Strobe - weird dark shadows

figmental1978 · 05-16-2009, 08:55 PM

I've been using a Vivitar 285HV off camera for about a year now and in the last few months I started getting this very strange dark shadow area on the bottom of my photos. I have no idea what it is and was wondering if you fine people did.

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beem · 05-16-2009, 10:20 PM

According to the EXIF it looks like these shots were taken right at 180th of second, which is the fastest sync speed of the K10/20D. Try shooting at a slower shutter speed to see if that helps.

figmental1978 · 05-16-2009, 10:34 PM

ok, that fixed it right up, thanks. But the issue is why? and it sucks if I can only shoot at 125th.

Damn Brit · 05-16-2009, 10:40 PM

Maybe the flash is getting worn out and has less power than it once did.

SOldBear · 05-16-2009, 11:17 PM

Originally posted by figmental1978

... it sucks if I can only shoot at 125th.

Try it at 1/160 sec - not as good as 1/180 but better than 1/125.

Is the problem consistent no matter what mode (auto, manual at full power, manual at reduced power) the flash is in? Have you tried another flash with the camera body? The problem can be in the body, especially if the problem is consistent regardless of the flash setting.

Venturi · 05-16-2009, 11:27 PM

Originally posted by figmental1978

ok, that fixed it right up, thanks. But the issue is why? and it sucks if I can only shoot at 125th.

First, clean the contacts on both the hotshoe and the flash's shoe mount. If that doesn't fix it then...

Try using a different flash @ 1/180. If you get the same result, it's a problem with the camera's shutter. If the shadow goes away with a different flash then there's an issue with the flash's circuitry.

beem · 05-16-2009, 11:41 PM

I agree with Venturi.

If you have another flash available try using it at 180th and see what happens. I'd shy away from doing the test with the built in pop up flash as you might have a slight problem with your hot shoe, though it doesn't hurt to try.

If the other flash works out better for you it may turn out that you have a synchronization/timing issue with your strobe + body combination.

figmental1978 · 05-17-2009, 12:26 AM

SOldbear - The K10D manual shutter below 180th is 125th. I've also tested it out in other modes and it still happens at 180th but fine at 125th.

Venturi - I'm using the flash off camera, so the cactus V2s transmitter is on the hotshoe. I just tested it on camera at 180th and the shadows are gone...very weird, almost x-files like.

beem - Unfortunately I don't have another flash or a friend with a flash.

figmental1978 · 05-17-2009, 12:30 AM

I cleaned all the contacts and shoe mounts on the transmitter, recievers, flash and camera and tested it again off camera and same problem. shadows at 180th, fine at 125th.

tcdk · 05-17-2009, 03:34 AM

New batteries in your cactus triggers....?

MPrince · 05-17-2009, 04:17 AM

Originally posted by figmental1978

SOldbear - The K10D manual shutter below 180th is 125th. I've also tested it out in other modes and it still happens at 180th but fine at 125th.

To go from 180th to 160th you'll need to change your exposure setting steps from 1/2 EV steps to 1/3 EV steps.

MPrince · 05-17-2009, 04:23 AM

Originally posted by tcdk

New batteries in your cactus triggers....?

Sounds like the right solution, but even that might not help. Using a radio transmitter is going to introduce a very slight delay and in the case of cactus triggers, may be enough to prevent using max synch speed. I usually shoot a max of 160th when using the cactus triggers, though I often shoot slower than that.

MPrince · 05-17-2009, 04:29 AM

Originally posted by figmental1978

Venturi - I'm using the flash off camera, so the cactus V2s transmitter is on the hotshoe. I just tested it on camera at 180th and the shadows are gone...very weird, almost x-files like.

If you can shoot at 180th with the flash on-camera but not with the cactus, then I'd say the cactus trigger is the problem here. And if I remember correctly that is one of the "features" of the cheaper triggers--they don't work reliably, especially at max synch speed. I usually shoot below max synch speed anyway, but I don't think my cactus triggers fire at all at max synch speed. They work fine at 160th though.

mattdm · 05-17-2009, 04:56 AM

Originally posted by figmental1978

ok, that fixed it right up, thanks. But the issue is why? and it sucks if I can only shoot at 125th.

If the radio trigger is introducing a bit of a delay, the rear shutter curtain could be starting to come up before the flash goes off. Increasing the time the shutter's open avoids the problem.

Unless there's significant other light (like, the sun), the actual exposure is only the flash — the camera shutter won't really matter.

tcdk · 05-17-2009, 05:44 AM

Originally posted by MPrince

Sounds like the right solution, but even that might not help. Using a radio transmitter is going to introduce a very slight delay and in the case of cactus triggers, may be enough to prevent using max synch speed. I usually shoot a max of 160th when using the cactus triggers, though I often shoot slower than that.

Except, in this case it used to work, but now it doesn't.... so something changed. And I'm guessing batteries, as they have the ability to change on their own...

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05-16-2009, 10:20 PM	#2
beem Junior Member Join Date: Feb 2009 Location: Toronto Posts: 29	According to the EXIF it looks like these shots were taken right at 180th of second, which is the fastest sync speed of the K10/20D. Try shooting at a slower shutter speed to see if that helps.

05-16-2009, 10:34 PM	#3
figmental1978 Veteran Member Join Date: Feb 2007 Location: Melbourne Posts: 789 Original Poster	ok, that fixed it right up, thanks. But the issue is why? and it sucks if I can only shoot at 125th.

05-16-2009, 10:40 PM	#4
Damn Brit Guest	Maybe the flash is getting worn out and has less power than it once did.

05-16-2009, 11:17 PM	#5
SOldBear Veteran Member Join Date: Feb 2009 Location: Alameda, CA Posts: 3,206	Originally posted by figmental1978 ... it sucks if I can only shoot at 125th. Try it at 1/160 sec - not as good as 1/180 but better than 1/125. Is the problem consistent no matter what mode (auto, manual at full power, manual at reduced power) the flash is in? Have you tried another flash with the camera body? The problem can be in the body, especially if the problem is consistent regardless of the flash setting.

05-16-2009, 11:27 PM	#6
Venturi Veteran Member Join Date: Mar 2008 Location: Tulsa, OK Photos: Gallery Posts: 2,636	Originally posted by figmental1978 ok, that fixed it right up, thanks. But the issue is why? and it sucks if I can only shoot at 125th. First, clean the contacts on both the hotshoe and the flash's shoe mount. If that doesn't fix it then... Try using a different flash @ 1/180. If you get the same result, it's a problem with the camera's shutter. If the shadow goes away with a different flash then there's an issue with the flash's circuitry.

05-16-2009, 11:41 PM	#7
beem Junior Member Join Date: Feb 2009 Location: Toronto Posts: 29	I agree with Venturi. If you have another flash available try using it at 180th and see what happens. I'd shy away from doing the test with the built in pop up flash as you might have a slight problem with your hot shoe, though it doesn't hurt to try. If the other flash works out better for you it may turn out that you have a synchronization/timing issue with your strobe + body combination.

05-17-2009, 12:26 AM	#8
figmental1978 Veteran Member Join Date: Feb 2007 Location: Melbourne Posts: 789 Original Poster	SOldbear - The K10D manual shutter below 180th is 125th. I've also tested it out in other modes and it still happens at 180th but fine at 125th. Venturi - I'm using the flash off camera, so the cactus V2s transmitter is on the hotshoe. I just tested it on camera at 180th and the shadows are gone...very weird, almost x-files like. beem - Unfortunately I don't have another flash or a friend with a flash.

05-17-2009, 12:30 AM	#9
figmental1978 Veteran Member Join Date: Feb 2007 Location: Melbourne Posts: 789 Original Poster	I cleaned all the contacts and shoe mounts on the transmitter, recievers, flash and camera and tested it again off camera and same problem. shadows at 180th, fine at 125th.

05-17-2009, 03:34 AM	#10
tcdk Senior Member Join Date: Mar 2007 Location: Copenhagen, Denmark Posts: 279	New batteries in your cactus triggers....?

05-17-2009, 04:17 AM	#11
MPrince Veteran Member Join Date: Sep 2006 Location: WV Posts: 1,495	Originally posted by figmental1978 SOldbear - The K10D manual shutter below 180th is 125th. I've also tested it out in other modes and it still happens at 180th but fine at 125th. To go from 180th to 160th you'll need to change your exposure setting steps from 1/2 EV steps to 1/3 EV steps.

05-17-2009, 04:23 AM	#12
MPrince Veteran Member Join Date: Sep 2006 Location: WV Posts: 1,495	Originally posted by tcdk New batteries in your cactus triggers....? Sounds like the right solution, but even that might not help. Using a radio transmitter is going to introduce a very slight delay and in the case of cactus triggers, may be enough to prevent using max synch speed. I usually shoot a max of 160th when using the cactus triggers, though I often shoot slower than that.

05-17-2009, 04:29 AM	#13
MPrince Veteran Member Join Date: Sep 2006 Location: WV Posts: 1,495	Originally posted by figmental1978 Venturi - I'm using the flash off camera, so the cactus V2s transmitter is on the hotshoe. I just tested it on camera at 180th and the shadows are gone...very weird, almost x-files like. If you can shoot at 180th with the flash on-camera but not with the cactus, then I'd say the cactus trigger is the problem here. And if I remember correctly that is one of the "features" of the cheaper triggers--they don't work reliably, especially at max synch speed. I usually shoot below max synch speed anyway, but I don't think my cactus triggers fire at all at max synch speed. They work fine at 160th though.

05-17-2009, 04:56 AM	#14
mattdm Veteran Member Join Date: Feb 2007 Location: Boston, MA Photos: Gallery Posts: 2,948	Originally posted by figmental1978 ok, that fixed it right up, thanks. But the issue is why? and it sucks if I can only shoot at 125th. If the radio trigger is introducing a bit of a delay, the rear shutter curtain could be starting to come up before the flash goes off. Increasing the time the shutter's open avoids the problem. Unless there's significant other light (like, the sun), the actual exposure is only the flash — the camera shutter won't really matter.

05-17-2009, 05:44 AM	#15
tcdk Senior Member Join Date: Mar 2007 Location: Copenhagen, Denmark Posts: 279	Originally posted by MPrince Sounds like the right solution, but even that might not help. Using a radio transmitter is going to introduce a very slight delay and in the case of cactus triggers, may be enough to prevent using max synch speed. I usually shoot a max of 160th when using the cactus triggers, though I often shoot slower than that. Except, in this case it used to work, but now it doesn't.... so something changed. And I'm guessing batteries, as they have the ability to change on their own...