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# How much light is typically lost through an umbrella?

In terms of f-stops, how much light is typically lost when shooting through an umbrella?

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That's going to vary a great deal depending on whether it's a bounce or shoot-through, what material is used, etc. In general, the range can be as little as 1/2 stop (or less) through to several stops. If you're interested in a particular brand, you can probably find details on light loss in the product literature. Lastolite, for example, will supply the light loss information for their umbrellas.

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I specified shoot-through for this question. I would expect shoot-through has less light loss vs. reflected, ignoring the added distance for the reflected setup. Would you think that would bring in the higher end of your answer ("several stops")? E.g., 1/2 stop (or less) through to 2 stops, for example? – jfklein13 Aug 16 '10 at 17:29
I know you specified shoot through, but I figured I would answer more generically to umbrellas since many are convertable. Anyways, for one of the Lastolite umbrellas, the loss on shoot through is 0.6f and for bounce is 0.2f. So, the material being used has a major impact in the outcome. – John Cavan Aug 16 '10 at 17:33
Oh, to give you a further idea on the variety here... Interfit shoot through umbrellas are 0.5 stops and bounce are 1.5 stops! More loss and an opposite swing to Lastolight. – John Cavan Aug 16 '10 at 17:35

Saying it a different way, a regular reflected white umbrella (with black cover) is seen to meter 0.7 to 1.0 stops stronger than the same umbrella as shoot-through (without cover), if both are metered at same distance from the fabric. And reflected is slightly softer light too, if at same distance. (Yeah, the shoot-through can be placed closer, and you'd have to use it when that is needed, but that's hard to compare). The black cover doesn't affect the usable light, it only prevents the rear spill.

So that says nearly 2/3 of the light spills out of the back of a shoot-through. The other third is either absorbed or transmitted... How much for which one seems unimportant if we use reflected. :) http://www.scantips.com/lights/umbrellas3.html

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