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

[mom2rtk]

I'm just going over some photos I took on our recent trip to Florida. My camera gets ignored a lot over the course of the year, but gets a good workout when we take trips.

I noticed toward the end of the trip, that a number of the flash shots I took were greatly overexposed. At first I thought I might have been careless and not set it properly. But now I see a couple shots I took in the same series, both in program mode with the same settings, and one is vastly overexposed.

I'm pretty convinced there was a malfunction somewhere. So how do I know if it was a flash or camera issue? I thought I might just try some test shots here at home, but so far have not been able to replicate it after taking a lot of flash shots in quick succession. But it happened a number of times over the last couple days of our trip.

My camera is the T2i and the flash was my 270ex. I'm guessing it was the flash, but sure don't want to end up with a duplicate of that flash (and 150 fewer dollars in my pocket) if it turns out it was the camera.

 

[KCmike]

Could it be a heat and humidity issue? Florida can be brutal. I'm just trying to think of issues that might be different from the two locations.

 

[cisobe]

my 580ex does this every now and then. but when it happens, it happens for several shots in a row. Removing the flash, wiping the contacts, and putting it back into the hot shoe usually fixes this.

I'm in Hawaii, so it's pretty humid here too...

what mode are you shooting in? do you have any example pictures of the overexposed images?

 

[mom2rtk]

Could it be a heat and humidity issue? Florida can be brutal. I'm just trying to think of issues that might be different from the two locations.

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.

my 580ex does this every now and then. but when it happens, it happens for several shots in a row. Removing the flash, wiping the contacts, and putting it back into the hot shoe usually fixes this.

I'm in Hawaii, so it's pretty humid here too...

what mode are you shooting in? do you have any example pictures of the overexposed images?

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

 

[mom2rtk]

Update: I still haven't put my finger on the problem. I took the camera and flash to my dad's birthday party last night and almost every shot was massively overexposed. I was sort of glad because I thought it had gotten bad enough that I might be able to figure it out now. I took the flash off and took the rest of my shots with the pop-up flash and did fine.

So today I decided to take some test shots around the house to try and pin this down. I figure if I can get it to do it again with any regularity, then I can switch to my 430ex and see if I can replicate it there. All I want to do is determine if the problem is the flash or the camera.

Of course, today I took over 200 shots in a row with the problem flash and can't get it to replicate.

I'm close to just taking a stab at this and buying a new flash. But am I wrong in assuming that it could just as easily be a problem with the hot shoe?

 

[mamaCta]

Go buy a new flash and test it as much as you can before the return period is up. If it happens again you will know it was the camera and you can return the flash for a full refund.

 

[mom2rtk]

Go buy a new flash and test it as much as you can before the return period is up. If it happens again you will know it was the camera and you can return the flash for a full refund.

I actually have another flash (the 430ex). My plan was to shoot the questionable 270 ex until I could replicate the problem, then swap out for the 430ex and shoot about twice as many shots as it took to get the problem to occur. But of course now that I'm home again I can't get it to happen again. I guess at the very least I'll start carrying both flashes for a while so I can test it the minute it happens again under the same conditions. I just like the portability of the smaller 270ex and want to replace it if the flash is the problem.

Or maybe I'm looking for any justification to buy a new camera.

Mostly I just want to figure it out. Something is definitely up.

 

[GrillMouster]

You may have accidentally changed the flash mode to manual or dialed up flash exposure compensation. After you've checked out that possibility and that doesn't solve the problem, then try cleaning the contacts as follows:

Turn off camera & flash and remove batteries from both. Pour alcohol into a small container or the cap of the alcohol bottle. Dip one end of a Q-tip into the alcohol and squeeze out as much alcohol as possible. Wrap a microfiber cloth around the damp end of the Q-tip (so some of the alcohol transfers absorbs into the cloth). Wipe down the contacts on both the flash and camera hotshoe contacts with the ever-so-slightly damp microfiber-wrapped Q-tip. Immediately cover the dry end of the Q-tip with a dry portion of the microfiber cloth and use that to wipe the contacts dry. Let the camera & flash rest for several minutes just be sure that they're completely dry. Inserting the batteries and test.

 

[zackiedawg]

BTW just as an aside - have you tried post-processing the overexposed photos? Even if you shot in JPG, if all of them are anything like the example you posted above, there looks to still be the detail retained in the highlights, enough that you could likely salvage the shots by bringing down the highlights, making a duplicate layer and blending them in 'multiply' mode, or adjusting the curves. And if you shot in RAW, they are likely even more recoverable. In the shot above, it looks like only Mickey's chest/shirt is really blown out...all the other highlights look like they'd have a lot of recoverable range.

 

[mom2rtk]

You may have accidentally changed the flash mode to manual or dialed up flash exposure compensation. After you've checked out that possibility and that doesn't solve the problem, then try cleaning the contacts as follows:

Turn off camera & flash and remove batteries from both. Pour alcohol into a small container or the cap of the alcohol bottle. Dip one end of a Q-tip into the alcohol and squeeze out as much alcohol as possible. Wrap a microfiber cloth around the damp end of the Q-tip (so some of the alcohol transfers absorbs into the cloth). Wipe down the contacts on both the flash and camera hotshoe contacts with the ever-so-slightly damp microfiber-wrapped Q-tip. Immediately cover the dry end of the Q-tip with a dry portion of the microfiber cloth and use that to wipe the contacts dry. Let the camera & flash rest for several minutes just be sure that they're completely dry. Inserting the batteries and test.

The Flash E/C was actually dialed down. I think it was at -2/3. And there are no buttons on the flash to change its mode. Is there any setting through the camera (other than FEC) that I might have changed accidentally? Of course the bewildering part of this is that it has only done this on some exposures, not all.

Thank you so much for the step by step cleaning instructions. I will try that and see if it helps. Of course, it's driving me crazy that it seems so intermittent. I took 200 flash shots in a row a couple days ago and couldn't get it to do it again.

 

[jimim]

I like what some else said. But a new one and then return it if need be. Best but has that model in stock usually right? I think with some processing u will be ok too. Nothing to be blown up too large prob right? If for just memories and a scrap book I bet u'll be cool! Good luck!

Sent from my iPhone using DISBoards

 

[mom2rtk]

BTW just as an aside - have you tried post-processing the overexposed photos? Even if you shot in JPG, if all of them are anything like the example you posted above, there looks to still be the detail retained in the highlights, enough that you could likely salvage the shots by bringing down the highlights, making a duplicate layer and blending them in 'multiply' mode, or adjusting the curves. And if you shot in RAW, they are likely even more recoverable. In the shot above, it looks like only Mickey's chest/shirt is really blown out...all the other highlights look like they'd have a lot of recoverable range.

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.

 

[mom2rtk]

I like what some else said. But a new one and then return it if need be. Best but has that model in stock usually right? I think with some processing u will be ok too. Nothing to be blown up too large prob right? If for just memories and a scrap book I bet u'll be cool! Good luck!

Sent from my iPhone using DISBoards

I think right now the problem is too intermittent to have the "buy and return" plan work. So far I have not been able to replicate it back at home. It happened at Disney, then at the birthday party. Maybe I'll set my daughter lose around the house today with it today with orders not to come back until it happens. But I'm just afraid that if I can't replicate it with the questionable flash enough, then I can't believe the new one is better with any confidence.

I'll try cleaning the contacts as suggested above, then I guess I'll just have to wait it out and see if it starts happening more frequently.

If it's going to go bad, it just needs to do it already so I can figure it out!

Thankfully none of the shots in question were huge losses. I had duplicates of the Mickey one that were fine. And I took more at the birthday party with the pop-up flash when I saw the external was acting up again. I just want to be able to rely on it but can't right now.

 

[nbaresejr]

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.

I am far from an expert with a flash but i dont trust ETTL at all. 1st i hate that the flash defaults to 400 iso when i connect it. I have to set that to stay at ISO 100 or 200 depending on what i am shooting. I also ususally manually set the AV and TV.

As to why it does it from time to time I have no idea.

 

[mom2rtk]

I am far from an expert with a flash but i dont trust ETTL at all. 1st i hate that the flash defaults to 400 iso when i connect it. I have to set that to stay at ISO 100 or 200 depending on what i am shooting. I also ususally manually set the AV and TV.

As to why it does it from time to time I have no idea.

I am far from a flash expert. I still use program mode when I shoot flash most of the time, so what do I know? I make most of my adjustments through FEC. But I've done this for years and have never had this sort of problem. I had chosen a higher ISO to increase the ambient light in such a dark location.

 

[mikegood2]

My first thought was that it was possible that you had your flash exposure set to an overexposed setting but that was obvious not the issue. As far as your second (birthday) shot is concerned I think your issue is that your ISO was set at 1600, if you had it set at 100/200/400 I'd think that your shot would have been far less overexposed. When I shoot indoors at a higher ISO and then use a flash forgetting my lower my ISO I'm far more likely to get results like that. You might want to set up a test shot and vary your ISO and see what differences you see. I'm far from an expert or even competent with a flash but when I shot and my shots are underexposed I have a tendency to jack up my ISO to compensate and the opposite when it's overexposed.

Also, are you shooting with your flash directly aimed at the screen or are you bouncing it? If shooting direct, which I try not to do whenever possible, my shots are more likely to be overexposed. When bouncing the flash they are more likely to be underexposed.

 

[mom2rtk]

My first thought was that it was possible that you had your flash exposure set to an overexposed setting but that was obvious not the issue. As far as your second (birthday) shot is concerned I think your issue is that your ISO was set at 1600, if you had it set at 100/200/400 I'd think that your shot would have been far less overexposed. When I shoot indoors at a higher ISO and then use a flash forgetting my lower my ISO I'm far more likely to get results like that. You might want to set up a test shot and vary your ISO and see what differences you see. I'm far from an expert or even competent with a flash but when I shot and my shots are underexposed I have a tendency to jack up my ISO to compensate and the opposite when it's overexposed.

Also, are you shooting with your flash directly aimed at the screen or are you bouncing it? If shooting direct, which I try not to do whenever possible, my shots are more likely to be overexposed. When bouncing the flash they are more likely to be underexposed.

I'm more than open to the fact that my flash skills need some help. But the other shots I took with the same settings were fine. Well, not perfect, but definitely overexposed.

My flash was aimed at the subjects. I do keep a diffuser cap on it. Not sure that it helps a lot, but it's there. I have shot at 1600 in similar lighting before and found the results to be adequate.

I would be quite open to the idea that the ISO was wrong if it did that consistently. But it really is hit and miss.

After a couple of the overexposed shots I took the external flash off and went with the pop-up flash on the camera. Same settings, same ISO. Not perfect, but not the mess the other shot was:


IMG_0097 by mom2rtk, on Flickr

Hopefully I'll get a chance to try cleaning the contacts soon and send my daughter around taking more test shots. I don't get to use the camera much this time of year but hate to just leave it sit and mess up more shots down the road. We're taking my son to college in about a month and I'd like to take a few shots in his room (when he gets one, but that's another whole story.....).

 

[mikegood2]

Like you, my flash skills definitely need more work! In the past I've thought I was getting better, with fairly good flash shots one day, only to have inconsistent ones the next.

I don't know if shooting at ISO 1600 was the problem but it was the one number that stood out to me. Maybe the camera is more susceptible to occasional exposure problems with a higher ISO or reads it based on 100? Also, I'm not sure about the canon flashes, I have a Metz 58 AF-1 for mine, but is it possible that some settings on the flash were changed. I know when I got my t4i I played around with some of the wireless flash settings and screwed up some of my settings for my flash.

Also, like it was mentioned earlier, cleaning your hot shoes contacts wouldn't be a bad idea. When I was shooting at the Epcot character spot 2 weeks ago today (WOW can't believe it was that long ago) I had issues with my flash. For some reason I didn't bring my external flash with me and used my pop up flash with a cheap diffuser that attached to my hot shoe. That diffuser messed up my camera and I was unable to adjust my flash exposure ( it actually disappeared from the menu) and my flash actually didn't go off a few times. Luckily we purchased a Photopass and a few of my photos appear to have been OK and my camera was OK later that day.

 

[cisobe]

I looked at your example pictures. The first one with Mickey doesn't look too bad and may have been metered off Mickeys black ears or suit so the flash though it needed to expose two stops over... The other overblown shots look like what happens when my 580 ex's ettl messes up and does a full 1/1 flash. Most likely cause for this is a miscommunication between the camera and the external flash. The built-in flash has an internal connection and isn't subject to dirt oil or grime, which is why it probably worked fine when your 270 didn't. The 430ex contacts may be cleaner then the 270 or make better contact with the hot shoe.

 

[MICKEY88]

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