Photoflex Starlite vs. Westcott Spiderlite
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Research and design are the cornerstones of the Photoflex philosophy. When we make a product, it must be practical and durable. All of the advertising copy in the world won't get you an extra stop of light when you really need it. We want our customers to know that when they buy a Photoflex product it will be useful to them.
To the left is a piece from the Photoflex museum, a four lamp fixture, one of our many prototypes tested over ten years ago. We were trying to get more light output from a single fixture, but scrapped the idea after rigorous testing in our in-house studio.
In this lesson we will examine the shortcomings of this approach and then we will take a look at Westcott's present endeavor with their Spiderlite TD5.
(Click on any image below for an enlarged view.) |
Topics Covered:
- Statement of light theory
- Developing a brighter light source
- Westcott attempts a brighter light source
Lighting Theory
Photographers have always had their own way of doing math; ask one what two times 5.6 is and they'll tell you 8! At the bottom of this math is a simple principle, one stop open is twice as much light, and one stop closed is half as much light.
The misconception we run into is this: more lamps = more light = more stops of photographic range. If we have one lamp and add another of the same power, then we have doubled the light. But if we add still another lamp, we haven't doubled the output again. To do that we would have to add two more lamps. |
Developing a Brighter Light Source
Which brings us to twelve years ago in the Photoflex Labs. We wanted to create a versatile light for achieving better depth of field and shutter speed options.
We came up with this prototype (figure 1) at the time, and were never satisfied. It now lights our founder's bathroom and works alright for makeup application. |
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 Figure 1 |
The problem inherent with this design is that in order for the maximum power of the lamp to be used, the path of the light output must be unimpeded. As soon as light strikes another object or is refracted through that object it loses power and is changed. Using twice as many lamps isn't going to cut it now. We need possibly three times as many lamps to make up for the light that is lost trying to pass through the other lamps.
Because these lamps are so closely positioned, sitting parallel to each other, they end up blocking a good percentage of the light emitting at 90 degree angles from the lamps' filaments. |
After running this idea through the paces, it was apparent that we needed to revisit the drawing board. The idea correctly identified the need to have more light with more power, but our prototype didn't deliver.
So instead of re-inventing the wheel, we made an alternative prototoype using a proven light source. Taking our already durable and high-output light, the Starlite QL, we quadrupled the output of the Starlite by using four of these light heads on a newly designed 4Star Connector (figure 3).
Now we have four lamps and four light heads that can each put out 1,000 watts. We still have the some light restriction due to the added lamps, but because we spaced them out more, we were able to get a much higher light output from four, one-thousand watt lamps than from four 250-watt lamps. |
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This design not only fit the criteria for light output, it also completed the versatility requirement we have for all Photoflex products.
Instead of having to buy a new light, you could use two (figure 4) or three or four lights you already owned. Plus, if you found yourself in a fix and needed a fill light, a fixture is easily removable from the 4Star Connector and used on its own. |
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 Figure 2 |
We also maintained the ability to attach the soft box without the lamps or fixtures in place, thereby removing the most delicate parts from harm's way.
With a simple piece of aluminum, we were able to solve the problem to present an affordable and versatile solution (figure 5). |
 Figure 3 |
Westcott Attempts a Brighter Light Source
Fast forward to 2005, Westcott announces its "cutting-edge" Spiderlite TD5 (figure 6) with "the ability to run from 1 to 5 lamps all with no shift in color temperature". Of course they fail to mention that color temperature is not affected by the number of lights. Exposure however is quite affected. |
We see here (figure 7) the tungsten-halogen configuration with five lamps. Going back to our earlier example we can see that light restriction has not been taken into account and has in fact been made worse by adding a fifth lamp. Now the outside lamps only have a 180 degree unimpeded spread and the center lamp much less than that.
Also, each light is only 150 watts; 750 watts of total output. A single Starlite by itself provides 1000 watts. |
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 Figure 4 |
In order to achieve a daylight color balance ,Westcott introduced the flourescent lamp. Each lamp is 25 watts, and while this may be quite energy efficient, it does not deliver lumens.
Remember that depth of field and shutter speed are some of our main photographic tools. When we limit these tools we limit our image making potential. So while it may be true that lights will last forever and produce a 5600K light source, you'd still have to place the Westcott light about six inches away from your subject, and even then you'd still not have enough light!! |
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What it all comes down to is the meter reading. Fancy wording and assurances of quality mean little when you want f/5.6 and can only get f/2.8.
The Photoflex difference is that we have a light meter, and we use it.
You can settle for a lighting system of limited quality or you can obtain a system that is expandable, efficient, reliable, and productive. |
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