iPhone's 240fps on a DSLR
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rottie102

Original Poster:

4,033 posts

208 months

Tuesday 9th December 2014
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I like the super slow-mo effect and would love to use it for some videos but I don't have an iPhone 6 and not planning to buy one just for that. 720p is enough for my needs.
Also the quality of filming on a full frame DSLR with a good lens will be much better than tiny iPhone's sensor.

Now, what are best/needed settings to get the best result? I'm guessing shooting at 60fps and slowing it down four times will give me 240fps equivalent but what should the shutter speed be in the first place to get best quality and silky smoothness?

RobDickinson

31,343 posts

278 months

Tuesday 9th December 2014
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Slowing it down 4 times will give you 15fps.

To get 240 fps you need to speed it up 4 times, which mostly will look ridiculous.

And you seem to be confusing resoluton (720) with framerate.

Take a step back, tell us what you want to achieve and what gear you have at the moment to do that.

_dobbo_

14,619 posts

272 months

Tuesday 9th December 2014
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If you shoot at 60fps/720p you can slow it down to 24fps which will get you about 0.4 times real speed. Slowing down any more might start to look a bit jerky, but you can give it a go.

Shutter speed isn't a factor in video, as the shutter stays open when recording.

rottie102

Original Poster:

4,033 posts

208 months

Tuesday 9th December 2014
quotequote all
RobDickinson said:
Slowing it down 4 times will give you 15fps.

To get 240 fps you need to speed it up 4 times, which mostly will look ridiculous.

And you seem to be confusing resoluton (720) with framerate.

Take a step back, tell us what you want to achieve and what gear you have at the moment to do that.
Ok, it will "look like" 240fps with quality of 15fps.

and the 720p was in reference to what my DSLR can shoot at 60fps. 1080p is only 30 or 25fps

As I mentioned - I want a SUPER Slow Motion, just like iPhone6's 240fps.

https://www.youtube.com/watch?v=eGilvHv0_bE

I have a 1Dx and a 5DMkIII but they seem to be the same in terms of Video capabilities.


Edited by rottie102 on Tuesday 9th December 16:03

Simpo Two

91,532 posts

289 months

Tuesday 9th December 2014
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You may be better off looking at camcorders. I believe that super slo-mo will knacker light sensitivity.

ecsrobin

18,532 posts

189 months

Tuesday 9th December 2014
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A GoPro or an iPhone 6 will get you the result you want wink

sgrimshaw

7,574 posts

274 months

Thursday 11th December 2014
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Can it be done using software?

Disastrous

10,202 posts

241 months

Thursday 11th December 2014
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You want Twixtor and 60fps.

Short answer is you won't get anything out the camera that approaches 240fps. It will look juddery as hell. Twixtor is a plugin that basically creates ghost frames (I think, not really studied HOW it does it) to smooth out your slomo stuff.

andrewrob

2,913 posts

214 months

Thursday 11th December 2014
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Disastrous said:
You want Twixtor and 60fps.

Short answer is you won't get anything out the camera that approaches 240fps. It will look juddery as hell. Twixtor is a plugin that basically creates ghost frames (I think, not really studied HOW it does it) to smooth out your slomo stuff.
Yes it places artificial frames between your real ones by looking at the one before and one after and effectively joining the dots.

Panasonic GH4 will do 96fps from but obviously still quite a way off of 240fps

dozen

147 posts

230 months

Thursday 11th December 2014
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You need one of these:

http://www.visionresearch.com/Products/High-Speed-...

I would suggest renting as the purchase price is rather high.

Jakg

3,970 posts

192 months

Thursday 11th December 2014
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Disastrous said:
Short answer is you won't get anything out the camera that approaches 240fps. It will look juddery as hell. Twixtor is a plugin that basically creates ghost frames (I think, not really studied HOW it does it) to smooth out your slomo stuff.
Don't ask me how, but my Sony TG3 produces slow-motion video (for only a few seconds) at a 240fps equivalent.

Quality isn't great though (Normally pin-sharp 1080i but quality drops a lot in this mode).

http://youtu.be/sx_3RoiHPUg

I think your best bet is a camcorder.

Super Slo Mo

5,373 posts

222 months

Thursday 11th December 2014
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_dobbo_ said:
Shutter speed isn't a factor in video, as the shutter stays open when recording.
Depends on the camera. Proper video/movie cameras use shutter, although I hope it's obvious that the shutter speed can't drop below the frame rate, if that makes sense.

We use the Sony FS700 on some of the televised rugby matches, it runs at 200-400 fps depending on conditions, albeit with a £15k Canon lens on the front, which has a maximum aperture of around F1.0m. The results are very good, although it's probably a bit overkill for the hobbyist. They can be rented for not too much mind you.

To get 1/4 speed out of a normal 60 fps camera isn't going to look too great, although it is possible. At 15 fps you will see the individual frames, it'll be jerky, although with the interpolating software mentioned earlier, it's probably acceptable enough.

Oh and BTW, strictly speaking you're after Hi-mo, or ultra Hi-mo, so called 'Super Slo Mo' cameras used to run at 2 - 3 times frame rate, giving a playback speed of around half to third speed.

Ignore my username also, I'm far from an expert on this subject, I just chose it 'cause I work in the industry and thought it vaguely relevant.

Bacardi

2,235 posts

300 months

Thursday 11th December 2014
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Disastrous said:
You want Twixtor and 60fps.

Short answer is you won't get anything out the camera that approaches 240fps. It will look juddery as hell.
In camera with a capable camera is best, but you can achieve some great results in twixtor. However you need to be careful of backgrounds and your set up. You can also isolate areas with masks which will fine tune the result. Typically your shutter speed is double your frame rate so that the shutter angle will give nice blur to blend the frames smoothly 25fps-1/50. For twixtor you need to shoot at 1/1000 + to give the software as much sharp info as possible, although playing anything back at normal speed shot with a high shutter speed will give very jerky playback.

This movie explains some of the pros and (potentially awful) cons of twixtor http://youtu.be/M_LE96nGqik

What you can achieve http://vimeo.com/21919856
How it was done in twixtor http://vimeo.com/23151793

Obviously you need twixtor, a platform to run it under like AE, PR, FCP etc and be au fait with the software. An iPhone 6 might be cheaper and quicker.

rottie102

Original Poster:

4,033 posts

208 months

Thursday 11th December 2014
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Bacardi said:
An iPhone 6 might be cheaper and quicker.
st, it looks that way...

How come iPhone can do it and my amazing full frame camera smile can't when normal video quality is incomparable? Is it software only?

ecsrobin

18,532 posts

189 months

Thursday 11th December 2014
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rottie102 said:
Bacardi said:
An iPhone 6 might be cheaper and quicker.
st, it looks that way...

How come iPhone can do it and my amazing full frame camera smile can't when normal video quality is incomparable? Is it software only?
A GoPro is cheaper than an iPhone.

RobDickinson

31,343 posts

278 months

Thursday 11th December 2014
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Theres a bunch of cheap P&S cameras that can do high fps. Gets more expensive if you want 240fps at 1080p or something.