Is Canon scamming us on 1.6 / Ettl?

[kawter2]

I have been thinking about this!!!

Basically all the 580ex conversion gimmick did was have the flash multiply the focal length info that the camera sends by 1.6 (or 1.3 depending on the camera model) and uses that as the actual focal length.

CUMMON wouldnt it be feasable and just as easy for Canon to have an option in the firmware of the camera that translates the focal length on the camera side!! It seems like you are doing the same thing on the 580...? I know they want to market a new flash and make all the $$ by getting people to upgrade and a but....

I would like to see an option on a firmware update (after they have sold enough 580's to make $$$) that would allow you to send lens info normal, or x's 1.6


Just my $.02

[pcasciola]

As much as I hate to use the word, the 580EX's head actually zooms to match the "cropped" area of the lens that the 20D or 1D Mk II is actually seeing because of the smaller sensors, so that the flash is not wasted on subjects outside of the cropped area. And, there was in fact a firmware upgrade for the 1D Mk II to take advantage of this feature.

Ok, there I said it, twice. Crop. You all happy now? :)

[kawter2]

As much as I hate to use the word, the 580EX's head actually zooms to match the "cropped" area of the lens that the 20D or 1D Mk II is actually seeing because of the smaller sensors, so that the flash is not wasted on subjects outside of the cropped area. And, there was in fact a firmware upgrade for the 1D Mk II to take advantage of this feature.

Ok, there I said it, twice. Crop. You all happy now? :)


I understand, what i am saying is that a 50mm should be using a 80mm flash spray. The camera could do the conversion before it gets to the flash... Right now the camera sends the data as (ok please excuse my flash back to H.S. algebra)
FL = Focal Length
LFL = actual focal of the lens itself
CF = crop factor

NOW
LFL=50 so 20D sends FL=50 (the 20D is telling my 550 that the lens is @ 50mm)

Possiblity
when you turn the function on in the camera CF=1.6
LFL=50
LFL x CF = FL
50 x 1.6 = 80
Now the 20D tells the 550ex or any other flash that it actually has a an 80mm lens on it


Man that isn't going to make sense!! ha!

[Vita Rara]

Made sense to me. Seems like you could just input your crop factor into the flash and have it adjust. Just need to remember it when changing bodies.

[pcasciola]

Actually it does make sense. :)

I see what your saying now. I wonder why the camera passing back the lens focal length * 1.6x would be wrong compared to the way the 580 does it? There must be a reason, unless I just fell for the marketing scam!!!

[kawter2]

unless I just fell for the marketing scam!!!


:) Things like this (if my theory is true) make me wonder about the term "Dark Side" hahah! :)

[PacAce]

And what would you have the camera put in the EXIF information for the FL that the picture was shot at? 50 or 80? I can see where this can get really messy.

[scottbergerphoto]

As much as I hate to use the word, the 580EX's head actually zooms to match the "cropped" area of the lens that the 20D or 1D Mk II is actually seeing because of the smaller sensors, so that the flash is not wasted on subjects outside of the cropped area. And, there was in fact a firmware upgrade for the 1D Mk II to take advantage of this feature.

Ok, there I said it, twice. Crop. You all happy now? :)That might be true if the flash was facing the camera and aimed into the lens aperture.;) In actuality, the light from the flash is bouncing off your subject and going all over the place with some of it coming back to enter the lens aperture. The zoom is just keeping the beam of light narrower so it can travel further to match the corrected focal length of the lens.
Regards,
Scott

[pcasciola]

The zoom is just keeping the beam of light narrower so it can travel further to match the corrected focal length of the lens. That's what I meant to say, but I guess I just said it wrong. If that's the case, is kawter2 correct in saying the 20D could just do that translation and transmit the adjusted focal length to the flash, instead having that logic done in the flash and therefore limited to working on on only the 20D and 1D Mk II?

[scottbergerphoto]

I suspect that having the instructions for that come from the camera could result in problems with other Canon flashes that are not programmed to respond to that information and cease to function properly. I wouldn't be very happy if I couldn't use my 3 550EX's because an instruction set from the camera was locking it up.

Scott

[Hellashot]

The 580EX is also a little more powerful with half the recycle time of the 550EX.

[kawter2]

I suspect that having the instructions for that come from the camera could result in problems with other Canon flashes that are not programmed to respond to that information and cease to function properly. I wouldn't be very happy if I couldn't use my 3 550EX's because an instruction set from the camera was locking it up.

Scott

Im not saying to send a whole diferent set of data, just increase the number by 1.6 That is why you would have a Cfn so you could turn it off. But I can't imagine how sending a larger number would ever mess the flash up.


The 580EX is also a little more powerful with half the recycle time of the 550EX.


I'm not questioning the validity of the 580ex,

I'm just questioning the fact that the FLASH has to be the comonent that says... OHH this should be increased by 1.6.

IMO This is a bug that Canon is calling a feature of the 580

[Tom W]

I suspect that they could have put the feature on either the camera or the flash. And if they put it on the camera, somebody else would start a thread asking why Canon was scamming us by using up precious camera ROM on a feature that could just as easily be put on the flash.

[kawter2]

somebody else would start a thread asking why Canon was scamming us by using up precious camera ROM on a feature that could just as easily be put on the flash.
Since when does anyone know how much camera ROM they have left.

I think presented with the option of that vs buying a 580 vs manyally changing the zoom on the flash, the 3lines of code / 15 bytes would be well worth it

I dunno, I just have never even thought twice about how much ROM the new firmware is going to take up