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tests done for max flash power -SB900 SB700 yongnuo 560III
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<blockquote data-quote="WayneF" data-source="post: 316276" data-attributes="member: 12496"><p>No, not weird, or rather, very specialized purpose.</p><p></p><p>In manual flash mode, you simply set full power or 1/4 power, and that is what the flash does, period. It is up to the camera to set ISO and aperture to appropriate usable values. The flash could not care less, it just flashes at the specified power level.</p><p></p><p>But some flashes (SB-900, SB-800) have the automatic A mode (Auto mode, non-TTL auto). In this mode, the flash is self-metered, and has a front sensor that reads back its own flash, and it terminates the flash power level to be appropriate to the light result it sees. Works rather well, but the sensor is not through the lens, it sees and meters a different area than the lens or camera sees. But to know what the appropriate target exposure goal is, it has to know which fstop and ISO the camera is using, so it can compute the same exposure. CLS flashes obtain these numbers automatically from the hot shoe, but if the flash is off camera (no hot shoe), this A mode has to have a menu to set the ISO and fstop, so it can compute exposure. Just for this A mode (non-TTL auto). And for any GN mode, or manual mode distance scale too, but those don't work if not on the hot shoe.</p><p></p><p>But Manual or TTL flash has no use for it, does not need to know fstop or ISO.. All they have to do is flash at the power level setting specified for them to use.</p><p></p><p></p><p></p><p>But what mode did they recognize off camera? Did you verify it? Such tests need to carefully control all variables. I don't exactly suspect this, but something was strange, unreasonable results for SB-700, and other than procedure, this is all I can think of. To be certain, I would set their menus directly to FX mode.</p><p>If the SB-700 was doing DX zoom, it would almost fully explain it.</p><p></p><p></p><p></p><p>A weak or damaged capacitor can only hurt, it cannot tremendously boost performance. <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile :)" loading="lazy" data-shortname=":)" /> Something was happening that you were not controlling.</p><p></p><p></p><p>Yeah, I also have a Yongnuo YN-565EX (includes TTL and remote wireless), and it is an incredible bargain. Not quite a Nikon regarding some minor features or warranty, but its performance is great, more power than a SB-700 for 1/3 the price. </p><p></p><p>The tests should be carefully controlled. All the flash specifications specify their output level (Guide Number). We already know what to expect. Procedure makes small variations, but any large variation should be questioned. If widely different than specified expectations, it should attract attention.</p><p></p><p>Carefully measure and control and publish your distance, so you can know how reasonable, and others can see it too.</p><p></p><p>For example, if GN is 111.5 (feet) for the specified zoom and power level used, then GN = distance x fstop. </p><p>If fstop is 16.9, then distance should be 111.5 / 16.9 = 6.6 feet.</p><p>Or, if distance is 6.6 feet, then metered fstop should be 111.5 / 6.6 = f/16.9</p><p></p><p>Metered value can be affected by side reflections in a small room (adding to the direct value), etc.</p></blockquote><p></p>
[QUOTE="WayneF, post: 316276, member: 12496"] No, not weird, or rather, very specialized purpose. In manual flash mode, you simply set full power or 1/4 power, and that is what the flash does, period. It is up to the camera to set ISO and aperture to appropriate usable values. The flash could not care less, it just flashes at the specified power level. But some flashes (SB-900, SB-800) have the automatic A mode (Auto mode, non-TTL auto). In this mode, the flash is self-metered, and has a front sensor that reads back its own flash, and it terminates the flash power level to be appropriate to the light result it sees. Works rather well, but the sensor is not through the lens, it sees and meters a different area than the lens or camera sees. But to know what the appropriate target exposure goal is, it has to know which fstop and ISO the camera is using, so it can compute the same exposure. CLS flashes obtain these numbers automatically from the hot shoe, but if the flash is off camera (no hot shoe), this A mode has to have a menu to set the ISO and fstop, so it can compute exposure. Just for this A mode (non-TTL auto). And for any GN mode, or manual mode distance scale too, but those don't work if not on the hot shoe. But Manual or TTL flash has no use for it, does not need to know fstop or ISO.. All they have to do is flash at the power level setting specified for them to use. But what mode did they recognize off camera? Did you verify it? Such tests need to carefully control all variables. I don't exactly suspect this, but something was strange, unreasonable results for SB-700, and other than procedure, this is all I can think of. To be certain, I would set their menus directly to FX mode. If the SB-700 was doing DX zoom, it would almost fully explain it. A weak or damaged capacitor can only hurt, it cannot tremendously boost performance. :) Something was happening that you were not controlling. Yeah, I also have a Yongnuo YN-565EX (includes TTL and remote wireless), and it is an incredible bargain. Not quite a Nikon regarding some minor features or warranty, but its performance is great, more power than a SB-700 for 1/3 the price. The tests should be carefully controlled. All the flash specifications specify their output level (Guide Number). We already know what to expect. Procedure makes small variations, but any large variation should be questioned. If widely different than specified expectations, it should attract attention. Carefully measure and control and publish your distance, so you can know how reasonable, and others can see it too. For example, if GN is 111.5 (feet) for the specified zoom and power level used, then GN = distance x fstop. If fstop is 16.9, then distance should be 111.5 / 16.9 = 6.6 feet. Or, if distance is 6.6 feet, then metered fstop should be 111.5 / 6.6 = f/16.9 Metered value can be affected by side reflections in a small room (adding to the direct value), etc. [/QUOTE]
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tests done for max flash power -SB900 SB700 yongnuo 560III
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