June 22, 2018, 07:09:43 PM

Author Topic: Updated: Canon Speedlite 470EX-AI Additional Images & Information  (Read 8446 times)

Viggo

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Re: Updated: Canon Speedlite 470EX-AI Additional Images & Information
« Reply #30 on: February 24, 2018, 06:26:49 PM »
What could be cool is of one could lock the bounce point so when you change camera angles the flash adjusts as to keep the same light like it was on a light stand ;D
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Re: Updated: Canon Speedlite 470EX-AI Additional Images & Information
« Reply #30 on: February 24, 2018, 06:26:49 PM »

brad-man

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Re: Updated: Canon Speedlite 470EX-AI Additional Images & Information
« Reply #31 on: February 25, 2018, 10:17:09 AM »

<li>The guide number is 47 (105 mm). It is driven by 4 AA batteries.</li>

This seems like a very low guide number. My EX 430 ii has a guide number of 141. Who would use this flash?

Where do you have that GN of 141 from for your EX 430II? This flash has a GN of 43 @ 105mm/ISO100.

The name of the flash is a hint to the GN EX 430 = GN 43
EX 580 = GN 58
EX 600 = GN 60

and now EX 470 = GN 47

Feet vs. meters, I presume. 43 m ≈ 141 feet. 47 m ≈ 154 feet. 'Muricans really should use meter-based GNs like the rest of the world—it's not like the literal "distance" meaning of GNs is very relevant these days anyway.

Oops. Never really considered myself a "Murican" before, but in this instance, I guess I'm guilty. I still wouldn't consider buying a speedlite without RT, but I guess this release is for the kit lens crowd who won't be buying a second flash.

ajfotofilmagem

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Re: Updated: Canon Speedlite 470EX-AI Additional Images & Information
« Reply #32 on: February 25, 2018, 12:09:23 PM »




Oops. Never really considered myself a "Murican" before, but in this instance, I guess I'm guilty. I still wouldn't consider buying a speedlite without RT, but I guess this release is for the kit lens crowd who won't be buying a second flash.
It seems to me that 470EX AI is intended for photojournalists, more specifically the paparazzi, who does not have time to adjust the flash head to avoid shadows. It's not just a matter of price as it is not really practical to carry 2 or 3 600EX RT units, and position them in a theater staircase or lobby of a hotel where a famous person will pass in a hurry.
« Last Edit: February 25, 2018, 12:17:02 PM by ajfotofilmagem »

neuroanatomist

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Re: Updated: Canon Speedlite 470EX-AI Additional Images & Information
« Reply #33 on: February 26, 2018, 12:10:08 AM »
I think I know what E-TTL does. But how can the camera "decide" if there is a good angle of the flash without knowing what is in front of the flash reflector? IMO there is a need for some device in the flash that helps to measure the reflectivity of the bounce surface. This has to be used for flash positioning. And at least: If there is no bounce surface the flash has to detect this and switch to direct light only instead of wasting light into the sky.

I thkn you're sounding like those who saw the 'dual-sensing IS' feature on the M50 and concluded that it has IBIS: reading too much into this.

Back to the facts ... below

Quote
With an electric head rotation device, the 470EX-AI automatically determines the optimal bounce position eliminating unnecessary shadows.

The goal is to eliminate unnecessary shadows, which is a geometry problem. The solution requires knowing the distance to the subject (which the lens provides, that's E-TTL II), and the distance to the bounce surface (which, presumably, is what the sensor on the front of the flash head measures). 

Sure, it's possible that the flash measures the reflectivity, color, angle (not all ceilings are flat), temperature, roughness, and/or Rayleigh scattering properties of the bounce surface. But I'll bet it measures only distance. That would cover the case where someone tries to use it under the open sky, or under a 40' ceiling.

My argument against measuring only the distance is that there is no substantial difference between open sky or a black ceiling at 3m distance.

My idea of a tiny LIDAR in the flash could report reflectivity of the bounce surface as a side product of its operating system - but LIDAR is speculative, I know only the VL53L0X ranger and it needs two windows but is very cheap (I think $5 if you buy a pack of 1000 pieces) and works up to 4m with well reflecting targets. Distance resolution is about 2mm 1 sigma and it works in the near IR which is not too far from the visible part of the electromagnetic spectrum.

Remote Rayleigh scattering and surface roughness analysis is - maybe - a little bit to complicate for a 400 $/EUR package that is also an AI flash :)

Back to the facts ... below

Quote from: Canon
At the core of Canon’s Speedlite 470EX-AI Flash is the innovative, new AI Bounce technology. AI Bounce automatically and intelligently determines and dictates the optimal angle of flash based off two distance variables: the distance between the camera and the ceiling, and the distance between the camera and the shooting subject.

I think you'll agree that Canon's description of their AI Bounce technology bears more than a passing resemblance to my description, highlighted above. 
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Viggo

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Re: Updated: Canon Speedlite 470EX-AI Additional Images & Information
« Reply #34 on: February 26, 2018, 02:33:03 AM »
Hey! I was right, you CAN lock the position and it will automatically turn when moving the camera ;)

https://youtu.be/lPb9uWM83bU
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hne

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Re: Updated: Canon Speedlite 470EX-AI Additional Images & Information
« Reply #35 on: February 26, 2018, 04:28:00 AM »
Crystal ball reading points go to Viggo and neuroanatomist.

I like the idea of flash angle being constant while camera moves. Even better if they had mechanics that allowed faster/continuous rotation of the flash head.
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slclick

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Re: Updated: Canon Speedlite 470EX-AI Additional Images & Information
« Reply #36 on: March 01, 2018, 05:34:05 PM »
No support for 5D3. That's one way to get those stubborn 5D3 holdouts to upgrade.
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Re: Updated: Canon Speedlite 470EX-AI Additional Images & Information
« Reply #36 on: March 01, 2018, 05:34:05 PM »