Photo Notes A place to talk about making images.

Getting a good exposure is important, but getting the right light is MUCH more important. Digital cameras make this much

This is what the shot looked like without strobes. It is the right exposure, but the wrong light.

easier than ever before! People often rely on a meter when they should look at what they are doing. But even when I shot film for a living I didn’t rely on the meter, I relied on the Polaroid instant images I made with the camera. I suspect part of the difficulty is that it is frightening to turn the meter off and rely on your eye and proof image and histogram, but now that we have these tools we should not be so afraid to turn off the meter.

In teaching classes I keep trying to find ways to say that you have to move into the land BEYOND metering. When you use a strobe meter you get a response that tells you how to make a middle density, but the meter doesn’t tell you how to make it look right. There is no automatic way to make it look right, only the application of brains can do that. When I make a shot with strobes and a digital camera, the first thing I do is to put the camera on manual. The camera meter can’t read strobes, except for the proprietary strobe. So the camera meter is useless. I do not use a hand held strobe meter, as it doesn’t give me useful information. The only things I pay attention to are the histogram and the proof image on the camera back, or, even better, an image on a computer tethered to the camera. More than metering these two tools tell you about your image.

In this version I've put in a couple of lights and things look better. I know what to do becaues I am examining what I've done step by step.

Let me suggest a plan for seeking the right exposure:

1)   Set the shutter speed to the sync speed.
2)   Set the aperture to your middle aperture, whatever that is on the lens you are using
3)   Take a picture, it will probably be wrong.
4)   Move the aperture dial to let in more or less light based on test exposure 1, you can look at the histogram to help determine how much to change the aperture, but the proof image should tell you if you need to change the exposure a lot or a little. If you are using more than one light consider the balance of the lights. Remember the aperture affects the strobes, the shutter speed doesn’t.
5)   More test exposures and changes of light placement and light power until the strobes are right.
6)   If you need to use ambient light increase the shutter speed until the balance looks right. This same technique will work if you are mixing strobes and daylight. This was why the Polaroid bill was so high with film cameras, but with digital these test exposures are free, so we should not be afraid to make them. If you practice this you will actually end up being able to find the right exposure quite quickly.

In this version I added a couple more lights to open up the far wall with more light. No meter could have done this. I need to look at what I'm doing.

This is the essential trick with strobes, to evaluate and change our images in search of the right levels for our lights and our exposures. With the histogram and the proof image on camera or in the computer we have better tools for creating the right exposure than any meter could give us, but it does take repeated testing. If you use a hand-held meter you will get an answer, but very often it will be profoundly wrong.

This shows the final placement of the lights.

I have written elsewhere about fluorescent lights for photography. I didn’t say anything complimentary there, and I don’t intend to say much that is nice in this blog. So if you really love the new compact fluorescent lights as studio lights, it might be best to stop now. Still, the results of my tests were somewhat less dire that I had anticipated.

I was finally able to borrow one of these lights (a Top Lighting PB-85 120v 85 watt) so that I could run tests. I certainly didn’t want to buy one. I did several tests: first I used my spectrometer to look at the color distribution of the light, that is look at the light spread into a rainbow. My spectrometer is made from cardboard, a couple of razor blades and a small piece of diffraction grating. It is not a tremendously accurate device. It was not designed to be used with a camera. Still I am including pictures of daylight and of the fluorescent tube. You can see that daylight is continuous, smooth. The fluorescent has big bright lines and big dark lines, so no continuous spectrum. So the nature of this light is very, very different from daylight.

Fluorescent Spectrum, notice how the spectrum is banded rather than continuous

Sunligth Spectrum, it is smoother in the spectrometer.

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In my second test I made a picture of a Macbeth Color Chart with strobe light and the fluorescent light. The color of the two shots was very different, so I would not want to use the fluorescent light with my strobe. However when both shots were white balanced, in the computer, the shots were very similar. Really the fluorescent tube was a closer match than I would have expected, after the white balance. Please keep in mind that white balance will not enable to correct a shot for two different light sources.

Fluorescent version of the Color Checker, white balanced.

Strobe version of the Color Checker, white balanced.

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In the third test I made 10 shots at a shutter speed of 1/180 to see if the light would be consistent on all the shots. I did not expect this to go well. Fluorescent tubes are supposed to vary with the cycling of alternating current electricity. In this country the power cycles 60 times a second. So 1/180 should be only part of a cycle. In this shot the color did not vary by as much as 1%, really quite impressive. Since the shots all looked the same, I am not including them.

Finally I compared the overall quantity of light to a 600 watt Smith Victor quartz light. The quartz light was 8 times more powerful than the fluorescent  light. Although I could use an array of these lights to increase power, I could not get the power and hard light effect that I can get from quartz lights.

On the whole the light performed better with color than I had anticipated. However the unusual spectrum leaves me suspicious that there will be problems in the real world, especially with fabrics. Certainly the low power disappoints me, but if your camera performs well at high ISO levels, this may be less of a problem for you.

Thanks, John

Please check out my classes

An Introduction to Photographic Lighting

Portrait Lighting on Location and in the Studio

Business to Business: Commercial Photography

There are a lot of lighting products on the market, and many of them are mostly hype. There are only so many ways you can manipulate light, and few of them are new. So you can make a light source larger with an umbrella, soft box or a light panel. If you want to put light in just one part of an image you will probably need a snoot, grid spot, or barn doors. There are other ways to do these things, but they do about the same things. Changing the name doesn’t change the product much.

One of the things people have tried to do for a long time is to make the little light source on a camera mount strobe, like the Nikon SB 900 or the Canon 580, act like a bigger light source. When you have a large light source the light hits the subject from all points of the source, so you get less shadowing and softer transitions between highlight and shadow. Vivitar introduced a bounce card for the 283 strobe in about 1976, so the manufacturers have been at this for a while. The Vivitar bounced all the light off a card, simple but didn’t change things all that much. Later designers bounced light off the walls of the room, so that there was a lot of fill light. This was more effective. So you see products from Sto-fen, Lumiquest and Gary Fong. There are differences in the way they move the light around and where they move the light, but the idea is similar: some light goes directly to the subject and some is bounced. Now this idea works, and it is probably the best idea for event photography, and will work well in other situations.

Taken with a direct flash. See the hard shadows and the high contast? What a difference the BOOTY LIGHT makes!!!

Booty light shot!!

I have decided to introduce a NEW and FABULOUS way to spread light from a camera mount strobe, or many other kinds of strobes. Did I say it is NEW and WONDERFUL? I have to make sure I use enough hype here. It is the BOOTY light, yes this FABULOUS new light is actually a shoe covering. You can by TWO for only 79¢, YES less than a dollar. That makes these WONDEFUL, NEW units less than one half of one per cent as expensive as a Gary Fong Lightsphere II. Didn’t I say this is FABULOUS?

Seriously these are useful tools. I have used them on several occasions, because I needed to be quick of I needed a camera mount strobe to add to a monolight on a stand. In addition to the before and after shots, necessary to introduce something as WONDERFUL as this, I have a shot from a recent project where I used the booty light and just one other strobe with an umbrella. I had to work quick on this shoot. So think about it: Don’t you need a Booty light? Here’s a link: http://www.envirosafetyproducts.com/product/Tyvek-Shoe-Covers.html You can also buy them in quantities of over 100, even CHEAPER!!!

Thanks, John Siskin

Ps. One size fits mostly all! WONDEFUL!!!

Pps. Collapses for easy storage and WILL KEEP THE CARPETS CLEAN!!

My classes:

An Introduction to Photographic Lighting

Portrait Lighting on Location and in the Studio

Business to Business: Commercial Photography

Booty Light on a Norman 200B, one size fits almost all!!

Booty Light on shoe, It's dual purpose!!

Another location shot with the BOOTY LIGHT the booty light is the only light on the outside of the door, the strobe with the umbrella is in the room past the door.