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Canon Speedlites and Manual Lenses
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PostPosted: Sun Mar 04, 2007 6:43 pm    Post subject: Canon Speedlites and Manual Lenses Reply with quote

I've been spending this wet Sunday afternoon reading a massive article http://photonotes.org/articles/eos-flash/index.html about modern flash metering, a subject that's left me WAY behind over the last 10 years or so. I don't know if I'm any wiser than when I started.

It seems flash metering has become automated in much the same way as autofocus and auto-exposure and, just like using MF lenses, my feeling is I'd still prefer to manually set the aperture (or am I being old-fashioned?)

As I understand it, Canon DSLRs use a flash metering system called E-TTL, which sends a pre-flash to meter the light returning from the subject. The camera and lens communicate with the flash unit to set the sync speed, aperture and the flash duration. Apparently only Speedlite models ending in EX are compatible with my 400D camera. In various places in the article it states other flashes won't work, and it doesn't mention MF lenses at all.

The 400D manual says non-EX Speedlites have to be used in manual mode (if provided) and non-Canon units can be used on the hot shoe if I set a shutter speed of 1/200th or longer.

My head's hurting Confused

The question is this: is there any benefit buying an expensive new EX Speedlite to use with manual lenses? If the answer's no, then what would you recommend? Can I use my old Sunpak?


PostPosted: Mon Mar 05, 2007 3:29 am    Post subject: Reply with quote

Peter, I'm wondering if using a focus confirm adapter (chipped) would
allow E-TTL flash. I'm wondering if the camera/flash would treat it as
an AF lens, then. In aquatic photography, Nikon's i-TTL and Canon's
E-TTL flash systems are a godsend. Trying to photograph fish in a tank
of water without it, involves lots of trial and error, but it can be done.

If you have a chipped adapter, try to borrow someone's 550EX, 580EX,
etc, and see what the results are. I'd be very curious! Smile

Bill


PostPosted: Mon Mar 05, 2007 6:13 pm    Post subject: Re: Canon Speedlites and Manual Lenses Reply with quote

This is a very interesting topic, Peter!

I think I'll test this one day. I use a E-TTL- and digitally compatible Cullmann flash gun that works perfectly with the EF-lenses.

I should test it with a normal and a confirmation adapter.

peterqd wrote:
... Can I use my old Sunpak?


If your Sunpak does not use high voltage and if it is compatible to digital DSLRs.
Old flash guns use very high control voltages (on the hotshoe). You will destroy your DSLR if you used them. (Sometimes the destruction happens very slowly, so you wouldn't realise at once.)
Flah guns for film cameras used a ttl-"reflection" from the film material itself to measure the duration of the flash. Sensors in DSLRs reflect the light differently, thus measurement will not be correct. That's why modern (digitally compatible) flash guns use a pre-flash.

Carsten


PostPosted: Mon Mar 05, 2007 7:42 pm    Post subject: Re: Canon Speedlites and Manual Lenses Reply with quote

LucisPictor wrote:
peterqd wrote:
... Can I use my old Sunpak?


If your Sunpak does not use high voltage and if it is compatible to digital DSLRs.


When I bought the Sunpak, Carsten, digital cameras had never been heard of and computers were machines that had to be built in rooms big enough for an Atlantic liner. It still works on my Spotmatic so I guess that's where it's staying!

Thanks for the useful advice.

Peter


PostPosted: Mon Mar 05, 2007 8:50 pm    Post subject: Reply with quote

Peter,
You didn't mention what model of Sunpak you have but here's a link
that lists various manufacturers, models of strobes and there trigger
voltages:

http://www.botzilla.com/photo/strobeVolts.html

I use the Sunpak 355AF on my Canon G1 and G2 with no problem but
according to Canon you want to steer clear from using voltages above
6V. There's a few who use routinely the Sunpak 383 Super on their
G series with no problems, and its voltage has ranged from 5-7.2V. The
6V limit applies to all Canon digital that have a hotshoe.

Bill


PostPosted: Mon Mar 05, 2007 8:54 pm    Post subject: Reply with quote

No problem, Peter!

You can measure the voltage, though, using one of those:
http://en.wikipedia.org/wiki/Voltmeter

Activate your flashgun and measure the voltage between several contacts.

I have an old one (AGFA) that produces 63 V there!!! Would kill my EOS!
Another one (Carena) shows 11 V there, still too high.

As far as I know, about 6V are OK for EOS cams, but don't nail me down on that.

Carsten

EDIT: OK, Bill confirmed just before me... Good!