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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Epic Slow Mo juttering

Ivan Kovax

Ivan Kovax

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Hey all,

I have noticed a jittering image doing a 100fps tracking shot across a line of people...

It is a high contrast situation.

Epic set at 100fps, 1/200 shutter, 800iso. Latest firmware.

I have restored the system which had no major impact...
So what do you think is going on here?

The camera is quite warm, though I doubt that is it...

Appreciated in advance!

Ivan
 
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On Both. It is clearly less pronounced on the computer, but there is still some jitter there.
 
jitter. As in the camera is shaking and it can be image stabilized. Or the footage is ruined jittering, like filming from a helicopter?

Can u post a small clip?
 
I am actually on the shoot now so I can't but I will later. Perhaps a better word is stuttering... Almost as if it was Shot at 1/1000...
 
No not at all a strobe effect... The lights are all tungsten as well, and all shutter speeds were set to a multiple of 50 (the frequency being 50hz here in Tokyo).

The closest way I could describe it without showing you video is STACATTO.
 
Bro, you are shooting 1/200. Close to 1/180 basically. That is the definition of staccato filming. Saving Private Ryan, Gladiator. It's the shutter speed they used. I personally love that look. If your still on set, try 1/48 for a quick record and see if you can still see it.
 
Will Keir said:
Bro, you are shooting 1/200. Close to 1/180 basically. That is the definition of staccato filming. Saving Private Ryan, Gladiator. It's the shutter speed they used. I personally love that look. If your still on set, try 1/48 for a quick record and see if you can still see it.
Click to expand...

Yeah, but he shot at 100 fps.
 
Will Keir said:
Bro, you are shooting 1/200. Close to 1/180 basically. That is the definition of staccato filming. Saving Private Ryan, Gladiator. It's the shutter speed they used. I personally love that look. If your still on set, try 1/48 for a quick record and see if you can still see it.
Click to expand...

You will never get 1/48th at 100fps as that combo is not humanly possible. Ever. Keep in mind shutter is usually set relative to frame rate unless your going for an effect like you mentioned. He is shooting a proper shutter with his projects fps.

Saving Private Ryan- 24fps with 45degree shutter which is 1/192.

Ivan is shooting 100fps at 45 degrees would be 1/800. But he is shooting for a 180degree shutter at 100fps which is 1/200. He is set for a 180 degree shutter.
 
So you are saying his 1/200, 100 fps choice is not a 180 degree shutter angle?

I need to lookup/read a bit more on this. at 24fps 1/180 or 1/200 is basically a 45 degree shutter. Yes? So what is Ivan's equivalent shutter angle based on his shooting choice?

Is there an equation for this reference?
 
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Will Keir said:
So you are saying his 1/200, 100 fps choice is not a 180 degree shutter angle?

I need to lookup/read a bit more on this. at 24fps 1/180 or 1/200 is basically a 180 degree shutter right? So what is Ivan's equivalent shutter angle based on his shooting choice?
Click to expand...

No. His 100fps at 1/200th is a perfect 180 degree shutter. I was explaining what the shutter speed would need to be at 100fps to match the Saving Private Ryan look you mentioned.

Its calculated by: fps x 360 (full shutter or open gate) / shutter speed to give you the corresponding shutter angle.

Therefore: 100 x 360 = 36,000 / 200 = 180 degrees
And so for: 24 x 360 = 8,640 / 48 = 180 degrees

You keep taking in terms of 24fps but he is shooting 100fps. At 24fps 1/200th is a 45 degree angle not 180.

180 degree shutter at 24fps is 1/48th. Ivan's is a 180 degree shutter at 100 fps.

The shutter speed is relative to the fps so 180 degrees at 24fps (1/48th) is different than 180 degrees at 100fps (1/200th). Both are 180 degrees but only at their respective fps. Hope that helps.
 
Will Keir said:
Bro, you are shooting 1/200. Close to 1/180 basically. That is the definition of staccato filming. Saving Private Ryan, Gladiator. It's the shutter speed they used. I personally love that look. If your still on set, try 1/48 for a quick record and see if you can still see it.
Click to expand...

Shooting at 1/48 at 100fps would equate to a 720 degree shutter, which, correct me if I am wrong is technically impossible :)
 
Ivan Kovax said:
Shooting at 1/48 at 100fps would equate to a 720 degree shutter, which, correct me if I am wrong is technically impossible :)
Click to expand...

Yeah not possible. Its only a 360 degree shutter... :)
 
Ivan,

Any luck on the strobbing? Post a R3D if you have a moment.
 
Matt Ryan said:
You will get a lot of motion blur at 1/48th at 100fps. Keep in mind shutter is usually set relative to frame rate unless your going for an effect like you mentioned. He is shooting a proper shutter with his projects fps.

Saving Private Ryan- 24fps with 45degree shutter which is 1/192.

Ivan is shooting 100fps at 45 degrees would be 1/800. But he is shooting for a 180degree shutter at 100fps which is 1/200. He is set for a 180 degree shutter.
Click to expand...

A few years ago, I was shooting a project and the director wanted the "Saving Private Ryan/Gladiator" look... I called a buddy of mine in sales, as he's an HD guru to ask how to set up my camera to emulate that look... "I'm not exactly sure... hold on and I'll get Janusz Kaminski on a conference call!" Janusz was VERY generous with his time and information... He told me "I tried using a 45 degree shutter angle, and that worked for the wide shots, but honestly, I used a 27 degree shutter angle on most of the medium and close ups... I think for a few shots we even went far more extreme like 17 or 20 degrees..."

I tried what he suggested and it came out great! Nice dude! Talent too!
 
Curt Pair said:
A few years ago, I was shooting a project and the director wanted the "Saving Private Ryan/Gladiator" look... I called a buddy of mine in sales, as he's an HD guru to ask how to set up my camera to emulate that look... "I'm not exactly sure... hold on and I'll get Janusz Kaminski on a conference call!" Janusz was VERY generous with his time and information... He told me "I tried using a 45 degree shutter angle, and that worked for the wide shots, but honestly, I used a 27 degree shutter angle on most of the medium and close ups... I think for a few shots we even went far more extreme like 17 or 20 degrees..."

I tried what he suggested and it came out great! Nice dude! Talent too!
Click to expand...

It's funny about the conference call! I had a similar experience in my Cinematography class at film school. My professor is writing a book on tools for cinematographers and their specs and how they function to get a certain look and why to use them, and Janusz called as he was one of the ASC DP's who my professor was working with on the book. So that call came in the middle of class and Janusz took the time out to answer a lot of the classes questions via conference call. He seems like a very generous and kind person. He happens to shoot amazing images as well.

That makes sense for mediums and close ups as they are less visually interesting and less detailed as the wides. You would need a stronger effect on the tighter shots to match the look of the wides.

Anyways, sorry to derail the thread!

Ivan, can we get a sample? preferably an R3D trim so we can see your meta as well as the effect.
 
Going back to the original post. The shutter does not seem to be the issue, shutter was set to 180 degrees. Without seeing the footage, my best guess is that you were tracking too fast past the people you were shooting. Even shooting slow motion playing back at 24fps, if the subject on the screen is moving too fast horizontally across the screen it will strobe. This is not a problem with the camera, this is just the facts with shooting footage at 24P or 25P.
Now this is of course without actually seeing your footage, maybe it is something else. It tends to be however, when anybody mentions strobbing/ jittering and tracking or Panning in the same sentence, moving the camera too fast is usually the culprit.
There are tricks to getting by this vulnerability of the slower frame rate of film, like having a subject move with the Pan in the foreground which focuses your eye on the subject vs the background, or just using slower pans, or even faster whip pans.
 
hey guys... thanks for your patience... i have gone straight from that shoot onto the back of another shoot so i havent had time to render anything and have been posting from my iphone... i will get something up by the weekend (if the forums arent drowned by red dragon and canon 4k announcements by then :)

thanks for all your concerns! I wanna sort this bug out!
 
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