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Cactus V6 Flash Compatibility -- Profiling Successes and Failures
Posted By: Class A, 05-13-2014, 08:34 AM

If you have successfully profiled a TTL flash with the V6, please post about it here.

Information whether remote control of power levels is working is welcome for all flash systems supported (Canon, Nikon, and Pentax) and any flash brand.

If you attempted to profile a flash and it did not work, please post about it here as well. Preferably, elaborate what the hurdle was (e.g., did not test as compatible, did not recycle quickly enough, ...).

I'll updated this first post regularly so that it will stay a summary of the experiences. Hence it will be easy to see which flash models are the awkward ones that refuse to play with the V6. I cannot image there will be many models that won't work, but let's see.

Compatible: (in addition to the predefined profiles; see the review for the original list of predefined profiles)
  • Pentax AF200T
    (the respective profile may also be used for the AF280T which on its own does not support profiling due to the lack of a sufficient number of manual levels.)

Don't Work:

Last edited by Class A; 09-30-2015 at 10:44 AM.
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05-13-2014, 10:31 AM - 1 Like   #2
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I've successfully profiled a Metz 36 AF-4P (Pentax), and found that the Metz 48-AF1 (Pentax) will work with the built-in profile for the 50-AF1.

In addition to those, the older Pentax AF-540FGZ works (with the built-in profile), but the AF-540FGZ II (WR) does not, and cannot be profiled. I've emailed Cactus, and they say they are working on decoding the P-TTL digital signal, even though I think you mentioned this in your review already.

The 540II was kindly loaned to me by Pentax Canada ($630, gulp!), but I handed it back and bought a lightly used 540 from stormtech (thanks, Stan!). I can also confirm that the V6 triggers will set off the V5's as well, so my non-TTL Yongnuo can play along at whatever manual power level I've set.

EDIT: yeah, yeah, yeah... pics or didn't happen:


Last edited by panoguy; 05-13-2014 at 11:12 AM.
05-13-2014, 02:54 PM   #3
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QuoteOriginally posted by panoguy Quote
I've successfully profiled a Metz 36 AF-4P (Pentax), and found that the Metz 48-AF1 (Pentax) will work with the built-in profile for the 50-AF1.
Thanks a lot for these.

I've added them to the list (crediting them to you by linking to your post).

Using the predefined 50-AF1 profile for the 48 AF-1 may give slightly incorrect results, in particular in the absolute power mode. The deviations could be negligible though.

Did you try to profile the 48 AF-1 at all?

P.S.: Using the "wrong" profile is a reasonable way forward, in particular for flashes that do not support analogue TTL but a digital version (i-TTL, E-TTL, and perhaps in the future P-TTL) only.

The latter models cannot be user-profiled but if an existing profile works with them then it could be all good. I assume power levels would automatically be correct, but I don't have a flash model with which I could test this hypothesis.

Last edited by Class A; 05-13-2014 at 03:01 PM.
05-13-2014, 03:52 PM   #4
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QuoteOriginally posted by Class A Quote
Using the predefined 50-AF1 profile for the 48 AF-1 may give slightly incorrect results, in particular in the absolute power mode. The deviations could be negligible though.

Did you try to profile the 48 AF-1 at all?
Ah, because of the difference in Guide Numbers! No, I didn't try to profile the 48, mainly because it was my main P-TTL flash (before getting the 540) and just wanted to get the triggers working after hitting the wall with the 540II. I might give it a go now that I understand how to make a profile.

05-21-2014, 10:59 PM - 1 Like   #5
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Metz 45CL-4 (analog)

I've been testing the Metz 45CL-4 with the Cactus V6 and here are the details of how I tested the combo, and my findings:

Profiling:
In a dimly lit room, I placed the Metz 45CL-4 analog version with the SCA 3000C cable and 3702 Pentax TTL module (firmware M2) and the Cactus V6 (firmware 1.0.152) on a table. I positioned the front of the reflector of the flash gun, and the V6's optical slave exactly 100cm from a wall painted in a flat white. I followed the instructions that came with the V6 unit, setting the flashgun first to TTL, and checking for compatibility, then taking a measurement at half and quarter power, and in "winder" mode which is 1/64th power [see my Update #2 for more details]. I choose the option to skip 1/8th, 1/16th, 1/32nd and 1/128th power levels because they are not available in manual mode on the 45CL-4.

A note on guide number (always in meters): During the profile creation process, the Cactus V6 asks the user to input the guide number of the flashgun being profiled. Most modern flashes have a zoom head with a Fresnel lens on the front to concentrate the light as needed for different focal lengths. The Metz 45 CL-4 does not have a zoom head, it is always set to a 35mm focal length. Here's the thing to understand though: even though the quoted guide number of the 45CL-4 (45, in meters) may be lower than most top-of-the-line flashes these days, it actually emits more Joules of energy, albeit over a wider angle. Putting a flash head in a softbox negates the advantage of the zoom head, it levels the playing field as it were. So if one were to zoom the Metz 58, for instance, out to the 35mm position to match the 45CL-4's angle of coverage, the GN would be 35. So, by doing a little algebra... in a softbox, the 45CL-4 would actually provide as much light as a zoomable flash with a GN of 75!! That's a lot of power, and one of the main reasons to own this flashgun. Since I will most often be using the 45 in a softbox, I choose to input the GN as 75 ...or rather I would have, except the V6 only allows the user to input guide numbers up to 70, so I did that instead. The only time this really come into play is when using "absolute" power mode on the V6 in order to calculate the contribution of flashes with different max GNs. I can deal with a little discrepancy.

Testing:
I positioned my newly profiled 45CL-4 and the Cactus V6 on a light stand, then placed another light stand 300cm (3m) away to give an approximation of an average working distance, and to it I attached my Sekonic 758 DR light meter using the factory default calibration with the dome in the down position, pointing directly at the flash head. The flash head was "bare bulb" with no wide angle spreader attached. Using a second V6 as the controller, I took readings at each full stop. Ideally there would be a corresponding change of 1 stop for every power level on the V6's dial. Here are the results from the Sekonic meter.
  • Full - f/11 and 1/10th
  • Half - f/8 and 4/10ths
  • Quarter - f/5.6 and 4/10ths
  • 1/8th - f/4 and 5/10ths
  • 1/16th - f/2.8 and 4/10ths
  • 1/32nd - f/2.8 and 3/10ths
  • 1/64th - f/2 and 8/10ths
  • 1/128th f/2 and 4/10ths
  • "Lo" Power - f/2 and 3/10ths
Not exactly as accurate as it could be, still it a big improvement over only having 4 manual power levels, with a notably large gap between 1/4th and 1/64th 1/40th power.


Without changing the setup I then tried using the factory profile that came with the V6 for the Metz 58AF-2 (still using the 45CL-4 in the test though), and here are the results:
  • Full - f/11 and 1/10th
  • Half - f/8 and 5/10ths
  • Quarter - f/5.6 and 4/10ths
  • 1/8th - f/4 and 5/10ths
  • 1/16th - f/2.8 and 6/10ths
  • 1/32nd - f/2 and 9/10ths
  • 1/64th - f/2 and 0/10ths
  • 1/128th - f/1.4 and 5/10ths
  • "Lo" Power - f/1.4 and 1/10th
Here the results were better, still not the ideal 1:1 relationship of input to output, but at least it managed to break 6 stops of variability, with a more predictable shape to the curve.

Conclusions:
The V6 is compatible with the Metz 45CL-4 with some limitations. The factory profile for the Metz 58AF-2 though provides finer controls over then unit than the custom profile generated by the V6.

Why is that? Well, it is likely because of the large gap between one-quarter and 1/64th 1/40th power levels on the 45CL-4. The Cactus must interpolate the proper quench timings in milliseconds for the intermediate power levels based on only a few data points. It may also be that 1 millisecond may not be a fine enough scale to resolve all the 10ths-of-a-stop between power levels (i.e. the sum of the parts may be greater than the sum of the whole... stop)

Perhaps Cactus will some day provide us a software based profile creator to allow users to tweak the quench timings based on their own measurements with their particular equipment.

Thoughts:
One might choose to see the V6/Metz 45 combo for it's faults - uneven scaling, six rather than eight stops of variability, and difficult-to-quantify GN - as a less than ideal system. Fans of the 45CL-4 however know just how much power the little potato masher brings to a location shoot, especially when fitted with a softbox or umbrella vs. a shoe mounted flashgun. The V6 adds much finer controls to the unit than were ever available through Manual, Auto or TTL, making it a welcome companion to the 45CL-4, and breathing new life into a trusted old workhorse.

I am very happy with the V6s, and I can't wait to try them and my new RF60s on a location shoot. I don't see them replacing my studio strobes, but I can conceive of situations in the studio where the ability to change power levels quickly and turn on and off groups of lights might trump the need for raw lighting horsepower.

Last edited by maxfield_photo; 06-03-2014 at 09:24 AM.
05-22-2014, 01:56 AM   #6
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QuoteOriginally posted by maxfield_photo Quote
I've been testing the Metz 45CL-4 with the Cactus V6 and here are the details of how I tested the combo, and my findings:
Thanks a lot for this great report!

It is interesting to see how much in agreement both custom and ("wrong") predefined profile are until 1/32 power. After that the predefined one remains pretty linear (it gets flatter as it ideally should, though) and the custom one gets too flat too quickly.

We cannot really fault the predefined profile for not being more accurate as it was made for a different flash model, but ideally your custom profile should have given you better accuracy.

I agree with you that the reason for the lack of accuracy is most likely the large gap between 1/4 and 1/64. It would be nice if some day Cactus made it possible to save profiles to a computer in a way that would allow user manipulation. Alternatively, they may also come up with a different interpolation/extrapolation approach that works better with flash models that have such large gaps between their manual levels.

It would have been very interesting to see your light meter readings for the manual levels of the Metz 45CL-4. If the Metz worked perfectly, the values you should get are

1/1: f/11 + 0.1
1/2: f/8 + 0.1
1/4: f/5.6 + 0.1
1/64: f/1.4 + 0.1

I would have expected the V6 to replicate the level at 1/64 power exactly. It would be great if you could verify whether the Metz actually emits f/1.4 + 0.1 in winder mode, or whether it emits f/2 + 0.8.

Maybe the winder mode does not really correspond to 1/64 power?

Last edited by Class A; 05-22-2014 at 02:03 AM.
05-26-2014, 01:05 PM   #7
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[UPDATE]

As Class A suggested, I have taken some manual readings from the Metz 45CL-4 in order to give some context to the results from the V6 tests. I've maintained all the variables from my earlier tests, (distance, ambient lighting, dome position). To be clear, nothing was connected to the 45 for this test, I triggered it using the test button on the flashgun itself. Here are the results:
  • Full Power = f/11 and 1/10th
  • Half Power = f/8 and 5/10ths
  • Quarter Power = f/5.6 and 4/10ths
  • "Winder" mode = f/2 and 7/10ths
The numbers don't match with the expected outcome. We would expect to see one full stop difference between full and half power, but I have a theory as to why that isn't the case. I think that either a) the capacitors in my old analog 45CL-4 can no longer hold a full charge, or b) that the t.1 flash duration extends beyond the sampling time of my Sekonic 758 (I suspect that this is the case). The light meter is designed to give a percentage reading of flash to ambient, and I set the shutter speed to 1/60th, which should be enough to capture any flash discharge in theory, but I'm not sure if the Sekonic is metering the flash for that entire time. Since the profiling procedure for the V6 doesn't use the full power reading as a data point, it shouldn't affect the shape of the curve.


What does affect the curve though is "Winder mode". I had always understood that "winder mode", which is used to take a series of exposure in quick succession, was 1/64th of full power, but after consulting the manual for the Metz 45 it appears that "Winder" mode is 1/40th power, so 1/3rd of a stop less than 1/32nd power. Since I was entering this as 1/64th power, I think it was significantly impacting the shape of the curve, and therefore the accuracy of the quench timings from the V6. I think for now, still the best option is to use one of the factory profiles that come with the Cactus V6 like like Metz 58AF-2, and keep checking the Cactus site for updates.

Last edited by maxfield_photo; 08-24-2014 at 08:09 AM.
05-26-2014, 02:12 PM   #8
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QuoteOriginally posted by maxfield_photo Quote
What does affect the curve though it "Winder mode". I had always understood that "winder mode", which is used to take a series of exposure in quick succession, was 1/64th of full power, but after consulting the manual for the Metz 45 it appears that "Winder" mode is 1/40th power, so 1/3rd of a stop less than 1/32nd power.
Ah, I suspected as much.

Thanks a lot for going through the effort of checking the manual levels.

Using the Metz 58AF-2 profile is an option, but if you aren't sick of profiling yet, you could also try to profile the Metz 45 again by just using manual levels 1/2, and 1/4. Just skip all the other levels.

05-27-2014, 04:11 AM   #9
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Anybody tried profiling with a Godox 850? Would be great to combine some of the V6 trigger options with faster recycling and long battery life.
05-27-2014, 07:34 AM   #10
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QuoteOriginally posted by howieb101 Quote
Anybody tried profiling with a Godox 850?
Apart from the proprietary clip-on radio triggering system, the V850 has a simple single pin hot-shoe only.

It therefore does not qualify for control with the V6.

QuoteOriginally posted by howieb101 Quote
Would be great to combine some of the V6 trigger options with faster recycling and long battery life.
You have two options to reach this goal:
  1. Use a Godox V860C which is supported by the V6. The V860C is considerably more expensive than the V850, though.
  2. Use a battery pack for the RF60 (or any other flash that supports this option and is compatible with the V6).
The RF60's tripod mount can be used to attach a battery pack so you'd still be handling one unit basically. I haven't been able to try that yet, so I don't know how well it works in terms of form factor.

If you don't like the regular eight AA battery power packs, there are also newer (but also more expensive) Li-Ion packs that may speed up handling.
05-28-2014, 07:34 AM   #11
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QuoteOriginally posted by maxfield_photo Quote
I choose to input the GN as 75 ...or rather I would have, except the V6 only allows the user to input guide numbers up to 70, so I did that instead.
I had reported your problem as soon as you mentioned it and just learned that the maximum GN you can input will be raised in future firmware upgrades.

From now on, anyone can directly report problems, ask questions, or make suggestions in the brand new Cactus Support Community Forum.
05-28-2014, 11:55 AM - 1 Like   #12
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[UPDATE #2]

After discovering that "Winder" mode on the Metz 45 CL-4 is actually 1/40th power (source: Metz 45CL-4 user manual), and not 1/64th power as is reported on some websites, I decided to try profile it again using only two data points, half and quarter power. The results, for those who like the gory details, are as follows (again, same testing setup as before):
  • Full = f/11 .1 (I suspect this reading is lower than what is actually being emitted)
  • Half = f/8 .5
  • Quarter = f/5.6 .5
  • 1/8th = f/4 .7
  • 1/16th = f/2.8 .9
  • 1/32nd = f/2.8 .4
  • 1/64th = f/2 .9
  • 1/128th = f/2 .5
  • "Lo" Power = f/2 .4
The conclusion is still the same, for now (May 2014), using the Metz 58 AF-2 profile with the 45 CL-4 +SCA 3000C +SCA 3702 Pentax module yields both more predictable results and a wider range of power than the profile generated by the V6. Perhaps a Metz Mecamat could improve the results, but sadly, I don't own one.



I would speculate, though this is dangerous without more data, that users may find that a factory profile, even if it is not the correct one, may be preferable to using a V6-generated profile IF the flash unit in question only supports a few manual power levels.


I have posted a suggestion to the newly created Cactus V6 forum that a software utility might allow obsessive individuals like myself the ability to tweak and fine tune the timings of custom generated profiles, and then possibly even share them with the rest of the community. There is already a precedent for this. Adobe hosts a database where users can post and download lens correction profiles for use in applications like Lightroom and Photoshop. Users can also rate the accuracy of custom profiles, so that others may see which are worth downloading.
05-29-2014, 04:20 AM - 1 Like   #13
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As promised tests with a variety of Metx 'Stuff'
Learning - failure either means unsupported or inability to complete profile during tuning phase
Metz 45 CT4 + sca311 = failure (this is Canon FD ttl so probably unsupported)
Metz 45 Digital + sca 3402m6 thought failure but if switch the little switch on sca to off and power off/on the flash for every change ttl/m/m2/etc you can profile
Metz 45 Digital + sca 3102m3 = success
Metz 45 Digital + SCA 3702M = Failure
Metz 45 Digital + SCA 3702M3 = Failure (note if you use a p-ttl profile i.e Pentax 540 then though you can happily go from 1:1 to 1:1/128 you cant go back seems to stick)

Metz 54mz3 + sca3702M = Success
Metz 54mz3 + SCA702M3 = Failure
Metz 54mz3 + sca3402M6 = Success
Metz 54mz3 + sca3102M3 = Success

Metz 45 Digital + SCA 3702M3 = it is possible to profile if you enable 2nd flash head but doesn't appear to fire 1:1 at the 1:1 setting though you do get 8 power steps.

Last edited by awaldram; 05-29-2014 at 04:45 AM.
05-29-2014, 11:16 AM   #14
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QuoteOriginally posted by maxfield_photo Quote
The results, for those who like the gory details, are as follows (again, same testing setup as before):
Thanks, unfortunately this is indeed not better than the earlier version in which you included the "winder" level in the profiling. In fact, including the "winder" level held linearity a little bit longer (till 1/16).

QuoteOriginally posted by maxfield_photo Quote
I have posted a suggestion to the newly created Cactus V6 forum that a software utility might allow obsessive individuals like myself the ability to tweak and fine tune the timings of custom generated profiles, and then possibly even share them with the rest of the community.
Thanks for that, I'm sure there are a few more who would use this for tweaking.

It should then also be possible to share successfully tweaked profiles among each other (which won't be necessary for any but the more exotic flashes, but still).
05-29-2014, 11:19 AM   #15
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QuoteOriginally posted by awaldram Quote
As promised tests with a variety of Metx 'Stuff'
Thanks a lot for sharing; I think I'll have to somehow summarise this for inclusion in the overview (and point to the details here).
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