Industry News: Hasselblad announces the X1D II 50C medium format camera, and the XCD 35-75 zoom lens

Jan 29, 2011
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That's from the official specification, though.

Besides, you don't need full power output for fill flash if you don't need HSS. You have GN12.5 (in meters) for the 80mm flash zoom at 1/16 of full power, which means you have pretty decent burst capability. With HSS at 1/1000, you will get the same GN for just a single full-power shot.
Yes and the official specification is incorrect as per my link. Flashes don’t flash that fast.

Again I was not asking about the utility of speedlites, which I use to their maximum effect when needed, I was asking what use is a 1/2000 sync speed to people “shooting portraits with strobes”
 
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If I am not mistaken, this is the smaller "medium format" sensor size, just like the new Fuji. I have a hard time figuring out why someone would choose this over the Fuji GFX system? (I am not being sarcastic, this is an honest question).
For the flash sync at all shutter speeds, something the Fuji can’t do and why I passed on it. I shoot on location portraits mixing ambient with strobes and having to use ND filters or HSS/HS greatly reduces the flash output. This camera solves that issue in a compact body rather than a studio sized MF.
 
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Yes and the official specification is incorrect as per my link. Flashes don’t flash that fast.

Again I was not asking about the utility of speedlites, which I use to their maximum effect when needed, I was asking what use is a 1/2000 sync speed to people “shooting portraits with strobes”

For the flash sync at all shutter speeds. Needed when combining ambient with flash outdoors. I shoot on location portraits mixing ambient with strobes and having to use ND filters or HSS/HS greatly reduces the flash output.
 
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What specific uses is a 1/2000 flash sync speed when there isn’t a flash made that outputs any kind of decent power in 1/2000 of a second.

The "Elinchrom ELB 400 Action To Go Kit" is one system that I am aware of that can sync fast enough. Specs on B&H list 1/2800 at full power. I have never used it myself.
 
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Again I was not asking about the utility of speedlites, which I use to their maximum effect when needed, I was asking what use is a 1/2000 sync speed to people “shooting portraits with strobes”
There are some new strobes out there, all rated around 500J, powered by lithium ions cells and fully capable of some kind of TTL, like the Profoto B1X. This thing claims 1/1000s flash duration for t0.5 at full power, and probably half that at half power.
 
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Jan 29, 2011
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Who cares about t 0.5 times? A child who doesn’t know what they are but knows shorter is better?

I am instantly suspicious of any flash company that quotes t0.5 times, the tail is always longer than the initial burst so a t0.1 of slower than 1/500 is nothing to boast about. My Einsteins at 1/4 the cost and more power are 1/360 sec at full power and have incredibly short durations off full power. Seriously, who is doing this set in TTL? I use ETTL when it is appropriate and think it is very good, but do you know the algorithm they use to reduce fill rating as EV changes? Nobody outside Canon does, you can’t do this stuff in TTL!

My point, that nobody seems to be taking up, is this, if your ambient exposure is 1/2000 sec then you are trying to mitigate a lot of light, to do that you need a lot of flash power to be brighter than that. I don’t know of an affordable system that can do that so I am asking, what, specifically, are people going to use to shoot with a 1/2000 sync speed?

I use ETTL fill flash with speedlites, sometimes in HSS to lower my ambient exposure, I use battery powered Einsteins outside. I have looked at all these systems and even have leaf shutter lenses, I still haven’t found a solution to provide enough flash light in situations where I need to use 1/2000 for my ambient exposure.
 
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Apr 25, 2011
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My point, that nobody seems to be taking up, is this, if your ambient exposure is 1/2000 sec then you are trying to mitigate a lot of light, to do that you need a lot of flash power to be brighter than that.
Not really, if it's Sunny-16 at f/2.8. If your subject is 5 meters away and you use a -1 EV fill flash, you only need about GN10 of flash exposure (if my calculations are correct).
 
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SecureGSM

2 x 5D IV
Feb 26, 2017
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Who cares about t 0.5 times? A child who doesn’t know what they are but knows shorter is better?

I am instantly suspicious of any flash company that quotes t0.5 times, the tail is always longer than the initial burst so a t0.1 of slower than 1/500 is nothing to boast about. My Einsteins at 1/4 the cost and more power are 1/360 sec at full power and have incredibly short durations off full power. Seriously, who is doing this set in TTL? I use ETTL when it is appropriate and think it is very good, but do you know the algorithm they use to reduce fill rating as EV changes? Nobody outside Canon does, you can’t do this stuff in TTL!

My point, that nobody seems to be taking up, is this, if your ambient exposure is 1/2000 sec then you are trying to mitigate a lot of light, to do that you need a lot of flash power to be brighter than that. I don’t know of an affordable system that can do that so I am asking, what, specifically, are people going to use to shoot with a 1/2000 sync speed?

I use ETTL fill flash with speedlites, sometimes in HSS to lower my ambient exposure, I use battery powered Einsteins outside. I have looked at all these systems and even have leaf shutter lenses, I still haven’t found a solution to provide enough flash light in situations where I need to use 1/2000 for my ambient exposure.
Hi Private,
I thought I will share this link with you:


Definitely an interesting resource as they measured actual flash durations for many good strobes at various power level settings.
It appears that quite a few units would provide a descent output at 1/2000 sec flash duration. Enough for a fill on a sunny day outside.
Not arguing your points here just wanting to share pass on some information that may be useful to some (arguably).
 
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Who cares about t 0.5 times? A child who doesn’t know what they are but knows shorter is better?
How about one who holds a doctorate in electrical engineering, with focus on telecommunication, who designed and built communication devices which went into commercial production, and therefore knows, that this t0.5 time is very relevant for estimating the relevant time frame for light output.

If, for whatever reason, you want 1/2000s exposure time, then a flash is a perfect fit, if it outputs most of its light power (even 75% is good) within this short time frame. BTW Profoto does list t0.1 time, it is irrelevant here, though.
I am instantly suspicious of any flash company that quotes t0.5 times, the tail is always longer than the initial burst so a t0.1 of slower than 1/500 is nothing to boast about. My Einsteins at 1/4 the cost and more power are 1/360 sec at full power and have incredibly short durations off full power. Seriously, who is doing this set in TTL? I use ETTL when it is appropriate and think it is very good, but do you know the algorithm they use to reduce fill rating as EV changes? Nobody outside Canon does, you can’t do this stuff in TTL!
I don't have such a flash unit myself, but I know folks who have this one, or a Chinese knockoff, and they use it extensively in this airTTL mode. Apparently it works, like it or not.

Your Einsteins may be the best product line ever, and you may be the smartest person in the world for using them (at least as long as you don't write nonsense about the relevance of t0.5 times), but there are indeed people who want to shoot wide open and outdoors.
My point, that nobody seems to be taking up, is this, if your ambient exposure is 1/2000 sec then you are trying to mitigate a lot of light, to do that you need a lot of flash power to be brighter than that. I don’t know of an affordable system that can do that so I am asking, what, specifically, are people going to use to shoot with a 1/2000 sync speed?
I did the calculations a while back: direct sunlight is comparable to 5000W incandescent light from a directed source (think construction light) held at 1m distance. Put it at 3m distance and you'd need 50.000W. If you have a shutter time of only 1/2000s, we're talking 25J sunlight here. If you start with two of these 500J flashes, turn them down to half power to make light output fill the 1/2000s shutter time, then you still have 300 - 500J at your subject. If that's not enough, I don't know what is.
 
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Apr 25, 2011
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I did the calculations a while back: direct sunlight is comparable to 5000W incandescent light from a directed source (think construction light) held at 1m distance.
I would put it slightly differently for the ease of understanding: sunlight is about 1 kW/sq.m of incandescent light (of color temperature about 5000K). At 0.5ms, it gives us 0.5 J/sq.m of radiant exposure of the target. If your flash setup needs to cover 3x2 meters of the object plane, it needs to compete with just 3J of sunlight.
 
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I would put it slightly differently for the ease of understanding: sunlight is about 1 kW/sq.m of incandescent light (of color temperature about 5000K). At 0.5ms, it gives us 0.5 J/sq.m of radiant exposure of the target. If your flash setup needs to cover 3x2 meters of the object plane, it needs to compete with just 3J of sunlight.
Sorry, that would be incorrect. While sunlight does create a light density of about 1 kW/m^2, incandescent light has very poor efficiency. You'd need about 20 kW of incandescent light spread over 1 m^2 to get the equivalent of sunlight. Once you consider this, our numbers are not that different.
 
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Apr 25, 2011
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Sorry, that would be incorrect. While sunlight does create a light density of about 1 kW/m^2, incandescent light has very poor efficiency. You'd need about 20 kW of incandescent light spread over 1 m^2 to get the equivalent of sunlight. Once you consider this, our numbers are not that different.
We are not talking about tungsten light at all.

Unless you are into absorption spectroscopy, sunlight is incandescent (i.e. black body radiation) light with the color temperature 5800K. Roughly the same as flashlight.
 
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We are not talking about tungsten light at all.

Unless you are into absorption spectroscopy, sunlight is incandescent (i.e. black body radiation) light with the color temperature 5800K. Roughly the same as flashlight.
Compact flashes and studio strobes are very much incandescent lights and have light efficiency very much like regular tungsten lights. Therefore it is a very useful comparison between a 1000J flash/strobe vs. a 1000W construction light with a halogen bulb shining for a whole second. Both require about 1000J of electricity, but give you only about 50J of visible light. The 1 kW/m2 you quoted for sunlight, on the other side, are already light radiation. You'd need a 20.000J flash/strobe shining into 1 m2 to match one full second of sunlight, or a 20.000W flood light.

Yes, sunlight is incandescent, but the 1 kW/m2 state light radiation power density, not the power needed to generate this kind of light power density.
 
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Apr 25, 2011
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Compact flashes and studio strobes are very much incandescent lights and have light efficiency very much like regular tungsten lights. Therefore it is a very useful comparison between a 1000J flash/strobe vs. a 1000W construction light with a halogen bulb shining for a whole second. Both require about 1000J of electricity, but give you only about 50J of visible light.

Yes, sunlight is incandescent, but the 1 kW/m2 state light radiation power density, not the power needed to generate this kind of light power density.
Do not idealize sunlight. It's just black body radiation. It's a very inefficient light source. This 1 kW/m2 is mostly just heat.

Tungsten light has about 3% of luminous efficiency (watt to lumen compared to an ideal monochromatic source).
Flash light has about 7% of luminous efficiency.
Sunlight has about 13% of luminous efficiency.
Modern white led sources have up to 25% of luminous efficiency.
Ideal white source emulating just Sun's visible spectrum would have 37% of luminous efficiency.
 
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If I look at this document here, total power density of solar radiation at earth surface is about 1.35 kW/m2, of which 520 W/m2 fall into the visible range. This would suggest an efficiency of about 38.5%. This efficiency is a lot higher than an ideal black body radiator would theoretically give, and the spectrum shown in this document shows clear deviation from black body radiation spectrum.

At the same time efficiency of light bulbs depends strongly on power, with high powered lamps faring much better (5%) than 25 or 40W lamps (2%).

So where does this lead us? In order to get 520 W/m2 visible light power with photo flood lights, we need about 10.000 W of incandescent light shone into 1 m2. If a decent strobe outputs 200J within 1/2000s, its effective light power equals 400.000 W, which is much stronger than sunlight. You could use one strobe to illuminate a circle of 7m diameter and are still as powerful as direct sunlight hitting at 0° angle off the surface normal.

You can twist and turn this over again and again: even if you throw a factor of 2 or 3 into this to cover some additional inefficiency, it is quite possible to match direct sunlight with portable strobes. If optimal depth of field suggests largest possible aperture, then very short sync times can be a benefit to those who want to take advantage of it and who can afford such a toy.
 
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