help! mass cornfusion

[bob-e]

Now I am admittedly a slow learner. I usually read, field test, read again, test, etc. I've read the flash faqs and have learned a good bit, but boy am I stumped by my Sigma DG500 Super. After playing in manual, I resorted to P mode and ETTL and have extreme underexposure. If it's all in the faqs, please help anyway, cuz I'm just not getting it. Thanks so much. Examples (if you can't read the exif, let me know)

http://i143.photobucket.com/albums/r133/baub-e/-7-3.jpg

http://i143.photobucket.com/albums/r133/baub-e/-6-5.jpg

http://i143.photobucket.com/albums/r133/baub-e/-5-6.jpg

[3Turner]

Bob, I was reviewing the exif info on the shots and I cannot figure out what would be the cause of it....although I don't have the same flash unit. The only difference I see from the three shots is one is at 1000 ISO & F3.5, while the other two are at F4 and 400ISO.

BTW, I was expecting something different when I saw the title 'help! mass cornfusion'. Hopefully someone with the same flash unit or experience can explain, cause Lord knows that I've run into the same situation and was never able to figure it out. I however, never thought of posting here to ask what was going on. Good luck.

[jm_usmc]

Bob,

I have the same flash unit on an XT. I keep the camera set to +2/3 exp comp and +2/3 flash comp. These settings are needed since my XT underexposes if set to 0.

Jeff

[jra]

Are you shooting with on camera direct flash or bounced flash? If you're using direct flash, It looks as if it's not even firing. If you're bouncing it, try dialing up your FEC (as mentioned above) and see what effect that has.

[SkipD]

Bob, I am convinced that your flash unit never flashed in sync with the shutter. There are no visible shadows at all to indicate that it did. Even underexposed you should see some evidence of shadows on the walls behind the various items and people in the images. I cannot see any evidence of the flash going off at all.

[poloman]

I agree with Skip. My first thought was "the flash didn't go off!". Unfortunately I can't tell you why. I noted that your shutter speed on the third one was 1/60, well within sync speed. Check your hot shoe? Make sure flash is on?

[Jim M]

It looks to me like the flash is not firing in sync or it is not firing at all. The exposure looks like it is coming from ambient light. The exif data indicates that the flash was firing, so I'm inclined to think it's a timing issue. However, I suppose it could be firing such a low power as to be undetectable. I find that hard to believe that at ISO 1,000 at f/3.5 you couldn't detect any light coming from the flash even if it wasn't much. Try taking a flash picture into a mirror with the flash in the reflection to see if anything is coming out of the flash when the shutter is open.

[SkipD]

Try taking a flash picture into a mirror with the flash in the reflection to see if anything is coming out of the flash when the shutter is open.That's a good suggestion. Also, take a shot while you are actually looking at the flash to see if it is working at all.

Let's assume for the moment that you see the flash nice and bright while holding the camera away from your face and you are looking at the flash, but you cannot see the flash lit in the mirror photo. If this is the case, you probably have a switching circuit and/or shutter system related problem in the camera that is triggering the flash at the wrong time.

[Jim M]

Well, I sure took my time typing that reply! But it does seem we all reached the same conclusion that in those pictures there is nothing being contributed by the flash.

[Az2Africa]

The Exif data says the flash fired. Maybe at the wrong time? Or is it just saying the camera thinks it fired?

[bob-e]

Thanks guys. Now I feel like I'm not going crazy. The flash is definately firing as I can see the subject lit up in the viewfinder, but when I chimp, I see massive underexposure. I am firing the flash direct. The built in flash works fine. Could my flash unit be bad? I bought it used. :(

[Az2Africa]

You should not see the subject lit up in the viewfinder, as the mirror should be blocking it during the shot and flash. It my be firing too late.

[bob-e]

Just checked the mirror. In P mode, flash fires, photo is pitch black. Built in flash works perfect. I had it on second curtain, but changed it back and still no change. Boosted the flash to +3--no change. Couldn't fin FEC in the camera. Is that only for built in flash though?

[SkipD]

Thanks guys. Now I feel like I'm not going crazy. The flash is definately firing as I can see the subject lit up in the viewfinder, but when I chimp, I see massive underexposure. I am firing the flash direct. The built in flash works fine. Could my flash unit be bad? I bought it used. :(Try a Canon EX-series flash such as a 430EX - possibly a demo unit in a store. That will prove whether the camera is OK.

If the built-in flash is timed correctly it is possible that the camera's switching circuitry is OK. It is still possible, though, that the hotshoe switching circuits are separate from those that operate the built-in flash and may be defective. The test with a Canon EX should really tell the story for you.

You could also test your flash on another Canon EOS camera to add to the evidence.

[FlashZebra]

Any chance the Super Sigma is producing an ETTL preflash, but no follow up exposure flash?

Can you put the super sigma in manual mode and see if you can effect exposure?

Enjoy! Lon

[bob-e]

It actually did the same thing with my 350D, but I thought I just didn't have the hang of it. Bad flash? Not repairable? I want to make doubly sure before I ask for my money back from the guy I bought it from on here. He actually had 2 of the same flash and I only bought 1.

[SkipD]

It actually did the same thing with my 350D, but I thought I just didn't have the hang of it. Bad flash? Not repairable? I want to make doubly sure before I ask for my money back from the guy I bought it from on here. He actually had 2 of the same flash and I only bought 1.If the flash failed with two cameras, get rid of it. I would put the probability at 95%-plus that the flash is defective given that additional information.

[bob-e]

Any chance the Super Sigma is producing an ETTL preflash, but no follow up exposure flash?

Can you put the super sigma in manual mode and see if you can effect exposure?

Enjoy! Lon


In manual I can get it to testfire, but not fire with shutter release.

[FlashZebra]

In manual I can get it to testfire, but not fire with shutter release.
Take the flash off the camera.

Turn the flash off.

Get a coarse rag.

Moisten the rag ever so slightly.

Rub the heck out of the 5 contact pins on the flash foot.

Also try and rub the contacts on the side rails.

Test the flash again.

Enjoy! Lon

[bob-e]

Take the flash off the camera.

Turn the flash off.

Get a coarse rag.

Moisten the rag ever so slightly.

Rub the heck out of the 5 contact pins on the flash foot.

Also try and rub the contacts on the side rails.

Test the flash again.

Enjoy! Lon

Done. Nothing in M mode. Still works in P, tv and av, but out of sync I guess.

[bob-e]

So think I should send the flash back? Definately a flash problem? The seller has offered to refund minus shipping the flash back, his shipping costs and his paypal fees.

[3Turner]

Take the offer and send it back.

[poloman]

and post positive feedback for him.

[bob-e]

Well, problem was definately the flash. I ordered a new 430EX from B&H, it shipped out the same day and arrived a day earlier than expected. No response now from the Sigma seller, so I guess I have a paperweight. Tip for the day: Buy Canon, buy new, and buy at B&H. For the money I'm out on the Sigma and the 430, I could have had a brand new 550. Live and learn