From actual speed to slowmotion the same shot

[Jeremy Hughes]

Say you're shooting a film, somebody gets shot and you want to capture another person's reaction. Is there a way that you can change the frame rate from say, 24fps to 60fps in the same shot?

It would be very useful. And I've never heard anything about it.

[Michael Ragen]

They said speed ramping would be supported. We don't know the details yet.
For what you are talking about it might be best to shoot at 60 and do the ramp in post.

[damonbots]

Say you're shooting a film, somebody gets shot and you want to capture another person's reaction. Is there a way that you can change the frame rate from say, 24fps to 60fps in the same shot?

It would be very useful. And I've never heard anything about it.

You're referring to speed ramping.

and yes, I believe it will be an option

Edit: Doh!!!!!

[Joel Kaye]

Yeah, by ramping frame rates. Some cameras have a dial to change frame rates while shooting. RED should be capable, but I'm not sure I've ever seen a knob for frame rates on the body. Perhaps via USB.

[Stephen Williams]

For what you are talking about it might be best to shoot at 60 and do the ramp in post.

Hi,

That looks different to a speed ramp shot in camera IMHO.

Stephen

[Michael Ragen]

The potentiometer on the EVF is assignable so that might be an option. And I think Stewart said that the Supergrip could control shutter speeds, but I'm not sure if he meant change it while recording or not. It would be sweet if the Supergrip joystick could ramp frame rates.

[Daniel Reichenbach]

Hi,

That looks different to a speed ramp shot in camera IMHO.

Stephen

Software based speed up looks better than slow down in progressive mode. There is an advantage to do it in the camera and on the other hand, you have more control to do it afterwards.

[Hans von Sonntag]

Hi Daniel

Used optical flow stuff (The Foundry / Shake) a lot and think its a tool one should have. But the speed ramps I shot with the 435 where "better" (hard to discribe) but less accurate timing wise. Also shooting 50 fps gives you a different motion blur than eg. 20 fps. You don't have this in post (ok, you can use optical flow for motion blur...).

I once had an commercial with a drifting car. I shot it with 150 fps and that was a clever idea. Because the optical flow algorithm is calculation the hardly moving street and the fast moving car differently. The picture looked pretty odd. If I would have relied on post I would have screwed up the job (good old 35mm....).

Bottom line: Optical flow is great for may things but not for all (you have to test this before you shoot) and the ability to ramp in the camera is also good to have (especially with RED where you can instantly check your footage).

Hans

[Alexis Hanawalt]

Check out Twixtor from RE:Vision

I've used it to slow things down to 1% of their original speed and it's flawless.

[Tom Lowe]

Seems like figuring out your ramp and shooting it would be tough, whereas if you just shoot high fps and ramp in post you have more control. But that is an interesting point about blur.

[Rodrigo Lizana]

There´s no substitute for on camera speed ramping. Twixtor is a great software but it ain´t the same. Scenes with complex movement aren´t easy to ramp up or down in post. Also it´s true that it´s very common to shoot at higher frame rates and then do the "post wonders", you´ll never get such a pure ramp like when doing it on camera and on the field.
The ramps from a 435 looks fantastic no matter what the subject is doing and you can go all the way from 0.1 to 150 fps in a matter of seconds. The ramps on the Varicam goes from 4 to 60 fps and looks great to but you don´t have many control over like interval time, mark points, etc. like on the 435.
What´s very important is to have the abilty to program the ramp on the camera body but to start and stop it from a remote switch. When you´re going from say 60 to 24fps and you have to press a button on the camera to stop the ramp and keep recording at 24fps there are good chances that the shot gets moved at that point.

[Finner]

I use to ramp in the camera with the 435 a lot when it first came out but then found I just got better results shooting the whole thing at the top speed I wanted and then do the whole ramp in post. This works just as well, you have no stop or shutter issues to deal with and you can choose to the exact frame where and how fast or slow you want the ramp to take. I would recomend this as the best solution for doing ramps with a red.

[Daniel Reichenbach]

Check out Twixtor from RE:Vision

I've used it to slow things down to 1% of their original speed and it's flawless.

I use this plug-in often, but it works better on interlaced HD/PAL whatever than progressive 35mm picts. Thats why I shoot always this much frames I need for a perfect slomow and speed things up to normal framerates if needed

[Stuart English]

Ramping is in the camera spec. Start at frame rate A and end at frame rate B with an external trigger of some kind - GPI or Wireless included - to initiate the speed change. Once you get beyound that, then we need ot move to an external control system.

[JD Holloway]

Whoohoo!

2K 60 fps ramps here we come.
Now we just need a quadcore on-board processor (and maybe liquid cooling lol) so we can handle higher REDCODE data rates!

Maybe we can use the machine-gun barrel jackets from "Crossing the Line".

[Jeremy Hughes]

Ramping is in the camera spec. Start at frame rate A and end at frame rate B with an external trigger of some kind - GPI or Wireless included - to initiate the speed change. Once you get beyound that, then we need ot move to an external control system.

Can you set how long it'll take for the speed change to go from frame rate A to frame rate B in camera? Or do you just hit B (snap fingers) just like that?

[Finner]

Can you set how long it'll take for the speed change to go from frame rate A to frame rate B in camera? Or do you just hit B (snap fingers) just like that?

If you do a ramp this way unless you have a stop compensation device you will end up with very over or under expossed images.

[Alex Boothby]

You could compensation with shutter speed (in camera, electronic) rather than aperture (lens, mechanical) - although this would not look as smooth and would have ramped motion blur.

[Billy Summers]

If you do a ramp this way unless you have a stop compensation device you will end up with very over or under expossed images.

yeah, that's what's cool about using the 435 controller: it takes care of EXPOSURE.

Although I have a feeling RED is completely aware of this and will address it accordingly (if not already)

[Finner]

I see way more advantages to shooting at your top fps and doing the ramp in post. Can anyone that thinks doing the ramp in the camera is better please explain why to me?

[Alex Boothby]

Can anyone that thinks doing the ramp in the camera is better please explain why to me?

Post speed ramps are much safer (noncommittal) and more precise, but they suffer in numerous ways. The first is motion blur. When you post-speed up a shot by 200% the effect it creates is that of shooting on a 90 degree shutter. So a ramp from 48 fps to 24 fps (shot a 48 and ramped in post) would start with a 180 degree shutter look and end with a 90 degree shutter look. A far greater problem is stuttering. An old school frame based timewarp will simply omit frames during the ramp which will produce steppiness as you ease in and out of the ramp. Simple post ramps work best in solid multiples (50%, 100%, 200%, 300%, 400%...)

There are new tools available (like Motion Estimation in Flame, Fluid-Motion in Avid, and the Chronos spark by Furnace) which create little morphs between frames, effectively generating a new digital frame - this is great but has inherent problems. Render times are slow, image tearing, warpy backgrounds and render errors are frequent and the "new" digital frames are never as detailed or pure as the original source frames.

Finally we have the worst option which is field based time ramps, which have the wonderful effect of instantly making your film look like video. I remember watching the commercial for Speed 2 which was entirely sped up in post. (something to do with cruise ships not being speedy). Well the online editor chose to do all the speed ramps with field renders which made the whole film look like video. Needless to say this completely ruined the whole Speed 2 experience for me, and undoubtedly destroyed the film's critical acceptance and once again robbed Keanu of an Oscar. :ohmy:

[Adrian T.]

Needless to say this completely ruined the whole Speed 2 experience for me, and undoubtedly destroyed the film's critical acceptance and once again robbed Keanu of an Oscar. :ohmy:

The failure of Speed 2 was not due to bad speed ramps but to a ridiculously bad script. :waaa:

And by the way: Keanu wisely refused to appear in that one. :wink:

[fightordie]

Needless to say this completely ruined the whole Speed 2 experience for me, and undoubtedly destroyed the film's critical acceptance and once again robbed Keanu of an Oscar.

Keanu wasn't in Speed 2

[Alex Boothby]

You're killin' me!

[Dane Brehm]

I'm actually really surprised a no one from the AC side of things didn't pipe up with an anwser of any sort. I've spent hours on set working with a DP,Director and Talent to get a true in-camera ramp via a 435 but none the less a true in camera ramp. After you've done it a few times ( and a good 2nd) you can easily time it right using a RCU and a ICU to get the effect in camera.

Myself and my 2nd AC on "The Legend of Mary Worth" along with the DP and talent in 2 takes programmed a ramp from 24-88fps,180deg-11deg shutter ramp, iris pull from int-ext day, handheld on 100T w/85b while pulling focus on a 435. It looked great! The ramp effect was meant to represent him being poisoned and being chased from his home intercut with a flashback.

I just hope that when the time is right for RED that we'll have that same capability in a handheld or Wifi unit like a Bartech or a Arri RCU w/ remote start/stop.

[nzben]

On a film camera, running 25fps, the shutter will spin fully (360 deg) 25 times each second.

(talking PAL frame rates & angles for all you in the USA):
Presumming the shutter is set to 180 deg , the shutter is letting light fall on the negative half the time that it takes to make a full rotation (360/2 = 180).

Therefore the exposure time for this camera running 180deg shutter at 25fps is 1/50th of a second (25fps*2 = 50)

If we then set the camera to 50fps (double speed) but keep the same shutter angle of 180 deg, the shutter will be spinning a full rotation of 360 deg 50 times each second instead of 25, so the exposure time for each frame becomes 1/100th of a second (50fps*2 = 100).

Because the light comming through the lens is now falling on each frame for 1/2 the amount of time we need more light, so we open the lens apeture to compensate (in this case 1 stop)

On the Red camera shooting 25fps, to get the same exposure time for each frame as the film camera will get, the scan rate (or shutter setting) is used - set to 1/50th.

If you then set the camera to 50fps, you would also set the scan rate (shutter) to 1/100th IF you want the same characteristics as the film camera would have, and you would likewise have to compensate for light lose by opening the apeture of the lens.

.....but you dont have to, because the scan rate, can be set independently of the frame rate.

So you could have the camera capturing 50fps but still retain the 1/50th setting, which in the film world would be equivalent of a camera running 50fps with a 360 deg shutter.

What I find interesting is that the Red steps though various scan rates that equate to common shutter angles (eg 24th, 25th, 48th, 50th, 96th, 100th, etc), but is does not have a setting that relates to the cameras current top speed of 75fps (which would be 1/150th).

I won't go into too much detail on the implications of speed ramping, but if it was possible you could either ramp with a constant scan rate (which is not possible on a film camera), or the scan rate would have to be slaved to the frame speed of the camera, and be changing as the frame speed changed (essentially this is what happens on a film camera with electronic shutter doing speed ramps). I have no idea of how hard this would be to achieve electronically.

As others have pointed out, with in camera vs post ramps there is always a trade-off. Either you get the unique in-camera ramp look, or you shoot at your highest frame rate and get the complete control of a post ramp.

I would say that 95% of the shoots that I have been on where we ramped, we went for option 2.

[Michael Lindsay]

Post speed ramps are much safer (noncommittal) and more precise, but they suffer in numerous ways. The first is motion blur. When you post-speed up a shot by 200% the effect it creates is that of shooting on a 90 degree shutter. So a ramp from 48 fps to 24 fps (shot a 48 and ramped in post) would start with a 180 degree shutter look and end with a 90 degree shutter look....
:

As much as I would prefer to nail it in camera:

Most ramps I've done were exposure compensated with shutter angle so the end result is similar (ish) to dong it well in post. (I realise you can compensate with aperture as well)

Also I find that producing in-between frames (vector tracking) for a speed up is Ok.. Hard to deal with visible tearing is much more likely on a super slowmo...

The ideal for me would be to be able to nail it on the shoot with a slight aperture, shutter, gain (an animated ISO setting within meta data) compensation... Being able to tweak the ratio of these would be amazing... Anything less than at least 2 of the 3 might leave me opting for doing it in post..

As for Avid editors not setting their projects up as progressive and lazily creating field based effects (including slowmo)... I though it was a infectious epidemic back in the late 90s.. It used to amuse me that nobody seemed to notice. I don't know how many trailers/commercials/promos had the video look applied to their 35mm/S16mm content (ironic at the time with all the film look attempts on electronic capture by dropping fields)


regards

Michael

PS I believe the F23 can do electronic gain compensation..