, 2006 3:19 PM  
Anonymous Ken said...

Thanks for another fun and useful idea. I'll be trying this with other corrugated materials as Im close to art stores and home supply stores. Someone out there HAS to have some neutral colored materials.

Also I think most hotshoe flash users would have velcro on the heads anyway for attachments. (I see some on yours also)
I think 2 strips on the sides in cardboard with some velcro would attach perfectly to the head and also should fold up nicely if bent at the edge.

thanks again.

October 17, 2006 4:17 PM  
Blogger Greg Woolf said...

With all the election stuff going on, I'm sure everyone can have a corrugated plastic grid. :D

btw - you would probably be best to use pvc glue for the corrugated plastiboard.

you might want to take a look at these:

http://www.pegasusassociates.com/HoneycombLouvers.jsp

they are still fairly cheap!

October 17, 2006 7:40 PM  
Blogger okto said...

You should create an Instructable on this.

October 20, 2006 7:55 PM  
Blogger mikule said...

This is exactly what I was looking for for my regular single studio strobe. I put one together the other day and it works a treat, just have to be careful having cardboard so close to the modelling lamp...

October 22, 2006 2:24 AM  
Anonymous Jerry Friedman said...

It should be noted that the surface of the flash lens can get very hot with repeated shots, and can very easily burn the corrugated cardboard. I just singed mine from a five-minute shoot.

October 24, 2006 10:27 PM  
Anonymous Hou Enrong said...

maybe a silicone rubber version can be created for safer long-term use, with the higher temperatures. would anyone buy an industrial version? :) i really love this idea. if you need 3D sketches for a more durable prototype, just let me know. thanks for sharing!

November 24, 2006 4:24 AM  
Blogger jeff said...

Very cool! I whipped one up with a slight modification: I used 2" black gaffer tape to make a collar that allows the gridspot to be slipped on like a Sto-Fen Omnibounce. It's also a nice spill kill around the flash head.

http://i151.photobucket.com/albums/s135/chimpusmaximo/IMG_6708.jpg

May 10, 2007 7:50 PM  
Anonymous cameron obscura said...

I just made my first grids tonight, and found that if you cut a long strip and then cut through all but the last sheet of outside paper, fold over and repeat on alternate sides, you'll have a zig-zag pattern that is VERY easy to glue and arrange. Way less time-consuming than assembling separate strips, and neater, too!

May 30, 2007 3:44 AM  
Blogger Antonio said...

I know this is an old post, so sorry for posting to it at this date, but I bought a flash recently and I found your blog extremely useful, so I'm reading old posts too (which are also quite useful for someone new to the subject like me).

I made today a cardboard grid just like the one you have in the picture above (only that for now I'm holding it with my hand next to the flash light instead of using a rubber band).

The problem I have is that after the flash is triggered I can see a bit of smoke coming from the slightly burnt cardboard and it smells as burnt too. Does that happen to you? is it normal the first times but it will go away? Maybe it's because the flash is overpowered ? (it's a Metz 58 AF-1, which I used at full power as well as 1/64, 24mm, which I guess it's low enough).

Thanks for your site. Keep more posts coming!

June 03, 2007 11:03 AM  
Blogger D.P.S. said...

After a lot of procrastinating about getting started on this, I finally decided to bring some card board home from work and after digging around for awhile I hit the jackpot. I work at Dick's Sporting Goods, (if you live on the East Coast then you've probably seen or been in one before) we have mountains of cardboard left over after our delivery trucks come, and in a treadmill box there were the leftover packing contents, perfectly sized and shaped cardboard blocks for making grid spots. They are about 10 inches long, and 3 & 1/2 inches wide, so they may take a little cutting, but if they aren't crushed then they're great, rugged cardboard. So go to your local Dick's Sporting Goods, and ask the guys in the Bikes and Exercise department if you can have some of the cardboard left over next time they build a treadmill, (or a recumbent bike, or any other large fitness equipment) tell them Dan from store 275 in Apex, NC sent you.

August 13, 2007 12:36 PM  
Anonymous jessec said...

I tried to make a more polished version. Here is what I came up with:

http://jessecathcart.blogspot.com/


I still have to attach the gels and paint everything black.

By the way, how do I get my pictures and instructions on the Strobist site?

January 28, 2008 5:54 AM  
Blogger Brian said...

David,

Excellent how to. There is a grammatical error that I am sure you would like to remedy. Do a quick search for "shoft" in the article.

January 22, 2010 11:45 AM  
Blogger Ole Mikael said...

Superb idea.
In some situations it's also useful with an on-camera flash (sorry, I know I should wash my mouth) to avoid light-spill onto the surroundings and
give a feeling of intimacy by only lighting the center of the frame. Hard to control, though.

Sample (cropped shot@30mm):
http://www.flickr.com/photos/olemik/4323934184/

February 01, 2010 7:47 PM  
Blogger Steinhard said...

Awesome..
thanks for sharing.

January 14, 2011 11:07 PM  
Blogger Tommie said...

I have to admit, after successfully experimenting with your "bare bulb effect" using cheap Tupperware in my kitchen, this idea has me pretty excited as well.

Honestly, I find myself now trolling the photography gear sites trying to find things I can "DIY" and save some bucks for the real expensive stuff - like GLASS.

This is really cool stuff.

February 10, 2011 4:27 PM  

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