[barongreenback]

I'm in the market for a reasonably priced flashgun for my EOS350d and the Sigma EF-500 DG ST seemed to fit the bill - £80 less than the equivalent Canon Speedlite and the basic functionality that I needed. With this in mind I went into my local Jessops only to be told that for 'voltage reasons' this flashgun would not be compatible. Never one to believe anything that Jessops tell me I checked the Sigma website http://www.sigma-photo.co.jp/english...lash_500st.htm and it seems to indicate that it is in fact compatible. The only bit I don't fully understand is "Operation of TTL Auto system varies by Camera Model (If E-TTL II, E-TTL and TTL Automatic Exposure can be used then A-TTL Automatic exposure is not possible)."

So, if you've read this far, are Jessops telling me a load of rubbish or are they right?

Thanks.

[kenlynch]

Here's the compatability table from Sigma's site:

http://www.sigmaphoto.com/flashes/pages.asp?id=3261

It's compatible with the 300D so I can't see why it shouldn't work with the 350D.

[ash71]

I use that flahgun with my 350D and it works a treat. I dont use it for any creative effects, just to provide much better illumitation than the on board flash is capable of. As far as this goes I'm very happy with it. It charges fast and is simple to use.

I was after its bigger bro, the "SUPER" version but flash photograhpy isn't to high up my list of photographic priorities plus I don't really require the extra options/features it provides so thought I'd put the difference towards something else.

What did Jessops try to sell you instead?

[Peakoverload]

Jessops are talking total and utter garbage. There is no voltage difference between the Sigma and the Canon to make it incompatible or dangerous for use on any Canon EOS camera. I use the Super version on my 10D for the very reason you found, it's MUCH cheaper than the Canon 550EX and does pretty much everything it does. Buy it, use it, enjoy it and then tell Jessops where to go

[Johndm]

Most older and many new 'non brand' flashguns will indeed have a too high voltage running across their contacts. This can destroy the delicate circuits in modern DSLR's.

Canon say 6v max. To check, simply put a voltmeter across the guns contact pins and fire manually.....you might be suprised..
I had a old cheapie that showed over 400v......that went in the bin, and I got a 550EX..

[barongreenback]

Thanks for all the advice guys. Jessops tried to sell me the 430EX instead - a significantly more expensive option. I'm a little concerned about Johnm's comment though - I though Sigma were the people who reverse engineered Canon products?

[senu]

If you dont require the E-TTL II that the 350D features via its built in flash and the Canons own speedlites, then it most likely that if Sigma say its units are compatible for basic flash work they more than likely are. I must say im as puzzled as you are about possible voltage incompatibilities and will write Sigmas technical support for clarification.
A quote from Canons learning centre on the E-TTL II

" With E-TTL II, whether your subject is in the center of the scene or off to one side, the flash metering system does a superior job of recognizing its location and properly applying the right amount of flash to it. It doesn't matter whether you lock focus with the center AF point and re-compose, or whether you select an outer AF point and focus on the subject in the final composition.

E-TTL II differs from the previous
E-TTL metering system in two important ways. First of all, flash metering is no longer concentrated strictly upon the area surrounding the AF point(s) which are in use in your scene. Thus, it doesn't matter if you use the center AF point or select an outer AF point to focus on the subject. It doesn't even matter if you use manual focusing! The other major new feature with E-TTL II is that most (but not all) Canon EF and EF-S lenses supply distance information to the camera, which is used to help the system further refine its flash metering. (While a few lenses don't offer distance information, this is not a problem - E-TTL II still will work fine, and produce consistent results like you see here.)

E-TTL II is a great new refinement of an original great idea. As of February 2005, E-TTL II is available on the
EOS-1Ds Mark II, the EOS-1D Mark II, the EOS 20D, the EOS Digital Rebel XT, and the 35mm EOS Elan 7N and 7NE cameras. Unfortunately, previous cameras are not upgradeable to
E-TTL II"
Does this mean much to you???

[barongreenback]

Nope, still as confused as ever

It's only ever going to be for basic flash work - helping candid shots by using a bit of bounce flash rather than anything overly creative. Thanks for the info.

[dood]

Even if used for basic use, you'll get consistently better results with ETTL II. The camera and flash do their thing automatically, you don't have to set anything up for ETTL II. I use a 300D which does not support ETTL II and even with the rather expensive 550 EX flash gun I get several shots that are just not well exposed, even if using full auto mode. I think this is because I am restricted to ETTL. I would think that if your camera supports ETTL II (which it does) you would benefit greatly from using it, so don't shortchange yourself by going for a flashgun that does not support ETTL II. This is just my gut feel, other members who have directly compared ETTL and ETTL II may be able to give more objective feedback.