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Hello all,

 

I was just curious as to what frame rate people are shooting with their Canon DSLR's? I have been shooting with 30p @ 1080p with a shutter speed of 1/60. I know that typically cinema's standard is 24p, so it got me thinking that maybe I should change. Would shooting 24p at 1/50th give a more pleasing look? I was looking at Vincent Laforet's website and this is the settings he suggests.

 

How does this change my video? What differences would I notice between the two 30p and 24p?

 

Based on other posts on Wetpixel about shutter speed, I think I understand why I need to be double the frame rate (or close to it, in the case of 24p and 1/50)

 

Any help you could give me would be appreciated.

 

Thanks in advance.

 

Dustin

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"Right Click" and then "Save Link As" to download and view the 60p vs 30p vs 24p video.

The framerate of your video is 60p so the 24p section suffers because it gets resampled by the playback software. Also the 30p section shouldn't suffer but I can see that consecutive pairs of frames are not quite identical, but in theory they should be. So it's not really a useful comparison. It would be better to produce 3 separate videos with framerates corresponding to the framerate of the footage. Also beware that many computers may drop frames during playback of a big 50p H.264 video like that, which could be misleading.

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It all depends on your finishing format. If you're shooting for a client, they'll specify a framerate for any natural history footage they need you to shoot. If you're just shooting for yourself, then it's all about your personal preference of what "look" you prefer for your footage.

 

Personally, I'm a fan of 30p. I think it gives you a little bit smoother motion than 24p, without losing that "progressive flicker" look that everyone loves about film. The nice thing about shooting at 30p, as well, is that you can do a framerate convert to 24p and slow down the footage a little bit to give it a little extra gravitas.

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Ah the ol' why 24fps question. Vincent and other topside guys shoot 24p because of the esthetic quality film had and still has. You'll have to Google the effects of 24p. 30p or 29.97p is the NTSC standard for broadcast, although they also do a pull down to 24p on TV to cater for films over "air"

Visually you'll find 24fps doesn't do well with fast action, and becomes strobic (famous examples : battle scene in Private Ryan. Less famous and so bad I still have nightmares: GI Jane). With the advent of video, such limitations don't have to limit creative mind. That's why sport broadcasts tend to be 720p/60, for smoother motion.

The forward thinking minds of hollywood are pushing towards 48fps and even 60fps, and I anticipate this day with glee!

For underwater use, 24p is ok because only really fast action like hairballs will betray strobic motion. Fast schooling fish/dolphins etc. shot up close can make it show but most people can't see the difference.

In the end, it's an esthetic choice. Just remember what Nick noted, mixing different fame rates in a single sequence without proper conforming will tend to make things pretty ugly... Or not if you don't see it! ;)

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Ah the ol' why 24fps question. Vincent and other topside guys shoot 24p because of the esthetic quality film had and still has. You'll have to Google the effects of 24p. 30p or 29.97p is the NTSC standard for broadcast, although they also do a pull down to 24p on TV to cater for films over "air"

Visually you'll find 24fps doesn't do well with fast action, and becomes strobic (famous examples : battle scene in Private Ryan. Less famous and so bad I still have nightmares: GI Jane). With the advent of video, such limitations don't have to limit creative mind. That's why sport broadcasts tend to be 720p/60, for smoother motion.

The forward thinking minds of hollywood are pushing towards 48fps and even 60fps, and I anticipate this day with glee!

For underwater use, 24p is ok because only really fast action like hairballs will betray strobic motion. Fast schooling fish/dolphins etc. shot up close can make it show but most people can't see the difference.

In the end, it's an esthetic choice. Just remember what Nick noted, mixing different fame rates in a single sequence without proper conforming will tend to make things pretty ugly... Or not if you don't see it! ;)

 

 

Thanks for that Drew. I know you have done your fair share of video with a Canon DSLR. What frame rate do you shoot at? Or does it change based on what you are filming?

 

Based on your comments. It seems to me that 30p would be best for the majority of situations. And 24p might be good for others. But.....as you and Nick said, mixing could look ugly. So it seems to me that you would want to stick with one frame rate, if you wanted to mix footage.....Which I assume is what most people shooting underwater would want to do.

 

Am I thinking this through right?

 

Dustin

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The framerate of your video is 60p so the 24p section suffers because it gets resampled by the playback software. Also the 30p section shouldn't suffer but I can see that consecutive pairs of frames are not quite identical, but in theory they should be. So it's not really a useful comparison. It would be better to produce 3 separate videos with framerates corresponding to the framerate of the footage. Also beware that many computers may drop frames during playback of a big 50p H.264 video like that, which could be misleading.

 

I had a little concern about mixing frame rates at first. So I compared the final video to the original clips over and over again to see if there were noticeable differences. The 30p sample appear "identical" to the original during playback. The 24p footage is very very close and most people simply won't be able to tell the difference. Inserting 24p footage into a 60p movie made "less of a difference" then I first thought.

 

-------------------------------------------------------------------------------

 

To the OP,

 

Shoot some 720 60p, 1080 30p, and 1080 24p clips of slow and fast moving subjects and see for yourself if you like the strobing effect of the 24p. The movie industry is pushing toward the faster 60fps and 48fps standards because filmmakers want to deliver a more lifelike and immersive experience so 24fps movies will be phased out eventually mostly because more and more movie theaters are switching to digital projectors capable of 24 to 144fps.

Edited by A.Y.

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That brings up another topic. Since the Canon can shoot at 1920x1080 or the 720p, where do most of you stand on this setting? I have always shot it using 1920 but have friends who prefer the 720 mode.

Steve

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The forward thinking minds of hollywood are pushing towards 48fps and even 60fps, and I anticipate this day with glee!

I do too... I think... but the advance screening of the Hobbit at 48fps got a lot of criticism for looking like a TV live broadcast/ too much like video etc.. There is certainly something special about 24fps when it comes to fictional storytelling. Seems like it's much more difficult to lose yourself in a fantasy story when the framerate (and res) get really high. It makes me wonder whether they might be better to simply dump alternate frames of the Hobbit. I bet the thought has crossed their minds. But I suppose the shutter angle might then be too small. I wonder what shutter angle their 48fps is shot at... Maybe they're using 360 degrees now, rather than the customary 180 degrees of 24fps footage (anyone know?), in which case it would seem to be an option.

 

So it seems to me that you would want to stick with one frame rate, if you wanted to mix footage

Not wanting to answer for Drew, but... ABSOLUTELY! Mixed framerates are a PITA and to be avoided if possible.

 

That brings up another topic. Since the Canon can shoot at 1920x1080 or the 720p, where do most of you stand on this setting? I have always shot it using 1920 but have friends who prefer the 720 mode.

Steve

1080p all the way for me, as someone who is shooting to build an archive of footage for future use. If the camera can do 60p at 720, and only 30p at 1080, I might use 720-60p for the occasional project specifically for slow motion. But I would still want to be building my general archive in 1080p. It's simply more resolution/information. Having said that, I still downsample my 1440x1080i HDV footage to 720p for YouTube delivery, rather than do the slight horizontal upscale to 1920x1080. I do that mainly for smooth playability on the widest number of systems. If I was shooting one-off videos and dumping the footage after, rather than archive it, I might well choose 720p.

 

As for the framerate, I'd go with 30p over 24p in general for underwater footage. Again it's simply more information, and more flexible in post-production for various delivery scenarios. And as blaise says, you can easily slow down 30p by 20% to 24p, which really suits a lot of underwater shots. I really want to shoot 1080-60p as my general format in the foreseeable future (unless 4k becomes mainstream really fast), and I'm hoping that becomes more commonplace in projected stills/video cameras such as the Panasonic GH3 and Canon 70D, without having to invest in a FS700/RED etc.. Having said all that, Howard Hall shoots his stock at 4k-24p, or at least he was a couple of years ago, so who knows... Maybe 5k-120fps is the only way forward... ;)

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That brings up another topic. Since the Canon can shoot at 1920x1080 or the 720p, where do most of you stand on this setting? I have always shot it using 1920 but have friends who prefer the 720 mode.

Steve

 

Horses for courses really Steve. I almost exclusively shoot at 1080, but in curtain circumstances I have shot 720 for the slomo. A good example would be Dolphins while snorkelling at the surface in a lumpy sea where you are looking at maybe only getting a few seconds in which to get a nice and steady shot. You can then conform 720p60 to p24/p25/p30 and turn what would have been junk at 1080p25 into a useable sequence. The drawback is that 720p on the Canons actually isn't that great as all of the issues with HSDLR's seem to be magnified at that resolution.

 

Just FYI although I live in PAL-land and most of my non stock customers want a PAL delivery format I've still been shooting in 1080p30 a lot lately and then conforming to 25p. You get a hardly noticeable slow down but it definitely looks more pleasing than standard 25p.

 

Cheers, Simon

 

edit - should just add that IMO if you plan to shoot 720p60 without slowing it down then stick to 1/60 shutter rather than 1/125. 1/125 works better for slomo, but I have found it looks fairly nasty at normal speed.

Edited by SimonSpear

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That brings up another topic. Since the Canon can shoot at 1920x1080 or the 720p, where do most of you stand on this setting? I have always shot it using 1920 but have friends who prefer the 720 mode.

Steve

 

I shoot 1080 60p exclusively nowadays. Unlike 24p and 30p, 60p has no limitation on shooting panning shots and fast moving subjects, and I can use Aperture Priority to control depth of field and to prevent sensor dusts from showing up at F8 or higher. Most consumer camcorders and a few Sony still cameras already feature 1080 60p AVCHD 2 HD so soon all cameras will have it.

 

Fortunately, I work in the industry that has already embraced 60fps contents so no more 24p and 30p for me. Currently the high-resolution 60fps installations available to the general public are: Douglas Trumbull showscan films, Peter Jackson's King Kong adventure at the Universal Studio (6000X2048 60p), Simpson Ride also at the Universal Studio (4K 60p), and George Lucas's Star Wars / Star Tours Adventures at Disney's themed parks. Pioneers like Peter Jackson will encounter many difficulties, moving toward the high-resolution, high-frame-rate contents - it's the natural growing pain!

 

-----------------------------------

 

One more note on inserting 24p clip into a 60p movie. FCP X arrange the 24p frames in a 3:2 sequence: frame AAA, BB, CCC, DD, EEE, FF, GGG,...... so 24frames fit neatly in a 60 frame arrangement. So every other frame is displayed 1/60 of a second shorter (or longer). Frame-rate studies done by the entertainment industry have shown that human eyes can barely, barely detect 1/48 second of a difference between frames, but not 1/60 of a second. Keep this in mind: rules and limitations that apply to the slower frame rates don't automatically apply to 60fps! The only way to find out which rule to follow is to experiment yourself and see for yourself! ;)

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I was not thinking clearly and was wrong about the playback software doing any respampling of 24p to 60p. It would of course have been done by the encoding/rendering software. Sony Vegas Pro can use the same 3:2 sequence as the 24p section of A.Y.'s clip, or the frames can be interpolated, depending how you set the "resample" switch on each clip. Doing it the 3:2 way means your clip is continuously switching between 20p and 30p so I still think one should be a little cautious if scrutinising it to make a decision on framerate choice.

 

Simon, in what way does the 1/125 at 720p60 look "nasty"?

Edited by Nick Hope

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Different subjects and different delivery change what frame rate I use. I like the look of 24/25p playback but I may capture at 24,25,30, 48, 50 or 60p depending on what it is and whether you are going to slow it down etc. Simon used good example, bumpy footage of dolphins slowed shot at 60p and slowed looks better than 1080 25p. I really am not keen on the look of 48 / 50 fps playback at all. Remeber if shooting with a 180 degree shutter you will loose light shooting at higher frame rates too.

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The issue with source clips @ lower frame rates is that the resultant interpolation of the frames which aren't there by frame blending can create nasties and the "blur" effect can be distracting. It's often not noticeable, but it's there, especially when using crappy frame blending software.

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Simon, in what way does the 1/125 at 720p60 look "nasty"?

 

Just IMO of course but I have found that if you play back at normal speeds and don't slow down the footage then you get a very similar look at 1/125 60p to what you would get shooting 1/125 30p. I've seen this on virtually any footage with movement I have shot since 720p60 first became an option. The exceptions are when shooting from a tripod with little or no movement, or when shooting for slomo when 1/125 definitely works better.

 

Cheers, Simon

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How are you playing it back? Almost sounds like it's playing back at 30p and skipping alternate frames.

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How are you playing it back? Almost sounds like it's playing back at 30p and skipping alternate frames.

 

Not really an issue with playback method, it just looks like a too fast shutter speed was used. The effect is just as you would expect to get if you doubled the shutter speed at slower frame rates - after all it is being viewed at the same speed regardless of how many frames per second you are seeing.

 

I've not seen The Hobbit screenings at 48fps, but I can imagine what the uproar is about.

 

Cheers, Simon

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That surprises me. If all of the 60fps are being displayed during playback, I'd expect it to appear smooth even if there's an ultra-fast shutter and zero motion blur on each frame.

Edited by Nick Hope

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Could just be my eyes Nick, but to me at least it isn't an attractive look when played back at 'normal' speed. Interestingly I'm very happy with shutter speeds up to 1/500 when shooting 60p for x2 slowmo. Work that one out!! ;)

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Could just be my eyes Nick, but to me at least it isn't an attractive look when played back at 'normal' speed. Interestingly I'm very happy with shutter speeds up to 1/500 when shooting 60p for x2 slowmo. Work that one out!! ;)

 

24p was chose as the framerate for film because it's the lowest framerate at which our eyes and brains detect smooth motion. Your comment makes me wonder if there's an upper limit, too, at which we can't distinguish anymore; at that point, if there's enough frames there, the shutter speed might not make a difference because our brains aren't fast enough to process the number of images separately.

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To try to answer the original poster's question, there are tradeoffs with each frame rate you choose. As others have said, if you are shooting for somebody else, then they will dictate the frame rate. If you are shooting for yourself, then you need to be aware of some limitations in the camera.

 

HD-SLR's have an upper limit on the amount of data they record per second (this is where you hear about AVCHD 2.0 28Mbps (28 million bits per second) and AVCHD 1.0 21Mbps). It is the camera's job to compress a 1920x1080x24 bit frame into a frame that can be recorded without exceeding 28 Mbps (which is just 3.5 MB/s). If you look at the raw data rate for 1080p30 (1920x1080 pixels * 24-bits color per pixel * 30 frames per second), we are talking about compressing 178 MB/s into just 3.5 MB/s, which is a little over 50:1 compression! Cameras have very sophisticated compression algorithms. The first thing they do is throw out most of the color information (which is why it is so important to white balance when recording video). After that, they do tricks like encoding only the parts of the picture that change from frame to frame. Keep in mind that in the end, the camera cannot exceed the data limit (28 Mbps, 21 Mbps, or 17 Mbps). If you have ever seen a sporting event on TV, when they show a bunch of fans jumping up and down and waving things in the air, the picture starts to break up into lots of blocks. This is what happens when the compression algorithm can't keep up with the amount of changing data from one frame to the next.

 

Ok, so why did I tell you all of that? The different frame rates you asked about all need to get compressed into one of the bit rates of the standard. Canon uses 44Mbps for both HD modes (1080p and 720p) on their HD DSLR cameras, so the compression rates are the following (by video mode):

 

1080p24: 26 to 1

1080p30: 32 to 1

720p60: 29 to 1

 

So, as you can see, the different video modes require different amounts of compression. If the scene you are recording has very little fine detail or motion, then you probably won't see any difference between the formats (as far as loss of detail due to compression), but if you are shooting something with a lot of detail and a lot of motion (say a bait ball), then the higher the compression, the more loss of detail. What you have to do is shoot some scenes in the three video modes and watch the playback to decide if the loss of detail is visible or not.

 

The advantage of 720p60 is that you can slow it down 2 to 1 for nice slow motion shots of that bait ball. Of course, you have much less resolution (1280x720 vs. 1920x1024), but from what I have read, there isn't really more than 720p actual resolution in a 1080p recording from Canon cameras. Again, you need to do some test shots to see what you think based on what you shoot and how you display it.

 

By the way, you cannot compare data rates across cameras because each has their own compression algorithm, and the quality of the compression is different. The current king of compression for consumer grade cameras is the Panasonic GH2 (when hacked). People have been recording at an astounding 190 Mbs, which for 1080p30 is a compression rate of just 7.5 to 1. Also, that camera has a very good compression algorithm, so it does a lot with those 190 Mbs. Of course, whether you need that high of a data rate depends on what you are shooting and what you want to do with the video you shoot.

 

Here are two nice reviews of the video capabilities of the Canon 60D and 7D that I found on the internet. They explain a lot of the differences between video modes:

 

http://www.imaging-resource.com/PRODS/E7D/E7DVIDEO.HTM

http://www.imaging-resource.com/PRODS/E60D/E60DVIDEO.HTM

 

I hope this helps.

 

--Mark

Edited by DrMark

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That surprises me. If all of the 60fps are being displayed during playback, I'd expect it to appear smooth even if there's an ultra-fast shutter and zero motion blur on each frame.

The higher the shutter speed in relationship to the frame interval, the bigger the gap there is between the end of one frame recording and the start of the next. If the subject you are filming is high speed, it will appear to jump between frames.

 

e.g if you are shooting at 25p, you are recording 25 frames per second, or one frame every 1/25th of a second.

 

If your shutter speed is open for 1/50th of second, the first half of the frame interval will record, the second half wont. If we go to 1/250th of a second, the first 1/10th of the frame interval will record, the last 9/10ths wont

 

If you're having trouble visualising how that would look, think of somebody running across stage with a strobe light flashing, first in an even/binary on off on off, then in an uneven on, off for long interval, on, off for long interval

 

1/2 on 1/2 off is sort of the de-juro standard (180 degree shutter angle), although opinions as always differ.

 

 

If you have a look at the following timelapse (topside, sorry!), initial shutter speed was set to 1/800th of second, ramping to 5 seconds exposure on a 7 second interval

 

Big Ben Timelapse - Shutter effect example

 

You can see massive shutter effect at the start of the sequence, the shots slowly smooth out as the shutter speed tends more towards 50% of the frame interval (i.e. shooting to 180 degree shutter angle)

Edited by bottlefish

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I know about the trade-off between frame sharpness and motion blur, with 180 degree shutter angle being "standard". But Simon says this doesn't seem to apply to 60p shot at 1/125. I had even been thinking that one might be able to reduce the shutter angle to less than 180 degrees at these higher framerates (48p and higher) and still maintain smoothness. I think blaise may have a good point. Maybe our brains can't process all of 60 frames per second, so perhaps there is some shutter speed "ceiling" between 1/60 and 1/125, faster than which motion will cease to look smooth, no matter what the fps.

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