Godox H400P extention head power loss

[Richard Hopkins]

https://www.fredmiranda.com/forum/topic/1445828

I doubt that for a reason. According to this measurements the AD600 remote head has 1/2 of a stop power loss.

There is a lot wrong with the way Rob is doing those tests and I'm pleased to say that he's tightened up procedures a lot since 2016. I have tested that very same unit as accurately and carefully as I know how and got 0.25 stops drop with the head extension, the last 0.05 established by adjusting the test distance to see where the meter changed from 0.3 to 0.2.

There are lots of variables in extension cables - length, thickness, quality, and how much energy you're shoving through them. It's a bit like water through a hose pipe. Having said that, from my own tests and what I've picked up from various sources including conversations with Profoto, one-third of a stop is a pretty good yardstick. And I think that's because manufacturers build up to a standard and try to stay under that one-third stop because anything more would be commercially unacceptable.

 

[Serjojeee]

https://www.fredmiranda.com/forum/topic/1445828

I doubt that for a reason. According to this measurements the AD600 remote head has 1/2 of a stop power loss.

There is a lot wrong with the way Rob is doing those tests and I'm pleased to say that he's tightened up procedures a lot since 2016. I have tested that very same unit as accurately and carefully as I know how and got 0.25 stops drop with the head extension, the last 0.05 established by adjusting the test distance to see where the meter changed from 0.3 to 0.2.

0.25 of a stop sounds better, but it's still a substantial amount for 400 Ws strobe in daylight. Cause 400 Ws is barely enough with HSS in that scenario.

He also measured the extention head for AD600PRO which has a shorter cable (6 feet vs 8 feet) and says that it has 0.1 stop of a power loss.

There are lots of variables in extension cables - length, thickness, quality, and how much energy you're shoving through them.

I know that from a guitarist point of view. For passive pickups cables are important.

It's a bit like water through a hose pipe. Having said that, from my own tests and what I've picked up from various sources including conversations with Profoto, one-third of a stop is a pretty good yardstick. And I think that's because manufacturers build up to a standard and try to stay under that one-third stop because anything more would be commercially unacceptable.

Thanks for the info! I assume that it might be close to that 0.25 stop loss cause cables of AD600 and AD400PRO strobes have the same length.

I with Godox would make something like AD500PRO with the same form-factor as AD1200PRO. Shave some weight from the strobe unit (minus softbox mount, minus stand mount, and the unit can be made less rigid cause it will not withstand those forces). And the remote head is light and cheap to replace if it falls (and it will fall eventually, if you use it outdoors, it's just a matter of time, you just don't control the wind).

 

[Ed Shapiro]

https://www.fredmiranda.com/forum/topic/1445828

I doubt that for a reason. According to this measurements the AD600 remote head has 1/2 of a stop power loss.

There is a lot wrong with the way Rob is doing those tests and I'm pleased to say that he's tightened up procedures a lot since 2016. I have tested that very same unit as accurately and carefully as I know how and got 0.25 stops drop with the head extension, the last 0.05 established by adjusting the test distance to see where the meter changed from 0.3 to 0.2.

There are lots of variables in extension cables - length, thickness, quality, and how much energy you're shoving through them. It's a bit like water through a hose pipe. Having said that, from my own tests and what I've picked up from various sources including conversations with Profoto, one-third of a stop is a pretty good yardstick. And I think that's because manufacturers build up to a standard and try to stay under that one-third stop because anything more would be commercially unacceptable.

Call me old-fashioned, but for all practical purposes, I can't understand what so many folks are worried about the loss of even half a stop. If their power requirements are that critical, that a small loss of power is going to interfere withte shooting methods they simply require a more powerful unit or flash system that exceeds the "edge" of their power nedds so they can twakek it up when needed. In many instances, just moving in a light a bit close to the subject, changing up a reflector, or repositioning a modifier can compensate for a small power loss.

In my first post in this thread, I mentioned that the use of an extension cable, base on my long experience with a wide variety of flas gear, will usually entail a slight loss of power. For critical applications, there are cables that minimize power loss, due to resistance, to the utmost minimums, however, that wire in a practical length would exceed the cost of an entire Godox monolight.

The OP responded that this information was "irrelevant"- I suppose he has his reasons.


Ed Shapiro- Commercial and Portrait Photographer. Ottawa, Ontario Canada

 

[Richard Hopkins]

Call me old-fashioned, but for all practical purposes, I can't understand what so many folks are worried about the loss of even half a stop. If their power requirements are that critical, that a small loss of power is going to interfere withte shooting methods they simply require a more powerful unit or flash system that exceeds the "edge" of their power nedds so they can twakek it up when needed. In many instances, just moving in a light a bit close to the subject, changing up a reflector, or repositioning a modifier can compensate for a small power loss.

In my first post in this thread, I mentioned that the use of an extension cable, base on my long experience with a wide variety of flas gear, will usually entail a slight loss of power. For critical applications, there are cables that minimize power loss, due to resistance, to the utmost minimums, however, that wire in a practical length would exceed the cost of an entire Godox monolight.

The OP responded that this information was "irrelevant"- I suppose he has his reasons.

Ed Shapiro- Commercial and Portrait Photographer. Ottawa, Ontario Canada

Outdoors in bright sun you often need every last drop of power, especially when forced into HSS mode. Unlike studio work where it's easy to just bump the ISO to push the effective exposure, that doesn't work outdoors where the ambient brightness level sets the baseline.

There are workarounds, like hyper-sync or the ND filter method, and/or the other techniques you describe, but it's so much easier if you've got enough clout in hand.

 

[Serjojeee]

https://www.fredmiranda.com/forum/topic/1445828

I doubt that for a reason. According to this measurements the AD600 remote head has 1/2 of a stop power loss.

There is a lot wrong with the way Rob is doing those tests and I'm pleased to say that he's tightened up procedures a lot since 2016. I have tested that very same unit as accurately and carefully as I know how and got 0.25 stops drop with the head extension, the last 0.05 established by adjusting the test distance to see where the meter changed from 0.3 to 0.2.

There are lots of variables in extension cables - length, thickness, quality, and how much energy you're shoving through them. It's a bit like water through a hose pipe. Having said that, from my own tests and what I've picked up from various sources including conversations with Profoto, one-third of a stop is a pretty good yardstick. And I think that's because manufacturers build up to a standard and try to stay under that one-third stop because anything more would be commercially unacceptable.

Call me old-fashioned, but for all practical purposes, I can't understand what so many folks are worried about the loss of even half a stop. If their power requirements are that critical, that a small loss of power is going to interfere withte shooting methods they simply require a more powerful unit or flash system that exceeds the "edge" of their power nedds so they can twakek it up when needed. In many instances, just moving in a light a bit close to the subject, changing up a reflector, or repositioning a modifier can compensate for a small power loss.

In my first post in this thread, I mentioned that the use of an extension cable, base on my long experience with a wide variety of flas gear, will usually entail a slight loss of power. For critical applications, there are cables that minimize power loss, due to resistance, to the utmost minimums, however, that wire in a practical length would exceed the cost of an entire Godox monolight.

The OP responded that this information was "irrelevant"- I suppose he has his reasons.

To make myself clear. With logic in mind. When the question is literally "what is the number", the answer is "number". Not like words of anything, just a simple number.

And I don't argue with what you've said, I actually mostly agree with your statements. But I want to know the number. There are scenarios (full body portraits with big modifiers like 52" brollybox) that I really like, and with AD600PRO with short cable remote head it's 0.1 stop loss is really not that impоrtant cause you are starting with 600Ws, but with longer cable remote head of AD400PRO it's estimated 0.3 stop loss is starting to be important cause the strobe is not that powerful to start with. We are talking about 550 Ws vs 300 Ws strobes if you use remote heads for both. It's a huge difference of AD300PRO vs AD600PRO. I"ve never said that I own any of those, I use AD200 and have two options now - add another AD200 to use them in AD-B2 or sell it and buy AD400PRO with a remote head. And I started all this remote head search cause I've used AD200 a lot and I'm surprised that i'ts not broken yet cause it's falling from time to time. I guess that if I'll add another AD200 and the heavy AD-B2 bracket to the stand It'll fall even more frequently.

Ed Shapiro- Commercial and Portrait Photographer. Ottawa, Ontario Canada

 

[Ed Shapiro]

Call me old-fashioned, but for all practical purposes, I can't understand what so many folks are worried about the loss of even half a stop. If their power requirements are that critical, that a small loss of power is going to interfere withte shooting methods they simply require a more powerful unit or flash system that exceeds the "edge" of their power nedds so they can twakek it up when needed. In many instances, just moving in a light a bit close to the subject, changing up a reflector, or repositioning a modifier can compensate for a small power loss.

In my first post in this thread, I mentioned that the use of an extension cable, base on my long experience with a wide variety of flas gear, will usually entail a slight loss of power. For critical applications, there are cables that minimize power loss, due to resistance, to the utmost minimums, however, that wire in a practical length would exceed the cost of an entire Godox monolight.

The OP responded that this information was "irrelevant"- I suppose he has his reasons.

Ed Shapiro- Commercial and Portrait Photographer. Ottawa, Ontario Canada

Outdoors in bright sun you often need every last drop of power, especially when forced into HSS mode. Unlike studio work where it's easy to just bump the ISO to push the effective exposure, that doesn't work outdoors where the ambient brightness level sets the baseline.

There are workarounds, like hyper-sync or the ND filter method, and/or the other techniques you describe, but it's so much easier if you've got enough clout in hand.

Exactly- understood! That's my point too. If you are frequently work in bright sunlight or other ambient conditions with HHS, etc, you do need equipment that has the power you need in the most extreme circumstances that you encounter.

I do lots of studio work but also lots of location work, particularly on industrial and construction sites where I can't select the ideal time of day or wait for more compatible ambient lighting conditions so I use powerful, old-fashioned 2-piece strobes that pack 400 to 800 watt-seconds. If I can plug into the mains, I have some monolights with HHS and excess power as well. I found through bitter experience that the only time I need extremely high power is I don't have the right gear with me! So I usually overkill the gear in readiness.


Ed Shapiro- Commercial and Portrait Photographer. Ottawa, Ontario Canada