GODOX AD600 Witstro

BigIronCruiser wrote in post #17945191
I tried a dozen different channels, and the results were the same each time. Histograms from the back of the D800 with everything in manual mode are shown below. I talked to Edward (Cheetah), and he wasn't very encouraging when asked if Godox might address this in the near future.

In TTL mode, the X1-N/360II provides reasonably accurate exposures at all shutter speeds except 1/250. At 1/250, images are underexposed, and the histogram looks strikingly similar to what I'm seeing in manual mode.

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forum: Flash and Studio Lighting

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My recollection from the days when PW ControlTL was the only game in town is that there was a problem with timing at the max x-xync shutter speed. At some point they included a setting in the firmware for the ControlTL devices to select where FP-sync took over.

Since the off exposure seems to only be occurring at the max x-sync speed, and the test images shows gradation, my conclusion is that at 1/250 the light has been told to use FP-sync strobing (HSS) while the firing signal is x-sync which means that some light is expended before the shutter opens and its "late" opening is causing the gradation.

If this is only happening at or near the nominal x sync shutter speed it would be useful to see test images shot at 1/3 stop increments from 1EV below nominal x sync speed to 1EV above.

Considering propagation delay, manufacturing tolerances etc. such a precise test might help narrow the likely causes.

I imagine that would be useful to Godox.

When shooting a properly illuminated neutral-gray target in manual mode, everyone would expect the histogram to be nothing more than centered spike at all shutter speeds. This is exactly what I see at all shutter speeds except x-sync. Other than shifting the histogram left or right, changing +/- EV via the X1-N doesn't change anything.

In my rather simplistic mind, this seems like an easy firmware fix. Just do at 1/250 what they're already doing at 1/200. Done!

BigIronCruiser wrote in post #17945694
When shooting a properly illuminated neutral-gray target in manual mode, everyone would expect the histogram to be nothing more than centered spike at all shutter speeds. This is exactly what I see at all shutter speeds except x-sync. Other than shifting the histogram left or right, changing +/- EV via the X1-N doesn't change anything.

In my rather simplistic mind, this seems like an easy firmware fix. Just do at 1/250 what they're already doing at 1/200. Done!

What appears to be happening, is that the X-1N is sending a message to the light to begin using the HSS mode while the camera still thinks it should fire the strobe via the x-sync fire path.

Since cameras have different x sync speeds, and there is potential for propagation delay is why, I think, PW finally came up with the adjustable transfer point based on camera model.

That may be a bit more firmware customization than Godox wants to invest in an item they are offering for less than $50 retail. It might be easier to just use a shutter speed a bit above or below the problematic one.

Most (if not all) professional level Nikon bodies have a 1/250 x-sync speed, so getting this right might be worth some attention it that's their target market. I reported this to Godox (via email) a week ago, but haven't received any type of acknowledgement. As an early adopter, I would hope that they're at least listening.

Edward (Cheetah) also suggested avoiding 1/250. Sounds easy, but it's something that could easily be missed when working under pressure.

By the way, I tried to submit this via the Godox Support page, but it seems that a "Code" is required. Anyone know how to get (or find) a code that works?

Can you disable FP Sync in the Nikon camera's menu? If so, does that solve this 'at-max-sync-speed-wrinkle'? (Or does the X1 force re-enablement of FP Sync by default?)

Canon's 5Dc & 5DII had a bug in which, assuming HSS was enabled, the camera would (wrongly) enact both HSS timing and HSS pulsing, AT its max sync speed, rather than only when that speed was exceeded. (The 5DIII was sorted .. ) The solution was to not leave HSS enabled by default, on those bodies.

Hence my question above. Annoying, but better than unexpected 2 stop under-exposures. Maybe.

Nikon does provide an option that puts a limit on shutter speed when a flash is attached. Setting the limit to 1/200, as suggested, might be the safest alternative until (or unless) Godox comes up with a patch.

Here is the update with Canon 5D MkIII with the new V2 X-1c

Nice.

Here is the update Nikon D800e with new V2 X-1N

I think it was a sync / time issue, but again I'm not a tech, just my opinion.

Thanks for the new tests. What firmware do the transmitters have?

Owen

owenegan wrote in post #17946250
Thanks for the new tests. What firmware do the transmitters have?

Owen

both V1 and V2 i used were V11 and V12
All I know was they fixed the foot, not sure if they did anything inside the x-1

That's V. 11 Canon, and V. 12 Nikon, right?

owenegan wrote in post #17946290
That's V. 11 Canon, and V. 12 Nikon, right?

correct v12 and v13 will be release this month