View Full Version : 1080p 24fps - Overcranking and timelapse Questions


Jamie Baughman
February 8th, 2008, 11:54 AM
Hi folks,

I'm going to be shooting a short for a small town's chamber of commerce this weekend and I'd like to get a couple takes on the best way to shoot a time lapse as well as overcranking for slo mo.

Shot 1 in question is a timelapse shot. This town is called Los Gatos and there's a big stone cat that I'd like to shoot against the sky for the credits. Stone cat on the right side of the frame, left and middle area of the frame filled with blue sky and clouds rolling by. So this would be my timelapse shot.

Shot 2 would be some overcranked stuff on the main pedestrian area of the downtown area.

Basically just looking for "best practices" from folks who've set up similar shots.

Thanks in advance.

Paul Joy
February 8th, 2008, 12:30 PM
For the time lapse you've got two options, you can either undercrank (S&Q Motion) to a suitable frame rate (down to 1 fps) or you can use the frame record function and have it take images at a certain rate.

For the cloud time lapse shots I did http://www.vimeo.com/480384 I under cranked to 5/25 fps. Be careful if you go slower though, I have experienced banding in the images at lower framerates.

For slowmo just overcrank, be careful to match the local AC frequency if there's lights on, so for instance O/C up to 60 in a 60hz location and you should be fine. This was done at 50/25 http://www.vimeo.com/480479 (UK is 50hz).

To over crank you'll need to shoot in 720p, just remember that when your deciding what to shoot the rest of your footage in. You'll either have to upscale the 720 to 1080 or downscale the 1080. I just shot everything at 720.

Setting shutter to 180 degrees or off should result in good footage, off will result in more motion blur but be brighter.

Do some tests firsts though!

Paul.

Jamie Baughman
February 8th, 2008, 12:42 PM
Paul,

I'm still getting acquainted with the menu, so sorry for the question if it's something obvious, but why wouldn't I be able to overcrank at 1080p?

Thanks very much for your notes, extremely helpful and your shots on Vimeo are lovely.

Eric Pascarelli
February 8th, 2008, 12:46 PM
The EX1 only lets you shoot up to 29.97 fps at 1080.

59.94 at 720.

Paul Joy
February 8th, 2008, 12:49 PM
Why wouldn't I be able to overcrank at 1080p?


No probs Jamie.

You can to a point, the camera can only capture at a frame rate of up to 30fps in 1080p. That isn't really enough for decent slow motion, but the lower res of 720p allow you to crank up to 60.

There has been lot of discussion about why the camera can't do 1080p/60, I guess it's just a hardware limitation.

Jamie Baughman
February 8th, 2008, 12:50 PM
Thanks guy.

Very helpful.

EDIT:: Have either of you experimented with upscaled 720p to 1080p? Just wandering a) what the results looked like (i.e., good/bad) and b) how you did the upscaling.

Thanks again.

Phil Bloom
February 9th, 2008, 05:02 PM
looks great. I mix 720p overcrank with 1080p stuff all the time

Sebastien Thomas
February 10th, 2008, 12:43 PM
Mixing 720p and 1080p fromp the EX1 in FCP looks great. You just have to set your sequence in either 720 or 1080, depending on the result you want.
Then add your footage, it will be automaticaly converted. no other work to do :)

Mike Barber
February 10th, 2008, 01:58 PM
Mixing 720p and 1080p fromp the EX1 in FCP looks great. You just have to set your sequence in either 720 or 1080, depending on the result you want.
Then add your footage, it will be automaticaly converted. no other work to do :)

It's really that simple? No need to go through something like Compressor? I've been wondering about the up-rezing workflow as well. Are there any artifacts or other issues?

When you say it looks great, is this just on the monitor, TV or have you seen the result on a large screen (projected)?

Phil Bloom
February 10th, 2008, 01:59 PM
using final cut 6 it really is that simple. Mixed timelines. You can have dv, hdv, xdcam, dvcprohd, pro res and uncompressed 10 bit all in the same timeline and it will play no probs!

Mike Barber
February 10th, 2008, 02:04 PM
using final cut 6 it really is that simple. Mixed timelines. You can have dv, hdv, xdcam, dvcprohd, pro res and uncompressed 10 bit all in the same timeline and it will play no probs!

That's great! Phil, have you had a chance to see your work with the EX1 projected on a large screen? I am curious to know if you can tell what is native 1080 and what was up-rezed from 720 in a 1080 project on the "big screen".

Phil Bloom
February 10th, 2008, 02:05 PM
yeah last week. It all looked pretty good and hard to tell to be honest. It's been graded well to match anyway.

Mike Barber
February 10th, 2008, 02:12 PM
yeah last week. It all looked pretty good and hard to tell to be honest. It's been graded well to match anyway.

So someone who wasn't familiar with what was what to begin with wouldn't ever know (unless they were told)? If that's the case, it sounds like having to shoot one's overcranked footage in 720p isn't a big deal in practice at all.

Phil Bloom
February 10th, 2008, 02:13 PM
no not really. ideally it would still be 1080 as there is some loss of resolution, but it's not hugely noticeable.

Michael H. Stevens
February 10th, 2008, 02:28 PM
If the lost resolution can be noticed would it give a better result to not mix the time-line but up res the clip first? Or does that introduce its own problems?

Phil Bloom
February 10th, 2008, 03:09 PM
up res how? There is software that makes sd hd...but the difference between overcrank 720 and 1080 is so subtle is wouldn't be worthwhile.

If I gave you a 1080p version of Piccadilly Furs or Dungeness you would struggle to tell any difference at all! Perhaps only thinking it's 720 because it looks like overcrank. But there were loads of shots in my Kew Gardens film that were shot 1080p and then slowed down using Twixtor and also some normal speed shot in 720p that I forgot to switch back after overcranking

Michael H. Stevens
February 10th, 2008, 07:18 PM
Thanks, and I'm happy to know real pros leave switches in the wrong position too!

John Markert
February 10th, 2008, 10:40 PM
regarding overcranking, does the practice burn more card real estate?

why overcrank when you can slo-mo in post?

Michael H. Stevens
February 11th, 2008, 01:12 AM
Because the results are better. This one of the real pro features of the EX1

Mike Barber
February 11th, 2008, 04:31 PM
why overcrank when you can slo-mo in post?

Doing slow motion in post is a cheap way of achieving the effect and the result is usually indicative. For example, I was watching (for what must be the 30th time, not kidding) The Fellowship of the Ring last night and there are a few shots in there that are tragically suffering from the obvious ugliness of doing the slo-mo in post, despite being done in Avid (for example, the shot of Gandalf right after Frodo is stabbed by the cave troll in the Moria battle scene).

AFAIK, by doing slo-mo in camera, via overcranking, you can get the same high sampling rate of the actual motion as an overcranked film camera. In post, it is more like artificially slowing playback speed.

The result of doing it in post is usually choppier motion, and a look of slowed playback speed. Contrast with in-camera which has smooth motion and a look of movement through a medium denser than air or, say, a lighter or absence of gravity (like astronauts in outer space).

There are plug-ins that allow for a better "in post" achievement of slow-mo, but you are likely to get the best results in-camera.

EDIT:
A great book, which everyone should read, is Herbert Zettl's "Sight Sound Motion: Applied Media Aesthetics" (ISBN 0-534-52677-2) It has great info about, amongst other stuff, the dimension of time in film and video. Many pros here will no doubt be familiar with Zettl's authority on the subject of production.

Alex Raskin
August 3rd, 2008, 02:02 PM
Do you know if anyone made A-B test comparison of 720p60 slowed down in post, vs 720p24 overcranked to 60 fps in camera?

I'm under impression that simply shooting 720p60, then Interpreting the footage as, say, 20fps in After Effects will result in the same smooth motion as in-cam overcranking - but without the limitations of S&Q mode such as no sound etc., thus leaving more options for post.