cinematography Canon T2i and 1/48 shutter speed
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Okay, so I finally read up on how shutter-speed works in film, and now I see why you guys were weirded out when I talked about the shutter-speed not "matching" the frame-rate. Previously, I thought that if you were shooting a shutter-speed of say, 1/96, then your shutter is rotating 96 times. Now, I understand that the shutter rotates at the speed of the frame-rate, and the shutter-speed is only a question of how wide of an opening is left on the shutter. My bad. Now I get it.
Actually, I think the OP had the same mis-understanding, if you look at the question being asked. I think the OP thought that with 1/50 shutter-speed, the shutter is actually opening 50 times. If you were shooting film at 24FPS, 1/50 shutter-speed would be practically the same as 1/48 -- you would just have a slightly smaller opening. Instead of it being a perfect 180-degree opening, it would be somewhere in the ballpark of a 175-degree opening, but it would still "match" (to use the terminology I so incorrectly used, earlier).
However, (I can hear your collective groan), I still don't see how that changes things. Why does frame-rate have to be considered, when choosing shutter-speed? If you have a slower shutter-speed, your image will have more blur. If you have a faster shutter-speed, your images will be more crisp. That's true of still photography, and it's true regardless of whether you're shooting at 24p or 30p. 1/100 will have that high-speed-look, regardless of whether you're shooting 24p or 30p, no?
I'm gonna shoot some test-footage, and post it. That will put this to rest. And if I end up eating my words, so be it (wouldn't be the first time). But if I get to say "I told ya so", I reserve the right to do so.
Actually, I think the OP had the same mis-understanding, if you look at the question being asked. I think the OP thought that with 1/50 shutter-speed, the shutter is actually opening 50 times. If you were shooting film at 24FPS, 1/50 shutter-speed would be practically the same as 1/48 -- you would just have a slightly smaller opening. Instead of it being a perfect 180-degree opening, it would be somewhere in the ballpark of a 175-degree opening, but it would still "match" (to use the terminology I so incorrectly used, earlier).
However, (I can hear your collective groan), I still don't see how that changes things. Why does frame-rate have to be considered, when choosing shutter-speed? If you have a slower shutter-speed, your image will have more blur. If you have a faster shutter-speed, your images will be more crisp. That's true of still photography, and it's true regardless of whether you're shooting at 24p or 30p. 1/100 will have that high-speed-look, regardless of whether you're shooting 24p or 30p, no?
I'm gonna shoot some test-footage, and post it. That will put this to rest. And if I end up eating my words, so be it (wouldn't be the first time). But if I get to say "I told ya so", I reserve the right to do so.
Oops... I didn't expect this thread to build up so fast...
CF, thanks for the "conflict" you brought in that drew this topic insane.
Ernest Worthing, you made me cry with your:
There is one interesting thing that I mentioned with my DSLR. I live in 220V and 50Hz country. I have a tungsten light in my room. So, if I direct the camera to the light source and choose 1/50 shutter speed the light is still, and if I change it to 1/60 I can see "waves" of light (strobe it is called, isn't it?). These waves remain visible until I reach 1/100.
Though originally I was worried about 1/48 shutter speed I am not anymore, since 1/50 turns out to be ok to use.
But the shutter speed is crucial and must match the light frequency I use to avoid strobe (if strobe it is).
CF, thanks for the "conflict" you brought in that drew this topic insane.
Ernest Worthing, you made me cry with your:
There is one interesting thing that I mentioned with my DSLR. I live in 220V and 50Hz country. I have a tungsten light in my room. So, if I direct the camera to the light source and choose 1/50 shutter speed the light is still, and if I change it to 1/60 I can see "waves" of light (strobe it is called, isn't it?). These waves remain visible until I reach 1/100.
Though originally I was worried about 1/48 shutter speed I am not anymore, since 1/50 turns out to be ok to use.
But the shutter speed is crucial and must match the light frequency I use to avoid strobe (if strobe it is).
Ah yeah, PAL and NTSC.
50Hz and 60Hz.
Some lights (flourescent) flicker and so u must match ur shutter speed with the cycle of the light.
So 50Hz lights, 1/50.
60Hz lights, 1/60.
Either way ur close enough to ur 180 shutter angle.
This stuff can get a bit complicated if u get into detail with how the rolling shutter works and what gets exposed when but the above is what u need to know for practical purposes.
goodluck and now lets c some tests!
50Hz and 60Hz.
Some lights (flourescent) flicker and so u must match ur shutter speed with the cycle of the light.
So 50Hz lights, 1/50.
60Hz lights, 1/60.
Either way ur close enough to ur 180 shutter angle.
This stuff can get a bit complicated if u get into detail with how the rolling shutter works and what gets exposed when but the above is what u need to know for practical purposes.
goodluck and now lets c some tests!
Okay, honest question. Seriously inquiry, not being my normal sarcastic smartass. Can someone please explain to me why I need to take my frame rate into consideration, when choosing shutter speed? If there's a logical reason why those two things need to be related, I'd honestly like the explanation, cuz I just ain't seeing it.
And I've honestly tried to find an explanation. Guys, I'm pretty good at googling. And, nobody has explained it in this thread. You kinda just called me crazy, but didn't explain how what I was saying was wrong.
I think maybe this thread got off on the wrong foot because I misunderstood how shutter speed works in film, and I said a couple things that were probably weird-sounding to the people who come from a film background, and already understood how film works. But for DSLR, everything I've stated has shown that I get how it works.
I read an article arguing the the 180 shutter rule must ALWAYS be followed. So, if you're using the Red, and shooting 1000 FPS, you need to use a shutter speed of 1/2000. Are you F-ing kidding me?! I'm honestly supposed to believe that 1000 FPS 1/2000 will have the same "natural" look that audiences are accustomed to, with 24 FPS 1/48?
Look, for all intents and purposes, in this conversation, we're talking about 24, 30, and 60 FPS, no? So, following the 180 shutter rule, we should shoot at 1/50, 1/60, and 1/120, respectively, no?
I'm sorry, I'm not buying it. 24p will look different from 30p because of a different frame rate, but I don't see how that has any bearing on shutter speed. 1/100 will have a different look than 1/60, but I don't see how that has anything to do with frame rate.
1/60 will have a smooth look, regardless of whether you're shooting at 24p or 30p. 1/120 will have a choppy look, regardless of whether you're shooting at 24p or 30p. I shot some test-footage. I shot this test footage because I honestly wanna know for myself, not trying to just win a silly argument. Based on what I'm looking at (and of course I'm willing to post it when I've got time), if someone can't give me a clear reason why I'm wrong, I'm pulling the "I told ya so" card.
To be clear, my main point was this:
In deciding which shutter speed to use, you need not consider frame rate. In deciding which frame rate to choose, you need not consider shutter speed. I can't make myself any more clear than that; If I'm wrong (which I'm honestly still open to the possibility of), someone please tell me how I'm wrong.
And I've honestly tried to find an explanation. Guys, I'm pretty good at googling. And, nobody has explained it in this thread. You kinda just called me crazy, but didn't explain how what I was saying was wrong.
I think maybe this thread got off on the wrong foot because I misunderstood how shutter speed works in film, and I said a couple things that were probably weird-sounding to the people who come from a film background, and already understood how film works. But for DSLR, everything I've stated has shown that I get how it works.
I read an article arguing the the 180 shutter rule must ALWAYS be followed. So, if you're using the Red, and shooting 1000 FPS, you need to use a shutter speed of 1/2000. Are you F-ing kidding me?! I'm honestly supposed to believe that 1000 FPS 1/2000 will have the same "natural" look that audiences are accustomed to, with 24 FPS 1/48?
Look, for all intents and purposes, in this conversation, we're talking about 24, 30, and 60 FPS, no? So, following the 180 shutter rule, we should shoot at 1/50, 1/60, and 1/120, respectively, no?
I'm sorry, I'm not buying it. 24p will look different from 30p because of a different frame rate, but I don't see how that has any bearing on shutter speed. 1/100 will have a different look than 1/60, but I don't see how that has anything to do with frame rate.
1/60 will have a smooth look, regardless of whether you're shooting at 24p or 30p. 1/120 will have a choppy look, regardless of whether you're shooting at 24p or 30p. I shot some test-footage. I shot this test footage because I honestly wanna know for myself, not trying to just win a silly argument. Based on what I'm looking at (and of course I'm willing to post it when I've got time), if someone can't give me a clear reason why I'm wrong, I'm pulling the "I told ya so" card.
To be clear, my main point was this:
In deciding which shutter speed to use, you need not consider frame rate. In deciding which frame rate to choose, you need not consider shutter speed. I can't make myself any more clear than that; If I'm wrong (which I'm honestly still open to the possibility of), someone please tell me how I'm wrong.
exposure is why you need to consider it. More importantly, its about how much motion blur you have...
The frame rate determines how long that piece of film (or how long that cycle of the sensor) will be available for you to expose to light, but not how LONG you ACTUALLY expose for.
At 24 Frames Per Second, that gives you the possibility of exposing for as long as 1/24th of a second for each frame. Simple enough right. However, you may chose to not open the shutter at all, in which case you have no image, or open the shutter for the entire 1/24th of a second.. which might be cool if your doing some startlight stuff.. having the shutter open longer means more motion blur
Now, how much of that 1/24th of second you chose to expose for is determined by the shutter speed.
Some confusion is coming from mixing the way shutter speeds are described... a 180 shutter rule is NOT a time measurement, it is a measurement of an arc of a circle. Which DIRECTLY relates to the way the circular shutter is mechanically linked to the frame advancing mechanism of a motion picture camera. A 180 (degree) shutter is "half" a circle (360/2=180), which means that the frame is exposed for "half" the time the frame of film is in behind the lens.
So for 24p that = 1/24th of a second (for each frame remember) divided by 2 (half the available time) which is.. drum roll please.. 1/48th of a second.
I use shutter speed to help with exposure. I leave my frame rate on 24p. And increase the shutter speed to help in REALLY bright situations (where stopping down will lose my shallow DOF) sure, its a trade off with the silky smooth motion vs. the saving private ryan thing.. but meh.. im a noob so I dont care..
In regards to High Frames rates like 1000FPS I think that at that speed the film camera tech is different, rotating prisms etc, and it would be illogical to work with 180 degree shutter. Plus, if your filming at that rate, likely your goal has nothing to do with capturing a pleasing motion blur. which is the whole argument for 180 degree (or 1/48th of a second at 24p) shutter.. people like the blur of it..
The frame rate determines how long that piece of film (or how long that cycle of the sensor) will be available for you to expose to light, but not how LONG you ACTUALLY expose for.
At 24 Frames Per Second, that gives you the possibility of exposing for as long as 1/24th of a second for each frame. Simple enough right. However, you may chose to not open the shutter at all, in which case you have no image, or open the shutter for the entire 1/24th of a second.. which might be cool if your doing some startlight stuff.. having the shutter open longer means more motion blur
Now, how much of that 1/24th of second you chose to expose for is determined by the shutter speed.
Some confusion is coming from mixing the way shutter speeds are described... a 180 shutter rule is NOT a time measurement, it is a measurement of an arc of a circle. Which DIRECTLY relates to the way the circular shutter is mechanically linked to the frame advancing mechanism of a motion picture camera. A 180 (degree) shutter is "half" a circle (360/2=180), which means that the frame is exposed for "half" the time the frame of film is in behind the lens.
So for 24p that = 1/24th of a second (for each frame remember) divided by 2 (half the available time) which is.. drum roll please.. 1/48th of a second.
I use shutter speed to help with exposure. I leave my frame rate on 24p. And increase the shutter speed to help in REALLY bright situations (where stopping down will lose my shallow DOF) sure, its a trade off with the silky smooth motion vs. the saving private ryan thing.. but meh.. im a noob so I dont care..
In regards to High Frames rates like 1000FPS I think that at that speed the film camera tech is different, rotating prisms etc, and it would be illogical to work with 180 degree shutter. Plus, if your filming at that rate, likely your goal has nothing to do with capturing a pleasing motion blur. which is the whole argument for 180 degree (or 1/48th of a second at 24p) shutter.. people like the blur of it..
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After a 3 day hiatus that was forced on me by losing my internet connect, im back!
heres a link for u cracker:
http://blog.tylerginter.com/?p=385
have u come across this on google yet? i skimmed thru it and it looks helpful.
heres a link for u cracker:
http://blog.tylerginter.com/?p=385
have u come across this on google yet? i skimmed thru it and it looks helpful.
You are wrong
Sorry.As Wheat just wrote, it's about the EXPOSURE time in relation to the FRAME RATE.
This equation of SHUTTER SPEED to FRAME RATE has two distinct affects.
#1. How much light you need to get a decent exposure in that amount of time. Lower shutter speeds mean the shutter is open longer and you need less light to expose the frame in that time.
#2. The amount of "blur" is recorded to each frame.
at 1/24th shutter at 24Fps gives way too much motion blur and anything moving in the frame get smudgy. Similarly, when you do the shutter speed over 1/100th like SAVING PRIVATE RYAN with no motion blur, it has a completely different look to it and it's more staccato and sharp.
1/48th shutter for 24 Frames Per Second is the right balance between motion blur and focus on moving images that most people generally accept as a natural look for film and video.
So your shutter speed and frame rates combine to affect the image greatly, whether it's film or video.
Thanks for the responses, guys. I'm going to ask you to keep an open mind to the argument I'm about to make. I'm afraid none of you has offered a valid argument to answer my question, in my opinion. I'm glad it's you guys who answered my inquiry, because you're on the short list of the people I respect the most on this forum. However, I think this is one of those cases in which people follow something because it is so entrenched, but nobody ever questions why we follow the standard.
Imagine you're the guy who's inventing the first motion picture camera. Maybe, your first instinct might be to just leave the shutter open. Oh, no, it's too blurry! Okay, let's try less exposure. What shape do you think we should make the shutter?
Do you think that first camera-maker was considering shutter speed? On a hand-cranked camera? Or, do you think it's more reasonable that they decided that the most logistically feasible construction would be a 180-degree rotating shutter? Hmm, that looks better, let's stick with that.
Am I seriously supposed to believe that there is some magical quality about an individual frame that is exposed for exactly one half of the amount of time that it will be seen on-screen?
I'm
Not
Buying
It.
It's arbitrary. Completely arbitrary. The 180 shutter rule is bogus. It's a nice rule-of-thumb, to stick around a particular range of shutter speeds, if you want your footage to appear fluid. But to say that there's some magical relationship between frame rate and shutter speed is baseless. I'm still waiting for a logical explanation as to how one has anything to do with the other.
Do you take your frame rate into consideration, when selecting your ISO? No?
Do you take your aperture into consideration, when selecting your frame rate? No?
Aperture, ISO, and shutter speed all effect each other. Frame rate doesn't belong in the conversation. I'm sorry, but I'm gonna have to get really nerdy in my response to each of your answers.
So far, all you've explained is that frame rate and shutter speed are two different functions, entirely independent of each other. And, you've explained motion blur, which I assume every single person in this conversation is already well aware of.
I don't think I ever gave any indication that I thought the 180 shutter rule was a time measurement. Besides, you're talking about film, and that's a big part of the problem. We're dealing with new technology -- unless truly justified, there's no reason to follow the age-old standards of film, and so far, you've given no justification to the 180 shutter rule.
Yeah. wheat, I hope you wrote this for the benefit of all the newbs. I freely admit when there's something technical that I don't get (like, CMOS, earlier in this conversation). But dude, understanding CMOS doesn't really affect what a filmmaker does on set. But frame rate and shutter speed -- any filmmaker (especially one using DSLR) better damn-well have at least a basic understanding of both of these functions on their camera. I'm gonna give you the benefit of the doubt, and assume that you know you haven't taught me anything in this respect.
Of course I read it. It does a nice job of explaining the 180 shutter rule, and what it means, mechanically, on a film camera. It also nicely explains motion blur, or lack thereof.
But it says absolutely nothing about why we should follow this rule, on our DSLR's. The 180 shutter rule gets us into the ballpark of where we should stay, if we want fluid motion. But I see absolultely no reason as to why someone shooting 24p is better off at 1/50, instead of 1/60. Likewise, I see no reason why someone shooting at 30p is better of at 1/60, instead of 1/50. For that matter, I think 1/80 is perfectly suitable for either, with barely a difference.
Two distinct effects -- exactly! It is definitely about exposure time. And, it is definitely about frame rate. You've stated that they are related to each other, but you haven't explained how they are related to each other. That's because they're not. As you yourself said, they are two distinct effects.
Sorry, dude. You kinda just wrote a more succinct version of wheatgrinder's post. But you've not answered the question.
Check out this test-footage. In each of these clips, you can see a clear difference in motion-blur, as the footage progresses, from 1/50, to 1/60, 1/100, 1/160, and 1/500, respectively. I kinda just shot the 1/160 and 1/500 for shits-and-giggles. For purposes of this conversation, I think it safe to assume that none of us are shooting at such extremely fast shutter speeds, unless for some crazy dramatic effect.
Without cheating, can you figure out which clip was shot at 24p? Which one was shot at 30p? Or, did I pull a classic Cracker Funk trickeration, and shoot both of them at the same frame rate? In all honesty, can you really tell me that there is a big difference between one and the other?
Try not to be too distracted by the beautiful pups. The tan pit is my neighbor's. The other two are mine.
http://www.vimeo.com/14875805
http://www.vimeo.com/14875789
I win.
Imagine you're the guy who's inventing the first motion picture camera. Maybe, your first instinct might be to just leave the shutter open. Oh, no, it's too blurry! Okay, let's try less exposure. What shape do you think we should make the shutter?
Do you think that first camera-maker was considering shutter speed? On a hand-cranked camera? Or, do you think it's more reasonable that they decided that the most logistically feasible construction would be a 180-degree rotating shutter? Hmm, that looks better, let's stick with that.
Am I seriously supposed to believe that there is some magical quality about an individual frame that is exposed for exactly one half of the amount of time that it will be seen on-screen?
I'm
Not
Buying
It.
It's arbitrary. Completely arbitrary. The 180 shutter rule is bogus. It's a nice rule-of-thumb, to stick around a particular range of shutter speeds, if you want your footage to appear fluid. But to say that there's some magical relationship between frame rate and shutter speed is baseless. I'm still waiting for a logical explanation as to how one has anything to do with the other.
Do you take your frame rate into consideration, when selecting your ISO? No?
Do you take your aperture into consideration, when selecting your frame rate? No?
Aperture, ISO, and shutter speed all effect each other. Frame rate doesn't belong in the conversation. I'm sorry, but I'm gonna have to get really nerdy in my response to each of your answers.
So far, all you've explained is that frame rate and shutter speed are two different functions, entirely independent of each other. And, you've explained motion blur, which I assume every single person in this conversation is already well aware of.
I don't think I ever gave any indication that I thought the 180 shutter rule was a time measurement. Besides, you're talking about film, and that's a big part of the problem. We're dealing with new technology -- unless truly justified, there's no reason to follow the age-old standards of film, and so far, you've given no justification to the 180 shutter rule.
Yeah. wheat, I hope you wrote this for the benefit of all the newbs. I freely admit when there's something technical that I don't get (like, CMOS, earlier in this conversation). But dude, understanding CMOS doesn't really affect what a filmmaker does on set. But frame rate and shutter speed -- any filmmaker (especially one using DSLR) better damn-well have at least a basic understanding of both of these functions on their camera. I'm gonna give you the benefit of the doubt, and assume that you know you haven't taught me anything in this respect.
Of course I read it. It does a nice job of explaining the 180 shutter rule, and what it means, mechanically, on a film camera. It also nicely explains motion blur, or lack thereof.
But it says absolutely nothing about why we should follow this rule, on our DSLR's. The 180 shutter rule gets us into the ballpark of where we should stay, if we want fluid motion. But I see absolultely no reason as to why someone shooting 24p is better off at 1/50, instead of 1/60. Likewise, I see no reason why someone shooting at 30p is better of at 1/60, instead of 1/50. For that matter, I think 1/80 is perfectly suitable for either, with barely a difference.
You are wrong
As Wheat just wrote, it's about the EXPOSURE time in relation to the FRAME RATE.
This equation of SHUTTER SPEED to FRAME RATE has two distinct affects.
Two distinct effects -- exactly! It is definitely about exposure time. And, it is definitely about frame rate. You've stated that they are related to each other, but you haven't explained how they are related to each other. That's because they're not. As you yourself said, they are two distinct effects.
Sorry, dude. You kinda just wrote a more succinct version of wheatgrinder's post. But you've not answered the question.
Check out this test-footage. In each of these clips, you can see a clear difference in motion-blur, as the footage progresses, from 1/50, to 1/60, 1/100, 1/160, and 1/500, respectively. I kinda just shot the 1/160 and 1/500 for shits-and-giggles. For purposes of this conversation, I think it safe to assume that none of us are shooting at such extremely fast shutter speeds, unless for some crazy dramatic effect.
Without cheating, can you figure out which clip was shot at 24p? Which one was shot at 30p? Or, did I pull a classic Cracker Funk trickeration, and shoot both of them at the same frame rate? In all honesty, can you really tell me that there is a big difference between one and the other?
Try not to be too distracted by the beautiful pups. The tan pit is my neighbor's. The other two are mine.
http://www.vimeo.com/14875805
http://www.vimeo.com/14875789
I win.
there is nothing to win..
You experiments would be hard to tell apart if they were on film. Too close in tolerances.. its a bit like the 16bit vs 24 bit audio debate.. technical in nature but completely subjective in character..
I understand that your saying that you don't have to care about frame rate and shutter speed. True, you don't have to.
Some folks do...
the makers of cameras certainly do, and people who work with cameras for a paycheck do, but you don't have to.
As long as C=186,000MPS (approximate) shutter speed and frame rate will have "something" to do with each other.
ISO translate to sensor sensitivity, higher sensitivity comes at the cost of increased noise.
You, as the intelligent observer in this equation must collapse the wave function of probability to arrive at a pleasing image. How you arrive at your final solution is your choice, but you "canna change the laws of physics capin," and thus will be bound by the same universal constants as the rest of us. Ignore them at your peril!
You experiments would be hard to tell apart if they were on film. Too close in tolerances.. its a bit like the 16bit vs 24 bit audio debate.. technical in nature but completely subjective in character..
I understand that your saying that you don't have to care about frame rate and shutter speed. True, you don't have to.
Some folks do...
the makers of cameras certainly do, and people who work with cameras for a paycheck do, but you don't have to.
As long as C=186,000MPS (approximate) shutter speed and frame rate will have "something" to do with each other.
ISO translate to sensor sensitivity, higher sensitivity comes at the cost of increased noise.
You, as the intelligent observer in this equation must collapse the wave function of probability to arrive at a pleasing image. How you arrive at your final solution is your choice, but you "canna change the laws of physics capin," and thus will be bound by the same universal constants as the rest of us. Ignore them at your peril!
"to create the famous stuttery, strobing effect."
Which I think looks like complete crap. Was in a festival recently and several of the other films had it (not sure it was intentional on their part), mostly noticed it in exteriors with a lot of light.
Which I think looks like complete crap. Was in a festival recently and several of the other films had it (not sure it was intentional on their part), mostly noticed it in exteriors with a lot of light.
there is nothing to win..
You experiments would be hard to tell apart if they were on film. Too close in tolerances.. its a bit like the 16bit vs 24 bit audio debate.. technical in nature but completely subjective in character..
I understand that your saying that you don't have to care about frame rate and shutter speed. True, you don't have to.
Some folks do...
the makers of cameras certainly do, and people who work with cameras for a paycheck do, but you don't have to.
As long as C=186,000MPS (approximate) shutter speed and frame rate will have "something" to do with each other.
ISO translate to sensor sensitivity, higher sensitivity comes at the cost of increased noise.
You, as the intelligent observer in this equation must collapse the wave function of probability to arrive at a pleasing image. How you arrive at your final solution is your choice, but you "canna change the laws of physics capin," and thus will be bound by the same universal constants as the rest of us. Ignore them at your peril!
I know there's nothing to win. That kinda word usage is just my style of debate -- only intended in good fun. I guess it'd be better if I added a smiley next time, just to be sure.
Anyway, thanks for this response -- no disrespect towards any of the previous posts from you or anyone else, but until now, it has almost felt to me like the response to my earnest question, "why does this matter?", has been, "because I said so." Now, finally, we're getting technical, and that's what I was hoping for.
I'm still not quite convinced, but not out of stubborn-ness, more out of freely admitting that your argument went over my head.
You're argument: "As long as C=186,000MPS (approximate) shutter speed and frame rate will have "something" to do with each other."
I don't know if I can agree or disagree with that, because I don't even know what you're saying. Could you expand on it?
Also, just because the pros think something matters doesn't mean they're correct -- even pros will follow an out-dated convention, just because it's convention. Maybe if I understood your argument more, I could finally be like, ohhhhhhh, now I see, it does matter.
Thanks.
C as in the speed of light (about 186,000 miles per second)... I was being a smart a@# .. no, say it aint so!
Though my point was that as long as light has a finite speed (sure its fast, but it does take SOME time to bounce from your subject onto your sensor) and electronics operate just this side of C by the way .... that as long as it takes time for light to travel, then it will be necessary to deal with shutter speed and frame rate as these are both time domain issues, and as I said, photographic exposure is also a time domain problem. No matter how GOOD a sensor is, it can not change the laws of physics, some time will be required to gather light. How long that light is gathered is determined by the interaction by how long the frame is available and how much of that available time is given over to the light..
The bit about collapsing wave functions is a possible answer to the whole Schrodinger Cat thing
wherein the quantum state of any particle is in a state of superposition, best described in math as a wave function, until it is "observed" at which "time" the wave function is collapsed and the state resolves to a non superposition state, yes, no, on or off.. etc.
It has bearing, off topic as heck, but any time you start talking about the real nature of light, you got to deal with the strange "particle" vs "wave" nature of light.. so the very fundamental purpose of ANY camera, DSLR or otherwise, is turning that light energy into some other form so that we can look at it later.. but what are we seeing when we see a photo?.. oh boy...
but I digress.. lol
Though my point was that as long as light has a finite speed (sure its fast, but it does take SOME time to bounce from your subject onto your sensor) and electronics operate just this side of C by the way .... that as long as it takes time for light to travel, then it will be necessary to deal with shutter speed and frame rate as these are both time domain issues, and as I said, photographic exposure is also a time domain problem. No matter how GOOD a sensor is, it can not change the laws of physics, some time will be required to gather light. How long that light is gathered is determined by the interaction by how long the frame is available and how much of that available time is given over to the light..
The bit about collapsing wave functions is a possible answer to the whole Schrodinger Cat thing
wherein the quantum state of any particle is in a state of superposition, best described in math as a wave function, until it is "observed" at which "time" the wave function is collapsed and the state resolves to a non superposition state, yes, no, on or off.. etc.
It has bearing, off topic as heck, but any time you start talking about the real nature of light, you got to deal with the strange "particle" vs "wave" nature of light.. so the very fundamental purpose of ANY camera, DSLR or otherwise, is turning that light energy into some other form so that we can look at it later.. but what are we seeing when we see a photo?.. oh boy...
but I digress.. lol
Haha! I can't believe I let that one go over my head. I thought you were giving a straight-forward answer.
Yes, it is true that shutter speed and frame rate have something to do with each other, in that, if you're shooting at, say 24p, you can't shoot any slower than 1/24 (except I've heard that some DSLRs will magically do this, which is stupid). Anyway, yeah, we can agree that your frame rate's speed is a limiting factor on how slow a shutter speed can be, for reasons of basic physics.
But, of course that wasn't really what we were talking about.
Okay, so people are probably getting tired of my rant on this one, so I'll try my best to shut up now. But until I hear a really solid technical reason, something better than "because-the-pros-do-it", I'm left to believe that this is just an out-dated rule that we all follow because we all follow it.
CF, you're right - it's pretty arbitrary. Who knows exactly what the original reason for settling on 24 frames per second at 1/48th shutter was... probably a combination of technical and economic factors that have little bearing on what we're doing now.
But regardless of why it was settled on, the fact remains that it was - and audiences have now been conditioned by nearly a century's worth of filmmaking to accept the exact amount of blur and stutter that combination produces as 'normal' for a movie. So while there's no technical reason why you should stick with that particular combination there is a practical reason to - if you stray too far from it your footage will look 'odd' to most of your audience. That's fine if you're looking for a particular effect but otherwise probably not what you're shooting for, especially if you're trying to emulate the typical look of a theatrical film.
Now as far as the precise shutter speed, you're right that it's not too critical. 1/50th is close enough to 1/48th. 1/60th probably is too. As long as you're within probably 25% either way it's not likely to produce enough of a visual difference to matter - but once you get much beyond that you risk changing the motion characteristics noticeably. Too slow and you'll get the dreaded 'video look', too fast and you get excessive stuttering of motion.
You're also right that in your samples the difference is hardly noticeable. Of course you've also got almost no motion in the frame - since frame rate and shutter speed primarily effect motion rendering I wouldn't expect to see much difference in a primarily static shot. The spinning wheel hardly counts - it's spinning fast enough to produce blur at almost all of the shutter speeds. Try the same test with a handheld shot of the dogs running around and see if the difference isn't much more noticeable.
But regardless of why it was settled on, the fact remains that it was - and audiences have now been conditioned by nearly a century's worth of filmmaking to accept the exact amount of blur and stutter that combination produces as 'normal' for a movie. So while there's no technical reason why you should stick with that particular combination there is a practical reason to - if you stray too far from it your footage will look 'odd' to most of your audience. That's fine if you're looking for a particular effect but otherwise probably not what you're shooting for, especially if you're trying to emulate the typical look of a theatrical film.
Now as far as the precise shutter speed, you're right that it's not too critical. 1/50th is close enough to 1/48th. 1/60th probably is too. As long as you're within probably 25% either way it's not likely to produce enough of a visual difference to matter - but once you get much beyond that you risk changing the motion characteristics noticeably. Too slow and you'll get the dreaded 'video look', too fast and you get excessive stuttering of motion.
You're also right that in your samples the difference is hardly noticeable. Of course you've also got almost no motion in the frame - since frame rate and shutter speed primarily effect motion rendering I wouldn't expect to see much difference in a primarily static shot. The spinning wheel hardly counts - it's spinning fast enough to produce blur at almost all of the shutter speeds. Try the same test with a handheld shot of the dogs running around and see if the difference isn't much more noticeable.
Good point. That's probably as close as we'll get to any absolute "truth" on this one.
That actually was the original plan. But on this particular day, they weren't cooperating. The neighbor's dog was there as a supposed catalyst -- normally, they all go batshit crazy when he's over. No, not that day -- they just wanted to relax in the shade.
P.S. SEAHAWKS!!!!!!!! I don't know if you're a football fan or not, but if you are, man that game was ridiculous. I was not expecting that at all. My best bud is a Niner fan, and I'm a Hawk fan. I grew up in Seattle, but spent a couple years in Palo Alto. I love the Bay Area, but love to hate the Niners.
wow this is devolving
No, what I wrote was the EQUATION, meaning COMBINATION have two distinct affects when the shutter is open for that frame rate at a different amount of time...
It's easier for you to think you won an argument when you misquote people.
This can't be any simpler than this. The shutter speed and the frame rate are very much related. If the shutter is open at 1/48th at 24 frames per second, there is less exposure than having the shutter at 1/24th at 24 frames per second... kind of half. 1/24th is double the exposure time of 1/48th when running the at 24 frames per second.
The higher the frame rate, the more open the shutter needs to be. The reason, as was already explained, was because with a higher frame rate, there is less time for the light to expose the image there is, so you have to COMPENSATE with the shutter.
Light takes time to travel. The higher the frame rate means there is less time to for light to pass through the lens and create an image.
It can't get any more basic than that. You can't have one without direct affects on the other when it comes to frame rate and shutter speed. Anyone changing the shutter will clearly see how the image gets either brighter or darker in the eyepiece or on the monitor.
No, what I wrote was the EQUATION, meaning COMBINATION have two distinct affects when the shutter is open for that frame rate at a different amount of time...
It's easier for you to think you won an argument when you misquote people.
This can't be any simpler than this. The shutter speed and the frame rate are very much related. If the shutter is open at 1/48th at 24 frames per second, there is less exposure than having the shutter at 1/24th at 24 frames per second... kind of half. 1/24th is double the exposure time of 1/48th when running the at 24 frames per second.
The higher the frame rate, the more open the shutter needs to be. The reason, as was already explained, was because with a higher frame rate, there is less time for the light to expose the image there is, so you have to COMPENSATE with the shutter.
Light takes time to travel. The higher the frame rate means there is less time to for light to pass through the lens and create an image.
It can't get any more basic than that. You can't have one without direct affects on the other when it comes to frame rate and shutter speed. Anyone changing the shutter will clearly see how the image gets either brighter or darker in the eyepiece or on the monitor.
Mmm, I dunno, dude. I think I like ItDonnedOnMe's answer better.
I didn't misquote -- my quotes were quite exact. Perhaps I
misunderstood your point, or vice versa, but I didn't misquote.
You're making a circular argument. I'm sorry, but you haven't
really stated any concrete reasons why the 180 shutter rule is
worth a damn. And, to be completely frank (and it surprises me
to say this but), I think this most recent post of yours shows
some misunderstandings about the relationships between ISO,
shutter speed, aperture and frame rate (either that, or you
understand it, but over-simplified it to the point of being meaningless).
I'm currently biting my tongue, because you're one of my favorite
contributors on this forum, and I'm thinking I might be pushing
some buttons with my contributions to this particular thread
(which is not my intent), but if you really wanna debate it, I will.
That being said, I'm happy just settling on ItDonnedOnMe's answer.
Look at that fancy animated smiley!
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