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Mike Sertic October 31st, 2009 02:14 PM

A couple questions about the future over/undercranking features

1. Will "undercranking" be available for cameras that don't specifically offer variable frame rates? For example, if the camera is outputting 1080p24 over HD-SDI, would you be able to set the nano to record in factors of 24 frames per second as 220Mb/s I-frame, such as 12/8/6/4/3/2 fps? I guess this would be like the current timelapse feature, but at faster capture rates than are currently enabled.

2. For the consumer Panasonic cams that offer overcranking like the HPX170, is the HD-SDI/HDMI output 720p60 with duplicated frames like the varicams, and then the nano would just discard the duplicate frames when recording?

3. Is this the same way the EX1 and EX3 output under/overcranked 720p footage over HD-SDI? How about in 1080p?

Aaron Newsome October 31st, 2009 02:18 PM

Hi Mark. I can't remember if FCP can do an "Add" operation of two images, but it might be able to. It would be as simple laying the two images on separate tracks in FCP and using the Add mode for the layers of video. You'd need offset the tracks by 1 frame. If you want to accumulate 3 frames, you need 3 layers, each offset by a frame and the Add mode for all layers.

I never do it FCP so I've never tried. Motion, Shake or AE is much better suited to do this type of stuff.

There's probably a dozen ways to accomplish the accumulation and blur I talk about, but at the core of this idea is the "Add" operation. This literally adds the pixels of one image to another.

Of the dozens of ways to do this, here's a quick and dirty workflow, I'd take all the ODD frames from an XDR capture and put them into new Quicktime file:

shake 01214009.MOV -fo ODD.mov -t 1-1000x2

This command takes the XDR quicktime, grabs frames every other frame of frames 1-1000, and writes them to a new Quicktime file "ODD.mov"

Then I grab the even frames:

shake 01214009.MOV -fo EVEN.mov -t 2-1000x2

Now I have two files of 500 frames each. If I add them to each other, it is a literal ADD of every pixel in the image. There will be motion blur because of the accumulation. Highlights will be blown as well. Dark areas will be gained up because of the Add. But with shake, I combine them like this:

shake ODD.mov -iadd EVEN.mov -fo BLUR.mov -t 1-500

My new file blur.mov will show the accumulation from the Add operation. Obviously if you don't want to change the frame rate, don't use every other frame, use every frame just offset the starting frame by one. If you want to accumulate more frames, do it again and increment your starting frame.

All this from the command line without ever even opening the app. Again, just one of many ways you can do this. If the Add operation doesn't suit what you're trying to do, use a different operation, like Min, Max or some other creative way to combine the frames.

Bob Willis October 31st, 2009 02:33 PM

It would be much easier to capture timelapse with one of the new DSLR cameras and an intervalometer. This offers much more control of exposure especially for night shots. Then you can put all the frames together in Quicktime Pro.

Sony's Cinealta line have a function called slow speed shutter that will allow longer exposures but motion is blurred in the frame. Works on some types of shots and not so much on others.

Aaron Newsome October 31st, 2009 02:40 PM

You're probably right Bob, but I don't have a DSLR.

Dan Keaton October 31st, 2009 02:43 PM

Quote:

Originally Posted by Mike Sertic (Post 1440829)
A couple questions about the future over/undercranking features

1. Will "undercranking" be available for cameras that don't specifically offer variable frame rates? For example, if the camera is outputting 1080p24 over HD-SDI, would you be able to set the nano to record in factors of 24 frames per second as 220Mb/s I-frame, such as 12/8/6/4/3/2 fps? I guess this would be like the current timelapse feature, but at faster capture rates than are currently enabled.

Yes, we expect that you will be able to choose 1 to 23 frames for undercranking in the camera is outputing 1080p24. And 25 to 30 if overcranking.

For 720p mode, you have a range of 1 to 60 frames per second.

Quote:

2. For the consumer Panasonic cams that offer overcranking like the HPX170, is the HD-SDI/HDMI output 720p60 with duplicated frames like the varicams, and then the nano would just discard the duplicate frames when recording?
To the best of my knowledge, most cameras (except some high-end cameras), while under or over-cranking, output all of the frames via the HD-SDI/HDMI output.

One exception may be the PDW-F800 camera. (But it is sometimes difficult to read and understand all of the camera manuals.)

Quote:

3. Is this the same way the EX1 and EX3 output under/overcranked 720p footage over HD-SDI? How about in 1080p?
I am not certain, at this moment, about the EX1/EX3. I just attempted to find this in the manuals but could not find a definitive statement about the way the HD-SDI output works while in Slow & Quick Motion.

A quick test, with an HD-SDI monitor will show how it works.

Mark Job October 31st, 2009 02:56 PM

Quote:

Originally Posted by Aaron Newsome (Post 1440834)
Hi Mark. I can't remember if FCP can do an "Add" operation of two images, but it might be able to. It would be as simple laying the two images on separate tracks in FCP and using the Add mode for the layers of video. You'd need offset the tracks by 1 frame. If you want to accumulate 3 frames, you need 3 layers, each offset by a frame and the Add mode for all layers.

I never do it FCP so I've never tried. Motion, Shake or AE is much better suited to do this type of stuff.

There's probably a dozen ways to accomplish the accumulation and blur I talk about, but at the core of this idea is the "Add" operation. This literally adds the pixels of one image to another.

Of the dozens of ways to do this, here's a quick and dirty workflow, I'd take all the ODD frames from an XDR capture and put them into new Quicktime file:

shake 01214009.MOV -fo ODD.mov -t 1-1000x2

This command takes the XDR quicktime, grabs frames every other frame of frames 1-1000, and writes them to a new Quicktime file "ODD.mov"

Then I grab the even frames:

shake 01214009.MOV -fo EVEN.mov -t 2-1000x2

Now I have two files of 500 frames each. If I add them to each other, it is a literal ADD of every pixel in the image. There will be motion blur because of the accumulation. Highlights will be blown as well. Dark areas will be gained up because of the Add. But with shake, I combine them like this:

shake ODD.mov -iadd EVEN.mov -fo BLUR.mov -t 1-500

My new file blur.mov will show the accumulation from the Add operation. Obviously if you don't want to change the frame rate, don't use every other frame, use every frame just offset the starting frame by one. If you want to accumulate more frames, do it again and increment your starting frame.

All this from the command line without ever even opening the app. Again, just one of many ways you can do this. If the Add operation doesn't suit what you're trying to do, use a different operation, like Min, Max or some other creative way to combine the frames.

....Hi Aaron:
Thank you for that lengthy explanation. My apologies here but I have absolutely Zero understanding of what you wrote. I am currently in One to One instruction for Motion and Final Cut Pro. I am a very good Avid editor, and I do have Adobe After Effects CS4, but I'm looking for instruction on that too. I am on my first MAC as well. I'm a heavily experienced PC and Avid man, but that's not enough these days.

Aaron Newsome October 31st, 2009 03:38 PM

It's not hard to understand Mark. Take an image sequence, add it to itself. This is essentially the accumulation. If the copy of itself is offset by one or more frames, the accumulation will also show blurred objects that are moving in the frame.

Mark Job October 31st, 2009 05:44 PM

Hi Aaron:
You wrote: "It's not hard to understand Mark. Take an image sequence, add it to itself. This is essentially the accumulation. If the copy of itself is offset by one or more frames, the accumulation will also show blurred objects that are moving in the frame."

.......Yup. OK. What I find the hardest thing to do sometimes is to stop thinking like an editor and to start thinking like an animator or a graphic artist.


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