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Author Topic: The Future of the Flash? [CR1]  (Read 9873 times)

Mt Spokane Photography

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Re: The Future of the Flash? [CR1]
« Reply #15 on: July 19, 2011, 04:45:10 PM »
As somebody who owns four 550EX flashes used as slaves to a 580EX2, I very much hope that Canon introduces a small and cheap interface module that can be attached to the foot of a slave and allow it to be used with a new flash system.

Also, there is a "low energy" version of Bluetooth that seems custom designed for this application: low power requirements, fairly low data rates and low latency.


I'm not sure what you intended here?  Bluetooth range is very limited, not the several huindred feet needed.  Bluetooth latency in actual practice is also a concern, the rated but never quite achieved 6ms (more than 1/200 sec) would seem to be a big issue as well.

According to the Wikipedia page on Bluetooth Low Energy, the range is 200M or about 660 feet. The 6ms latency is from an unconnected state and I think that a master flash/camera and slave flash will be "connected" most of the time.  Also, 6ms is considerably shorter than most pro camera's shutter lag (40ms for the Nikon D3s and 55ms for the 1DMk4) and a motor driven camera at 10FPS will have a time between shots of 100ms.

Incidentally, the Wikipedia page is considerably more informative than bluetooth.com. If you have a better source please let us know about it.

I hope it happens, but I believe that a 15M range is what we will see, not 200m. Wikipedia had 50m in two spots and 200m range in another, just pick the one you want to believe!
From wikipedia:
Bluetooth low energy (BLE) is a feature of Bluetooth 4.0 wireless radio technology, aimed at new, principally low-power and low-latency, applications for wireless devices[1] within a short range (Up to 50 meters / 160ft -see table below). This facilitates a wide range of applications and smaller form factor devices in the healthcare, fitness, security and home entertainment industries.

There are no actual BLE products yet, but Bluetooth ver 2 was supposed to have a 30m range, but in the real world, 10 meters is the best I've seen, so i would expect no more than 15 m if 50m is the max possible range.

As for a 200m range, there are two mentions of 50m, and one of 200m in the article.   as the spec options are defined.

I would still be concerned about latency, particularly any variation in latency, a 0.1ms variation would be a failure.

A 55 ms lag time in shutter opening is a red herring, it does not lag the signal to the flash unit by 55ms.  The EX580 II flash durations are given below.  Do you believe that the signal is sent to the flash 55ms before the shutter opens??  With a typical 0.1ms duration, the flash would fire 54.9 ms before the shutter opens.



1/1 power = 1/1000 second
1/2 power = 1/2000
1/4 power = 1/4000
1/8 power = 1/9000
1/16 power = 1/15000
1/32 power = 1/21000
1/64 power = 1/30000
1/128 power = 1/35000


« Last Edit: July 19, 2011, 04:48:22 PM by Mt Spokane Photography »

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Re: The Future of the Flash? [CR1]
« Reply #15 on: July 19, 2011, 04:45:10 PM »

Bob Howland

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Re: The Future of the Flash? [CR1]
« Reply #16 on: July 19, 2011, 06:19:03 PM »
As somebody who owns four 550EX flashes used as slaves to a 580EX2, I very much hope that Canon introduces a small and cheap interface module that can be attached to the foot of a slave and allow it to be used with a new flash system.

Also, there is a "low energy" version of Bluetooth that seems custom designed for this application: low power requirements, fairly low data rates and low latency.


I'm not sure what you intended here?  Bluetooth range is very limited, not the several huindred feet needed.  Bluetooth latency in actual practice is also a concern, the rated but never quite achieved 6ms (more than 1/200 sec) would seem to be a big issue as well.

According to the Wikipedia page on Bluetooth Low Energy, the range is 200M or about 660 feet. The 6ms latency is from an unconnected state and I think that a master flash/camera and slave flash will be "connected" most of the time.  Also, 6ms is considerably shorter than most pro camera's shutter lag (40ms for the Nikon D3s and 55ms for the 1DMk4) and a motor driven camera at 10FPS will have a time between shots of 100ms.

Incidentally, the Wikipedia page is considerably more informative than bluetooth.com. If you have a better source please let us know about it.

I hope it happens, but I believe that a 15M range is what we will see, not 200m. Wikipedia had 50m in two spots and 200m range in another, just pick the one you want to believe!
From wikipedia:
Bluetooth low energy (BLE) is a feature of Bluetooth 4.0 wireless radio technology, aimed at new, principally low-power and low-latency, applications for wireless devices[1] within a short range (Up to 50 meters / 160ft -see table below). This facilitates a wide range of applications and smaller form factor devices in the healthcare, fitness, security and home entertainment industries.

There are no actual BLE products yet, but Bluetooth ver 2 was supposed to have a 30m range, but in the real world, 10 meters is the best I've seen, so i would expect no more than 15 m if 50m is the max possible range.

As for a 200m range, there are two mentions of 50m, and one of 200m in the article.   as the spec options are defined.

I would still be concerned about latency, particularly any variation in latency, a 0.1ms variation would be a failure.

A 55 ms lag time in shutter opening is a red herring, it does not lag the signal to the flash unit by 55ms.  The EX580 II flash durations are given below.  Do you believe that the signal is sent to the flash 55ms before the shutter opens??  With a typical 0.1ms duration, the flash would fire 54.9 ms before the shutter opens.



1/1 power = 1/1000 second
1/2 power = 1/2000
1/4 power = 1/4000
1/8 power = 1/9000
1/16 power = 1/15000
1/32 power = 1/21000
1/64 power = 1/30000
1/128 power = 1/35000

I never noticed the 50M range mentioned, so I guess we'll have to wait and see. As for variation in latency, we seem to be making different assumptions about how the communications channel would work. I am assuming that the master strobe/camera and the slave flash(es) will be in more-or-less constant communication, perhaps establishing a communication session when the shutter is first pressed. (That's where the latency comes into play.) The master would have to  give the slave(s) two types of information: (1) setup and (2) fire/stop firing. The application data rate is 0.26Mbps which means that each bit has a duration of 3.85usec. If we assume that the setup information is a 256-bit word (it could be shorter), that word would last 492usec. If we assume that the fire and stop-fire commands are both 32-bit words (they also could be much shorter), then their duration is 123usec. That is slightly less than 1/8000 sec. It seems like there is lots of time to do what needs to be done.
« Last Edit: July 19, 2011, 06:37:08 PM by Bob Howland »

Mt Spokane Photography

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Re: The Future of the Flash? [CR1]
« Reply #17 on: July 20, 2011, 12:44:40 AM »
It seems like there is lots of time to do what needs to be done.

Bob, I hear you, but I'm a doubter.

I do hope that BLE takes off and has good range.  I want it built into my hearing aid!

ianhar

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Re: The Future of the Flash? [CR1]
« Reply #18 on: August 23, 2011, 07:52:29 PM »
any update on the new flash system?

hhelmbold

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Re: The Future of the Flash? [CR1]
« Reply #19 on: August 24, 2011, 01:19:43 AM »
Quote
Canon better do this, because Nikon definitely will. The only problem I see is not being compatible with third party flashes (unless they release their own receivers). Id hate to have to use two systems for my PCB lights + speedlights....

I don't think Nikon will... they already have :) Unfortunately I have to admit that Nikon is definately ahead in the Speedlight war... BUT Nikon's SB-900 has been out for quite some time and Canon can only improve on this.

In a way I must actually say that I don't mind a new Canon speedlight NOT being compatible with older versions, if it means we'll get a new amazing technology that works really well, whatever it would be. With time there will be 3rd party vendors making some kind of trigger that will make it compatible.

patz

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Re: The Future of the Flash? [CR1]
« Reply #20 on: October 02, 2011, 04:09:25 AM »
If they're going to use radio trigger wireless in the new flash, does it mean there won't be remote shutter release button which feature in 230ex ii and 380ex?

I want 430ex flash with remote shutter release button feature. I don't want to buy RC1 or RC6. Should I wait til next year? When do they usually announce new stuff? and How much can we trust the news source?

Thanks a lot.

dr croubie

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Re: The Future of the Flash? [CR1]
« Reply #21 on: October 02, 2011, 05:01:34 AM »
If they're going to use radio trigger wireless in the new flash, does it mean there won't be remote shutter release button which feature in 230ex ii and 380ex?

I want 430ex flash with remote shutter release button feature. I don't want to buy RC1 or RC6. Should I wait til next year? When do they usually announce new stuff? and How much can we trust the news source?

Thanks a lot.

I don't see why you don't want an RC-6, best $20 i've ever spent, and not much bigger than a $1 coin or two. And you can't really use the flash-as-remote and flash-as-flash at the same time for self-portraits, unless you're damn quick in repositioning it (or yourself) after pressing the button.
Still, if you take that into account (or shoot things like macro where you need a remote release and flash) it could still save you $20.

Not sure if there's a regular pattern with flashes, the 320 and 270v2 only just came out, i'd guess the 580v3 (or 600+?) would be announced with a new 1D/5D body.
The 430 was June 05, 430v2 June 08, so it's "due" for replacement this year, but everything's been changed around a bit lately, so you might be waiting a while. 580v2 is just as old, maybe the replacements for both will get announced at the same time (with radio release? inbuilt in next 1D line?)
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Re: The Future of the Flash? [CR1]
« Reply #21 on: October 02, 2011, 05:01:34 AM »

patz

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Re: The Future of the Flash? [CR1]
« Reply #22 on: October 02, 2011, 01:13:46 PM »
I don't see why you don't want an RC-6, best $20 i've ever spent, and not much bigger than a $1 coin or two. And you can't really use the flash-as-remote and flash-as-flash at the same time for self-portraits, unless you're damn quick in repositioning it (or yourself) after pressing the button.
Still, if you take that into account (or shoot things like macro where you need a remote release and flash) it could still save you $20.
I'm using 600D. I thought if I set up the wireless, when I press the  the remote shutter release button (on the flash like 320ex) it will trigger the camera to shoot the picture. The slave flash (same 320ex) will also fire the flash. That's why I though buying only an ext flash which has remote shutter release function would be enough.

When do Canon usually announce their new stuff? If it's Jan or Feb, I think I can wait.

Mt Spokane Photography

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Re: The Future of the Flash? [CR1]
« Reply #23 on: October 02, 2011, 02:11:29 PM »
yeah it is about time they build a next gen flash,
one that use lithum ion battery, much like the one on their dslr.

First, a high power fast discharge lithium battery has to be invented, and engineers have been unsuccessful doing it for several years now. 

A powerful flash requires a high current to get a fast recycle time.  Its ok if you don't mind several seconds between flashes, and a low powered flash, but not for a professional level high powered flash with rapid recharge.

Its nice to criticise a company for not inventing a flash with a non-existennt battery, invent one and you will be rich overnight.

This is one of the things that also makes electric cars powered by lithium-Ion batteries expensive.  They must put a large number of expensive batteries in parallel to get the high current rates.

I could just hear the cries when a flash that needed six of those $100 camera batteries in parallel came out.

dr croubie

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Re: The Future of the Flash? [CR1]
« Reply #24 on: October 02, 2011, 08:05:18 PM »
First, a high power fast discharge lithium battery has to be invented, and engineers have been unsuccessful doing it for several years now. 
This is one of the things that also makes electric cars powered by lithium-Ion batteries expensive.  They must put a large number of expensive batteries in parallel to get the high current rates.

Actually, i've worked with electric cars (more specifically, the chargers for them), and the batteries are all in series, not parallel. The cells are 2.5-3.5 volts or so, in series to make a 12V battery, in series to make about 350-400V or so in the car. Only the cells are made of a few batteries in parallel, think of how many you can fit in 1/4 of a 12V car-sized battery.
Take one 12V battery, and its short-circuit current is about 4000 Amperes. As in, don't drop your spanner, you won't find it again. Or your arm. (Ask a guy called Peter from Valence about that).

There's also different types of batteries. Lithium, Lithium Ion, Lithium Polymer.
Lithium are what your normal AA batteries are, non rechargeable, and probably 20-30 different flavours of chemical inside.
Lithium Ion is what's in your mobile phone. High internal resistance makes for useless in flashes. Only paralleling a few of them into a 3V cell (then seriesing them into a 12V car-sized battery) works for current cars like the Miev and Leaf, but it ain't the best solution.
Lithium Ion-Polymer are the next gen, and stupidly expensive, but they'll be in the next lot of cars once tech improves and the price comes down.

hmmm, back to flashes? problem is, the way they're built right now is with 4xAA batteries in series to make 6V. Put Lithium-* batteries in there, and the recycle will be too slow, they only work as well as the weakest cell, unless they're all together in one pack, with a BMS and can self-balance when they charge.
It *is* possible to make a custom-sized battery pack (like in your camera), even making them 2V or 3V and parallel for higher current, but then you lose the ability to use AA cells, and you'd definitely have to increase the smarts in the flash to monitor the charge level, and you'd pretty much have to bring a spare to any semi-important shoot...
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Re: The Future of the Flash? [CR1]
« Reply #24 on: October 02, 2011, 08:05:18 PM »