Flash problem result of low trigger battery?

[SCoombs]

I went out today to do some sports stuff with my two Godox AD600 ProII with an XProII trigger and had a a very difficult and situation arise where as I tried to dial in the flash power for the first shot I just couldn't get the lighting to illuminate the subject well. I had one of the lights about 8 feet up with an umbrella angled around 45 degrees and about 6 feet away from ones of the girls volunteering for me to take a few tests to dial in the light.

The flash was going off, but most shots looked like they had no lighting on them. I think I had started at 1/8 and so I pushed it up and up all the way to 1/1 and still wasn't getting what looked like the light was illuminating her. This didn't make sense to me for my 600w unit. I had her move closer to around 3 feet away and suddenly I was getting shots like this: very bright on her arm and nothing anywhere else. I moved her around and tried different angles but kept getting the same. I took off the umbrella, then took off the "barrel" on the flash so it was just a bare bulb - same thing. I was relatively embarrassed at this point and trying to find things to say to help reassure the people waiting that I actually do know what I am doing!

Eventually I dialed in some shutter speed that was giving me what looked like mostly even exposures and started doing shots until after around 10 people the battery on the trigger died. After replacing it I kept going but had mentally moved on from the earlier problems so I didn't think of it. I just happened to be shooting a group at this point so I had to adjust the lighting anyways and it was working great. After this I gradually realized that all of my other shots were working much better now.

On the way home I started thinking trying again to figure the whole thing out and it occurred to me about the battery having died and I started to realize or at least suspect: was the low battery on the trigger causing the flash timing to be wrong/slower so that I was only illuminating the trailing edge of the sensor readout? Is that a possible symptom of a low trigger battery like this? For me, it would explain why I was getting nothing when the person was a bit further away and then, after I pushed it all the way to 1/1 it wound up well over-exposed for part of the frame.

 

[Ellis Vener]

I don't think your problem is related to the battery charge or low trigger voltage.

What I think is part of the problem is that at a shutter speed of 1/400th, you are in HSS (High Speed Sync) territory. This means that as soon as you choose a shutter speed shorter than 1/200 or 1/250th, the flash will max out at 1/4 power no matter what you have set it to. With a 600 w-s flash, that means the maximum amount of energy released is 150 w-s. With a white umbrella, that is going to reduce your maximum working distance.

Also, although it has been a while since I used a Godux AD600 Pro series flash (I switched from the AD600 Pro to the Paul C Buff Celestials a couple of years ago), It is my recollection that for HSS triggering, you have to use the flash and the trigger in TTL and not manual mode. But I could be mistaken in my recollection. I definitely remember having a similar problem to yours with an AD600 Pro with an outdoor portrait in HSS mode, and that was with a Canon EOS 5DS, which, for me, rules out it being a Nikon-specific problem.

What I don't get, however, is the background exposure. Even at f/1.8 and 1/400th at ISO 64, it seems like the background should be much more overexposed than it appears to be. Were you also using an ND filter, or did you reduce the background exposure during processing?

 

[SCoombs]

I don't think your problem is related to the battery charge or low trigger voltage.

What I think is part of the problem is that at a shutter speed of 1/400th, you are in HSS (High Speed Sync) territory. This means that as soon as you choose a shutter speed shorter than 1/200 or 1/250th, the flash will max out at 1/4 power no matter what you have set it to. With a 600 w-s flash, that means the maximum amount of energy released is 150 w-s. With a white umbrella, that is going to reduce your maximum working distance.

Although I posted one here at 1/400 as an example, I went down to 1/250 and 1/200 and as low as 1/100 in the 10 minutes or so I was trying to figure this out and had the same sort of issues regardless. The truth is I might be more ready to accept this as a partial explanation if I was using my AD200Pro, but at 600w it's harder for me to believe. I've shot the AD600ProII several times before as well, both indoor and out, and was able to get plenty enough power from it to shoot even at greater distance. In fact, I recently did a very large group photo covering a horizontal distance of about 40 yards taken well into the evening lit only with the two Godox AD600ProIIs each set more than 10 feet from the focal plane angled in on either side and these were plenty powerful enough to give me very nice even light on the entire 40 yards (and 20 feet tall) worth of people.

Also, although it has been a while since I used a Godux AD600 Pro series flash (I switched from the AD600 Pro to the Paul C Buff Celestials a couple of years ago), It is my recollection that for HSS triggering, you have to use the flash and the trigger in TTL and not manual mode. But I could be mistaken in my recollection. I definitely remember having a similar problem to yours with an AD600 Pro with an outdoor portrait in HSS mode, and that was with a Canon EOS 5DS, which, for me, rules out it being a Nikon-specific problem.

I don't know if it was required with any previous lights, but the AD200Pro and the AD600ProII do not require me to use TTL for HSS.

What I don't get, however, is the background exposure. Even at f/1.8 and 1/400th at ISO 64, it seems like the background should be much more overexposed than it appears to be. Were you also using an ND filter, or did you reduce the background exposure during processing?

Neither - no ND filter, no processing at all other than to crop it down a tad and to get rid of the face/jersey.

 

[Ellis Vener]

Not having been there, I don't know what else could cause these problems. I hope you figure it out. Maybe its an issue with the lens

--
Ellis Vener
To see my work, please visit http://www.ellisvener.com
I am on Instagram @EllisVenerStudio
“It's not about the f-stop." -Jay Maisel
Don't be "a photographer.” Be photographing. (Paraphrasing William Faulkner's advice to writers.)

 

[Gato Amarillo]

I have had similar problems with the Adorama/Godox single pin trigger, also cured by fresh batteries.

Of course the single pin is a very basic trigger, manual only, and I am not sure how this would relate to other triggers, but I am now careful to keep trigger batteries fully charged.

Gato

 

[A-Marc]

I don't think your problem is related to the battery charge or low trigger voltage.

What I think is part of the problem is that at a shutter speed of 1/400th, you are in HSS (High Speed Sync) territory. This means that as soon as you choose a shutter speed shorter than 1/200 or 1/250th, the flash will max out at 1/4 power no matter what you have set it to. With a 600 w-s flash, that means the maximum amount of energy released is 150 w-s. With a white umbrella, that is going to reduce your maximum working distance.

Although I posted one here at 1/400 as an example, I went down to 1/250 and 1/200 and as low as 1/100 in the 10 minutes or so I was trying to figure this out and had the same sort of issues regardless. The truth is I might be more ready to accept this as a partial explanation if I was using my AD200Pro, but at 600w it's harder for me to believe. I've shot the AD600ProII several times before as well, both indoor and out, and was able to get plenty enough power from it to shoot even at greater distance. In fact, I recently did a very large group photo covering a horizontal distance of about 40 yards taken well into the evening lit only with the two Godox AD600ProIIs each set more than 10 feet from the focal plane angled in on either side and these were plenty powerful enough to give me very nice even light on the entire 40 yards (and 20 feet tall) worth of people.

could be that if the trigger is still in HSS mode, you still send out HSS signals to the flash, no matter what shutter speed you dial in. So eventually you still dont get full 1/1 power from the flash at 1/200 .

my godox triggers go bonkers with low battery, means that they start to change settings on their own. mostly they start to change the channel and the step settings. its quite easy to realise when battery if too low.

Also, although it has been a while since I used a Godux AD600 Pro series flash (I switched from the AD600 Pro to the Paul C Buff Celestials a couple of years ago), It is my recollection that for HSS triggering, you have to use the flash and the trigger in TTL and not manual mode. But I could be mistaken in my recollection. I definitely remember having a similar problem to yours with an AD600 Pro with an outdoor portrait in HSS mode, and that was with a Canon EOS 5DS, which, for me, rules out it being a Nikon-specific problem.

I don't know if it was required with any previous lights, but the AD200Pro and the AD600ProII do not require me to use TTL for HSS.

What I don't get, however, is the background exposure. Even at f/1.8 and 1/400th at ISO 64, it seems like the background should be much more overexposed than it appears to be. Were you also using an ND filter, or did you reduce the background exposure during processing?

Neither - no ND filter, no processing at all other than to crop it down a tad and to get rid of the face/jersey.

 

[Ellis Vener]

That all sounds reasonable.

 

[Gato Amarillo]

The main problem I saw with low batteries was partly exposed frames, similar to what the OP posted. I expect this was caused by a very slight delay in the flash firing.

Gato

 

[fotowbert]

SCoombs wrote in part:

...

On the way home I started thinking trying again to figure the whole thing out and it occurred to me about the battery having died and I started to realize or at least suspect: was the low battery on the trigger causing the flash timing to be wrong/slower so that I was only illuminating the trailing edge of the sensor readout? Is that a possible symptom of a low trigger battery like this? For me, it would explain why I was getting nothing when the person was a bit further away and then, after I pushed it all the way to 1/1 it wound up well over-exposed for part of the frame.

Since low batteries in the trigger seems to be the most likely cause of your problem for the record what type of batteries were you using in the trigger, rechargeable cells or the Godox recommended disposable alkaline cells?

• John

 

[Jacques Cornell]

I have had similar problems with the Adorama/Godox single pin trigger, also cured by fresh batteries.

Of course the single pin is a very basic trigger, manual only, and I am not sure how this would relate to other triggers, but I am now careful to keep trigger batteries fully charged.

Gato

I'm a big fan of NiMH (Eneloops!) for high-drain devices like speedlights and video LEDs, and I never had any issues with them in Godox triggers. But, just in case, I've since switched to alkalines in my triggers. They hold a charge for up to 10 years in a drawer, and I go through less than a dozen of them in a year. I don't fret over their charge level, and it's easy enough to bring an extra pair. If I encounter odd behavior from a trigger, my very first step would be to replace the batteries with a fresh pair of alkalines.

--
Event professional for 20+ years, travel & landscape enthusiast for 30+.
http://jacquescornell.photography
http://happening.photos

 

[SCoombs]

A quick update on this: As I have gotten into more detailed editing of these shots, it's pretty clear to me that this was an issue with the way the strobe was operating but only before I changed the trigger batteries. One especially tell-tale sign is that in some photos where the kid is holding the ball out (and so closer to the flash) there is on the very edge of the bright/dark line on the ball the kind of banding that people tend to see in HSS on the Nikon Z bodies when using less powerful/lower quality flash units. I haven't had this problem with the AD600s or the AD200s, but I see it right on the edge of the line where I was getting illumination vs not - but only before I put fresh batteries in the trigger.

 

[FastCats7]

Yeah I find that a low battery trigger causes me all sorts of issues. The meter on the Godox triggers aren't always accurate either. So once it moves away from a full bar, I usually change them out. Especially for a wedding!

But also like every wireless strobe, just let them have time to recharge the caps inbetween strikes as well.