kmac
Active member
Needing advice on external flashes power and versatility needed...i have a canon 40d sigma lens 17-70mm2.8/4.5..any suggestions??
thanks karen
thanks karen
external flashes
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nartreb
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* crickets *
I can't recall seeing anybody carrying an external flash when hiking. Without a ceiling to bounce the flash off, you'd want a pretty big diffusive reflector, I guess. Maybe Grumpy will chime in.
Personally I try to avoid blinding people or wildlife (or myself) when I'm hiking at night, and flash is no good for landscapes and kind of tricky for macros, so I don't think it'd be worth the extra bulk.
I can't recall seeing anybody carrying an external flash when hiking. Without a ceiling to bounce the flash off, you'd want a pretty big diffusive reflector, I guess. Maybe Grumpy will chime in.
Personally I try to avoid blinding people or wildlife (or myself) when I'm hiking at night, and flash is no good for landscapes and kind of tricky for macros, so I don't think it'd be worth the extra bulk.
For hiking I don't bother with a flash. I just pump the ISO as hard as I can and use either the stabilized 17-85mm or when I really need the lens speed, the 50mm f/2. If I could afford it (and justify it) I'd get the 70-200 f/2.8 L-series.
However, for events (weddings, parties, etc.) having an external flash is crucial.
With my 40D I use a Speedlite 580EX II and it's wonderful. It's top of the line, but IMHO it's not worth having an underpowered flash. I can bounce off high ceilings or do direct flashes from a long distance. With the 40D I can either use P mode and everything will coordinate, or use Av or Tv and the camera will meter as if there was no flash and then fire the flash for fill, or use full M mode and set to, say, 1/125 and f/4 to f/8 and it will meter in real time when the flash fires. I can control all the features of the flash from either its own controls or from the camera's menus. I have an old 420EX and can use it as a remote slave to the 580 to really even out the shadows in portraits or stills. It also helps autofocus in dim light by sending out a grid pattern of red lines, as opposed to the built-in flash which has to strobe. And of course an external flash is far enough away from the lens to really minimize any red-eye effects (and bouncing you won't get any). Also, it has a built-in extendable bounce (catchlight) card, and diffuser. And while it has a quick recycle time, you can also buy an external power pack for it if you're going to be taking a lot of shots quickly.
Okay, it's a pretty penny, but if you're serious about your 40D, get the serious flash that will work for you in all conditions and scenarios.
edit: the other nice thing about a high-end flash is that based on exposure it can really dial its power back, so if doing, say, a closeup of some plant, it's possible to not completely wash it out. And if you're trying to get one of those really nice photos of a dark, colorful sunset with a deer or moose in the foreground lit by fill flash, it can fire its guts out with a 58 guide number.
However, for events (weddings, parties, etc.) having an external flash is crucial.
With my 40D I use a Speedlite 580EX II and it's wonderful. It's top of the line, but IMHO it's not worth having an underpowered flash. I can bounce off high ceilings or do direct flashes from a long distance. With the 40D I can either use P mode and everything will coordinate, or use Av or Tv and the camera will meter as if there was no flash and then fire the flash for fill, or use full M mode and set to, say, 1/125 and f/4 to f/8 and it will meter in real time when the flash fires. I can control all the features of the flash from either its own controls or from the camera's menus. I have an old 420EX and can use it as a remote slave to the 580 to really even out the shadows in portraits or stills. It also helps autofocus in dim light by sending out a grid pattern of red lines, as opposed to the built-in flash which has to strobe. And of course an external flash is far enough away from the lens to really minimize any red-eye effects (and bouncing you won't get any). Also, it has a built-in extendable bounce (catchlight) card, and diffuser. And while it has a quick recycle time, you can also buy an external power pack for it if you're going to be taking a lot of shots quickly.
Okay, it's a pretty penny, but if you're serious about your 40D, get the serious flash that will work for you in all conditions and scenarios.
edit: the other nice thing about a high-end flash is that based on exposure it can really dial its power back, so if doing, say, a closeup of some plant, it's possible to not completely wash it out. And if you're trying to get one of those really nice photos of a dark, colorful sunset with a deer or moose in the foreground lit by fill flash, it can fire its guts out with a 58 guide number.
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FYI: guide number is an indication of the power of the flash. The 580EX II's guide number of 58 (that model number is not a coincidence) means that at ISO 100 it can properly expose a subject 29 meters away at f/2. The formula is simple: f = guide/distance.
If you do the math, you'll see that with a strong flash like this, even with a slower f/5.6 zoom, made up for by a sensitive ISO setting, subjects dozens of feet away can still be properly exposed.
Here's an example - this was taken with an 8mm fisheye lens on the shores of Lonesome Lake, and shows the extent that the flash could reach:
If you do the math, you'll see that with a strong flash like this, even with a slower f/5.6 zoom, made up for by a sensitive ISO setting, subjects dozens of feet away can still be properly exposed.
Here's an example - this was taken with an 8mm fisheye lens on the shores of Lonesome Lake, and shows the extent that the flash could reach:
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Grumpy
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External flashes are incredibly useful tools, once you master their use. I’ve used them professionally for more than 40 years, and continue to learn new tricks.
One of the great techniques is something that once was called “synchro-sun” in which a flash was used to “fill” (add light to) shadow areas in sunlit scenes or subjects.
Modern automated flash units take a lot of the guess-and-calculate work out of using them. Being a Nikon guy, I don’t have the knowledge to recommend a unit for Canon cameras. Right now, I use a Nikon SB-800 flash with my pro-level SLR setup.
A diffusion dome (inexpensive) is a useful flash accessory. It both reduces flash power and “softens” the light. Also, a cord that allows you to remove the flash from the camera (usually unGodly expersive) allows for much more control over the flash.
And, for the record, I do carry a flash unit while hiking, if the photo objectives for the day anticipate lighting situations in which it will be useful (which is to say, frequently).
G.
One of the great techniques is something that once was called “synchro-sun” in which a flash was used to “fill” (add light to) shadow areas in sunlit scenes or subjects.
Modern automated flash units take a lot of the guess-and-calculate work out of using them. Being a Nikon guy, I don’t have the knowledge to recommend a unit for Canon cameras. Right now, I use a Nikon SB-800 flash with my pro-level SLR setup.
A diffusion dome (inexpensive) is a useful flash accessory. It both reduces flash power and “softens” the light. Also, a cord that allows you to remove the flash from the camera (usually unGodly expersive) allows for much more control over the flash.
And, for the record, I do carry a flash unit while hiking, if the photo objectives for the day anticipate lighting situations in which it will be useful (which is to say, frequently).
G.
Which reminds me - another fun thing to do with an external flash is to experiment with first and second curtain flash settings with long exposures. In simpler english, if you're doing a long exposure, does the flash fire when the shutter opens, or when it closes. The difference is quite astounding, and the classic example is taking a picture of a car as it drives by in the dark.
With first-curtain sync, you'll light up the car as it's further away from you, then as it drives the rest of the way past you in the dark, it won't really show up on camera except for the streaks from its headlights, which will look wrong because the streaks will be ahead of the car. But it will also mean the headlight streaks don't obscure the car.
With second-curtain sync, it will look normal as the flash fires right at the end, after the streaks have been exposed, and so the car appears at the front of the streaks and the feeling of forward motion is correct.
With first-curtain sync, you'll light up the car as it's further away from you, then as it drives the rest of the way past you in the dark, it won't really show up on camera except for the streaks from its headlights, which will look wrong because the streaks will be ahead of the car. But it will also mean the headlight streaks don't obscure the car.
With second-curtain sync, it will look normal as the flash fires right at the end, after the streaks have been exposed, and so the car appears at the front of the streaks and the feeling of forward motion is correct.
