Keith
The best camera is one that still works!
Did some product shots today with the studio lighting kit I got recently and the camera (DP3M) appeared to sync with the strobes at pretty well any shutter speed and aperture combination I chose ... which certainly makes the whole process very easy!
Why are leaf shutters so superior when syncing with a flash?
Why are leaf shutters so superior when syncing with a flash?
Merlijn53
Established
Is this a serious question?
btgc
Veteran
Because of way they allow light to reach film/sensor? Leaf shutter pops open for certain time, while curtain shutters, to ensure speeds shorter than sync speed, travel in way that gap moves across frame and here is culprit - at times shorter than sync speed flash will freeze one of curtains moving. So I understand it, but take this with a grain of salt.
Keith
The best camera is one that still works!
In a word yes ... why is a leaf shutter so much more flexible in this situation? I'm an available light shooter generally and have no idea about flash but do understand that when using my D700 there are specific shutter speeds for syncing with flash.
And I do understand the mechanical differences between the shutters of the two cameras and how they work.
Why wouldn't it be a serious question? I'm not ashamed to admit I haven't a clue.
YYV_146
Well-known
The curtain shutter takes time to travel the entire focal plane. The sync speed is therefore constrained by said speed. With leaf shutter cameras (as well as leaf shutter lenses of medium format systems) the process is essentially instantaneous. Larger leaf shutters often struggle to perform at comparable speeds to focal plane shutters (because of the time involved in fully closing the blades), on the other hand, they can always sync at those speeds.
The X100(S), RX1, RX100 can all sync at the fastest shutter speed of a given aperture. I don't do a lot of strobe work, but I certainly want to own one of those bodies just for the convenience...
KR has an article that explains flash sync pretty well: http://www.kenrockwell.com/tech/syncspeed.htm
The X100(S), RX1, RX100 can all sync at the fastest shutter speed of a given aperture. I don't do a lot of strobe work, but I certainly want to own one of those bodies just for the convenience...
KR has an article that explains flash sync pretty well: http://www.kenrockwell.com/tech/syncspeed.htm
Keith
The best camera is one that still works!
Thanks ... so the flash will never overtake the shutter operation, or if it did would you get more of a vignetting effect? I noticed with the Nikon that if you exceed the recommended sync speed you start to see the edge of the focal plane shutter.
Solinar
Analog Preferred
I believe the strobe's pulse duration is only 1/10000 th of a second.
Focal plane shutters once past their synch speed will have the their second curtain closing before the first curtain has fully opened - which results in a gap or slit moving across the film plane. Think of a open slit traveling across the frame.
The opening between the two shutter curtains might only travel across the film plane at 1/50th of second on an a horizontal shutter curtain. At 1/50th of a second, once the first shutter curtain fully opens, the second curtain is ready to start covering up the film plane.
This - or - any slower shutter speed is when the strobe can fire.
For example: the strobe's max intensity is a 100 times shorter than 1/100th of a second. For the above shutter, if the flash fires when the first curtain has fully opened - the second curtain has already begun to move and is already covering up part of the film plane - provided the chosen shutter speed is faster than 1/50th of a second.
With a leaf shutter - all the leafs are fully open at one moment - even for 1/500th of second. The strobes duration is 20 times faster than 1/500th of second - It's peak duration will be long over when the shutter leaves simultaneously begin to close 1/500th of a second later.
Best Regards,
Focal plane shutters once past their synch speed will have the their second curtain closing before the first curtain has fully opened - which results in a gap or slit moving across the film plane. Think of a open slit traveling across the frame.
The opening between the two shutter curtains might only travel across the film plane at 1/50th of second on an a horizontal shutter curtain. At 1/50th of a second, once the first shutter curtain fully opens, the second curtain is ready to start covering up the film plane.
This - or - any slower shutter speed is when the strobe can fire.
For example: the strobe's max intensity is a 100 times shorter than 1/100th of a second. For the above shutter, if the flash fires when the first curtain has fully opened - the second curtain has already begun to move and is already covering up part of the film plane - provided the chosen shutter speed is faster than 1/50th of a second.
With a leaf shutter - all the leafs are fully open at one moment - even for 1/500th of second. The strobes duration is 20 times faster than 1/500th of second - It's peak duration will be long over when the shutter leaves simultaneously begin to close 1/500th of a second later.
Best Regards,
Keith,
With a leaf or lens, shutter there is, at any set speed, always a point at which the shutter blades have fully parted, and are exposing the entire film gate simultaneously. By designing the synchronisation mechanism accordingly, the contacts for the circuit can be made to close precisely at this point.
A focal plane shutter, on the other hand, generally "cheats" at its faster speeds. Instead of the second curtain releasing after the first curtain has fully opened it chases the first curtain across the gate at increasingly narrower gaps as the speed increases. So the gate is exposed progressively by the "slit" between the curtains. Firing a flash at any speed above the shutters "sync" speed, (if the particular camera actually permits this in the first place, modern electronic types will often simply say "no" when you try to exceed their sync speed) will result in a flash exposure. But only within the exposed slit between the curtains for the duration of the flash.
Another way of looking at it is that (in the context of FP shutters) the sync speed is the highest speed the shutter is capable of running, where the second curtain can wait until the first curtain has completely run off, before closing the film gate.
Ansel Adams's book "The Camera" has an excellent discussion and analysis of the two shutter types, their varying efficiency at different speeds and their strengths and weaknesses.
I like leaf shutters a lot. They're not for every photographic chore ever contrived (they tend to max out at 1/1000 for the most part) so for situations like motor racing for example, they may not be the best choice. For general imaging on the other hand daylight flash fill at any speed is there any time you want it, and they can be so smooth. And for all the much vaunted silence of a Leica FP shutter, a good Synchro Compur in Eg. a Rolleiflex, craps all over it for quietness.
I like them so much the 35mm SLR I probably use the most is one of my many Contaflexes. Put one of those on a tripod, fire the mirror and no other 35mm SLR is as smooth (except perhaps a Bessamatic, another lens shutter SLR).
Cheers
Brett
With a leaf or lens, shutter there is, at any set speed, always a point at which the shutter blades have fully parted, and are exposing the entire film gate simultaneously. By designing the synchronisation mechanism accordingly, the contacts for the circuit can be made to close precisely at this point.
A focal plane shutter, on the other hand, generally "cheats" at its faster speeds. Instead of the second curtain releasing after the first curtain has fully opened it chases the first curtain across the gate at increasingly narrower gaps as the speed increases. So the gate is exposed progressively by the "slit" between the curtains. Firing a flash at any speed above the shutters "sync" speed, (if the particular camera actually permits this in the first place, modern electronic types will often simply say "no" when you try to exceed their sync speed) will result in a flash exposure. But only within the exposed slit between the curtains for the duration of the flash.
Another way of looking at it is that (in the context of FP shutters) the sync speed is the highest speed the shutter is capable of running, where the second curtain can wait until the first curtain has completely run off, before closing the film gate.
Ansel Adams's book "The Camera" has an excellent discussion and analysis of the two shutter types, their varying efficiency at different speeds and their strengths and weaknesses.
I like leaf shutters a lot. They're not for every photographic chore ever contrived (they tend to max out at 1/1000 for the most part) so for situations like motor racing for example, they may not be the best choice. For general imaging on the other hand daylight flash fill at any speed is there any time you want it, and they can be so smooth. And for all the much vaunted silence of a Leica FP shutter, a good Synchro Compur in Eg. a Rolleiflex, craps all over it for quietness.
I like them so much the 35mm SLR I probably use the most is one of my many Contaflexes. Put one of those on a tripod, fire the mirror and no other 35mm SLR is as smooth (except perhaps a Bessamatic, another lens shutter SLR).
Cheers
Brett
YYV_146
Well-known
I'm not quite sure...maybe someone with an X100 could test this out at f2 and a few different speeds?
I've also notice the shutter issue you mentioned, the shutter can be seen in the frame if the speed is too high.
sevo
Fokutorendaburando
The flash can never overtake a leaf shutter, as the latter (like the aperture) acts across all the image uniformly.
Which does not mean that you can shoot at each and every speed without consulting spec sheets - large studio flashes will often have a burn time in the 1/50-1/250s range, slower than the fastest speed of modern small to mid size leaf shutters, so that the shutter may cut into the flash exposure, or limit the aperture size. Where the latter is an issue the lens will be rated to have less than its maximum aperture at top speed, when using continuous lighting - another side effect of the opening/closing phase of leaf shutters limiting the aperture diameter.
Which does not mean that you can shoot at each and every speed without consulting spec sheets - large studio flashes will often have a burn time in the 1/50-1/250s range, slower than the fastest speed of modern small to mid size leaf shutters, so that the shutter may cut into the flash exposure, or limit the aperture size. Where the latter is an issue the lens will be rated to have less than its maximum aperture at top speed, when using continuous lighting - another side effect of the opening/closing phase of leaf shutters limiting the aperture diameter.
lynnb
Veteran
Keith, the advice above is correct.. a way to overcome the disadvantage of the moving slit exposure is to have a flash duration long enough to cover the entire time the film is exposed by the moving slit. However, a long-duration flash takes a relatively huge amount of energy (think of it as a continuous light for the duration of time that slit takes to expose the entire film gate), and therefore the flash guide number is effectively reduced.
My Canon 580 EX units have a setting (HSS, or high speed synch) to do this and I just put up with reduced flash range when I want to use flash with a shutter speed that involves a moving slit, i.e. any speed above 1/200 on my 5D. I'm sure Nikon's SB800/900 would have a similar setting.
In the old days, magnesium flash powder had both high intensity and long duration - ideal for focal plane shutters that couldn't expose the entire frame at once. (Edit: if focal plane shutters existed back then!).
My Canon 580 EX units have a setting (HSS, or high speed synch) to do this and I just put up with reduced flash range when I want to use flash with a shutter speed that involves a moving slit, i.e. any speed above 1/200 on my 5D. I'm sure Nikon's SB800/900 would have a similar setting.
In the old days, magnesium flash powder had both high intensity and long duration - ideal for focal plane shutters that couldn't expose the entire frame at once. (Edit: if focal plane shutters existed back then!).
Solinar
Analog Preferred
Bring back the old FP flash bulbs. I believe their flash duration lasted longer than 1/30th of a second.
Best Regards,
Best Regards,
lynnb
Veteran
For in-depth tutorials about flash, see www.strobist.com
sevo
Fokutorendaburando
They did - in fact, the regular large format press cameras in the first half of the 20th century (whether SLR or strut folder) had focal plane shutters...
Keith
The best camera is one that still works!
Thanks for the replies ... it never occured to me that the actual duration of flashes could vary so much. It must be why the old flash bulbs provide a rather different look to modern strobes?
Merlijn53
Established
In a word yes ... why is a leaf shutter so much more flexible in this situation? I'm an available light shooter generally and have no idea about flash but do understand that when using my D700 there are specific shutter speeds for syncing with flash.
And I do understand the mechanical differences between the shutters of the two cameras and how they work.
Why wouldn't it be a serious question? I'm not ashamed to admit I haven't a clue.
I'm sorry, I come from an era when this was common knowledge. My fault to think it still is
Scrambler
Well-known
Leica manuals into the 1950s said their cameras could flash synchronise at any speed - using a FP bulb. It was only the electronic flash era which saw flash synchronisation on focal plane shutters being restricted.
Keith, Think of what a leaf shutter is: a very fast moving and fully closing aperture. If you set off the flash at maximum aperture (midpoint of the shutter time) then you have synchronisation at any speed. If the flash is late or still burning then you restrict the light input during the closing phase of the shutter, but the effect is the same as a smaller aperture rather than the focal plane shutter shadowing.
Keith
The best camera is one that still works!
I'm sorry, I come from an era when this was common knowledge. My fault to think it still is
No worries!
I never picked up a camera seriously until 2006 when I joined here and have only just recently started using strobes.
I am a luddite in many areas!
Sparrow
Veteran
... that's what the two plugs are on the back of an M2 are for ... FP and X sync, FP for bulbs and X for this new-fangled electronic things, both spoil a good photo equally well ...
mfunnell
Shaken, so blurred
Never a truer word spoken in (half) jest!... that's what the two plugs are on the back of an M2 are for ... FP and X sync, FP for bulbs and X for this new-fangled electronic things, both spoil a good photo equally well ...
...Mike