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Old May 29, 2014, 11:28 AM   #11
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Tcav - not sure why you continue to try and argue about flash use when you have no real-world experience with it. But let me help you out a bit since you are in an area you don't understand (i.e. flash). When using flash indoors it is often beneficial to balance ambient and flash light. In that way you do not get a stark subject and dark background. That's not always desirable. If you prefer though I can show you photos demonstrating where flash IS overpowering ambient light (necessary when you want flash to freeze motion):


The relevant point for the OP is that TCAVs assertion that flash is not of much use is not based on reality. In reality, for those of us that actually use external flashes, they can throw light far enough for 200mm or 300mm lenses.


There is no reason in this thread to move more into how to balance ambient and flash depending on the desired affect. The only important point is external flashes are quite capable of doing the job the OP requires. And, if the OP is too far away for a good external flash they are too far away for a 200mm lens.
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Old May 29, 2014, 7:12 PM   #12
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The last flash I used used bulbs. I gave up on flash before I used up my supply of bulbs. So, no, I don't know much about flash.

But I do know something about lighting, and I can say without fear of contradiction, that the first two photos you posted as examples of how flash could be used did not use flash as their primary source of light.





... or even as fill flash.

While I do understand that the working distance that you refer to is about focus accuracy, especially with regard to moving subjects, and as you are a recognized expert in the field, I accept that at face value. But sometimes focal length is just about composition. The reason I know that is because, while you state here that the working distance for a 50mm lens is 15 feet, I've seen many perfectly acceptable photos taken with 50mm lenses that contain subjects at much greater distances. So a 200mm focal length would be perfectly acceptable for a group shot on a stage much farther away that the working distance of 75 feet.

Plus, Canon's most power Speedlite 600RX has a Guide Number of 60 (meters, or 197 feet) which means it has a working distance of 70 feet with an aperture of f/2.8 and an ISO of 100. So even with Canon's best flash, the ISO would have to be 400 to get a working distance that would cover the stage in a typical multipurpose room when shooting from the back. Anything less that the 600RX would certainly be in the range that would result in significant image noise.

Is that what you're suggesting? that BeverlyLanders should have gotten Canon's best flash to shoot her granddaughter's elementary graduation program? Because anything short of that wouldn't have been any better that what she got without it.
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Old May 30, 2014, 4:05 AM   #13
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BTW, even that scenario still presumes that BeverlyLanders would need an f/2.8 lens on top of Canon's best flash. My guess is that her current lens had a maximum aperture of f/5.6 where she was trying to use it, which greatly reduces the effect even Canon's best flash would have on her results.
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Old May 30, 2014, 8:46 AM   #14
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Those "factory specs" are at ISO 100, now up the ISO to 3200 which just about any modern DSLR can handle and adjust the flash range accordingly.
A consumer lens would work just fine at f/5.6

If you want to look foolish in a crowd you can also add a flash extender which just about adds a couple more stops to the effective range, as long as you are using a 300mm or longer lens.

And it does not need to be canons top end flash I have some old sigma 500 series flashes that have similar range specs and cost less than a 1/3 of the name brand.
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Old May 30, 2014, 6:36 PM   #15
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I have no doubt, so long as the ambient light is good enough to cause the primary shadows like those that are visible in the photos that JohnG posted.
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