Shallow depth of field and flash shooting
Discussion
Why I can't choose lower shutter speed than 1/200 shooting with flash? Is this the minimum time for the flash to "light up" and otherwise the picture would be taken BEFORE the flash? Then why the shutter can't open for smaller amount of time AFTER the flash is already active?
It's really annoying that you don't have more flexibility with shallow DOF and flash not causing the pictures to be overexposed.
It's really annoying that you don't have more flexibility with shallow DOF and flash not causing the pictures to be overexposed.
It's a bit of a complicated question to be honest. The aperture controls flash light, and shutter speed controls ambient.
I don't know why you can't set anything slower than 1/200th, are you in manual mode, if not there is your answer. Then you also have front and rear curtain, another thing to read up on.
If you're wanting to shoot wide open at something like 1.4 then an ND filter may be required to bring to flash power even lower depending upon flash type, situation etc etc etc.
I would recommend a thorough read of the strobist website as it's a huge subject and I can't really answer your question here in full.
www.strobist.com
Regards,
Matt.
I don't know why you can't set anything slower than 1/200th, are you in manual mode, if not there is your answer. Then you also have front and rear curtain, another thing to read up on.
If you're wanting to shoot wide open at something like 1.4 then an ND filter may be required to bring to flash power even lower depending upon flash type, situation etc etc etc.
I would recommend a thorough read of the strobist website as it's a huge subject and I can't really answer your question here in full.
www.strobist.com
Regards,
Matt.
It's called the maximum flash synch speed.
The shutter actually consists of two shutters (called curtains), one of which slides down to expose the sensor (or film) and the other follows behind to re-cover it. At high shutter speeds these two operations overlap and so at no moment is the sensor totally uncovered by the curtains: either the lower portion of the sensor is yet to be uncovered by the first curtain or the upper portion has already been re-covered by the second curtain. Therefore, even though the flash only fires for no more than 1/1000th of a second, its light will be unable to reach the entire sensor, regardless of at which moment during the exposure it fires.
Some flashes have a "high speed synch mode" which solves the problem by flashing multiple times during the exposure. The downside is it takes up a lot of power and reduces the maximum flash brightness.
The other solution is to use a neutral density filter on the lens which reduces the amount of ambient light getting to the sensor. The downside of this method is that it also reduces the amount of flash light reaching the sensor, so you need enough 'spare' power in the flash to overcome this.
The shutter actually consists of two shutters (called curtains), one of which slides down to expose the sensor (or film) and the other follows behind to re-cover it. At high shutter speeds these two operations overlap and so at no moment is the sensor totally uncovered by the curtains: either the lower portion of the sensor is yet to be uncovered by the first curtain or the upper portion has already been re-covered by the second curtain. Therefore, even though the flash only fires for no more than 1/1000th of a second, its light will be unable to reach the entire sensor, regardless of at which moment during the exposure it fires.
Some flashes have a "high speed synch mode" which solves the problem by flashing multiple times during the exposure. The downside is it takes up a lot of power and reduces the maximum flash brightness.
The other solution is to use a neutral density filter on the lens which reduces the amount of ambient light getting to the sensor. The downside of this method is that it also reduces the amount of flash light reaching the sensor, so you need enough 'spare' power in the flash to overcome this.
Edited by SamHH on Saturday 21st August 14:20
rottie102 said:
Why I can't choose lower shutter speed than 1/200 shooting with flash?
You mean higher shutter speed. Higher = faster (1/200th). Lower = slower (1/15th).That's because 1/200th of a second is the longest that your shutter remains open in order for the camera to give the flash the command to fire. The Nikon D70 can sync at 1/500th but that's about as good as it gets, most cameras go up to 1/250th max
Actually newer nikons with the newer speedlights can sync up the way up to the max shutter speed with only a loss of power/range to take into account.
This can be done on camera or withy the nikon cls system.
Have a read here: http://nikonclspracticalguide.blogspot.com/2008/03...
This can be done on camera or withy the nikon cls system.
Have a read here: http://nikonclspracticalguide.blogspot.com/2008/03...
itsnotarace said:
rottie102 said:
Why I can't choose lower shutter speed than 1/200 shooting with flash?
You mean higher shutter speed. Higher = faster (1/200th). Lower = slower (1/15th).That's because 1/200th of a second is the longest that your shutter remains open in order for the camera to give the flash the command to fire. The Nikon D70 can sync at 1/500th but that's about as good as it gets, most cameras go up to 1/250th max
I just bought a RayFlash ( http://www.ray-flash.com/ ) and have been playing with it...
Ok, another question - I have a Sigma 530DG ST and when focusing, focused and even few seconds after the shot with my Sigma 50mm 1.4 it goes CONSTANTLY 50-70-50-70-50-70-50-70 and so on and so on... Like it couldn't work out lens'es focal length. It's noisy, annoying and most likely makes the batteries die much faster. It does it in all the modes - ETTL, Mh and Ml. I kind of solved it by flipping the built in diffuser down but that sets the focal length at 28mm , not 50mm and also limits the flashes power.
Any ideas? Or do I have to buy Canon's 580EX which I'm sure won't have this issue.
MUSKA - I'm a Canon guy
Is it similar with 550D and 580EX?
Edited by rottie102 on Saturday 21st August 14:35
You can always rent if you need something in a hurry.
Even an old flash like an SB-28 will do the job if you're shooting in manual. I have three of them and they're perfect for all my needs, and each one was £80.
And they will work on your canon
Even an old flash like an SB-28 will do the job if you're shooting in manual. I have three of them and they're perfect for all my needs, and each one was £80.
And they will work on your canon
Edited by Muska on Saturday 21st August 14:45
Pete Baraka said:
As already pointed out, there are a few different ways of achieving this effect. This was in bright sun, f4.5 & 1/3200 sec exposure, off-camera 580exII speedlite and a PocketWizard TT1/TT5 combo.
Pete
You see, my problem is that due to a nature of rayflash it has to be ON camera... I know that I can choose whichever shutter speed I want if the flash will be off camera.Pete
Plus f4.5 is not a shallow depth of field for me
Edited by rottie102 on Saturday 21st August 17:17
rottie102 said:
You see, my problem is that due to a nature of rayflash it has to be ON camera... I know that I can choose whichever shutter speed I want if the flash will be off camera.
Plus f4.5 is not a shallow depth of field for me
I think you're misunderstanding what the maximum synch speed is. It is a physical limitation imposed by the camera's shutter system. The limitation is the same wherever the flash is situated and however it is triggered. It might be that your camera prevents you from exceeding the synch speed when there is a flash on the hotshoe and doesn't so prevent you with a remotely triggered flash, but the problem will be the same either way. Plus f4.5 is not a shallow depth of field for me
The ways to get around it are to use an ND filter so that you don't exceed the max synch speed, or to use a flash that has a high speed synch mode.
Edited by SamHH on Saturday 21st August 17:53
rottie102 said:
Why I can't choose lower shutter speed than 1/200 shooting with flash?
There's a custom function (on many Canon DSLRs) that fixes the shutter speed at the x-sync speed when in AV mode. Might be worth checking whether this has been set. Also, in "auto" modes, the camera will tend to select the x-sync speed as a "suitable" speed for you auromatically. Have you tried it with the camera in Manual mode?Simpo Two said:
rottie102 said:
You see, my problem is that due to a nature of rayflash it has to be ON camera... I know that I can choose whichever shutter speed I want if the flash will be off camera.
Crazy idea - stick some paper in the hotshoe so the camera doesn't know there's a flash on top?
How were you planning to fire it if it was off camera?
However, even if you can then set it up to a faster shutter speed, you'll probably get half an image or a black frame because the flash will miss the exposure.
You could do worse than buy an old Nikon D70 - they synch up to 1/2000th (with studio lighting, not sure with a Speedlight)
However, even if you can then set it up to a faster shutter speed, you'll probably get half an image or a black frame because the flash will miss the exposure.
You could do worse than buy an old Nikon D70 - they synch up to 1/2000th (with studio lighting, not sure with a Speedlight)
Edited by Simpo Two on Sunday 22 August 17:27
rottie102 said:
Guys, it's not on of those RTFM topics
The camera is in manual and the option for fixed sync time is disabled ...
Sorry mate, I misunderstood you - should've read the whole thread!The camera is in manual and the option for fixed sync time is disabled ...
So the problem you're having is that even at ISO 100 (or lowest useable ISO) and at maximum x-sych speed, you cannot get the narrow DoF you want because you're forced to use a high aperture setting. In that case, your only options (as I understand it) are to use a neutral density filter (or polariser) or high-speed sync (HSS) on your speedlite.
As you're using a ring-flash, I assume you are planning some macro or portrait work. If so, HSS will probably work just fine. The problem with HSS is that it's limited in usefulness if the "subject" is not close to you. I'd give that a test first. In fact, it's probably best to leave a speedlight with HSS enabled all the time; just in case.
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