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Old Oct 25, 2004, 3:08 PM   #11
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Well thanks for all the replys NHL. I am going to a game tonight, so i will try
some shots out with my flash. What would be some base settings you would start out with to take some action shots with tonight?
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Old Oct 25, 2004, 3:22 PM   #12
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Set the camera on manual, the flash should still be set on E-TTL, you can control both the shutter and aperture this way while the flash exposure is still automatic

Fix the shutter to 1/200s and then watch the LCD distance scale move as you vary the aperture. If the subject is too far then increase the ISO. Remember the aperture now controls the ambient light as well... and you can darken/brighten the background with the aperture -> watch the -2..-1..v..+1..+2 EV scale.
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Old Oct 25, 2004, 4:39 PM   #13
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Thanks allot, i will try it out tonight. I will let you know how it goes tomorrow.
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Old Oct 25, 2004, 11:04 PM   #14
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FYI

This is from the 550EX manual: http://www.pbase.com/canon550ex/image/23295788/original

-> The max. Guide Number (GN) changes from 55 (in meter @ ISO-100) to 38.9 - or even less in 'FP' mode as the shutter is increased, ie @ 1/320s the output power is cut in half!

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Old Oct 26, 2004, 8:42 AM   #15
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Found this interesting article last night on how flashes stop the fastest action.

http://www.naturephotographers.net/a.../jm0703-1.html


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Old Oct 27, 2004, 4:03 PM   #16
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NHL, my guide number on this sigma super states it is 165' @ ISO100 at 105mm focal length. My question is, how can i calculate the distance (ie 165')at 200mm focal length.

I am sure the 165 will drop, i just cant fiqure the formula.

Thanks ahead,

Bobby
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Old Oct 27, 2004, 4:44 PM   #17
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I'm afraid the 165' @ ISO100 at 105mm focal length will be the same as 200mm -> There's no adjustment of the moving lens elements in the flash, as when it's set for lesser focal lenghts for example. The angle of coverage is changed inside the flash to concentrate the light toward the center and it physically stops out @ 105mm.

The minimum angle from the flash will be for a 105mm, so with the smaller FOV of the flash at 200mm you'll be 'wasting' the extra light... very similar to cropping the extra illumination

Changing the ISO will increase the GN though!
Another idea is the 'Better Beamer' or use another head as a slave
http://www.birdsasart.com/accs.html#BEAMER
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Old Oct 27, 2004, 5:06 PM   #18
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Your right, i misunderstood the focal length number. I was under the impression that if you used a higher zoom lense than the focal length stated by the flash, the number would change. But I am getting better at understanding the flash world:shock:.

thanks agian
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Old Oct 27, 2004, 5:26 PM   #19
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BTW @ 105mm setting we are already wasting the light with a 100mm since this flash (same as the 420/550EX) is designed for full frame cameras, ie with the 1.6x we are only using the FOV of a 160mm! :evil:

-> The new 580EX 'knows' which type of camera it's mounted on and will compensate accordingly for the crop factor... We'll just have to get over its price! :?
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Old Nov 1, 2004, 12:44 PM   #20
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Thanks for all the help on the flash questions NHL. I am off and running now with the flash. I got this shot last friday night under very foggy conditions.

Manual mode: shutter speed 200, f/5, ISO800 (Canon 10D& 70 to 200mm 2.8L Lens). The flash was on full power which is 1/700th sec. in manual mode. This player was about 25 to 30 yards away.


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