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Panasonic V750 100 fps

whenthesethings

Standard Member
This camera is supposed to record 100fps (PAL version) slow mo.

All the clips I have shot in slow mo. show up in quicktime movie inspector as 50 fps. Is this correct? I was hoping it would be 100fps so I could slow down even further to 25 fps (via editing) and it still remain smooth video.

Forgive me if I've missed something obvious but I am a newbie!

thanks

Dave
 

12harry

Distinguished Member
Hi.
There is software that can read a file and tell you all the tech.
( pse. Search, dunnow the name )
However, why not put it in an Editor and look at "Properties" 0 that should give it to you straight? It will also allow you to "stretch time" ( Movie Studio typically 3x), but it will wreck the audio . . . so make sure you have some Wildtrack at the event, to play with.

I'm getting the impression you're not entirely happy with this purchase.... did Posters here suggest this model?

Don't worry about the Newbie aspect... we're all learning over time. Have you thought of joining a Film Making Club? - that will sort out most issues, given Time.
Good luck.
 
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Terfyn

Well-known Member
FULL HD Slow Motion Video recording uses the following settings:

j Level Shot Function: Off
j [ZOOM MODE]: [Opt.Zoom 20k]
j [REC MODE]: [1080/28M]
j [HYBRID O.I.S.]: [OFF]
j [AUTO SLOW SHTR]: [OFF]
≥ The shutter speed is 1/100 or more.
≥ The number of pixels/frame rate of FULL HD Slow Motion Video recording are fixed to
1920k1080/50p.

That is the spec for the slow motion operation of the 750.
 

vkmast

Active Member
There is software that can read a file and tell you all the tech.
( pse. Search, dunnow the name )
He probably means MediaInfo.
However, why not put it in an Editor and look at "Properties" 0 that should give it to you straight? It will also allow you to "stretch time" ( Movie Studio typically 3x), but it will wreck the audio . . . so make sure you have some Wildtrack at the event, to play with.
Movie Studio "typically" lets you stretch (or compress) a video event within the range of 25% (1/4 speed) to 400% (4x).
Have you thought of joining a Film Making Club? - that will sort out most issues, given Time.
If that doesn't, Time will ;).
 

whenthesethings

Standard Member
Thanks for comments. I use Powerdirector for editing as it handles AVCHD really well. I thought the recording would be 100fps so I would then have to slow it down in PD. PD info for clip is 50 fps.

I think I understand where the 100fps claim comes from. It's slow mo when played so if I speed it up to normal speed ( x2 ) it would equate to 100fps, right?
 

grahamlthompson

In memoriam
Thanks for comments. I use Powerdirector for editing as it handles AVCHD really well. I thought the recording would be 100fps so I would then have to slow it down in PD. PD info for clip is 50 fps.

I think I understand where the 100fps claim comes from. It's slow mo when played so if I speed it up to normal speed ( x2 ) it would equate to 100fps, right?

A tad confused.

If you create a project using a 1080p50 preset, how many frames of individual video do you get in one second ?

Is each frame different to the rest. Easiest way to check this, is film using a macro setting some sort of stop watch with a sweep second hand or a digital timer like you get on a tablet or smart phone.

If you look at each frame by zooming in to frame level, is each frame different (It's common for camcorders to cheat by repeating frames, this technique makes it obvious that is what is going on) ?

As to speeding up the footage it depends what you mean. Generally if you elect to speed up footage in a editor it retains the frame rate allocated to the project. The speed up is achieved by dropping frames.
 

12harry

Distinguished Member
Testing SloMo
A stop-watch advances regularly, so the software could guess easily.

glt - do you think the test-object needs to be random?
- This will prevent any "guessed frame" ( in Software ), being the average of the two either side. My own thoughts are moving towards a form of Ishihara Test, where numerals/patterns are created by coloured random dots. For humans it tests any form of colour-blindness, but for a digital sensor it should make any "Guessed Frames" complete nonsense, whereas if the sensor really is achieving ( Say 100 fps) then each frame will be correct. ( Tested by examining a look-up table ).
This would require a slightly variable ( stable ) time-generator, so as to match the sensor correctly. The "Dots" Can be LEDs, but I've not concluded the pattern form; although a simple matrix 5x8 would be reasonably easy to construct.
Thoughts?
 

grahamlthompson

In memoriam
Testing SloMo
A stop-watch advances regularly, so the software could guess easily.

glt - do you think the test-object needs to be random?
- This will prevent any "guessed frame" ( in Software ), being the average of the two either side. My own thoughts are moving towards a form of Ishihara Test, where numerals/patterns are created by coloured random dots. For humans it tests any form of colour-blindness, but for a digital sensor it should make any "Guessed Frames" complete nonsense, whereas if the sensor really is achieving ( Say 100 fps) then each frame will be correct. ( Tested by examining a look-up table ).
This would require a slightly variable ( stable ) time-generator, so as to match the sensor correctly. The "Dots" Can be LEDs, but I've not concluded the pattern form; although a simple matrix 5x8 would be reasonably easy to construct.
Thoughts?

Why random, the sweep second hand moves in discrete increments. Footage truly shot at 100 fps will show a smooth progression of the second hand with 100 frames between two points 1 second apart. Even better is to use a digital stopwatch with a hundredth of a second display. Plenty of free ones for Android and ios tablets and phones. Interpolated frames would be obvious as there is no way the moving second hand could be recreated with that amount of accuracy (it's image is only a few pixels wide).

Simple frame doubling is very easy to spot because you have adjacent frames that are identical.

This digital timer is ideal has it has a clear 100th second display.

https://www.appbrain.com/app/stopwatch-timer/com.hybrid.stopwatch
 
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Terfyn

Well-known Member
Why worry? The Slo-Mo is very smooth.
 

grahamlthompson

In memoriam
Why worry? The Slo-Mo is very smooth.

The point is that depending how it works it could be very simple to re-create post-edit.

The slow-mo on the CX410 looks very smooth, when you actually analyse it it's clear it's simply a frame repeating algorithm (not every other frame).

If you simply shoot at 1080p50 and then time stretch in a good editor it is just as smooth and has no limit on the crude in camera effect that clearly runs out of buffer space.

Already posted how the CX410 achieves this.

If someone with the actual camera actually analysed how it works, it's more than likely any camera with 50fps capability could achieve the same effect.

Unless of course the camera really can shoot at 100fps, which seems doubtful considering the minimum shutter speed required. Depending on the available light, the max aperture of the lens and the iso/noise capability of the camera then any shutter speed slower than 1/100th of a second could not possibly capture every frame.

The fundamental is you cannot capture more frames/second than the fastest shutter speed you have for the current lighting conditions, consistent with the basic camera capability. This is the absolute speed limit, adding a high speed buffer may allow the camera video processing to keep up for a while until the buffer runs out of space.

If most any consumer camcorder can do this even in average lighting conditions, it must be cheating in some way.

So far no-one seems to want to find out how.

If someone with the camera shoots a short clip, more than willing to check how it works (not exactly rocket science) and try and reproduce.

In fact this is one area where a camera capable of 50fps can help, namely in producing smooth slowmo effects.

You cannot get over the basic physics involved.

As I already said consumer cameras have to cheat to get this sort of capability. If they do you can do the same post production without the inbuilt limitations of the camera frame buffer limits.

A video camera is simply a still camera capable of recording at high frame rates, it has the same exposure limitations as a still camera, which are second nature to any still photographer and then add the time required to compress the image (which is why a frame buffer is required). DSLR's also require a frame buffer for automatic multiple image capture, exceed the buffer then the frame capture rate drops dramatically. The difference is the amount of high speed buffer required. Compare the storage required for a 24Mp dslr compared to a 1920 x 1080 camcorder.
 
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Terfyn

Well-known Member
The camera records at 100fps (PAL) and interpolates to 200fps.

What is this rant all about? The camera, will if required, produce a Slo-Mo effect. It works and seems to work well. Of course it can be created in a PP editor but Panasonic want to sell cameras so an extra "gimmick" will do no harm.
I will probably never use the "silent movie" or "8mm movie" effects either but they are there if I want them.

You cannot get over the basic physics involved
They said you could not fly to the moon and the earth was flat. I suggest if GLT is so obsessed that he buy a V750 and find out for himself.
 

grahamlthompson

In memoriam
The camera records at 100fps (PAL) and interpolates to 200fps.

What is this rant all about? The camera, will if required, produce a Slo-Mo effect. It works and seems to work well. Of course it can be created in a PP editor but Panasonic want to sell cameras so an extra "gimmick" will do no harm.
I will probably never use the "silent movie" or "8mm movie" effects either but they are there if I want them.

You cannot get over the basic physics involved
They said you could not fly to the moon and the earth was flat. I suggest if GLT is so obsessed that he buy a V750 and find out for himself.

What rant.

Simply trying to ascertain if the camera is truly capable of recording at 100fps. As any Engineeer would do, finding out how it actually works. Sorry but simply saying it works and sticking your head in the sand isn't exactly a very sensible approach. Lot's can use computers, very few understand how they work and are able to write code to make them perform useful tasks.

It's a good job others don't share your attitude.
 

Terfyn

Well-known Member
What rant.

Simply trying to ascertain if the camera is truly capable of recording at 100fps. As any Engineeer would do, finding out how it actually works. Sorry but simply saying it works and sticking your head in the sand isn't exactly a very sensible approach. Lot's can use computers, very few understand how they work and are able to write code to make them perform useful tasks.

It's a good job others don't share your attitude.

So you are now claiming that Panasonic have lied about their camera. As a Chartered Engineer I am well aware if the need to know certain basics and to apply them. If you were really an Engineer, you would reason the matter out properly. I suggest that if the camera records at 100fps when in Slo-Mo mode and then interpolates to 200fps, it would be reasonable to assume that the camera is frame doubling.
The Slo-Mo operation is designed to be used in short bursts (for example - a golf shot) and it only allows three Slo-Mo operations in one take, this, to me, suggests a buffer of limited size.

As for "sticking my head in the sand" What a silly comment. No person knows everything and sometimes we need to take things on trust. As a Chartered Engineer I was responsible for the design and construction of high pressure gas systems. That meant I had to rely on the specifications and test results from the equipment manufacturers so, apart from a final analysis, I assumed that the kit would do as the makers claimed. Overall the performance and safety of the installation was paramount. So with the V750, I do not need to know the detail of a particular function just its performance and limitations when applied to my videos.

Perhaps we are best avoiding your particular attitude as it is clearly becoming obsessive.
 

rogs

Well-known Member
Now, now -- I can see that this is all going to end in tears before bedtime! :)

I can see both points. Like many camcorder features, it's probably presented in the 'best' light, from a sales point of view......

If it works well and it does what you expect, then there is no need to know what is actually happening....
However, I'm with glt on his view that it would be nice to know what is actually happening. I have my doubts that this camcorder is actually recording 100 full frames per second... but maybe???.......

The idea of 'frame doubling' is an annoying concept. Two of my Panasonic cameras are supposed to record 'AVCHD lite' as 720/50p. That is clearly to meet a Blu-ray standard. In reality (and it does state it it in the detailed specs) the sensor output is 25p, and each frame is 'recorded' twice. So it looks like 25p, from a motion smoothness point of view. Not good.

You can improve it quite a lot by decimating the footage by 2 and then using a (free!) AVISynth script to create a 50p version, with new interpolated frames. Looks pretty good (mostly!)

So doubtless you could do the same thing with 50p footage doubled to 100fps..... now whether the extra hassle involved doing it in software gives better results than the same thing being done 'in camera' might be an interesting experiment to check out........

In any case, these kinds of experiments are interesting to some folk, and not to others.

But they're not compulsory, so I can't see any need to fall out over the 'rights' or 'wrongs' of doing them...or not??:)
 

grahamlthompson

In memoriam
After some research despite the unhelpful comments of a certain poster.

The camera records at 100fps and saves the buffer at 25fps, thereby producing slowmo at 0.25 speed. What I can't find is how long you can film for. Not sure why any owners of this camera are reluctant to release a short clip (have they something to hide).

You can find demo footage on You-Tube and it does indeed look very smooth but without a clip it's only an impression. It would be interesting to see how this footage would look incorporated into a project containing only 1080P50 other footage.

Incidentally I worked in the CEGB/NGC operational planning department for 40 yrs, amongst a small team of specialist engineers responsible for formulating and implementing maintenance and construction access to the UK high voltage grid. It was a bit of a standing joke as I planned the line diversion work required to build the Birmingham Northern Relief road for several years on the trot. only to find the work postponed. The road in the end wasn't built until after I retired. :)

Interesting to note National Grid now also plan and operate the national gas grid in addition to the electrical one.
 

Terfyn

Well-known Member
Here is one for the obsessives. The middle section of the video is in 750 Slo-Mo.



Now there's smooth.
 

Terfyn

Well-known Member
After some research despite the unhelpful comments of a certain poster.
The camera records at 100fps and saves the buffer at 25fps, thereby producing slowmo at 0.25 speed. What I can't find is how long you can film for. Not sure why any owners of this camera are reluctant to release a short clip (have they something to hide).


Isn't it odd that now a certain poster has an example of the Slo-Mo, he is remarkably silent. Perhaps it was all for show. 'Nuff said.
 

PhilipL

Well-known Member
Hi

Thanks for comments. I use Powerdirector for editing as it handles AVCHD really well. I thought the recording would be 100fps so I would then have to slow it down in PD. PD info for clip is 50 fps.

I think I understand where the 100fps claim comes from. It's slow mo when played so if I speed it up to normal speed ( x2 ) it would equate to 100fps, right?

The camera will video 100 frames per second, so each second contains essentially 100 still images taken in a second, pretty good going. The file produced however is a normal video file that stills says "Hi, I'm a 50 frames per second video file". When it's played, it gets played like normal and we see just 50 frames per second, so it takes 2 seconds to see 1 second of the original footage, hence a 50% reduction in speed.

There is nothing to stop us slowing that down even more, for example we could over-ride the frame-rate and play it back at 25 frames per second, now it takes 4 seconds to see 1 second of the original recording.

The benefit with recording at a higher frame-rate to get slow motion is for a 50% reduction in speed you still get 50 unique frames per second, so action looks super smooth. If we just took 50 fps and slowed it by 50%, it is only 25 fps so it may not look as smooth, and if we wanted it at quarter of the speed, we are left with just 12 fps if captured at 50 fps, which would not be enough to create the illusion of smooth motion.

You could take the footage that was recording at 100 fps and speed it up to 100fps in an editing package and see it at normal speed, however this wouldn't work as most computer monitors and TVs can only display up to 60fps. So to play it back at normal speed the software would drop every other frame to get 50fps, now it would play back at normal speed, but you haven't gained anything, if anything because the encoder had to work at twice the speed to capture 100 frames per second rather than 50, the quality will not be as good as just capturing at 50fps in the first place.

Regards

Phil
 

grahamlthompson

In memoriam
After some research despite the unhelpful comments of a certain poster.
The camera records at 100fps and saves the buffer at 25fps, thereby producing slowmo at 0.25 speed. What I can't find is how long you can film for. Not sure why any owners of this camera are reluctant to release a short clip (have they something to hide).


Isn't it odd that now a certain poster has an example of the Slo-Mo, he is remarkably silent. Perhaps it was all for show. 'Nuff said.

Eh - I posted the results of what I could find out about how it works, in the absence of an actual clip to play with what else is there to say ?

I still don't know for certain how long you can film continuously at 100fps, nor if the camera interpolates to 200fps (as suggested in some reviews). Without this information it's simply not possible to say how useful or otherwise the feature is.
 

Terfyn

Well-known Member
It is useful for any practical purpose where I want to slow down movement. For example I used it to record the grandchildren jumping and leaping about - they enjoyed the results!

It is rare that you would want to record slowed action for any length of time. My short video of the second hand in reality rather boring. The movement is fairly slow anyway so additional slowing just adds to the monotony.
Where it may be more useful is in analysing a sporting movement. (I use the example of a golf shot) Any action where analysing the technique is important could benefit from the slow motion option even 'though the 750 is a rather crude tool for that job as there is only one slo-mo speed.
I still believe that Panasonic include it as a sales gimmick to push their camera over another camera of a similar specification. Its a "nice to have" that I would rarely use in any serious video work, like the Wi-Fi link which may become useful sometime for filming in the wild.
Another example that Panasonic push is the use of the camera as a baby monitor. I don't expect many mothers would leave their precious baby in the tender hands of a video camera while enjoying a night out - I could be wrong of course. But it could sell another camera.
 

grahamlthompson

In memoriam
One of my Sony camcorders already has the so called golf shot capability. It will run for just about long enough to capture a golfer making a drive shot. It's a very short burst but it's a lot slower than the indicated slow down the Panny appears to make. Is it 0.25 times (100 fps recorded at 25fps) or 0.125 times (100 fps interpolated to 200fps and recorded at 25fps) ?
 

Terfyn

Well-known Member
I suspect the 750 will give a longer sequence, effectively as long as the icon is pressed and held, but at a faster speed. The software allows three actions of the slo-mo in one continuous shot so there is a limit set by the camera. Your comments reinforce my view that this is a gimmick with limited use.
I bought the camera as a progressive step in picture and sound quality from my three year old V700 and, in that respect, I have not been disappointed. The Wi-Fi, Slo-Mo, interval timer etc. come with the package just like, with a car, you can expect power steering, air conditioning, reversing sensors and bluetooth as a norm these days.
 

rogs

Well-known Member
I'm sure this feature can be very useful, but it does rather assume that you know in advance exactly where you need the 'slo-mo' in your footage?
There may, for example, be a specific part of a sporting sequence that you would like to slow down.... but you don't know in advance exactly when the exciting bit is going to happen!
For that capability, the free program MVTools can give some very impressive results.... although it does need a bit of playing around with!
Unlimited smooth 'slo-mo', wherever you need it.. and for however long the sequence may need to be!....
But it's a bit fiddly, so most folk will probably stick with the in camera version - if you know what you need to slow down, in advance!...
 
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Terfyn

Well-known Member
There is still some confusion here. The camera records normally during a sequence, both video and audio are picked up but, when you want a slo-mo, you just press the icon on the LCD.
The camera will allow three slo-mo sequences in any one shot.
 

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