Second Curtain appearance but not on

Graham Cracker

Lately during several shoots in which I am using my flash an occasional picture or two will show up and the bottom half on the picture is very dark. Almost like I have second curtain on but I don't. Then it will be fine for many more shots. Random in pattern, flash is firing, does this mean my shutter is sticking,( thought the picture is in focus), batteries in flash are wearing down? ( thought they continue to work for at least 25-50 more shots and maybe only 1 more instance of this. I deleted all the recent ones so I don't have a physical example, Anyone have this and know what it is? I am shooting 1DM3, Sigma 24-70 2.8 with 580 EXII flash when it happens. Thanks Patrick

jeffreaux2

Graham Cracker wrote: »

Lately during several shoots in which I am using my flash an occasional picture or two will show up and the bottom half on the picture is very dark. Almost like I have second curtain on but I don't. Then it will be fine for many more shots. Random in pattern, flash is firing, does this mean my shutter is sticking,( thought the picture is in focus), batteries in flash are wearing down? ( thought they continue to work for at least 25-50 more shots and maybe only 1 more instance of this. I deleted all the recent ones so I don't have a physical example, Anyone have this and know what it is? I am shooting 1DM3, Sigma 24-70 2.8 with 580 EXII flash when it happens. Thanks Patrick

What shutter speed?

pathfinder

Try shooting a series of exposures in Manual Mode, varying the aperture and the shutter speed, without flash, altering your shutter speed from 1/100th to 1/4000 th. And see if you have a dark bar across the long dimension of your frame. I did have to have the shutter in my 1DsMkII replaced because it was sticking, and it was only noticeable at higher shutter speed settings.

Graham Cracker

jeffreaux2 wrote: »

What shutter speed?

It has varied 1/300 and down indoors and outside.

Graham Cracker

pathfinder wrote: »

Try shooting a series of exposures in Manual Mode, varying the aperture and the shutter speed, without flash, altering your shutter speed from 1/100th to 1/4000 th. And see if you have a dark bar across the long dimension of your frame. I did have to have the shutter in my 1DsMkII replaced because it was sticking, and it was only noticeable at higher shutter speed settings.

Thanks, I will try it tonight

Qarik

if it is only happening with a flash at that shutter speed, it sounds like something maybe wrong with your high speed sync setting.

Graham Cracker

Qarik wrote: »

if it is only happening with a flash at that shutter speed, it sounds like something maybe wrong with your high speed sync setting.

It is only with the flash. It even happened with some external studio lights. If it was a settings issue wouldn't it happen all the time?

jeffreaux2

Graham Cracker wrote: »

It is only with the flash. It even happened with some external studio lights. If it was a settings issue wouldn't it happen all the time?

What is the native synch speed for your camera?

You should use that shutter speed or slower with flash....unless flash is set up fohigh speed synch.


Im not familiar with the camera you use but I doubt seriously that it can synch up at 1/300 unless you are using high speed synch.

Qarik

most cameras can't fire flash at fill strength faster then 1/250s or 1/200s. At 1/300s your shutter speed is faster then that so you have to enable the high speed sync on your camera which changes the full burst of your flash into mini bursts of flash. if do not enable this then you may experiences issues with flash exposing only portions of your image when the shutter is open. Most of the time the camera won't let you go past the native sync speed unless the high speed sync is enabled though I can't be sure of your case.

pathfinder

For most studio strobes, you want to use a shutter speed no faster than ~1/200th or so. I usually use 1/160th.

1/300th means that your shutter is closing prematurely, and part of your frame will be dark as a results.

Most studio strobes do not support High Speed Synch, only EOS speedlites and a few copies like the Sigma series.

Graham Cracker

pathfinder wrote: »

For most studio strobes, you want to use a shutter speed no faster than ~1/200th or so. I usually use 1/160th.

1/300th means that your shutter is closing prematurely, and part of your frame will be dark as a results.

Most studio strobes do not support High Speed Synch, only EOS speedlites and a few copies like the Sigma series.

I have had varying speed, but only one shot when shooting. Generally I like to shoot at f8 and about 1/80th and again the dark part is still in focus. I have tried to reproduce but to no avail this week, but it has happened about 3-4 times with no warning.

Graham Cracker

Qarik wrote: »

most cameras can't fire flash at fill strength faster then 1/250s or 1/200s. At 1/300s your shutter speed is faster then that so you have to enable the high speed sync on your camera which changes the full burst of your flash into mini bursts of flash. if do not enable this then you may experiences issues with flash exposing only portions of your image when the shutter is open. Most of the time the camera won't let you go past the native sync speed unless the high speed sync is enabled though I can't be sure of your case.

my 1DM3 will go to 1/300th and I use this for indoor/ night sports but it has happened with portraits shooting at 1/80th as well. I'll keep trying the various suggestions and see if I can reproduce to show. Thanks for the input and time.