Canon 7D flash sync speed
Jan 4, 2016 18:32:55 #
I have just started to use my 7D with studio flashes. In the hand book it says that the max sync speed is 250th but with the camera set at this speed there is noticeable dark section in the shot. This is caused by the shutter curtain not being fully open during flash. Changing the speed to 180th overcomes the problem. Has anyone noticed this on the 7D ? The difference in speed is considerable, the camera is quite old and well used so I'm wondering if this is something that can be fixed or should I just accept it. Any thoughts?
Jan 4, 2016 18:52:24 #
Accept it. For some reason many canons max sync speed is less for studio flash. What does it do with a speedlite in the hotshoe?
Jan 4, 2016 18:56:08 #
If you use radio trigger it adds some delay. Also studio flash may have longer duration than portable flash.
Jan 4, 2016 19:07:48 #
Cockney wrote:
I have just started to use my 7D with studio flash... (show quote)
My 7D does the same thing. With speedlights it works at 1/250 and below but with my studio strobes I have to go down to 1/160.
Jan 4, 2016 19:08:51 #
Cockney wrote:
I have just started to use my 7D with studio flash... (show quote)
C, are you doing very fast movement studio work? Do you have a lot of ambient light with wide-open, fast lenses?
I guess I'm not sure why it matters. Can you add a stop or two then just drop the ss a bit?
Not sure I've been at that sync with a 7ll and strobes.
I'll admit, I had that very problem just this morning shooting a Model but I was using a 5s which only syncs at about 200th. I was at f1.8 for DoF and had to throw some extra diffusion over the lights!!!
Maybe your strobes are just really slow?!?! :lol:
Good luck. ;-)
SS
Jan 4, 2016 20:04:55 #
Are you on full manual mode?
Do you really need to shoot at that fast of a shutter in the studio?
Think of it this way:
The black box: There is no ambient light at all. the only light is the light that is from your studio light.
The shutter can be very slow. Because once the light hits your subject, there is no more light available that is going to enter the lens. you could walk around with the shutter open for as long as you want and it will have no effect at all.
You don't need a fast shutter speed.
Play around with your lights in a darkened room and see how the settings on your camera effect exposure. its a fun exercise
Do you really need to shoot at that fast of a shutter in the studio?
Think of it this way:
The black box: There is no ambient light at all. the only light is the light that is from your studio light.
The shutter can be very slow. Because once the light hits your subject, there is no more light available that is going to enter the lens. you could walk around with the shutter open for as long as you want and it will have no effect at all.
You don't need a fast shutter speed.
Play around with your lights in a darkened room and see how the settings on your camera effect exposure. its a fun exercise
Jan 4, 2016 20:33:11 #
I have several radio transceivers.
The least expensive one syncs at about 1/125th sec and my Pocket Wizard works at almost 1/250th. But as others have said, if you're shooting in an indoor studio situation, why do you need the top sync setting anyway?
The least expensive one syncs at about 1/125th sec and my Pocket Wizard works at almost 1/250th. But as others have said, if you're shooting in an indoor studio situation, why do you need the top sync setting anyway?
Jan 4, 2016 22:57:22 #
Cockney wrote:
I have just started to use my 7D with studio flash... (show quote)
Based on a tutorial DVD I purchased when I bought my Speedlite: The first curtain raises and then, while the sensor is wide open, the flash fires. Then the second curtain raises and shuts the sensor, and both curtains then return to their starting point. About 1/200 - 1/250 is the fastest shutter speed that will allow the sensor to be fully open when the flash fires. Shutter speeds faster than the "Max Flash Sync Speed" are such that the second curtain starts to raise before the first curtain is fully open then, instead of a fully open sensor, the two curtains form a slit that travels across the sensor (The faster the shutter speed, the narrower the slit). A normal flash can only expose one slit of the sensor. I don't know if all speed lights have high speed sync, but if you have a flash that does, that can overcome the max flash sync speed problem. When you put the flash in High Speed sync mode, it allows the flash to "pulse" or make a series of flashes as the "slit" travels across the sensor, thus providing uniform flash to all parts of the sensor.
Jan 5, 2016 00:02:46 #
The OP says he's using studio flashes.
There are only a few of those capable of High Speed Sync and they aren't the kind of thing that come cheap. The Dynalite Baja is the least expensive one I'm aware of and it's $600 per unit.
There are only a few of those capable of High Speed Sync and they aren't the kind of thing that come cheap. The Dynalite Baja is the least expensive one I'm aware of and it's $600 per unit.
Basil wrote:
Based on a tutorial DVD I purchased when I bought my Speedlite: The first curtain raises and then, while the sensor is wide open, the flash fires. . ......
Jan 5, 2016 00:03:35 #
GoofyNewfie wrote:
The OP says he's using studio flashes.
There are only a few of those capable of High Speed Sync and they aren't the kind of thing that come cheap.
There are only a few of those capable of High Speed Sync and they aren't the kind of thing that come cheap.
Good point.
Jan 5, 2016 00:12:54 #
Jan 5, 2016 00:42:14 #
GoofyNewfie wrote:
(I want a couple of those really bad!!!)
Hey, $600 is not all that much!! The Einstein's are almost that much!!! :thumbup:
SS
Jan 5, 2016 01:51:02 #
Thanks everyone, I will check the sync speed with my speed light but thinking about the points raised I suspect the flash units may be the cause, they are Godox dx300's which are at best entry level, thanks for all of your replies. Steve
Jan 5, 2016 02:13:39 #
Also the radio trigger is rated at 1/200 (now I've checked) so looks like I should be happy with 1/180. Just curious as I!m new to studio.
Jan 5, 2016 02:31:42 #
Cockney wrote:
Also the radio trigger is rated at 1/200 (now I've checked) so looks like I should be happy with 1/180. Just curious as I!m new to studio.
C, a fast sync speed is really only important if you using it for fill in bright light where you need the speed to cut the ambient.
In a studio situation, mostly for action you use the strob speed which can be on for only a few thousands of a second.
The lower the power you use, the shorter the light duration. Some good strobes at very low power are only at 1/20,000 sec. That strobe just needs to fire somewhere in that 1/180th time window. Pretty easy feat for a very fast strobe. Good luck!!! ;-)
SS
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