technical: more sticks, screens and bulbs
Today’s tech section is a chance to tie up some loose ends started over the last month or so. A little stick-in-a-can (from the DIY lighting videos) and a little bulb shootout follow up are on tap.
I’ve been promising stick-in-a-can and screen info and here it is:
 |
 |
 |
| The screens are made using 1″x2″ lumber. These are the kind of “L” brackets we use, along with the supplied screws. Always drill a pilot hold to thread the screws into when dealing with thin wood. As with all projects, find the straightest lumber you can. | Small but important tip: Affix the diffusion material to the front of the screen using white tape. If you use black tape it will be obvious in reflections (play “see the big black square reflected in the chrome toaster”). We’ve used clear packing tape but then the warm color of the wood reflects onto the set. Hmmm, we should be painting the wood white, too. You learn something new every day…. | In this profile you can see how the sticks are anchored to the edge of the can. In the videos I’ve mentioned how much more versatile this makes the stick-in-a-can, being able to clamp things to the very edge. Recognize all of the kinds of cans used (reuse, recycle)? Straight lumber is really important here. |
 |
 |
 |
| Vital: note the wood screws holding the stick in place. The paint can will need the top lip (where the lid goes on) cut away, then put the stick straight against the edge, drill a couple pilot holes and sink the screws. The concrete alone will NOT hold the sticks in forever. This will. And please don’t drop them onto the ground at an angle. if you dent the bottom of the can it won’t be flat and you’ll have a stick-in-a-wobbling-can. | A note about clamps. I like the old school metal ones on the left. The big chunky middle one relies a big rubber tip (nice in theory) but when that gets lost the clamping surface isn’t so great. Same with the over-thought design on the right. I hate these things. The little orange plastic tips flip all around and are never flat when they need to be. Buy the metal ones and be done. | Here it is, the diffusion material. Okay, so the project isn’t as cheap when you buy a nice big roll of 3008 Tough Frost 48″x 25′ (100 Sq. Foot Roll) Diffusion Material |
I had some great comments on the bulb shootout. The Reveal bulb held great promise but ended up being
disappointing in both color and quality of light. jlbec concluded “In other words, they’re for lighting your house, not your pictures :-)”. I literally laughed out loud. It’s worth mentioning that we use the Reveal bulbs (the frosted flavor, not the clear glass) in our digital darkroom / computer room and are happy with them.
NormMonkey pointed out that one of the stars of the test, the flourescent spiral, might have some unseen flaws: “One thing to note about fluorescent bulbs: they don’t create the full spectrum of light, the same way that a white-hot filament (or the sun) does”.
He suggested shooting a color chart so that’s just what I did. Small photos are below and you can get the full size charts by clicking on them. A quick look with the Info Dropper showed that the colors did respond a bit differently (reds were punchier with the tungsten) but nothing leapt out with the naked eye. If you plan to do any color-critical work (like reproducing artwork) then there might be a better choice than the fluorescents…but for most things you’re probably safe. If anyone out there wants to take the bulb-ball and run with it let me know what you find out, I’m definitely interested.
| Tungsten (100 watt GE Soft Light) | Fluorescent Spiral (nvision: daylight) 27 watt = 100 watt |
 |
 |
Now let me spout a little tech junk about the above files: the photos were shot with a Canon 20D, RAW files converted in CS2 / ACR to sRGB with black levels at 5/5/5, mids 131/131/131 and white levels at 148/148/148, so, in theory, it should be pretty darn controlled for comparison.
Whew, that’s it for now. I do want to thank you for the great comments and suggestions. There will definitely be a white balance video coming up!
- Jim T.
| Links |
|
* The videos and articles on prophotolife.com are funded through affiliate relationships with quality companies like Amazon.com and Calumet Photo. When you make a purchase from one of these vendors using a link on this site it puts a small percentage of that sale back into our operational fund (and for that we're thankful).
I agree with you about the clamps. The plastic ones are cumbersome to use.
I loved the bulb shoot-out, and was very happy to see the results of the color charts! Have you had any experience with daylight balanced bulbs, like the trumpet-shaped ones:
http://store.tabletopstudio-store.com/lightbulbs.html
I’d be very curious to see what the color response of those bulbs is.
I only recently ran across those on this site about cheap studio lighting for quilt pictures:
http://www.hollyknott.com/stq/lighting.htm
(I must say, I like your stick in a can a lot more than their stick on four shelf-brackets)
I’ll take a stab at exploring the realm of fluorescents vs. incandescents.
The GretagMacb… er, X-Rite, chart is on my wishlist but for now I found a shoebox at a friend’s house with a similar checkered colour pattern. While it’s no good for accurate colour profiling, I’ll try it for colour comparisons between bulbs.
Hopefully I won’t annoy mah hunnybear too much with random bulb scavenging around the house. I’m sure she’s used to my photography antics by now *grin*.
Norm,
please keep in mind, that the shoebox is printed using inks, that most likely suffer from metamerism. The perceived color of an metameric ink shifts radically with changing the temperature of the light source.
Thats why GM/X-rite and any other standart color charts are printed using special inks.
This is one of the best sites I have ever found. Thanks!!! Very nice and informal. I enjoy being here.
after another viewing of your past videos. I have started to set up my basement with DIY lighting. I have updated the stick in a can to save on space (keeping the wife happy) and more usefull for my needs. I have placed a 1.25 inch PVC in a old bucket with Quickcrete.(I cut the PVC to 4 ft in length so I can store in a closet)
After the quickcrete hardened, I connected my light to a 1 inch piece of pvc. This fits down in the 1.25 just right. I can move the light from about 4 ft to about 7ft. A clamp will hold it in place and I can easly move it left and right. Excludng the light cost was under 15 dollars. I hope that someone finds the helpfull.
Does anyone have a suggestion on another source/kind of diffusion material? Certainly it must be possible to buy less than 100 square feet of something that might work just as well as the Tough Frost mentioned above? Great videos and follow-up material. Thanks.
Instead of acetate, has anyone tried rip-stop nylon at your local fabric store? I’ve heard people talk about it in other lighting projects, but have never tried it (total newbie here).
TIM
Jim,
One thought / suggestion, I decided to make some diffusion screens up but didn’t have any lumber handy, I did however have some white poster board. I cut a 2″ “frame” so I can reuse the center piece as a reflector and taped the screen to the foam core frame. They will not be as sturdy but they are light weight, white and very easy to position plus you get to reuse the middle piece as a reflector.
Great videos and tips, they are much appreciated!
Chris.
Jim,
Do you know if it would work to use a white (or translucent) shower curtain liner for the diffusion screen material? I just thought of this yesterday, and I was thinking that maybe the shower curtain liner would be more cost effective than using the acetate sheeting. What do you think?
Thanks for the great videos!
Brad
Leave your response!
Search Prophotolife.com
Recent Articles
Further Reading
Pages
Categories
Archives
Recent Comments
Most Popular Posts
Related Posts
Most Commented
Tags
approach around the net assisting bulbs business creativity customer service education equipment exposure film fine art gear history insurance interview lenses lighting logo design marketing nature photographer photographers pinhole portrait preview professional organizations RAW review stick-in-a-can studio taxes technical video workflow