Does film camera have the same problem with strobes?
So could this be fixed in post?
|
|
09-25-2007, 05:58 PM
Does film camera have the same problem with strobes?
So could this be fixed in post?
09-25-2007, 06:17 PM
Yes and no.Originally Posted by purefilm
Depending on frame rate a film camera can miss a flash but I have yet to see half frame flash exposures.
However when shooting high-speed sfx or food (lets say orange juice spray and you want to see every drop individually), High-speed flash is used (photosonics).
These flash strobe twice per film frame position. Once so the op can see what he or she is shooting.
Hope this helps.
09-25-2007, 06:31 PM
The flashes in Crossing were a mix between real and simulated (added in post), you can see the effect on the real ones very clearly.
09-25-2007, 07:15 PM
Syncing gunfire between multiple subjects may pose a real problem for some of the stuff I need to shoot, no?
09-25-2007, 07:32 PM
So is this something that eventually can be fix, or is just something we will have to deal with? Will it be impossible to say shoot a live concert? Where you have no control?
09-25-2007, 10:11 PM
wow... this could be a bit of a problem. How do HMI's work in slow motion?
Is it possible red can have a switch to change from a rolling shutter to say a fixed 1/24 or 1/30th of a shutter for FX?
Lightning, flashing lights from cop cars, airplanes, lighthouses, hmi's, gun fire, sun reflecting off shimmering water - would all look unnatural compared to normal film or video?!
Some are not possible or practical to sync... can RED create a better solution that would look more like a normal shutter?
09-26-2007, 12:10 AM
Totally agree. not being able to shoot with HMI's would be really bad. Not to mention all the other things you bring up.
Flashes happen all the time in many different ways.
09-26-2007, 04:34 AM
I agree it could be a problem for certain things, but I don't think people should start worrying that anything that flashes would look odd. It will only have the horizontal split effect on a light that transitions between off and on almost instantaneously ie in the time between when the rolling shutter is on one line of the image and when it is on the next. This will not be the case for most naturally occuring phenomena like the sun glinting off something. Nor I suspect (but somebody who knows more about lights than me feel free to jump in) on normal tungsten lighting which I think ramps up from off to on, even if the ramp time is very short.
09-26-2007, 07:16 AM
This effect is common to most electronic camera's/sensors. You have to have your strobes sync'd!
Unlike gun-fire/muzzle flashes a strobe flash is extremely short in duration (unless I'm missing something I've always been under the impression that strobes produced burst of light that were no longer than a few thousandth's of a second) enough to cause the type of problem we're discussing.
One of the general work arounds is to use the electronic equivilent of a 360º shutter and leave the strobe to do the work of providing that "staccato" feel.
Start going into faster shutter speeds un-sync'd and the chances are you'll miss the occasional flash or in some instances (like this) the flash'll go off midway through an exposure/readout and only appear to illuminate part of the frame.
JohnF
09-26-2007, 07:25 AM
Note:
Unlike the on/off light curve (more like a square wave) of a strobe a muzzle flash has more of a light curve (bell shaped) so gun fire is more likely to vary in brightness rather than be totally missed. though of course this does depend on ones shutter speed.
If you really need to catch it then always think 360 shutter...
Anyone know different?
JohnF
| « Previous Thread | Next Thread » |
