Canon Speedlite TTL question

Planapo · Post by **Planapo** » Fri Dec 04, 2009 12:52 pm

I've got a voucher/gift card $\:D/$ to be spent at a local electronics store, and at the moment they are offering the Canon Speedlite 430EX II for a reasonable price.

As I have never worked with such a new version of TTL flash on an autofocus/digital body I would like to know, if these modern TTL modes only work with modern lenses built for the EOS system, or if this modern TTL would also work with whatever non dedicated "old" lens/objective I'd use on simple extension tubes or "old" (Olympus, Pentacon etc.) bellows with a digital Canon EOS body. Can anybody of you enlighten me?

Thanks in advance.
--Betty

Charles Krebs · Post by **Charles Krebs** » Sat Dec 05, 2009 2:19 am

Betty,

It'll be fine with your arsenal

.

DaveW · Post by **DaveW** » Sat Dec 05, 2009 2:28 am

Hi Betty,

You may find these links for Canon flash useful.

http://photonotes.org/articles/eos-flash/

http://software.canon-europe.com/files/ ... ork_EN.pdf

DaveW

Planapo · Post by **Planapo** » Mon Dec 07, 2009 5:52 am

Charlie, I had hoped for an answer like yours. Gotta go to that shop now and get me that Speedlite, before they go bankrupt and my voucher is worthless, one never knows ...

Dave, the sites you have linked to are providing very good information, hadn't found those with my own quick search before! Bookmarked in my "flash folder"!

Thanks both of you for your input!

--Betty

Harold Gough · Post by **Harold Gough** » Mon Dec 07, 2009 8:54 am

Assuming the meter to be in the camera body, and the electrics to be compatable (trigger voltages or whatever) this is strictly a private encounter beween the flash and the sensor, the lens being the gooseberry.

Harold

Planapo · Post by **Planapo** » Mon Dec 07, 2009 12:48 pm

Harold, With Canon's E-TTL II it's not always like the lens would be a "gooseberry". I know you're committed and probably not aware of it, but modern compatible lenses with their chips being electronically wired to the camera body do send back distance information which then can be computed into exposure algorithms under E-TTL II.

So the lens is not always just the gooseberry anymore, it may engage in a functional threesome together with body and flash.

--Betty

DaveW · Post by **DaveW** » Mon Dec 07, 2009 1:46 pm

Distance information is handy but not essential, though preferred for close-up by Canon and other makes TTL flash:-

http://www.lensplay.com/lenses/lens_ettl2.html

Nikon introduced distance information chips in their lenses in 1996.

http://nikoneurope-en.custhelp.com/app/ ... a_id/12089

Minolta/Sony do also, but I cannot find if Olympus do?

This is Nikon's explanation of their various flash modes and when the distance information of "D" or "G" etc lens chips are needed. No doubt the other makes work similarly.

http://nikoneurope-et.custhelp.com/app/ ... a_id/31285

DaveW

Harold Gough · Post by **Harold Gough** » Tue Dec 08, 2009 3:21 am

Planapo wrote:Harold, With Canon's E-TTL II it's not always like the lens would be a "gooseberry". I know you're committed and probably not aware of it, but modern compatible lenses with their chips being electronically wired to the camera body do send back distance information which then can be computed into exposure algorithms under E-TTL II. Betty

Hmm, that sounds a bit like technology for the sake of it. My camera just turns off the lights when enough light has reached the film plane, irrespective of how it got there. I'm sure someone will explain the error of my thinking.

Harold

Planapo · Post by **Planapo** » Tue Dec 08, 2009 8:25 am

Harold, There is no error of your thinking.
It's just that I had thought there could be the possibility that the Canon Speedlite 430 EX II needed such electronic contacts that only dedicated modern lenses provide, to fuction properly, and hence then would not work with my old manual focus lenses and bellows. But according to Charles' answer, luckily this is not the case and this flash doesn't necessarily need to have electronical contatct to the lens or any distance informtion and so seems to be backward compatible with the old gear.

--Betty

Harold Gough · Post by **Harold Gough** » Tue Dec 08, 2009 8:36 am

Thanks, Betty.

Re: "Harold, There is no error of your thinking."

May I have a note to that effect, for my wife?

Harold

DaveW · Post by **DaveW** » Tue Dec 08, 2009 8:54 am

The clever bit now Harold is the camera decides where the important exposure light is returning from using information where the lens is focused, so prioritises this for exposure, not just total amount from the entire scene for the exposure. Sensing the light returning from the object the lens is focused on and largely ignoring returns from the background, so as not over/under expose the subject of interest, as I understand it?

http://en.wikipedia.org/wiki/Through-the-lens_metering

Manufacturers are no longer bothering updating most film cameras since they are now ceasing their production, therefore their technology is now stagnant.

It is likely Nikon's pro film camera will be it's last film camera, and how long that will stay in production will depend on a declining demand. That will apply to any others still being manufactured too. So eventually only very basic film cameras will be available new, produced probably in the Third World.

However there will be plenty on the secondhand market for years to come, but don't expect further technological advances in film camera design anymore, it's no longer commercially rewarding to provide it..

DaveW

Harold Gough · Post by **Harold Gough** » Tue Dec 08, 2009 12:20 pm

DaveW wrote:The clever bit now Harold is the camera decides where the important exposure light is returning from using information where the lens is focused, so prioritises this for exposure, not just total amount from the entire scene for the exposure. Sensing the light returning from the object the lens is focused on and largely ignoring returns from the background, so as not over/under expose the subject of interest, as I understand it?

That only works if the point chosen has about 80% reflectance.

What would impress me would be spot flash metering.

Harold