Ramped Speed Changes?

seejay1031

seejay1031

Well-known member
After looking at every shot of the HVX I could find, I have not seen a physical switch for the fps adjustment. This probably means that the adjustment is done in a menu. :thumbdown but then I got to thinking, if the user settings buttons could be set to speed change than perhaps it could also have programable ramp speeds also. Just think of what you could do if midway through a fast motion shot, you hit a user button has preprogrammed ramp (or no ramp and an immediate jump) to 60 fps, then hit it again and back to the original fps. Does anyone know how exactly the fps will be changed, and if it can be changed mid shot? Maybe someone who works for Panasonic.
 
Fear not. The frame rate is adjusted with the +/- synchro scan buttons on the inside of the flip out LCD. They are accessible. On the VariCam, yes, it can be changed mid shot, ramped, whatever. That's because the VariCam has every frame rate between 4 and 60. I don't think it's been announced one way or another if there will be all the framerates, or only selected ones in the HVX200.

Also remember that to maintain the same exposure and depth of field characteristics, there must also be a shutter speed ramp. That's the clincher. VariCam can do that as well... But, we just don't know about the HVX yet.

A third party manufacturer does make a programmable framerate / shutter ramp controller, but it's really expensive compared to the price of an HVX200 alone.

Sit tight.
 
By "any frame rate between 4 and 60" you mean integer values I assume. DVCPRO-HD is only a 60 frame container, so it can't store 5.56 or 47.3 frames per second... can it?

-Spiff
 
Im really torn, I had just bought my DVX about 4 months ago, and even though I am in love wit it, I feel like I should have held out for the HVX, despite the excitment of this cameras realease, does anyone believe it is going to be a small upgrade from the first generation prosumer HD cams, or is this going to be the real deal?

-Matt-
 
Sorry for not being more exact. Yes, whole numbers. 4,5,6,7,8,9, etc.

It could be (?) they've chosen to reduce the number of framerates to, say HMI-safe speeds? I frankly don't have any idea. At NAB the buzz words were, "selectable framerates between 4 and 60 fps" which doesn't necessarily imply each whole number between 4 and 60. Though, it would seem extraordinary that it wouldn't include them all, especially on a camera which has defined itself as the one that leaves no feature behind...

Sfaik, 5.56 or 47.3 are not available options on VariCam. However, you can go into the engineering menu to enable 1-3 fps, but that occasionally leaves a sticky pixel and it's usually best left alone. But.. it is there for those inclined.
 
Dyrseve989 said:
Im really torn, I had just bought my DVX about 4 months ago, and even though I am in love wit it, I feel like I should have held out for the HVX, despite the excitment of this cameras realease, does anyone believe it is going to be a small upgrade from the first generation prosumer HD cams, or is this going to be the real deal?
Click to expand...
We're all expecting it to be the real deal.

Don't fret though -- just put your DVX to work. Shoot events or weddings or something. You've got four or five months between now and when the HVX comes out. All you have to do is make $200 per week with your DVX, then you'll have $4,000 towards the purchase of the HVX -- sell your DVX on ebay, put that money towards it, and you'll have your HVX free and clear.

Plus you'll have five months of business experience, an established base of clients, and you'll also have five months of shooting experience! :thumbsup:
 
BrianAWells said:
Also remember that to maintain the same exposure and depth of field characteristics, there must also be a shutter speed ramp. That's the clincher. VariCam can do that as well... But, we just don't know about the HVX yet.

A third party manufacturer does make a programmable framerate / shutter ramp controller, but it's really expensive compared to the price of an HVX200 alone.
Click to expand...

Please correct me if I am wrong, but this shouldn't be a major problem.

Unlike film, where the exposure time is governed by the shutter angle and film speed (eg 60fps will have a shorter exposure than 24fps for the same shutter angle) digital capture does not have this limitation.

The iris and shutter speed can be locked off, at say f2.8 and 1/100th and can remain that way whilst shooting at any frame rate (up to 100fps in this case due to the 1/100th sec shutter), because the exposure time is not dependant on the frame rate.

Obviously you would have to ste the shutter speed to 1/(highest shutter speed used) which could cause problems with low light levels. Also you would see the higher shutter effect (sharp without motion blur) on your standard framerate part of the shot.

Does that make sense, or is my logic incorrect?
 
Makes sense to me, mmm. Ultimately, the capability of recording speed ramps must be built-in the camera in the sense of being able to "flag" the proper frames on recording for proper pulldown extraction. (which, obviously has nothing to do with shutter speed, I know...)

Getting into this a little deeper, I wonder how editing programs deal with ramp pulldown extraction, whether it's all handled in 60p or 24p or a derivative of. Seems it would depend on your FRC playback settings (24 fps?)... Can Final Cut Pro even handle a speed ramp from VariCam? What about the standalone FRC-27... Does it handle ramps? If so, it would seem reasonable that if ramps are possible with the P2 VariAlta then it too will have to have some sort of playback ability.

Brian
 
Does pulldown even enter into it? As the adjustable fps is on the 720p P2 option, I was under the impression that there is no pulldown. In other words, every frame is placed into P2 compressed seperatly. If your shooting 48 fps, it lays down 48 frame per second, then you switch to 60 fps and it lays down 60 fps on the p2. Then when you import into your 24p nle timeline it should all just playback at 24fps by itself, and everything should playback at the speed you intended. right?
 
seejay1031 said:
I was under the impression that there is no pulldown.
Click to expand...

Yes, but only P2 can lay it down that way. The VariCam (the only video camera on the market which has selectable framerates 4 - 60 fps and speed ramps) records 60 complete frames per second to tape and the redundant frames are stripped upon capture... anything else would require a highly complex tape mechanism which would run at 56 different speeds, depending on the framerate...

Thing is, it just hasn't been done before on solid state media and I don't know how or if it will even be an option on this camera. It just seems kind of complicated to pull off, but then again, I'm not a camera engineer...

Sure hope we get it!
 
_I follow everything you guys are saying, but if someone feels like explaining, please define Ramps for me. Is it a pre-set preferred (or standard) shutter speed for each frame rate so that if you switch the fps mid-shot the camera changes with it the shutter speed?

_It is "officially" not known if the HVX will be able to switch Fps mid-shot?
 
It has not been officially discussed, as far as I know.

Speed "ramping" is the process of shooting at one frame rate, and then "ramping" to another rate -- i.e., if you're shooting at 24fps, you can "ramp" to 60fps, and depending on how long you want that ramp to take it can be instantaneous or long & drawn out. The technique was very popular in TV commercials a couple of years ago.

The VariCam is the only video camera that can do it. Some film cameras can do it, but as Wells pointed out, they need to have coordination between the shutter, iris, and frame rate all tightly controlled to keep the exposure the same throughout.
 
I asked this very question at the DVXUser meeting at NAB this year and Jan replied with much good humor that there would have to be a few features left to the VariCam, so unfortunately as of that date, the HVX200 was not intended to do speed ramps in camera.

-David C. Smith
LA / OC D.P.
www.filmstox.com
 
filmstox said:
I asked this very question at the DVXUser meeting at NAB this year and Jan replied with much good humor that there would have to be a few features left to the VariCam
Click to expand...

NOOOOOOOOOOOOOOOOO!!!!!! Say it isn't so. Jan, I demand that you respond to this lying, stinking thread and refute these claims. Please. Please. PLEEEASSEE.

man, i thought i'd found the ultimate camera, but if they are purposly leaving out certain things basic things (any film camera could do this, even a $200 K3) then no, its not the perfect camera, pretty damn good, but not perfect. And thats something panasonic will have to live with. (why can't these other companys put up a fight, at least that would push Panasonic to the next level... Sony, your useless)
 
Well you'd have to adjust the apeture at the same time to maintain exposure, (and thats like next to impossible) but ... well, damnit Brian I want to do it on the HVX, so what if its really hard on a film camera? :laugh:
 
Hi,

The HVX200 will not do a ramp. Point being is that there is not a full range of variable frame rates, like 4,5,6,7,....up to 60 which is what you would need to make this work. And since it doesn't then why put it in.

Sorry,

Jan
 
How about instead of not including ramping, make the camera do all thoose framerates and then you can include ramping too! :laugh:

That is what Sony would do :)
(Just trying to spur Jan on...lol)
 
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