This article will explain the importance of knowing what your flash sync terminal voltage is, and show you how to measure the voltage to make sure your flash is safe to use with your digital camera.
Vivitar 285 'Zoom Thyristor' Flash Head
(283 and 285HV are similar)
A few months ago, I was looking into purchasing a flash to use with a slave for my Canon PowerShot S2 IS, and I was very fortunate in finding a Vivitar 285 flash head for $20 at a local auction. And, best of all, it was unused (but an old model...). It worked great with my Canon, but after my Canon died, I bought a Nikon D40 (which I used to take the pictures on this page), which had a flash hot shoe on the camera's body. Luckily for me, I had read earlier that some Vivitar flash units used very high flash sync terminal voltage (sometimes over 200V!), and the only way to find out if my 285 was safe was to measure the voltage on the flash unit.
Unfortunately, though, finding a guide for (a) how to measure the voltage and (b) what voltages are safe for my camera was very tough. I found this site, which explained the process of measuring the voltage, but didn't have many pictures, and this site [botzilla.com], which lists voltages of many Vivitar (and other) flash heads, but, as I didn't see any really nice guide to the process, I decided to make my own guide here.
'Made in Japan'
The basic problem is this: many modern digital cameras' circuitry will be harmed (sometimes fried) if you use a flash with a sync terminal voltage greater than 6 volts. And many older flash units weren't manufactured to a strict voltage specification—especially if they were manufactured at different facilities. Supposedly, Vivitar 285/285HV flash units that read 'Made in Japan' on the bottom (see illustration) were the dangerous ones. But some are safe to use (mine included).
If you measure the across the center pin on the bottom of the flash and the rail contacts in the hot shoe connection on the flash while the flash is fully charged (with its green ready light on), you will be able to determine if your flash head is able to be used with your camera.
How to Measure the Sync Terminal Voltage
What you will need:
A flash head (duh!)
A Multimeter (digital or analog)
Digital Multimeter (can be had for <$20!)
Turn on your multimeter, and set it to DC voltage, at the highest range (I set mine to 1000V to start).
Turn on your flash head, and set it to the highest power setting (on the 285, set the dial on the front (on the 'vari power' module) to 'M').
When the flash is fully charged (and the green ready light is on), flash it using the red test button, then let it recharge again.
After it's recharged, put the black test lead from the multimeter on the electrical connection pin inside the hot shoe rail on either side of the bottom of the flash, and the red test lead from the multimeter on the bottom hot shoe electrical connection pin (see illustration).
Your multimeter should show a reading; if the reading is very low, turn the multimeter's range down to something like 100 or 200 volts. If the range is still too high, turn it down again, until you can read what the voltage difference is between the two leads on the flash. After the flash is fully charged on my unit, the voltmeter reads '6.14' volts. (Note: While the flash is charging, your meter will read anywhere from 0.0 to 0.2 volts - this is normal).
To make sure the flash is consistent in its voltage, it's a good idea to press the test button a few more times and see if the voltage stays the same (+/- a few hundreths of a volt).
If the voltage is around 6V or lower, it should be safe to use on most digital SLR or digital point and shoot cameras with a hot shoe for the flash. If there is any doubt, contact the manufacturer and ask what the maximum flash sync terminal voltage for your particular camera model is (some Canon cameras, including the PowerShot G series, might not even accept more than 4V!).
If you need a better way to hold the light you use while taking pictures with the DIY Greenscreen you just made, or you need a better way to control where light goes for keying out backgrounds in Photoshop, read through this tutorial on how to make a quick and durable (and highly configurable) lightstand out of one of those old, sort-of broken cheap tripods you have sitting in your closet. Even if it's your main tripod, you should be able to modify it so you can swap it for a lightstand or standard tripod pretty easily.
Here's my old tripod, modified to mount monolights or other photographic lights (like an off-camera speedlight) via the bolt you can see at the top of the picture.
Here's a closeup of my umbrella/hot shoe light stand adapter that I mounted on my modified tripod. You can get an umbrella/hot shoe adapter on eBay or any photographic supply store for less than $20.
1 - The Materials
As in the case of my $0.02 macro studio (with which I use my tripod/light stand), I like being resourceful with my money. If I have something I can use for more than one purpose, I will do so. I have an old tripod (about 20 years old) that is a bit squeaky and doesn't pan or tilt well anymore. So I went to the hardware store to find some parts to modify the tripod into a makeshift (but sturdy) light stand. You'll need:
An old (or new) tripod. Preferably one without a 'quick connect' camera mount - the top surface needs to be able to be drilled through.
A 3/8" (or so) diameter bolt, with a washer an nut to fit on it (Get them at your local hardware store). You don't need to be exact here, but this will basically be the part your monoligh or umbrella stand adapter will fit onto. Total Cost: about $1.
A powered drill and a bit with a diameter larger than the bolt you bought. If you're old school, you could use a hand-powered drill... but don't whine to me about how sore your hands will be!
2 - The Setup
For visual learners, here's a picture of the tripod head with the bolt on it (a step-by-step setup guide is below):
Basically, take a drill bit that's a tad bit larger in diameter than the bolt you bought, drill a hole in the tripod's flat surface, then put the bolt through, with a washer on either side, and a nut to secure the bolt to the tripod head.
Here's a step-by-step procedure:
Go to the hardware store and get a bolt that's about 3/8" diameter, with two washers and a nut to put on the bolt.
Take your tripod and pop the head off, or swivel the head in such a way that you can drill a hole through it without damaging anything or anyone else.
If you can't get at the tripod head with your drill unless you remove the part that screws into your camera, you can usually remove that using a small socket wrench or needle-nosed pliers... Take that part off if you need to.
Using a drill bit that's a tiny bit larger (in diameter) than your bolt, drill a hole through the flat top part of the tripod. A wood drill bit should work fin for plastic; if the tripod has metal, you'll have to get a metal-drilling drill bit.
With a washer on it, stick your bolt through your newly-drilled hole, so the head of the bolt is on the underside of the tripod's mounting surface (see the illustration above).
Put another washer on over the end of the bolt that's sticking up from your tripod, then secure everything with a nut.
That's it! Now you can stick a monolight or an adapter for your hot shoe flash on the bolt, and use the tripod to direct where the thing is pointing and how high it is.
Notes About the Tripod Light Stand
If you need a light stand that's taller than, say, 5', don't use your old tripod; get a real light stand instead so you don't have safety issues (a cheap tripod can easily fall over if you put a large light on it, with an umbrella, then raise it to the maximum height, chances are you will break something.
If you don't have an old tripod to do this to, it might be cheaper (and less stressful) to get a real light stand. You can get them in any height up to about 13', with air-cushioned supports, etc. for less than $50. This modification was practical for me because I have a new Bogen tripod (one that will actually last) and no use (other than as a light stand) for my old cheapo tripod.
There are tons of creative ways you can mount your lights on various objects. This is only one of a million ways you can find cheap mounts for your strobes. I learned on Strobist how to use some $3 hardware clamps as 'clip light stands.'
Don't put really heavy lights on a cheap, fragile tripod. Usually these tripods have a maximum weight of something like 3 pounds. Putting a 5 pound light with a two pound umbrella on it would be what I call a "bad idea."
This article will explain how to remove or 'key' green screens or blue screens or remove plain color backgrounds in Photoshop (works with versions 5, 6, 7/CS, CS 2 and CS 3). You might want to do this kind of thing after using your brand-new DIY Greenscreen you just made...
From this...
...to this!
Videographers often use green screens to film people and put backgrounds in that were either too hard to create in the real world or were too hard for the actors/talent to travel to. In photography, 'green screening' can be very useful for many different purposes. Not only does it make it easy for someone to change the scenic background behind a person, it also can help to make distinctive portrait backgrounds or 'cut out' an object that you would like to be able to manipulate easier.
(Quick Note: This guide is simply explaining one Photoshop technique (among many) for removing solid color backgrounds. To acquire a good, evenly-lit background is a completely different topic (and one which I don't have time to discuss here).
The easiest and most effective method for 'keying' (removing) any plain color (green, blue, or any other color) background in Photoshop (as long as the subject has none of that color in his/her clothing or makeup!) is to use the 'Color Range...' command, located in the 'Select' menu. (You could also remove the background by using the 'magic wand' or drawing with the pen or lasso tool around the subject, but if you have a good, solid color background (even with less-than-stellar lighting), it's much easier to use the Color Range command.
There are also many other ways to 'knock out' the green or blue (or other colors, for that matter!) that can be easier or harder, depending on your source photo. You could use the Magic Wand, using special plugins, using a Channel mixer adjustment layer, or mask your image in quick mask mode. The biggest advantage to using the Color Range command is that you can easily set up an Action for batch processing photos, and your selection can be used for many /sites/lifeisaprayer.com/files/articles/photography.
The step-by-step instructions below work with Adobe Photoshop CS, but should be similar (if not exactly the same with other version of Photoshop, including CS2, 5.0, 6.0 and 7.0).
Step-By-Step Instructions
Open the photo you would like to remove the green screen from in Photoshop.
Select 'Color Range...' from the 'Select' menu.
After the Color Range dialog box comes up, click on the eyedropper tool, drag the 'Fuzziness' slider to about 30, check the 'Invert' checkbox, choose 'Grayscale' from the 'Selection Preview' popup and make sure the 'Selection' radio button is pressed.
With the eyedropper tool, click in the green area of the image (either on the main canvas or in the 'Color Range' dialog. You should see much of the green area as white, and the rest of the image (which will be selected) black. If there are still areas (because of non-uniform lighting) of the green screen which are not white, hold down the Shift key and click on them with the eyedropper until all of the green area is selected.
This selection should work pretty well, but if there are still pixels here and there that are white, you can lower the Fuzziness until it's easier to click on the areas. Also, you can hold down the shift key and click and drag your mouse across an area to select many points at once, instead of clicking for each point. To select with even greater accuracy, you can zoom in by pressing 'Command' - '+' (Mac) or 'Control' - '+' (Windows).
Once you're satisfied with your selection, click 'OK'.
You should see the object you are trying to select selected. If there are any problem areas (i.e. you see scrolling ants in areas inside or outside your selection that shouldn't be selected), use the lasso tool (hold down Shift or Option (Mac)/Control (Windows) to add to or subtract from the selection) to make your selection perfect.
Now you are ready to remove the green or blue screen. Make sure you're working with the proper layer, and, if you are on the 'Background' layer, double-click it and click 'OK' to make it into a normal layer, then select 'Inverse' from the 'Select' menu to reverse the selection.
Now press the 'delete' button or select 'Clear' from the 'Edit' menu to remove the selection.
You will find that the edges of your object/person may have a slight 'halo' around them. Clean up the edges by choosing 'Layer>Matting>Remove White Matte' or by choosing 'Layer>Matting>Defringe...'; usually 1-3 pixels will do the trick.
Now you can put any background you would like behind your cut-out object. Just make sure you place the background into a layer behind your current layer. (A good way to make quick-and-dirty portrait backgrounds is to choose a couple of colors in the color-pickers and to select 'Filter>Render>Clouds' then play around with noise, blurriness, etc.).
Tips for Improving Color Keys
Try to have well and uniformly lit backgrounds. You should try to use at least two lights for a green or blue screen background, to make sure it is evenly lit.
When taking pictures with a digital camera, make sure it is set to its highest setting; for higher-end cameras, use the RAW setting (which uses no compression and makes the green background much more uniform). For lower-quality cameras, set the JPEG compression to the maximum quality.
When filming, try to use the best quality tape and camera you can; DV compression is harder to work with when chromakeying, so try to use uncompressed footage if possible.
Experiment with the different settings—especially the 'Fuzziness'—in Photoshop; for some /sites/lifeisaprayer.com/files/articles/photography, it might be easier to have the 'Fuzziness' at '0' to select parts of the image, then raise the amount after you are satisfied with your selection. Photoshop's amazing array of abilities make it a wonderful tool to experiment with.
Perhaps you're tired of taking pictures with the DIY Greenscreen you just made, or you have had enough fun (for now) keying out backgrounds in Photoshop... but now you want something more. But you don't want to spend more than 2 minutes setting up for your next project. Well, how about a do-it-yourself mini macro studio that is made of materials you already have within arm's reach, and can set up in less than two minutes?
My iPod shuffle...
...and a pack of bubble gum.
Both of the above pictures were taken with the macro setup I made out of two pieces of printer paper and two pieces of scotch tape. That's it. That's all I needed. I've taken to liking the photographic philosophy I first learned at Strobist: whatever's simplest, cheapest, and quickest works, if it gets the job done.
In this article, I will outline how I made my mini macro setup, and how you could modify it (and light it) to make quick but beautiful pictures of small objects. If you're looking to make a or more durable macro setup, be sure to check out this tutorial on Strobist [hint: basically, use a cardboard box and bigger paper].
1 - The Materials
Keeping with the maxim, "cheap or free > expensive," I sought to take a quick picture of my iPod shuffle, just for fun, but I wanted to make it a pleasing picture, more matching the style and substance of the shuffle than my normal 'set it on the bed and see what you can do' pictures. So after reading about Strobist's macro studio, I thought, why not forget about the cardboard and stick with just the paper? Here's all you need:
Two sheets of white printer paper. Thick or thin, textured or not; it doesn't really matter. As long as they're flat and white, you're good to go.
Two pieces of tape. Scotch (clear) tape is best, but you can use any kind.
A light (or two) or an off-camera flash. Anything that produces light is okay. Even a high-powered flashlight may work.
2 - The Setup
For visual learners, here's a picture (a step-by-step setup guide is below):
The setup: one sheet of paper (cut), placed on flat surface, raised at the back by being taped to a tape dispenser; another sheet of paper simply folded three times and placed over the top of the first paper.
Here's a step-by-step procedure:
Take one sheet of paper, and cut it (longways) narrower by a few inches (you need not be exact).
Put a piece of tape at either end of the paper. Tape the front edge (closest to you/where your camera will be) to a flat surface (like a table), and tape the back edge to something laying around (like the tape roll in the top right of the above picture), and make sure the paper gradually bends upward (like in the below illustration).
Now take your other piece of paper and bend it either longways or sideways in such a way as to create a 'tent' to place over the first sheet of paper (see the above picture). This paper will make your light 'soft,' thus making this setup give a nice light gradient that will make your pictures look nice.
Now, place your object inside the tent, and light it. You'll want your light or lights (if you have two) mostly above the paper 'tent.' See the section below for tips on lighting.
Lighting the Mini Macro Studio
If you're like 99% of the picture-takers I know, you have a limited budget. And that budget applies to your lighting setup, as well. Luckily, if you have a tripod, you can use darn near any light source you can imagine, including flashlights, lamps, off-camera strobes, or even monolight strobes (if you're privileged to have one... but it isn't at all necessary). Here are some tips for lighting for the shot:
Put your light (or lights) about a foot above, and to either side, of the light tent. Basically, you want the light to cover as much of the tent as possible, to provide for the softest light (because the paper you use will diffuse the light and make it softly 'wrap around' the object you're taking a picture of.
Set your camera to 'M' mode (manual - if it has it) or 'S' mode (shutter-priority - if it doesn't have a manual mode) and, if you don't have an off-camera strobe (if you don't know what that is, you don't have one), you'll have to see how long of an exposure it takes to make a well-exposed (i.e. the lighting looks right) picture with whatever light source and paper thickness you have. If you're using a lamp, you'll probably have to set your camera to 1/10 of a second or longer, and you should manually set the aperture to a higher number (like f/10 or higher), and your ISO to the lowest setting (like ISO 50, 80, 100, or 200...). This will give you a sharp, noise-free, and beautiful picture (if your camera focuses correctly—otherwise set it to manual focus).
If you're using an off-camera strobe or monolight (triggered by slaves, PC sync cords, or whatever else you have), check out Strobist for some great tips and tutorials for off-camera lighting. In fact, if you're a photographer who has any aspiration at getting better pictures, read through some of the stuff on Strobist. It's that good.
Here's a picture of the lighting setup I used (a Vivitar 285 flash, attached to an old tripod (see how I did this) I had laying around via an umbrella light stand adapter, triggered by an ebay trigger; the flash was set to 1/16 power (that's all I needed) and aimed at the top right of the light tent).
More Tips for the Mini Macro Studio
Experimentation is key to becoming a better photographer. Change anything you want: try larger paper, try different light setups, try different colored paper for the 'seamless' background, etc.
Almost any camera (digital or film, cheap or expensive) can get the same quality picture as you see above with this setup. You just need to get the lighting down. Once you learn to control light, you can take beautiful pictures almost anywhere, with any kind of lighting equipment. To become a better photographer, play with the camera you have. Read it's manual. Don't go out and buy more expensive equipment unless you are truly limited by what you have now. Don't blame your camera for bad pictures (unless it's a really junky cheapo camera); that will lead to expensive equipment purchases that don't really help you.
[UPDATE 4/23/07] The kind folks at DIYPhotography.net have taken my $0.02 macro studio idea and run with it. For a few cents more, you can make a larger studio for objects larger than a pack of gum by simply using different paper and folding it to make it more stable. Check it out!
Here's another nice tutorial for a similar technique using only paper, but allowing for larger items.
