Overcrank of sorts...

Elton

Elton

Veteran
Hey everybody,

Here's a 1080i from the H1 shot SDI DVCPRO HD 1080i, then converted to DVCPRO HD 720 60p, and then conformed to 24p slow motion. I apologize for the underexposed clip, but it was a quick experiment late in the day and my color settings were a little off, but I thought some of you might be interested in alternative methods of slow motion.

There's a FCP DVCPRO HD 1080i 3 sec. clip for reference. The 24p slow mo clip is in h.264 QT format

www.homepage.mac.com/mrbarlowelton
 
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It will never look the same as real overcranking.
In fact we had a customer-agency two days ago who explicitely asked for filmslomotion. We showed them some really well done speedchanges in DigitalFusion , but he saw the "post look of it". He wants 32-50fps no matter what.
It is for video out, so if we get the HVX in time fine, otherwise we will rent a 16mm camera for this.

I know the SONY, Canon and even the DVX can produce decent slomo and accelerations with good postproduction, but it ain´t the same.
 
Can't say that I agree. I think it's possible to get that look but I'm going to try shooting different material in 1080i at different shutter speeds, and I think it will look very similar. I can see your point about a client wanting "film" slow motion though. The HVX does this very well.
 
Pretty nice looking footage, but I agree with alpi.. this isn't the same as the slow-motion on the HVX. Not really similar or close enough, especially if the subject is moving... and or if you are zooming. You can really tell it's done in post on that zoom move in your footage. Just doesn't look as clean..

I've been doing the post slow-mo for years with some pretty good results... but you can't get what 60fps will give you. You just don't have the info to do it.


I tell you what though, that sledding footage really brought back some unbelievable memoreis for me. I used to do that almost everyday when I lived in Montreal. That's a great way to waste a day. Where did you shoot the sleding stuff?

Thanks for the footage. The canon does look pretty darn good overall.
 
Hey Justyn,

That was up in Park City, UT. The tubing hill is a commercial operation with little tube tows you can ride up. Fun place, but not cheap. 30 bucks for an adult for up to 4 hours. Yeesh.
 
60i is just 60p with half vertical resolution. REAL 60p after you bob it. Bob deinterlacing is not processing and is not mixing fields or applying any dynamic algorithm. Nothing like 60i deinterlaced or 24F. True 1440x540 60p. Every single pixel of one of these 60 frames was taken at exactly the same time, which is the definition of progressive.

There are three drawbacks though.

1) Some lines may appear more blocky, not only due to the lower resolution but also because the lines of a field were not meant to be combined to a single frame but only to be interleaved with the other field, so they are not filtered for this use. This could be less or more visible depending in the scene. That's the main image quality drawback.

2) It is extra work. You need extra steps and proper software.

3) In some implementations there is no compensation for the fact that the two fields do not come from the same pixels. There is a difference in height of 1 pixel. This might be visible in some subjects.
 
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Good explanation limo. In all, I like the flexibility of downconverting (or cross-converting, depending on your definition) to 720p from 1080 material.

I think the H1 and HVX could intercut very well, especially in 720p.
 
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Btw, I have noticed that on the FX1 and on Canon you don't the 3rd problem. And that sensor is 960x1080 interlaced on the FX1 they say. Since you don't get that problem, could it be that the sensor is a normal square pixel sensor that works at 60hz? A 960x540 one sending out each frame as a field. The ratio is 960/540 1.77. Exactly 16:9:) But then the interlaced resolution would be far less than it is now in charts. Ok, I will quit this now, before Bob comes and this turns into a technical nightmare of a thread:)
 
Great find! Thanks for posting that link. I think Compressor does a very good intelligent deinterlace to make 60p.
 
I just saw you clip Elton. I believe nobody can tell if it came from the HVX or an interlaced camera.
 
You just replied on the wrong thread I believe. I'm surprised it looks so good and it's not even bob. It is motion compensated if 60i to 60p is not automatically bob.
 
I am very impressed Barlow. You have shown the XLH1 is a multi standard camera.

The H1 can do:
1080 60i
1080 50i
1080p 24fps
1080p 30fps
720p 24fps
720p 30fps
720p 60fps
720p Multi fps camera

Since the H1 can do over 800 lines of resolution from tests in 1080i, this can make one of the sharpest 720P 24 images out there. If you get the 50i 1080 option then you get all that 800 plus lines and can also have the sharpest 25fps 1080p of all these cameras. One reason is the core resolution of the XLH1 is so high that it allows you all these standards. Perfect for filmout and extreme resolution requirements for those that desire that.......

Wow! Keep up the good work my friend!
 
limo991 said:
You just replied on the wrong thread I believe. I'm surprised it looks so good and it's not even bob. It is motion compensated if 60i to 60p is not automatically bob.
Click to expand...

Yeah, sorry 'bout that. Yes, Compressor does do very nice motion compensation, so I think the reality is the H1 can give a nice overcrank too...given the proper treatment.
 
PappasArts said:
I am very impressed Barlow. You have shown the XLH1 is a multi standard camera.

The H1 can do:
1080 60i
1080 50i
1080p 24fps
1080p 30fps
720p 24fps
720p 30fps
720p 60fps
720p Multi fps camera
Click to expand...

Thanks Michael. The last one's a little sketchy, but possible too. One area I am sorely disappointed in the H1 is the lack of an intervalometer...but that can be achieved either tethered or in post, but it still sucks not to get time lapse in camera.
 
If you have 60p, some kind of software should choose every 2nd (30p) ,3rd (20p) ,4th(15p), 5th(12p), 6th(10p), 10th (6fps) 12th (5fps) 15th( 4p) 20th(3p) 30th(2p) and 60th (1p) to mention common variable frame rates :) Without creating/rendering new frames or dropping quality in any way. Actually ANY combination is possible. Every 7th (about 8.6p) etc. I haven't worked with low/high speed in any editor. But I believe they should implement a 1/n option for speedup without creating new frames. Or optimise speedup choices to use integer rates that have a quality and rendering time advantage,
 
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Any software that does this, i.e. automates the process? Twixtor, ReTimer?

Thanks for the input, limo.
 
Elton said:
Any software that does this, i.e. automates the process? Twixtor, ReTimer?

Thanks for the input, limo.
Click to expand...

From a programmers point of view, anything that has % input should optimise this automatically to avoid creating new frames. 200% for 30p 300% for 20p 400% for 15p 500% for 12p etc. Only a test will prove if a program interpolates even when it doesn't have to (frame skipping). You don't even need 60p for this thing. Straight 30p will do 15p, 10p, 7.5p, 6p, 5p, 4.3p, 3.75p etc.

I think Panasonic is making a big fuzz over this capability. It is certainly easier to do with a Varicam or HVX but it is not hard on interlaced cameras either if the resolution is higher (1080i compared to 720p). I have seen many variable frame rate effects from interlaced cameras in progressive output and it looks ok. A real variable frame rate (change of rate during the scene) is equally hard on HVX/varicam or an interlaced camera since you have to do this in post.
 
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