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30 fps vs 60 fps in 1080p - ?? what is the difference?

post #1 of 31
Thread Starter 
hi guys...

i got my Sanyo fh1 a couple of days ago....

i shot a few test videos in 1080i 60 fps .. 1080p 60fps ... 1080p 30 fps...

i cannot tell any difference between the 60fps and 30 fps while shooting in 1080p....

there must be a difference, which i am not able to appreciate ....

can anyone shed some light on when to use which frame rate, and why we would use such settings....

the knee jerk answer would be to use the highest setting at all times... but there must be situations when the 30fps is better vs. the 60 fps...

any and all advice is welcome...
post #2 of 31
at 60, you have 60 frames a second, things should move smoothly. At 30, its 30 frames, giving things a little more jerkyness to them, it takes in a litlte more light, and gives it more of a film like appearence... Generally, shooting in 60fps is preferred
post #3 of 31
Quote:
Originally Posted by sathni View Post

hi guys...

i got my Sanyo fh1 a couple of days ago....

i shot a few test videos in 1080i 60 fps .. 1080p 60fps ... 1080p 30 fps...

i cannot tell any difference between the 60fps and 30 fps while shooting in 1080p....

there must be a difference, which i am not able to appreciate ....

can anyone shed some light on when to use which frame rate, and why we would use such settings....

the knee jerk answer would be to use the highest setting at all times... but there must be situations when the 30fps is better vs. the 60 fps...

any and all advice is welcome...

The shutter is working faster at 60fps 1/60 of a second at 30fps it's 1/30 of a second ....hence more light.

In low-light situations you should use 30fps or 24fps.

60p is great for sports and motion but should be used in outdoor situations, on bright sunny days.
post #4 of 31
Quote:
Originally Posted by sathni View Post

hi guys...

i got my Sanyo fh1 a couple of days ago....

i shot a few test videos in 1080i 60 fps .. 1080p 60fps ... 1080p 30 fps...

i cannot tell any difference between the 60fps and 30 fps while shooting in 1080p...


it's 1080i 60 *fields* per second, vs. 1080p 60 *frames* per second.

i think that somebody posted that these sanyos record at a lower bitrate in interlaced mode?
post #5 of 31
Are you sure about the shutter being 1/30 for 30fps and 1/60 for 60fps? Seems way to low for normal light at least.....


Quote:
Originally Posted by ericvonzipper View Post

The shutter is working faster at 60fps 1/60 of a second at 30fps it's 1/30 of a second ....hence more light.

In low-light situations you should use 30fps or 24fps.

60p is great for sports and motion but should be used in outdoor situations, on bright sunny days.
post #6 of 31
you probably are not seeing the difference between 30p and 60p because your computer is not fast enough to playback 24mbps AVCHD video, and skips frames. Once you burn the video file to a dvd and play it on your dvd player, you will definitely be able to see a difference between the smooth motion of 60p and the stutter of 30p.
post #7 of 31
I downloaded a Sanyo sample and it plays just fine on my MBP 3.06GHz.

How can you see a difference when converted to a DVD with framerates of 25/30?


Quote:
Originally Posted by Nintendogs View Post

you probably are not seeing the difference between 30p and 60p because your computer is not fast enough to playback 24mbps AVCHD video, and skips frames. Once you burn the video file to a dvd and play it on your dvd player, you will definitely be able to see a difference between the smooth motion of 60p and the stutter of 30p.
post #8 of 31
Medium slow pans are where you are going to notice the most difference between 30p and 60p. Not too fast, but not too slow.

Pan your cam as fast as the second hand rotates around on the clock. If you still can't tell the difference between 30p and 60p when panning like that, then just use 30p for everything. You will gain in areas of lower light, etc. and any jerkiness that is caused by it will obviously not be an issue for you.

-Suntan
post #9 of 31
hmm.. I had some doubts that if I e.g. record at 60fps and convert it to say 720p30 for youtube or similar, if they other frames would just be discarded....
post #10 of 31
It's a motion thing. I record marching band like stuff and the difference is readily evident. Just look at the spinning wheels of a car, or other things moving fast. Or if you tend to do fast pans. Things just look better at 60p, since HD tends to bring out those other quirks. It can also look worse, if you're fumbling with the hands that shaking looks like you're fast forwarding through something when you're not. Most tend to favor it because a) it gives you the option of true Full-HD slow motion and b) if you take a frame grab, you have more choices (2x's as many). I find that very useful for lightning strikes.

For me spinning flags, drums, spinning rims on a wheelchair. It also comes in handy because some things look more normal in slow motion(1/2 speed), like walking. Or if you zoomed away from something too fast, you can do the slow motion thing to make it look like you didn't. Make that 4 second appearance of your hummingbirds, last 10 seconds in slow motion at 24p.

Not that you have any gains if you convert it to 30fps (DVD). There's a stutter that we're used to that some favor as it in theory gives more of a film look. 60p gives a nice intermediate option to output 30p or 24p and not have a noticeable skipping cadence. If there's traffic in the background, you can see that when the cars magically jump locations faster than the rest of the footage. Stupid american sony cybershot shoots 640x480@25fps for some reason. Quite evident at 30fps DVD when converted. 60p is much smoother all around. If you have an option to use it. Also with two unsynced 60p cams, you're at worst 1/4 of a frame off between the two cams converted to 30p in terms of perfect sync. Not that there's much need to be that accurate most of the time.

Yes, you sacrifice some low light, but the slower frame rates on the Sanyo come with much lower bitrate codecs, so you don't gain much going with other options. And it's low light is better at 60p, than most are at 30p.
post #11 of 31
Quote:
Originally Posted by ericvonzipper View Post

The shutter is working faster at 60fps 1/60 of a second at 30fps it's 1/30 of a second ....hence more light.

In low-light situations you should use 30fps or 24fps.

60p is great for sports and motion but should be used in outdoor situations, on bright sunny days.

I believe this one sounds the closest to being correct.
from around 30fps to 60, there's very little difference depending on motion speed. Mostly, 30 fps will suffice. Jerkiness will be much more noticeable at lower speeds.

(OLD THREAD WARNING!!!!)

of course, some might not even care about this thread any-longer.

60 fps is just smoother, but depending on the amount of motion, it might not even be apparent. Frankly, the reason I want something with High Res, and High fps, is so that I can use capture frames, almost like a few photos.
1920x1080 is sometimes all the higher you need.

Bumping an old thread, I just hope no one will mind.

If capturing swimming and diving and such, you may just wanna use the 60 fps.
The only place under 30 fps you will really start noticing much with normal recording and such, is around or under 20 fps.
My Intel Web Cam I use to have was a large exception though. I believe it captured internally at 30 fps, and then transferred down to 15. It only ever did at beast, 15 fps at VCD. But it done so like most cameras do 30.


Again, I don't even know if you care anymore, as this is like years old.
post #12 of 31
I liked that you bumped this - I am still undecided in regards to whatever to get a EU 50fps camcorder or import at 60fps from the USA, in order to get better sports videos....


BTW - is any online service like you-tube or vimeo yet supporting 50/60fps?????
post #13 of 31
"60 fps is just smoother, but depending on the amount of motion, it might not even be apparent."

This is NOT the only reason for why 60fps is superior: it does not take into account the way compression is done, which is to interpolate between frames. With more frames per second errors in interpolation are fewer, so the video is cleaner in terms of artifacts (there is less change in the what is being shot between frames). The videocamera, using AVCHD, does not take 60 or 30 full snapshots per second, most of the frames are guesses about what has changed between frames. Thus for action, 60fps produces higher quality video, not just "smoother" video.
post #14 of 31
Quote:
Originally Posted by markr041 View Post

The videocamera, using AVCHD, does not take 60 or 30 full snapshots per second, most of the frames are guesses about what has changed between frames. Thus for action, 60fps produces higher quality video, not just "smoother" video.

A conventional video camera does take 60 snapshots per second.

AVCHD Lite cameras indeed shoot only 25/30 frames and record them into 50/60 stream.
post #15 of 31
Quote:
Originally Posted by Ungermann View Post

A conventional video camera does take 60 snapshots per second.

Are you talking about MJEG (or Motion JPG)?
post #16 of 31
Quote:
Originally Posted by Darkside View Post

Are you talking about MJEG (or Motion JPG)?

I am talking about pretty much any 60 Hz camcorder except for:

(1) Cheap 15fps or 30 fps ones
(2) Cinema-style 24 fps ones
post #17 of 31
I'm still a little unclear on how refresh rates relate to frame rates of the camcorders record. I thought camcorders must record at 120fps to benefit using the 120Hz TV's.

I guess I'm wrong, because manufacturers are claiming that 120Hz TV's decrease motion blur with the same content compared to 60Hz TV's.
post #18 of 31
Hi

Quote:
Originally Posted by Darkside View Post

I'm still a little unclear on how refresh rates relate to frame rates of the camcorders record. I thought camcorders must record at 120fps to benefit using the 120Hz TV's.

I guess I'm wrong, because manufacturers are claiming that 120Hz TV's decrease motion blur with the same content compared to 60Hz TV's.

120Hz TVs create extra frames by using the frames before and after, this helps avoid motion blur, which is caused by LCDs holding onto the picture longer than say Plasma or CRT TVs, and as we follow motion our eyes blur it because they are moving across a series of static pictures, so the faster frame rate with pictures that bridge the gap help avoid this problem. Other options used is to flash the back light at a high frequency (scanning backlight) so we only get a flash of each frame and persistance of vision keeps it in our minds to bridge the gaps, and so that image moves with our eyes following and blur is reduced that.

The trouble with 120Hz TVs is of course those extra frames are pure guess work and sometimes you can see some odd artefacts.

In terms of frames per second, the higher the number the higher the temporal information we have, the higher the better, but some technologies like LCD cause this other problem. Plasmas are better with motion because each frame is drawn from black and doesn't persist as long before it's torn down and rebuilt again, although this can give rise to flicker, largely eliminated now by higher Hz panels.

Regards

Phil
post #19 of 31
"A conventional video camera does take 60 snapshots per second."

Not one using AVC compression. Why don't you look that up - learn about reference frames - I, B, P frames. No modern consumer camcorders take 60 snapshots per second.
post #20 of 31
Quote:
Originally Posted by markr041 View Post

"A conventional video camera does take 60 snapshots per second."

Not one using AVC compression. Why don't you look that up - learn about reference frames - I, B, P frames. No modern consumer camcorders take 60 snapshots per second.

Mark,

When I was editing my brother and his British rifle (https://vimeo.com/36973087) I used Sony PMB to make 7 .jpg copies from what I thought were 7 separate frames, or snapshots, in the 1080p file. Then in my editor, I inserted the .jpgs like a mini slide show to create an exaggerated slow motion effect with sound on top of only 2 of the 7 frames.

PMB makes it look like I was capturing 60 "snapshots" per second when shooting at 1080p. If not, what is it doing? Does PMB somehow create new data file .jpg snapshots from 1080p data with some kind of transcoding process?

Bill

On edit: Maybe rereading your post answered my question. Is it that 1080p60 is not using AVC compression? And, that's why the files are so big compared to the HX9V's other 'quality' settings?
post #21 of 31
Some frames are true compressed snapshots and other frames use prior snapshots plus new information (changes) - not a new snapshot - to make up - fabricate - a frame. So not all frames are of the same quality. With more actual snapshots per second, differences across frames used for making artificial frames are smaller, so the made-up frames are more accurate. So, there are not 60 snapshots per second. The Hx9v and the TM900 use AVC compression. The TM900 uses a more efficient compression variant and so gets more information for the same size file (and it is harder to encode and decode).
post #22 of 31
Quote:
Originally Posted by markr041 View Post

Some frames are true compressed snapshots and other frames use prior snapshots plus new information (changes) - not a new snapshot - to make up - fabricate - a frame. So not all frames are of the same quality. With more actual snapshots per second, differences across frames used for making artificial frames are smaller, so the made-up frames are more accurate. So, there are not 60 snapshots per second. The Hx9v and the TM900 use AVC compression. The TM900 uses a more efficient compression variant and so gets more information for the same size file (and it is harder to encode and decode).

Camera section and recorder section are different parts of a camcorder.

- The camera section (lens + sensor) makes 60 snapshots.
- The recorder section is then free to throw out information that is common between the frames/fields, making P and B frames. I frames are recorded fully. A series between two I frames is a GOP. Information is reduced, not "fabricated". Nothing is "made up" unlike 120 Hz or 300 Hz TV sets that can indeed "fabricate" extra frames for smoother motion in 24p movies.

Do not confuse people with your own idea of "fabricated" frames.
post #23 of 31
It amazes me when I think what I have learned from the two of you. And, of course, others as well.

I hope to meet you in person someday. The beer, coffee, cocktails or soft drinks will be on me.

Thanks.

Bill
post #24 of 31
"Do not confuse people with your own idea of "fabricated" frames."

Sorry, your are a bit misleading: the P and B frames are "predicted" frames based on algorithms (formulas) and limited information. Like all predictions, they are artificial and contain errors. "There are lies, damn lies and b-frames."
post #25 of 31
Quote:
Originally Posted by markr041 View Post

"Do not confuse people with your own idea of "fabricated" frames."

Sorry, your are a bit misleading: the P and B frames are "predicted" frames based on algorithms (formulas) and limited information. Like all predictions, they are artificial and contain errors. "There are lies, damn lies and b-frames."

You are a bit misleading as well by saying - or at least this is how I understood it - that 60p is, basically, fake and the frames in between are "manufactured". They are not. The camera section makes 60 snapshots. These snapshots are fed to encoder, which records some of these snapshots directly and others as P or B frames.

P-frames (predicted frames) are not predicted from a thin air. Instead, the encoder takes a frame and the subsequent frame it is about to encode and compares them, trying to figure out blocks that have moved and direction of this movement. This is not prediction as common people understand it, it is finding and describing movement between the frames in a mathematical way. Here, this what BBC says:

Quote:


The simplest inter-frame prediction of the block being coded is that which takes the co-sited (i.e. the same spatial position) block from the reference picture. Naturally this makes a good prediction for stationary regions of the image, but is poor in moving areas. A more sophisticated method, known as motion-compensated inter-frame prediction, is to offset any translational motion which has occurred between the block being coded and the reference frame and to use a shifted block from the reference frame as the prediction.

One method of determining the motion that has occurred between the block being coded and the reference frame is a 'block-matching' search in which a large number of trial offsets are tested by the coder using the luminance component of the picture. The 'best' offset is selected on the basis of minimum error between the block being coded and the prediction.

http://www.bbc.co.uk/rd/pubs/papers/...paper_14.shtml

So, the original frames being encoded are REAL, not FABRICATED. They are snapped with the camera section. They are encoded in a way to reduce their size, and yes, when encoded they have errors in them, they do not look EXACTLY like the original source frames, but this is what a good encoder strives to do: to encode a real frame using prediction mechanism, achieving as much similarity as possible. Therefore, the original frame must be there.
post #26 of 31
I think we are saying the same thing - the key point I am emphasizing is the encoding errors introduced in the P and B frames. I was not saying 60p is "fake"; indeed the initial point was that 60fps is superior to 30fps precisely because of the predictive compression algorithms used in AVC.

And I hope this all has clarified what is going on for others.
post #27 of 31
Quote:
Originally Posted by markr041 View Post

....And I hope this all has clarified what is going on for others.

No wonder it takes so long to see the red "REC" when I push the little movie button on that tiny camera! It has a lot to do!
post #28 of 31
And to bring back an old topic: that's why the TM900 has a fan!
post #29 of 31
Quote:
Originally Posted by markr041 View Post

No modern consumer camcorders take 60 snapshots per second.

I thought Motion JPEG does this by using I-frame only scheme. Hence, much less compression compared to AVCHD's codec using predictive P and B frame's high compression algorithm.

The GH2 let's you choose MJPEG for I-frame only or AVCHD for IPB. Of course you'd end up with a much large file with MJPEG since it has less compression.
post #30 of 31
You are correct about mjpeg. I meant no *modern* camcorder uses a compression scheme with all I-frames (what you and I meant by snapshots), which is very inefficient for no better quality (the GH2 is a great video camera for a stills camera, but it is not as good (shallow dof aside) as a comparably-priced camcorder with video zoom lens IMHO). Mjpeg is easier to edit than AVCHD precisely because it does not have a complex compression scheme, which is why some prefer it - but it is not preferred for its video quality.
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