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10-21-2011, 11:54 AM   #1
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kx flash problems

I have an 8 mo. or so Kx that has performed flawlessly until now. I swear the pop-up flash and the shutter are not in synch. I'm thinking the flash goes off just slightly ahead of the shutter. I haven't tried with either of my hot shoe flashes because I figured the flash fires due to an electrical charge so the hotshoe flashes should be out of synch also. Anybody ever have this problem? Is there anything I can do to fix it? My indoor pictures are blurry whether with the flash or without it. I suspect this is because the flash isn't firing at the right time. Thanks, Jim

10-21-2011, 12:29 PM   #2
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At what shutter speed are you using the flash?I believe they only sinc up to 180.
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10-21-2011, 12:33 PM   #3
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QuoteOriginally posted by jjhenders Quote
...the pop-up flash and the shutter are not in synch. I'm thinking the flash goes off just slightly ahead of the shutter.
It's not impossible, but the chance of the flash and the shutter simply not in sync is pretty slim.

Please do these 2 tests:

1. Take a few photos with the camera and the built-in flash visible in a mirror. Post the photos with EXIF data. They will help with trouble shooting.

2. Turn on the built-in flash, set the camera in 2 second delay. Take a photo. You should see in this order:
  1. Hit the shutter release.
  2. The built-in flash fires the preflash strobe.
  3. Mirror goes up.
  4. 2 second delay.
  5. Shutters open - flash fires the main strobe - shutters close.
Write back as what you observe.

QuoteOriginally posted by bjake Quote
At what shutter speed are you using the flash?I believe they only sinc up to 180.
If the shutter speed is above 1/180 sec, the flash will not fire in the first place.

Last edited by SOldBear; 10-21-2011 at 12:40 PM.
10-21-2011, 12:34 PM   #4
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First the flash is firing before the shutter (this is the pre P-TTL flash). The main flash should be in sync with the shutter. To see if you have a flash when the shutter is open take a photo looking into a mirror. If you see the flash the shutter and flash are in the same window of time. Next take a photo of a blank wall. Look for a dark band at the top or bottom of the photo. If you don't have a dark band the flash is in sync. If both of the above is not the case (and you are sure the flash is firing) then you may have to send the camera in for repairs. For more on how the P-TTL flash system works look for some of the past treads here.


DAZ

10-21-2011, 02:26 PM   #5
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Took 2 pics into mirror. Saw flash in both. Took 2 pics at blank wall and did not see a dark band at top or bottom. So according to DAZ, everything seems to be in synch. Maybe I'm just nuts. I dont know. Soldbear, on 2 sec. delay, I see the pre flash strobe, then when I push the shutter button a flash goes off, then darkness, then the shutter and flash go off. I don't know, maybe it's ok. I'm very technologically illiterate and the last time I tried to post pics it was an embarrasing failure. If I get the nerve to try again, I'll post the flash photos, but I'm thinking now that I might have a non-issue. Actually, I'm a little confused about it because I blew a lot of very important pics this weekend and I was convinced it was the flash synch not working. Thank you all for your help. Jim
10-21-2011, 02:34 PM   #6
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If I remember correctly (and I could be wrong with out checking) if you use a 2 sec delay (mirror lock up) the P-TTL pre flash will happen at the start of the 2 sec (it has to happen before the mirror is up) then when the shutter opens and the flash will happen. Are you using Mirror lock up?


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10-21-2011, 02:43 PM   #7
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QuoteOriginally posted by jjhenders Quote
Took 2 pics into mirror. Saw flash in both. Took 2 pics at blank wall and did not see a dark band at top or bottom. So according to DAZ, everything seems to be in synch.
If you see the flash firing in the pictures of the mirror, the flash is in sync with the shutter.

QuoteOriginally posted by jjhenders Quote
... on 2 sec. delay, I see the pre flash strobe, then when I push the shutter button a flash goes off, then darkness, then the shutter and flash go off.
I'm confused. Can you please list the events in order. From what you wrote (I'm just re-writing what you wrote):
  1. Preflash strobe
  2. Push the shutter button.
  3. A flash goes off.
  4. Darkness.
  5. The shutter and flash go off.
There must be a "Push the shutter button" before [1].

Why did you do "push the shutter button" between [1] and [3]?

Were there really three strobes: [1], [3], and [5]? When did the mirror go up?
10-21-2011, 03:29 PM   #8
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What flash mode are you using? If using slow speed or trailing curtain sync it may seem off because it will meter for the ambient while using the flash.
manual flash discharge will freeze action since it meters for the flash.
when you pop up your flash hit the flash button on the 4 way controller and select manual, see if that fixes it.

10-21-2011, 03:37 PM   #9
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okay, I'll try to be clearer. When I'm using single shot, 1. Press shutter button half way. Camera focuses. Nothing else happens. 2. Push shutter button all the way and I see the flash go off thru the viewfinder. On 2 sec. delay. 1. Push shutter half way, camera focuses. Nothing else happens (I'd swear when I tried it the first time, when I pushed the button half way, a weak light came from the flash, but it's not happening now). 2. Push the shutter all the way and the flash flashes. I see this flash thru the viewfinder. 3. Darkness. 4. shutter trips, flash goes off, though I do not see the flash thru the viewfinder the way I did with single shot.

DAZ, I'm not knowingly using mirror lock up since I'm not even sure why one would do that. To my knowledge I've never used it and wouldn't even know why one would use it.

I usually post in the beginner's forum. Now you know why. Jim
10-21-2011, 03:40 PM   #10
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crewl1, It's set to manual. To tell the truth, I'm not far enough on the flash journey to even know what the other functions do.
10-21-2011, 03:50 PM   #11
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QuoteOriginally posted by jjhenders Quote
(I'd swear when I tried it the first time, when I pushed the button half way, a weak light came from the flash, but it's not happening now).
If it's like the K-r, this was probably the AF assist beam. Was it greenish? It (sometimes - seems to have a mind of its own on the K-r) comes on when focusing in low light. It's not from the flash itself, it's mounted beside it, but I can see how if you weren't expecting it you could think it was from the flash unit.
10-21-2011, 04:02 PM   #12
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Jim,

From what I can tell, your camera & its flash are working perfectly.

Let me try to explain what you see:

>> When I'm using single shot, 1. Press shutter button half way. Camera focuses. Nothing else happens.

The purpose of the shutter button half-press is for focus and for ambient-light metering.

>> 2. Push shutter button all the way and I see the flash go off thru the viewfinder.

When you push the shutter button all the way, immediately the flash fires the pre-flash strobe for flash metering. This strobe is what you see through the viewfinder. Then the mirror goes up and the flash fires the main strobe. You don't see the main strobe through the viewfinder because during that time, the mirror is in the up position and is not reflecting light to the viewfinder.

The time between the pre-flash strobe and the main strobe is somewhere between 1/20 sec and 1/50 sec. Most people can't tell the two strobes apart. They think there is only one strobe.

The pre-flash strobe has to occur when the mirror is still in the down position because it needs the mirror to send the light to the light sensor, which locates behind the focusing screen.

In the case of 2 sec. delay, the exact same sequence happens. The only difference is that there is 2 sec. delay between the time the mirror goes up and the time the shutters open.

>> On 2 sec. delay. 1. Push shutter half way, camera focuses. Nothing else happens (I'd swear when I tried it the first time, when I pushed the button half way, a weak light came from the flash, but it's not happening now).

Same as the case above.

>> 2. Push the shutter all the way and the flash flashes. I see this flash thru the viewfinder.

Pre-flash strobe. Same as the case above. You can see it through the viewfinder because the mirror is still down, reflecting light up to the light sensor, and to your eye.

>> 3. Darkness.

The mirror is up (for 2 seconds).

>> 4. shutter trips, flash goes off, though I do not see the flash thru the viewfinder the way I did with single shot.

Same as above. You don't see the flash (pre-flash strobe) through the view finder because it's already happened 2 seconds ago.


Hope things are clear now.

Added: I just remember something: when doing this kind of test, please make sure "red-eye reduction" is turned off. It can cause confussion.

Last edited by SOldBear; 10-21-2011 at 04:10 PM.
10-21-2011, 04:08 PM   #13
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The weak shutter you saw may have been the K-x using the flash as a focus assist light. It will do this when conditions are dark enough that it can't focus on its own.
Post some samples of those blurry shots, with EXIF and perhaps we can see what conditions were present.
10-21-2011, 04:44 PM   #14
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Thank you, thank you, thank you everybody. It seems I have no problem. I just tested with my Sunpak flash and it and the pop up are working exactly as they are supposed to. I just can't figure out what I thought was happening on our trip to Vermont, but everything seems to be working so I'm no longer worried about it. But it wasn't wasted effort for me because I now know a lot more about the flash than I did before. I only wasted your time. Sorry. And Soldbear, I think you should be a teacher (if you're not). Your explanation was great!
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