this was of course discussed many times, but still... how come that Adorama & Godox dare to sell us (__SONY__) this strobe and call it TTL ? here is a simple test - read below :
Test conditions :
- Sony A7R2, firmware version "3.30" + FE55/1.8 lens, firmware version "02"
- no ambient light / no LED model light from the strobe to make sure we are dealing with strobe output only
- Flashpoint AC Adapter Unit for the XPLOR 600 R2 series monolights to make sure we have power for strobe (safer than battery)
- spot metering (not matrix, not center-w, no face detection/eye AF) + camera on tripod + totally static scene (inc. remote camera triggering) = so make sure we have identical conditions, including getting raw data with Rawdigger
- M mode on camera with fixed ISO
- making sure we have enough time for strobe to recharge between shots and we are not getting close to its power output limit (on both max and min power sides of the output range)
- Strobe firmware version "2.3"
- Transmitter firmware version "1.4"
- Shooting distance = at least 2-3 times x "minimum focus distance" for the lens
- Target is a uniform surface (plain styrofoam) with spot metering area completely inside it with a lot of margin around
- Data extracted using Rawdigger, avg green channel (raw data), selection area 400x400 and centered by Rawdigger within the frame, the same position, scene does not change (shooting from tripod, etc).
- FEC on strobe not used/zero
- FEC on camera not used/zero
- FEC on transmitter not used/zero
- no HSS, we are not going in that pandora's box, exposure time will be fixed = 1/250 (x-sync for A7R2)
Testing will check how changing _only_ aperture from f1.8 to f11 in 1/3 EV steps will affect exposure ( as measured in raw files using Rawdigger ) with TTL - the premise (that is what manufacturer/seller = Godox/Adorama implicitly promise a customer when selling a TTL strobe/transmitter ) is that TTL must make sure that exposure will remain rather consistent ( at least within 1/3 EV margin, no ? ) ... you wish ! see the test results - raw files available
so only from f4.0 onwards we can see something resembling TTL... between F1.8 and F4.0 - total BS.
and for comparison a simple Sony speedlite on camera (same scene)... now that looks like TTL all the way.
Now if test fails we pose few questions for Adorama & Godox
1) do you acknowledge the issue ?
2) do you plan to warn customers about the issue ?
3) do you plan to fix the issue through firmware or recall the products ?
as I customer with 2 x XPLOR600TTL and transmitter for Sony I am waiting for Adorama rep to chime in ( request raw files - I email you the link to download )