Godox AD600 and TT685 - Significantly Underexposed in TTL - Suggestions?

Jim,
The only other parameter I know that can affect exposure is if for any reason the "flash control" is set to "ADI Flash" instead. of "pre-flash TTL". But this option should be disabled unless an ADI compatible flash is on the hotshoe.

Juan

David,

You may be correct. The flash seems to be consistent just way too low.

When you looked at your photos may I assume that the exposure is incorrect in most of them. Due to the vagaries of ETTL in real life some are probably fine. In testing at a controlled target they all seem to be 1.7 to 2 stops off with the Ad600. In real life shooting I see less of an issue but then I am blending ambient with flash. In studio the issues is more obvious.

Jim

jmaher wrote in post #18040597
David,

You may be correct. The flash seems to be consistent just way too low.

When you looked at your photos may I assume that the exposure is incorrect in most of them. Due to the vagaries of ETTL in real life some are probably fine. In testing at a controlled target they all seem to be 1.7 to 2 stops off with the Ad600. In real life shooting I see less of an issue but then I am blending ambient with flash. In studio the issues is more obvious.

Jim

That's the thing Jim,
I used the AD600s three or four times in TTL shooting some MUA look book stuff. HERE. They were not under exposed.

I'm going to do some testing with Manny in the morning.

I went back and looked at my first use of the AD600 (as fill in daylight as well as a few studio) and while a few shots were unexposed the majority were fine.

Not sure what is going on. I set up the test because I thought I was recently seeing some underexposure and before i did I upgraded the firmware in both the trigger and the TT685.

Clearly in the controlled test I did the system underexposed. Maybe there is a problem with my AD600? However it is consistent in what it is doing. Maybe the firmware? Maybe something else?

Jim

Here is a test I did this morning.
The first image is Manny lit with a bounced TT685 in M. My trusty Minolta flash meter read f2.8, ISO 200 when placed at Manny's nose with dome pointed at camera.
Second image is TT685 in TTL mode, FEC 0. In Lightroom I increased the exposure .1 EV to get the same reading on the white square.

Third image is with XPLOR600 in M. Meter read F2.0+.9. As close as I could get to F2.8.
The fourth image is the XPLOR600 in TTL 0FEC, I had to increase exposure slider .69EV to get same reading in the white square.

The difference between the TT685 and the XPLOR600 TTL exposures is large enough to be problematic.

The camera flash setting was fill-flash. The metering mode was center.

I had the TT685 in an S bracket and placed the H600 head on the stand and aimed at the same point on the wall/ceiling joint to get the lighting as close to the same as possible. I had a stand reflector on the H600.

As best I can determine, Adorama is the exclusive distributor for the TTL version of the AD600.
I've sent an email to Helen asking her to alert the product management group for the XPLOR600 so they can address the problem with Godox.

David,

Thanks for all of your work. It seems your unit is off by 1 EV and mine by about 1.7 in ETTL.

I will also contact Helen.

Jim

jmaher wrote in post #18041347
David,

Thanks for all of your work. It seems your unit is off by 1 EV and mine by about 1.7 in ETTL.

I will also contact Helen.

Jim

It certainly seems that there is something in the XPLOR600 firmware that needs attention.
I was pleased to see the TT685s was delivering accurate exposure. That immediately narrowed it to the 600 in my view.

dmward wrote in post #18040706
That's the thing Jim,
I used the AD600s three or four times in TTL shooting some MUA look book stuff. HERE. They were not under exposed.

I'm going to do some testing with Manny in the morning.

David, were all of those were shot in TTL?

Robsphoto wrote in post #18042340
David, were all of those were shot in TTL?

Rob,
If you're talking about the MUA shots, no.
Some were M and some were TTL. Most were TTL.

During one session I also shot some using the FEL capability to get a TTL power setting and then keep it in the light via FEL while shooting subsequent images.

Just got back from a backyard wedding.
Used one AD600TTL for the groups, and some couple shooting in the forest preserve next to the house.
No problem with underexposure.

Will have to wait till the pictures are on the web gallery for the couple before posting.

I think this is turning out to be a learning curve situation. At least for me.

I will add my experience over the last couple of days for what it is worth.

First the good news. I tested my v860iis, on camera, off camera and compared with my own Sony flash (on camera). TTL seemed to be spot on and matched the Sony.

I used the ad600 as a sole light in a studio shoot a couple of days ago using TTL. I found the exposure basically erratic. Most of the time it was fine but every so often it would suddenly under expose at least a stop. I dont generally use TTL in a studio and the ad600 is my first ttl studio flash so there is a fair chance of user error here (especially as my modifier quite often enters the shot).

I decided to do a more controlled experiment. Set up the camera on a tripod, pointed at a fixed point. Set the ad600 on a light stand. Then took about 90 shots in a row. This time every shot was underexposed at least a stop but the exposures themselves were totally consistent.

Are people having trouble with Godox branded stuff or Flashpoint?

eventsof1768 wrote in post #18043904
Are people having trouble with Godox branded stuff or Flashpoint?

They are the same except for the silkscreened name and logo on the case.

I'm going to do some more testing this week.
Objective is to see if its really an algorithm setting or shooting techniques.

As I said in earlier post.
I had the XPLOR600 with remote head and Cheetah QS foldable silver BD with diffusion panel.
It was setup just off lens axis and about 10 feet from the groups. Sun speckled woods with open area behind them.
The guys had light grey tuxes. I had the camera set to Av, +1 EC. Light was set to -.7 FEC.

Every shot is consistently exposed. The camera meter was set to center weighted.

Based on this experience I have no concerns about the light delivering.