HSS metering now in my house

I'll be interested to hear how the tests go. Lovely bit of kit.
 
I don't want to invade your thread Mike but in case your interested here are some times from my strobes:-

Elinchrom ELB 400 Full power.
HS head advertised v recorded.

t0.5
1/550 1/549 port A (100%)
1/1100 1/1100! port B (33%)

t0.1
1/177 port A
1/411 port B

A head advertised v recorded.

t0.5
1/2800 1/2550 1st pop 1/2710 2nd pop 1/2630 3rd pop, not so consistant as HS head! port A (100%)
1/5700 1/5630 port B (33%)

t0.1 average 1/1050 port A
1/1880 - 1/1910 port B

Canon speedlight 600-exrt mk1

Full power.
t0.5 1/1110
t0.1 1/419

Min power.
t0.5 1/40400
t0.1 1/15900

It seems the readings vary depending on recharge time, maybe tube temp, distance and other factors in my hand held room lit test but it gives an idea, the ELB numbers are close and sometimes spot on but I found head to head pop to pop that some variation was seen, I fired the ELBs perhaps 20 times and recorded the closest to quoted numbers from Elinchrom. I think this meter will reveal some interesting facts about flash durations.
 
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arthurbikemad said:
I don't want to invade your thread Mike but in case your interested here are some times from my strobes:-

Elinchrom ELB 400 Full power.
HS head advertised v recorded.

t0.5
1/550 1/549 port A (100%)
1/1100 1/1100! port B (33%)

t0.1
1/177 port A
1/411 port B

A head advertised v recorded.

t0.5
1/2800 1/2550 1st pop 1/2710 2nd pop 1/2630 3rd pop, not so consistant as HS head! port A (100%)
1/5700 1/5630 port B (33%)

t0.1 average 1/1050 port A
1/1880 - 1/1910 port B

Canon speedlight 600-exrt mk1

Full power.
t0.5 1/1110
t0.1 1/419

Min power.
t0.5 1/40400
t0.1 1/15900

It seems the readings vary depending on recharge time, maybe tube temp, distance and other factors in my hand held room lit test but it gives an idea, the ELB numbers are close and sometimes spot on but I found head to head pop to pop that some variation was seen, I fired the ELBs perhaps 20 times and recorded the closest to quoted numbers from Elinchrom. I think this meter will reveal some interesting facts about flash durations.
Click to expand...

I've always found Elinchrom's claimed flash durations to be very accurate, measured on an oscilloscope, but they do vary slightly - in line with slight fluctuations in brightness. Those changes though are miniscule in practise. The biggest shifts are usually at minimum power.

Canon publishes t.5 flash durations for the 600EX-RT Mk2 which identical to the Mk1 in that respect - page 133 of the handbook http://gdlp01.c-wss.com/gds/6/0300024046/01/600exiirt-im-en.pdf And they are notably different to your figures, if not massively out, ie full power 1/890sec, min power 1/34000sec. My own figures for the 600EX-RT are pretty much the same as Canon's.

Recharge times are critical and figures will be all over the place unless the flash is 100% charged. The flash ready light is an unreliable guide, as are claimed recharge times. It is common for the ready light or beeper to come on at only 60-70% of full charge.
 
HoppyUK said:
I've always found Elinchrom's claimed flash durations to be very accurate, measured on an oscilloscope, but they do vary slightly - in line with slight fluctuations in brightness. Those changes though are miniscule in practise. The biggest shifts are usually at minimum power.

Canon publishes t.5 flash durations for the 600EX-RT Mk2 which identical to the Mk1 in that respect - page 133 of the handbook http://gdlp01.c-wss.com/gds/6/0300024046/01/600exiirt-im-en.pdf And they are notably different to your figures, if not massively out, ie full power 1/890sec, min power 1/34000sec. My own figures for the 600EX-RT are pretty much the same as Canon's.

Recharge times are critical and figures will be all over the place unless the flash is 100% charged. The flash ready light is an unreliable guide, as are claimed recharge times. It is common for the ready light or beeper to come on at only 60-70% of full charge.
Click to expand...

Thanks for the feedback, I have a few 600's so I may compare them, without getting to obsessed with numbers I felt the figures were good, my test was FAR from scientific and not controlled at all! All in all it was a quick play with the new meter, I am super pleased with it!
 
Mike, I've just noticed something in the Godox AD200 user handbook re flash durations. Page 14 here http://www.yangwuonline.com/Website PDF/A-030501-PIKA200/PIKA200-MANUAL-WEB.pdf Be interesting to see what you get there.

It says times are measured from the moment of triggering, not from the moment brightness reaches 50% or 10% of peak. Re our previous debate, I think this is wrong and the latter is the accepted standard, used by most other major manufacturers, including Sekonic I think. It's also possible that it's just a mistake in the handbook. It wouldn't be the first time and I've also spotted other obvious errors in there.
 
HoppyUK said:
Mike, I've just noticed something in the Godox AD200 user handbook re flash durations. Page 14 here http://www.yangwuonline.com/Website PDF/A-030501-PIKA200/PIKA200-MANUAL-WEB.pdf Be interesting to see what you get there.

It says times are measured from the moment of triggering, not from the moment brightness reaches 50% or 10% of peak. Re our previous debate, I think this is wrong and the latter is the accepted standard, used by most other major manufacturers, including Sekonic I think. It's also possible that it's just a mistake in the handbook. It wouldn't be the first time and I've also spotted other obvious errors in there.
Click to expand...

The diagram looks correct, so probably just a chinglish error but have been busy photographing, hope to test later today
 
mike weeks said:
The diagram looks correct, so probably just a chinglish error but have been busy photographing, hope to test later today
Click to expand...

No, the diagram is wrong too.
 
mike weeks said:
What is wrong?

Mike
Click to expand...

It shows timing starts from the moment of flash triggering, which is wrong, and not from the moment the flash pulse reaches 10% or 50% of peak value - which is the standard method used by all the major brands for t.1 and t.5 times, and pretty sure your Sekonic too. It's not a huge difference, but makes Godox times seem longer than rivals when making comparisons.

Edit: Look at your pics on post #5 above, in the first one, the difference between the two methods at t.5 would be massive, like 100% difference (extreme example, at minimum power) whereas with a t.1 reading on the second full power example, the difference is pretty much zero.
 
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mike weeks said:
OK this is Sekonic's definition page 101 for those not following http://m.sekonic.com/portals/0/documentation/l-858d_operating_manual_eng.pdf
Click to expand...

That doesn't actually explain it in words, but if you look at the little arrows on the graphic, it clearly shows they are using the correct method (visible on the meter's screen, too). And equally, the Godox graphic clearly shows that, in the handbook at least, they are not ;)

Edit: see my edit on post #20 above, with crossed posts I think you might have missed it.
 
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I find it kind of funny that none of this is about HSS given the title of the post. ;)

Because I was *bored, I put together some drawings to help explain everything.

Untitled-2.gif

#1 shows the amount of light above 10% output, the duration (T0.1) is the width of the base of that area
#2 shows the same for output above 50% (T0.5)
#3 shows how an IGBT flash reduces output by cutting off the tail, which causes T0.1 and T0.5 times to become more similar
#4 shows their importance relative to the amount of ambient collected. It shows a relatively low intensity of light (height) with a short timeframe (SS). In this scenario the flash peak is significantly overpowering the ambient. And the portion of light below 50% and above 10% is a significant amount of the total of all 3, which means it will contribute significantly to the final image. The result would be a very "flash looking" image.
(below 10% is never considered "significant." I doubt that's actually/entirely true, but maybe only in very specialized applications)

One thing I don't quite understand is the reason for the difference in the left edge of the curves shown in post 5. That should be dictated by capacitor discharge rate and bulb heat up characteristics... I would think it would remain pretty consistent unless there is a change due to residual heat buildup in the bulb or circuitry. Either way, I doubt it's of any real significance for any typical flash application.



*I wasn't bored enough to spend the time on making everything to scale
 
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sk66 said:
I find it kind of funny that none of this is about HSS given the title of the post. ;)

Because I was *bored, I put together some drawings to help explain everything.

View attachment 97166

#1 shows the amount of light above 10% output, the duration (T0.1) is the width of the base of that area
#2 shows the same for output above 50% (T0.5)
#3 shows how an IGBT flash reduces output by cutting off the tail, which causes T0.1 and T0.5 times to become more similar
#4 shows their importance relative to the amount of ambient collected. It shows a relatively low intensity of light (height) with a short timeframe (SS). In this scenario the flash peak is significantly overpowering the ambient. And the portion of light below 50% and above 10% is a significant amount of the total of all 3, which means it will contribute significantly to the final image. The result would be a very "flash looking" image.
(below 10% is never considered "significant." I doubt that's actually/entirely true, but maybe only in very specialized applications)
Click to expand...

(y)

One thing I don't quite understand is the reason for the difference in the left edge of the curves shown in post 5. That should be dictated by capacitor discharge rate and bulb heat up characteristics... I would think it would remain pretty consistent unless there is a change due to residual heat buildup in the bulb or circuitry. Either way, I doubt it's of any real significance for any typical flash application.

*I wasn't bored enough to spend the time on making everything to scale
Click to expand...

You're right, that's just the scaling, which Sekonic has changed on both axes so that the signal fills a good area of the graph and you can see what's what. I have to change scaling manually on my oscilloscope, and if that's not done, when you do a full power pop and then one at minimum power, the latter shows as just a tiny spike in the bottom-left corner. But in both cases, the rise-rate on triggering is actually always the same.

It's interesting to see the graphed output shown both ways, as it also gives a handy visual indication of relative brightness. Such as, a full-power normal sync pop, then without changing anything, switch to HSS and see how brightness falls away dramatically but then runs for a much longer time.
 
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HoppyUK said:
You're right, that's just the scaling, which Sekonic has changed on both axes so that the signal fills a good area of the graph and you can see what's what.
Click to expand...
I suspected that, but somehow I missed the unit change from millisecond to microsecond.

For those interested, and because I am now procrastinating rather than doing something more constructive, this is what a "fill flash" at reduced power scenario might look like.

Untitled.gif

In this scenario the ambient level is above the flash output (it would still leave ambient shadows). And we have collected enough total light so that the T0.1-T0.5 portion alone (yellow) is relatively small compared to the total. This is a scenario where flash doesn't freeze motion and there is great risk of motion blur.
It is also closer to what manufacturers (used to) consider "normal." While the area/qtty of the light added below 50% is (potentially) greater than the area above, it is smaller in relation to the total compared to the previous scenario (#4 above), and it is well below the intensity of the ambient (or other lights)... which means it will not contribute significantly to the image and is why T0.5 was adopted as the normal reference.


And this next scenario is a low ambient light situation (strength and qtty) where flash does freeze motion based upon the T0.1 time.

Untitled-1.gif

We often say that flash duration is your effective shutter speed, but that really isn't correct... it *can* be. And it can be the T0.5, T0.1, or some other duration, depending on the ambient light intensity and qtty recorded. In most typical uses, flash seldom freezes any significant rate of motion. And that's why HSS is very beneficial.

(ha! I brought it around on topic)
 
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HoppyUK said:
That doesn't actually explain it in words, but if you look at the little arrows on the graphic, it clearly shows they are using the correct method (visible on the meter's screen, too). And equally, the Godox graphic clearly shows that, in the handbook at least, they are not ;)

Edit: see my edit on post #20 above, with crossed posts I think you might have missed it.
Click to expand...

I have been in touch with them, they agree it is a mistake and it will be amended.

Mike
 
mike weeks said:
I have been in touch with them, they agree it is a mistake and it will be amended.

Mike
Click to expand...

Result! Also an error on page 19 re over-heat limits.
 
mike weeks said:
Not got that far in my testing, what are you seeing there?

Is it the do not exceed 100 and then quoting protection cuts in at 40 & 60?
Click to expand...

Yes, that's it.

And though it's not mentioned, I suspect that if you keep going after hitting the over-heat slowdown, shortly after it will shut down completely for 15 mins or so. In other words, it'll never get to 100. Want to test that?!
 
HoppyUK said:
Yes, that's it.

And though it's not mentioned, I suspect that if you keep going after hitting the over-heat slowdown, shortly after it will shut down completely for 15 mins or so. In other words, it'll never get to 100. Want to test that?!
Click to expand...

Now on my list but have sent the factory the question.

Mike
 
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