How to tell if it's a flash problem or a camera problem?

were they all taken with the same lens ?
is it possible that your lens randomly is not stopping down when you take the shot/ sticky aperture blades

All the same lens. I don't think it's a lens problem though. Or maybe that's just hopeful thinking since it's my favorite (and most expensive) lens.

I am pretty convinced the flash is putting out too much light on those shots since it's temporarily blinding me when it takes those shots.

I'm going to try cleaning the contacts but imagine it will be some time if I know that was it since it's an intermittent problem.

Thanks again to everyone for helping think this through!
 
are you looking throught the viewfinder while taking the shots
a wide open aperture could cause the blinding effect, it couldn't hurt to check that out , to eliminate it as a cause..
 
are you looking throught the viewfinder while taking the shots
a wide open aperture could cause the blinding effect, it couldn't hurt to check that out , to eliminate it as a cause..

Yes, I'm looking through the viewfinder. It seems like the flash is jut a TON brighter when I take those shots. Brighter than even if I had taken a flash with the aperture fully open at 2.8. I think it was set at 4.5 on the shots I posted.

Something to ponder though. That hadn't crossed my mind. I just wish there was a way to figure this out without just trying things and seeing over time if I don't notice the problem any more.
 
I had a similar issue on non flash photos, it was a sticking aperture. some pics looked great other random shots way over exposed..
I took the lens off and looked at the aperture blades, they looked fine. the exif data showed the apertures I had set

i then used a pen to move the little lever thing, that the camera usually controls, opened the aperture and released it and it stayed open...
 

Well, there certainly was a lot of humidity in both Sanibel and Disney. But I guess I wouldn't have a good idea whether it was a problem in Sanibel since I only used the flash on a few shots there. I use it more at Disney because of the character shots. I'm not sure if I had it off the camera at Disney once I put it on.



I wish I had thought to just take it off, wipe the contacts, and try it again. It did do this over a couple days, but I didn't have it off during that time.

Here's an example. I shot it in program mode at ISO 400, f/4.5 1/60. The next couple shots the flash did not fire. I'm sure because it needed to recover from that. Then the shot after that it fired and the exposure was fine with the same settings.


IMG_0111 by mom2rtk, on Flickr

The shot I posted earlier might be able to have some work done in post to help out. The ones I took at the birthday party were even worse. One resulted in a completely white frame. No other detail visible. Here's another I took:


IMG_0083 by mom2rtk, on Flickr

EXIF 1/60 f/4.5 exif 1600
EXIF on the whited out frame was the same.

And when those happen, I know it as I am temporarily blinded.

The settings you have listed, IMO, are not conducive to using a flash. Especially ISO 1600 at 1/60th and f/4.5. IMO, that setting every time (unless there is zero available light) will overexpose an image while using a flash.

Try changing to manual mode, both on your camera and flash. Set the flash to 1/2 power. Use ISO 400, f/5.6 or 8 and around 1/100. These settings are pretty typical of what I use for my indoor shots.

If your using the flash in auto mode and the camera in auto mode, there may be some issue with them communicating. ISO 1600 is way to high to use indoors with a flash IMO.

On your Mickey shot, the ISO is good, but if the shutter was 1/100 or 1/125 at f/5.6 that would have made a difference, adding a diffuser would make an even bigger difference. Its not much difference than what the camera chose, but its enough of a difference to make a difference (if that makes sense).

I rarely use my flash at 100% power and I always use a diffuser (even with my popup).
 
You may have accidentally changed the flash mode to manual or ....

GrillMouster alluded to this several days ago, and this was the first thing I thought of when I read this thread. If all your photos were consistently overexposed by flash, then maybe your flash was accidentally turned to "Manual" mode, and it was firing at full power 100% of the time.

I know that the EXIF data can tell you if the flash fired or not, but I forget if the EXIF data also says whether the flash was on TTL or Manual, or even whether used Flash Exposure Compensation (FEC). See if there's a way you can check your EXIF data for those photos, to see whether the flash was on Manual or TTL.

When I'm out and about, I generally keep my flash on TTL, which is the flash's version of automatic. In general, I think it works pretty well. If I do need to find-tune the flash power, I'll adjust the FEC. I usually set the camera itself to Manual or Aperture priority.
 
What do you have to do to repeat the problem? If you are snapping pics in succession does it happen more often on the first pic or some number in? Does this only happen in Program Mode?

My first thought was an issue with metering. Metering is done by the camera and the info is sent to the flash. Try to recreate the symptom with a different flash or with the internal flash.

If it's a sticky aperture it will show with the internal flash or any flash. If it's a metering issue then the problem will follow the camera body/lens. If that happens switch out a lens and try to recreate the problem. Especially it you are using a 3d metering mode, the lens could be sending junk data to the camera.

When all else fails, assume human error in messing up a forgotten setting somewhere and reset the camera to factory defaults.
 
The settings you have listed, IMO, are not conducive to using a flash. Especially ISO 1600 at 1/60th and f/4.5. IMO, that setting every time (unless there is zero available light) will overexpose an image while using a flash.

Try changing to manual mode, both on your camera and flash. Set the flash to 1/2 power. Use ISO 400, f/5.6 or 8 and around 1/100. These settings are pretty typical of what I use for my indoor shots.

If your using the flash in auto mode and the camera in auto mode, there may be some issue with them communicating. ISO 1600 is way to high to use indoors with a flash IMO.

The flash in auto (TTL) mode should have compensated, based on the ISO and foreground subject. So, I would agree that there was some sort of communication (or settings) problem.

ISO 1600 indoors with flash, is not necessarily too high. A higher ISO would increase the amount of ambient (background) light in the photo. A lower ISO would decrease the ambient light, making the flash look like the only source of light. Try it! You can have a quick, black background with ISO 100 at f/16. Now, with all settings the same, and flash still in auto TTL, increase the ISO. The subject should remain a consistent exposure, while you start to get more detail from the background ambient light.
On your Mickey shot, the ISO is good, but if the shutter was 1/100 or 1/125 at f/5.6 that would have made a difference, adding a diffuser would make an even bigger difference. Its not much difference than what the camera chose, but its enough of a difference to make a difference (if that makes sense).

Shutter speed doesn't matter much for flash photos (as long as it is below the sync speed, 1/200 for the T2i). I couldn't find the specs for the 270EX, but typically a flash duration is about 1/800th of a second. The 430EX at full power has a duration of 1/520; and at 1/8th power the duration is 1/2000. The flash is done emitting light long before the shutter closes. So, if you wanted to cut the intensity of the flash using your shutter speed, you need to be faster than those values. Which you can't do, because you will get weird shutter sync effects.

For flash photos, shutter speed controls ambient light. Even with the flash in manual mode at one power setting, the subject will be at the same exposure at 1/200 and 1/30 shutter speeds. The only difference will be the intensity of ambient light.
 








New Posts











Receive up to $1,000 in Onboard Credit and a Gift Basket!
That’s right — when you book your Disney Cruise with Dreams Unlimited Travel, you’ll receive incredible shipboard credits to spend during your vacation!
CLICK HERE









DIS Facebook DIS youtube DIS Instagram DIS Pinterest DIS Tiktok DIS Twitter DIS Bluesky

Back
Top Bottom