Archive 2014 · Big metering issue with YN622N-TX

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p.1 #1 · p.1 #1 · Big metering issue with YN622N-TX

I came across this issue today.

Basically if I have my Yongnuo YN568EX flash in TTL mode and control the power manually with the YN622N-TX I cannot meter it correctly with my Sekonic 308B flash meter.

Doing some tests the meter would say F2.8 if I left the flash in TTL mode and test fired the flash via the TX. If I set the flash manually to 1/1 and fired via the TX the flash meter would read f16 - the correct reading.

If I fitted the TX to my camera and fired the flash it would be even lighting using TTL on the flash and manually controlling the TX to 1/1 and also if I switched the flash to 1/1 overriding the TX unit. So I know the flash is kicking out the same power, but I have no way of getting a precise reading.
I have tried different channels/groups but it makes no difference.

The only way to get correct metering on the flash meter is to set the flash to manual. I haven't had this issue with previous Yongnuo units such as the 602 so I am guessing they are doing something different.

Anyone else come across this?

Jun 23, 2014 at 09:41 AM

BrianO
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p.1 #2 · p.1 #2 · Big metering issue with YN622N-TX

In TTL mode the flash fires a low-power pre-flash, measures the result, and adjusts the power for the exposure flash based on the reflected pre-flash. I suspect that in TTL mode your meter is locking on the pre-flash reading and ignoring the main flash.

In manual mode there is no pre-flash, so only the exposure flash is metered.

As to why it worked before and not now, did you change any settings on the meter, such as a faster shutter speed? Did the 602 actually trigger the flash in TTL mode (pre-flash emitted), or just in manual power mode (no pre-flash) via TTL (CLS) coding? Did the flash get changed accidentally from i-TTL to ETTL? Any other variables changed that you can think of?

Jun 23, 2014 at 12:08 PM

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p.1 #3 · p.1 #3 · Big metering issue with YN622N-TX

The 602s didn't use a pre-flash. That appears to be the issue.

Another thing that I have noticed is that if I have the TX unit in manual mode it makes no difference whether I have the TX unit set to 1/1, 1/2, or 1/4, it fires off at full power. Its only when I get to 1/8 power on the TX unit that the flash fires at a lower power setting. Maybe I have a faulty unit

Jun 23, 2014 at 02:10 PM

BrianO
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p.1 #4 · p.1 #4 · Big metering issue with YN622N-TX

pr4photos wrote:
...Another thing that I have noticed is that if I have the TX unit in manual mode it makes no difference whether I have the TX unit set to 1/1, 1/2, or 1/4, it fires off at full power. Its only when I get to 1/8 power on the TX unit that the flash fires at a lower power setting. Maybe I have a faulty unit

Do you see the power-level indicator on the flash change? If so, and it's firing at full power anyway, it's probably the flash and not the transmitter that's faulty. If not, it's likely the transmitter.

Jun 23, 2014 at 02:35 PM

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p.1 #5 · p.1 #5 · Big metering issue with YN622N-TX

No, that never changes on the flash, as the flash is set to ttl. The TX overrides that. If you set the flash to manual power you can't control the power with the TX

Jun 24, 2014 at 04:34 AM


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