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Blurry effect - shutter angle x fps


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Hello, 

I would like to recreate the blurry effect at the minute 0:40 on the video below. I will be using a Red Komodo. I understand I should use a shutter speed at least below 1/15  right? My main doubt is that I was reading the technical specifications of the Komodo and it says:  ¨The slowest shutter speed is 1/(recording frame rate). For example, if the recording frame rate is 23.98 fps, the slowest available shutter speed is 1/23.98 sec.¨ I have the manual and it doesnt mention if there is any fps lower than 23.98 available. Just by curiosity, I also checked the Alexa Mini menu and it displays 23.96 as the minimum fps. 

How to achieve this then? 

 

 

 

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You can't possibly have even an electronic shutter open wider than 360 degrees, so the limitation is the reciprocal of the frame rate.

That sequence was of course shot on film- it's either step-printed- you see each frame more than once, hence the freeze-frame effect- or printed from non-adjacent frames. It may even have been shot on an SLR with a motor drive.

You don't need to undercrank to get that effect- that's not how it was done. Undercranking speeds up action, it doesn't slow it down.

Edited by Mark Dunn
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As Mark said, this is step printed. At 24 fps, the longest shutter speed with a digital camera is (shutter angle at 360 degrees) is of course 1/24s. If you shoot at 8fps, the longest shutter speed is 1/8s. Then bring your footage into a 24fps timeline and each frame will be repeated 3 times, resulting in that choppy but blurred look you're after.

 

But at 1/8s exposure the motion blur will be very pronounced, so maybe choose a shorter shutter speed.

Edited by David Sekanina
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Thanks Mark and David! I was reading more pages in the menu of the Komodo, it looks like it has a recording frame rate of 11.99fps. In this case, with a 360 degree that would be 1/11.99 shutter speed and it would achieve the effect, no? 

Edited by Nathaly Pinheiro
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at 12 fps, every picture will be shown twice in a 24fps timeline - that's not very choppy. Hand drawn animations are actually shot that way, to reduce the amount of drawings. Analise the Chungking Express footage image by image and count how many times the same frame is displayed - I suspect 6 to 8 times, resulting in 3-4 fps

Edited by David Sekanina
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Given that Chungking Express was shot on film, the shutter speed was probably 1/48 (180 degree shutter). You can shoot the scene digitally also at 24fps, reinterpret the footage to a 8 fps footage in the software, and then put that 8fps footage back into a 24 fps timeline.

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I think I just get it know hahah   I was only focusing in the amount of motion blur in the scene, not actually the choppy effect. I havent heard about step printing before but I just read a little bit more about it.  

1 hour ago, David Sekanina said:

At 24 fps, the longest shutter speed with a digital camera is (shutter angle at 360 degrees) is of course 1/24s.

I was testing my sony a7iii camera and recording at 24fps I could get until 1/4 shutter speed. Is  it posible to do the same with more profesional cameras? RED and Alexa .

 

 

1 hour ago, David Sekanina said:

Given that Chungking Express was shot on film, the shutter speed was probably 1/48 (180 degree shutter). You can shoot the scene digitally also at 24fps, reinterpret the footage to a 8 fps footage in the software, and then put that 8fps footage back into a 24 fps timeline.

But how did he get the motion blur then? A 1/48  shutter speed wouldnt give this amount of blur 

Edited by Nathaly Pinheiro
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44 minutes ago, Nathaly Pinheiro said:

But how did he get the motion blur then? A 1/48  shutter speed wouldnt give this amount of blur 

The camera where the motion blur is strong moves very erratically. If I make 90 degree pan in a quarter of a second, the blur will be very pronounced even at a 48th of a second shutter speed. (I'm looking at the section around the 40 second mark)

 

EDIT: looking at it again, it was probably shot at either 4fps, 6fps on a film camera, resulting at 1/8s or 1/12s shutter speed (180 degree shutter angle of a film camera).

Do some tests with your Sony, shoot at those low frame rates and resulting shutter speeds and import the footage into a 24 fps timeline.

Edited by David Sekanina
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26 minutes ago, Nathaly Pinheiro said:

I was testing my sony a7iii camera and recording at 24fps I could get until 1/4 shutter speed. Is  it posible to do the same with more profesional cameras? RED and Alexa .

If I devide one second of time into 24 sections (that's what 24fps means), the longest shutter speed with a 360 degree shutter is 1/24s.

If I put a shutter speed of 1/4s on my camera, I can only shoot 4 frames per second. (Unless you travel at the speed of light where time behaves differently ?)

So either I don't understand you correctly, or your camera does some frame blending internally, where it combines 6 frames into one resulting in a virtual "1/4s shutter speed"

Edited by David Sekanina
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That's really beautiful stuff 0:40 to 0:50. It looks like an undercranked camera, probably 6 or 8 fps  with step printing, maybe using every second frame.  Maybe shot with an Arri II using maximum shutter angle. The step printing, the replication and the choice of skipping frames or not, is just about the look. I don't think one is obliged to realign with a 24fps timeline, though this might be a common start point.

You have enough info to just run some tests. Try to recreate how they did it with the Arri II.  If you cant undercrank slow enough, fake it with the shutter speed and try skip frame, "printing" every 2nd or 3rd frame.  Much of what you are looking for will come from the shutter speed.  And with a hand held camera following a moving subject, that subject can look surprisingly sharpish against the blurred background. 

I've just noticed that Chunking Express was made in  the 90s. I think there was a wave of backyard experimental film making using this step printing effect on DIY optical printers in the 80s. Maybe Kar-Wai Wong and Doyle were following on from that.

Enormous fun...

 

 

 

Edited by Gregg MacPherson
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1 hour ago, David Sekanina said:

shutter speed of 1/4s on my camera, I can only shoot 4 frames per second. (Unless you travel at the speed of light where time behaves differently ?)

So either I don't understand you correctly, or your camera does some frame blending internally, where it combines 6 frames into one resulting in a virtual "1/4s shutter speed"

hahahahah It got me confused too but I uploaded a screenshot of it. That´s what made me wonder if it is posible to record at 24fps with a lower shutter speed then 1/24 so I only get the blurry effect of the low shutter but not the choppy of using less frames than 24fps. Is it?
 

 

1 hour ago, David Sekanina said:

The camera where the motion blur is strong moves very erratically. If I make 90 degree pan in a quarter of a second, the blur will be very pronounced even at a 48th of a second shutter speed. (I'm looking at the section around the 40 second mark)

 

EDIT: looking at it again, it was probably shot at either 4fps, 6fps on a film camera, resulting at 1/8s or 1/12s shutter speed (180 degree shutter angle of a film camera).

Do some tests with your Sony, shoot at those low frame rates and resulting shutter speeds and import the footage into a 24 fps timeline.

I just counted and in each second of the video there are 6 images, each one repeated 4 times. 

Sure, I did some tests and 1/48, even moving very fast it wasnt as blurry as the reference. Something around 1/15 was closer. 

Edited by Nathaly Pinheiro
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12 minutes ago, Nathaly Pinheiro said:

I just counted and in each second of the video there are 6 images, each one repeated 4 times. 

Sure, I did some tests and 1/48, even moving very fast it wasnt as blurry as the reference. Something around 1/15 was closer. 

Great. That means you should shoot at 6 fps. The longest exposure time for 6fps is 1/6s. If this results in a too blurry picture, try 1/12, while still shooting 6fps, then 1/25s, still shooting 6 fps. Import these clips into a 24 fps timeline and pick the one that comes closest. If your Komodo can't shoot 6 fps, just use your DSLR in Photo mode, it can surely shoot 6 fps.

Edited by David Sekanina
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Think carefully: how can your camera capture a new image 24 times a second but have an exposure time per capture longer than 1/24th of a second?

That effect in “Chungking Express” comes from shooting at 6 or 8 fps with a 180 degree shutter angle so that the per frame blur is from 1/12 or 1/16 exposure times, plus the steppiness from having fewer motion samples per second. They shot film and step printed it but in digital, you just have to playback at the shooting speed.

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  • 5 months later...

I know this is an older post. If you're using a mirrorless cam, you can always experiment with shooting stills at a continuous frame rate and longer exposure times. You'll be limited by the buffer memory but if you play it back at 4 fps, you may have something. You should be able to import into DaVinci and an Image Sequence and adjust the frame rate accordingly.

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