why are my flashed pictures coming out like this?

Hey all,

I have a problem with my flash. I have a 420ex and a 30d combo. The problem is that sometimes i fire the flash and it does images like this

Your shutter speed is too high. What's the exif on this one?

Exposure: 0.003 sec (1/320)
Aperture: f/5
Focal Length: 50 mm
ISO Speed: 800
Exposure Bias: 0/3 EV


If i lower the shutter though the picture is completely blown out...

Blender7 wrote in post #5631171
Exposure: 0.003 sec (1/320)
Aperture: f/5
Focal Length: 50 mm
ISO Speed: 800
Exposure Bias: 0/3 EV

If i lower the shutter though the picture is completely blown out...

The shutter speed needs to be slower for the focal plane shutter to be fully open when the flash goes off. The "maximum sync speed" (or "X-Sync speed) published in your manual is the fastest shutter speed at which the first blade of the shutter is fully open before the trailing blade starts its travel.

With a 30D and any conventional flash source, you need to use 1/250 or slower to avoid the black bar at the edge of the image.

If you are "blowing out" the image with a slower shutter speed, then the exposure is affected by the ambient light far more than by the flash. Your exposure bias may be having an effect here as well.

Look at flash photography as two pictures, one ambient and the other flash. Neither can be allowed to overexpose the image and must be such the together they don't overexpose. Camera in manual mode, meter to just under expose the scene with the camera for the ambient, let the flash do its thing.

Your shutter speed exceeds the max sync speed of the camera. Either lower that or put the flash in high speed sync mode and deal with the subsequent reduction in range.

Your ISO is too high and/or f-stop too low for the existing light. Reduce ISO or raise the f-stop.

And I assume the flash is in ETTL mode. Adjust the flash to balance exposure with FEC.

lower your ISO! why 800? if you want to keep your aperture at f5, ISO 400 will take you down a full stop in shutter speed.

Blender7 wrote in post #5631171
If i lower the shutter though the picture is completely blown out...

Slow down the shutter speed, then either lower the ISO, stop down the aperture or reduce the flash power to control the flash exposure.

Titus213 wrote in post #5631215
And I assume the flash is in ETTL mode. Adjust the flash to balance exposure with FEC.

I doubt it. He wouldn't be able to exceed X-sync speed with a dedicated flash attached. He's using a PC cord or radio trigger system.

And with the 420EX, there's no way to reduce the flash power when it's triggered via non-dedicated connection. So you're left with the other options.

Curtis N wrote in post #5631243
I doubt it. He wouldn't be able to exceed X-sync speed with a dedicated flash attached. He's using a PC cord or radio trigger system.

And with the 420EX, there's no way to reduce the flash power when it's triggered via non-dedicated connection. So you're left with the other options.

Ouch, you are correct as usual. I realized after my post that it was a 420EX and limited in capability. But I didn't catch the inability to exceed sync speed.

I did noticed that the OP has a strange, apparently hairless critter lurking in the background.

If a slower shutter "blows out" the background, and the blowing out is done by ambient, there would still be plenty of ambient in the lower part of the image here, not a *black* bar. Also, if that were the case, what we see would *not* a sync speed issue, but instead a trip to Canon for a camera repair...

However, I think (hope) I see a tiny bit of detail in the lower left of the black bar, so I don't think the "blowing out" could be caused by ambient untill the shutterspeed is at least 5 stops slower.

So, I think this is an almost 100% flash exposure, and some other issue is causing overexposure when slowing down the shutterspeed.

If the *only* flash used is the hairlight from behind, then this is camera failure.

Thanks guys, the only flash that was used was the 420ex from behind. I have since been playing with shutter and aperature and ISO and it gives me what I want.
For this shot I was using cactus triggers and they have misfired a few times but this image does not have anything to do with the triggers because I have this problem when I shoot with the flash on my hotshoe.

what is that behind her to the right?

Blender7 wrote in post #5631959
Thanks guys, the only flash that was used was the 420ex from behind.

Okay, so the main light is ambient from the front? (Somehow I doubt that; wishful thinking)
In that case, I think either your shutter is broken or, more likely, the sub-mirror assembly is...

Edit: I saw you "got what you wanted", so the wishful thinking paid off

If the main light on the front is reflected flash (well possible), the "blowing out" is not caused by ambient, so I'm curious to one of the "blown out" shots, as well as one without flash.

the shot i posted had literally no ambient light. I was in a dark basement. And its weird that whenever I shoot above 250 sync speed that black bar comes up. I just did a test however and i did one shot with the flash using the cactus trigger and shot it at 320 and that black bar came up, I then took the flash and put it on my hotshoe and did the same shot and there was no black bar....This is too confusing.

Ahaaa this is because your cactus trigger does a couple of things

the main thing being it disables E-TTL flash hence anything above x-sync is not possible

Also, there's eeeever so slighty more lag between sutter release and flash, reducing the flash x-sync slightly.

Hope this answers your question?

Will respond if it doesn't

I bought a cactus yesterday, came today, great little things :P