FORUMS: list search recent posts

180 shutter or 1/1000 plus for 7d slo mo

COW Forums : DSLR Video

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
peter crawford
180 shutter or 1/1000 plus for 7d slo mo
on Jan 17, 2012 at 3:19:02 am

Hi people, im shooting a music video which involves a boxing scene where the director plans on lots of slo mo shots of faces being punched/ mouth guards flying out etc.

Im still trying to decide whether to shoot the whole thing with ex3,s/ 7ds or a mixture.

What should my settings be on a 7d to deliver a 25p output?
From what i understand already i should shoot 720 50p and conform to 25p in something like cine tools for editing in fcp, but ive read varying opinions on what shutter speed to use.
50p normally requires 1/100 shutter speed to give that 180deg film look and it seems most peolpe seem to recommend those type of settings but on the other hand examples online seem to get the smothest/ clearest results by using speeds from 1/1000 to 1/ 4000.

Does it all depend on how much you want to slow it down by?

Most of my footage will likely be 720p25 1/50 ( cant see the point of shooting in 1080 if my slo mo stuff is in 720p50.

Any advice truley appreciated

Peter

paxpincer


Return to posts index

Steve Crow
Re: 180 shutter or 1/1000 plus for 7d slo mo
on Jan 17, 2012 at 3:25:41 am

Here's a point to consider in favor of filming in 1080p versus 720. It would give you the added flexibility in post to reframe your shot if you ever need to, even a bit of a zoom in capability if you think of it that way...see something distracting in the frame?...easily get rid of it.


Return to posts index

peter crawford
Re: 180 shutter or 1/1000 plus for 7d slo mo
on Jan 17, 2012 at 3:58:11 am

Thanks steve, yeh thats a fair point, do you get just as nice results resizing and exporting inside the edit as opposed to resizing in say compressor first?

Thanks

Pete

paxpincer


Return to posts index


Phil Balsdon
Re: 180 shutter or 1/1000 plus for 7d slo mo
on Jan 17, 2012 at 4:17:57 am

This is a video I shot at 720p 50p and 1/120th sec shutter speed on a Canon 7D;

Editing was done in FCS (3) with a ProRes 1280 x 720p 50fps setting. It was a bit of an experiment doing a lot of things that were not really recommended with an HDSLR.

The first four introductory shots were conformed to 25fps in Cinematools. This was then slowed another 50% in FCP 7 frame blending OFF. Not speeding up the shutter speed to faster than 1/120th (or 180 degrees) left me some blurring on the movement, which for dance leaves a smoother motion flow. There is very little actual camera movement (panning and tilting) I felt that speeding it up more would have created a strobing effect where each frame seems to step to the next (you can see a bit of that in the sharp background of the wider 4th shot as it pans left to find the next dancer). This effect is worse when the camera is panning, tilting or zooming faster as the strobing transmits to the background as well.

Having said that when I used to shoot action sport in SD with SP Betacam for a broadcast network they liked 1/400th sec shutter speed, any faster looked a bit unreal but 1/400th looked good. If you are looking for those sharp droplets of sweat coming off a boxers face a faster shutter speed will give you that, if it's a wider shot of the boxers exchanging punches and you are looking for "graceful" smooth motion effect it might look better if you choose 1/120 and leave in a little motion blurring.

You might also like to take a look at Twixtor for your slow motion post work. There's a few really nice slo-mo examples on line that have used it, but I didn't.

Let us know how you go.

Cinematographer, Steadicam Operator, Final Cut Pro Post Production.
http://philming.com.au
http://www.steadi-onfilms.com.au/


Return to posts index

Rafael Amador
Re: 180 shutter or 1/1000 plus for 7d slo mo
on Jan 17, 2012 at 3:40:00 pm

[peter crawford] "using speeds from 1/1000 to 1/ 4000."
That's toooo high shutter speed and will produce an very unnatural look. More as a fast slide show than a movie.
That will also force you to work with a very open iris, so focus will be more difficult.
for slower motion, shoot p60 instead of p50, then conform to p25.
rafael

http://www.nagavideo.com


Return to posts index

Colin McQuillan
Re: 180 shutter or 1/1000 plus for 7d slo mo
on Jan 17, 2012 at 5:54:34 pm

[Rafael Amador] "That's toooo high shutter speed and will produce an very unnatural look. More as a fast slide show than a movie."

Not necessarily.. it depends on the intended purpose. If the purpose is to get sharp clean slomo of fast action without motion blur then yes - dial up that shutter. Heading north of 1000 is probably overkill - but then again you are after catching a fast punch and slowing it down, may be you want to go that fast to eliminate any motion blur for a Twixtor slomo to 10% playback.

As I mentioned another thread do some pre-production tests and find the look and technical work flow that gives you the look you are after...

Colin McQuillan
Vancouver, B.C.



Return to posts index


peter crawford
Re: 180 shutter or 1/1000 plus for 7d slo mo
on Jan 17, 2012 at 8:09:23 pm

Ok thanks guys, so it seems that for general boxing a bit of motion blur is needed so prob go with standard 720p25 with a 1/50 shutter( or 1080 and shrink) ,for slo mo 720 50 or 60p with a 100 or 120 shutter and if i ant to achieve super crisp slow mo with sweat on the face etc i could pump it up there towards 1 thousand if i use twixtor.

Just to be absolutley clear if i shoot 60p which involves switching to ntsc mode i want face any problems when converting to 25p? dont think ill need sound sync for this scene.

Also should i just use the overcrank feature on the ex3? It appears this yields better results?

Thanks again

Peter

paxpincer


Return to posts index

Andrew Somers
Re: 180 shutter or 1/1000 plus for 7d slo mo
on Jan 17, 2012 at 9:17:39 pm

Shutter speed relates to motion blur. Common cinema cameras use a 180 degree to 220 degree (open) shutter.

At 25 fps, then means 1/50th a second (for 180 emulation) or 1/40th second (for 220 emulation).


Why shoot at 50 fps and then down convert to 25?? Unless you need to go in and out of slow mo, that makes no sense to me.

If you shoot at 50 fps and a 1/100 shutter, but then drop half the frames, it is THE SAME as shooting at 25 fps and a 1/100 shutter. This is equiv. to a 90 degree shutter. If you shoot at 1/200 it is like shooting with a 45 degree shutter.

NOTE: The battle sequences in "Saving Private Ryan" were shot with a 45 degree shutter to give it that snappy staccato look.

1/1000 shutter will essentially eliminate motion blur - if you want that for an artistic reason go for it - but do tests first, you may not like the results.


Return to posts index

peter crawford
Re: 180 shutter or 1/1000 plus for 7d slo mo
on Jan 17, 2012 at 9:26:06 pm

O.k maybe i didnt rxplain myself properly i didnt mean down convert to 25 i meant put through cinema tools to flag the metadata to tell it to play back at 25fps, my understanding is this use all 50 frames to slow down rather than fcp recreating new frames to make it slow

But yes i will do tests

Thanks

Pete

paxpincer


Return to posts index


Colin McQuillan
Re: 180 shutter or 1/1000 plus for 7d slo mo
on Jan 17, 2012 at 9:37:53 pm

[peter crawford] "my understanding is this use all 50 frames to slow down rather than fcp recreating new frames to make it slow"

Yes. If you are using FCP 7 (or lower) you need to do this other wise, when putting 50+fps footage on a 25 to 29.97fps timeline, FCP will basically throw away all the extra frames - then when you slow the footage to 50% it just blends the remaining frames instead of reintroducing the extra frames.

Colin McQuillan
Vancouver, B.C.



Return to posts index

Tom Nelson
Re: 180 shutter or 1/1000 plus for 7d slo mo
on Jan 27, 2012 at 7:22:12 pm

Also before trying Twixtor in After Effects, simply use Time Remap, then frame blend. I find that if the video was shot properly, Time Remap works pretty darn good. I'd shoot it with a shutter speed somewhat on the fast side to avoid motion blur in camera, and then add it later. You certainly can't take it away in post.

Tom Nelson
Videographer/Editor
Essex Television Group


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]