View Full Version : EX3 slow motion clip and shutter speed question.


Ofer Levy
September 7th, 2009, 04:18 AM
Hi all,

What shutter speed should I choose when shooting slow motion at 720p 60 fps played in 25 fps?
I shoot all my other work in 1080 25p with 1/50sec shutter speed.
I used to just choose the 180 degrees but I realise it actually gives me 1/120 sec which is probably too fast.
Should I go 1/50sec or 1/60sec ?

The "Moorhen Fight" clip was shot with the EX3 feeding the Flash XDR at 720 60p I-Frame only at 160Mb/s conformed in Cinema Tools to 25fps. Here too the shutter speed was set to 180 degrees. (1/120sec) I used Nikon 200-400 f4 lens with Mike Tapa's Nikon G to EX3 adaptor.

Video Gallery (http://www.oferlevyphotography.com/Videos.aspx)

Thanks in advance,

Ofer Levy Photography (http://www.oferlevyphotography.com)

Piotr Wozniacki
September 7th, 2009, 05:06 AM
Ofer,

If the playback is 25 fps, I think you should go with 1/50th.

Ofer Levy
September 7th, 2009, 05:10 AM
Ofer,

If the playback is 25 fps, I think you should go with 1/50th.

Thanks Piotr that makes sense to me - wonder if everyone agree....

Cheers mate,

Ofer

Andy Wilkinson
September 7th, 2009, 05:17 AM
Well this is what I typically use too...but it really depends on what "look" you're after and what exactly the end use is.

As you all well know, you can use a much faster shutter speed to give crystal clear individual (progressive) images which are sometimes needed (say for a sports technique/training sequence or in a technical assessment of a fast moving mechanical process in close-up, for example). However, when played back at normal speed this approach will give a slightly unnatural "stepped" motion look.

With 1/50 you get a bit of motion blur which makes it all look much better for most of the more usual uses (at least to my eyes!).

YMMV.

Piotr Wozniacki
September 7th, 2009, 05:50 AM
Andy,

I guess Ofer's dilemma is more between the 1/50th (as compatible with PAL, or 50 Hz area's framerates, display refresh rates, etc), and 1/60th (as more "compatible" with his overcranked fps material BEFORE slowdown).

My bet is that if delivery is 25 fps on a PAL (HD)TV of 25/50/100 Hz refresh rate, the 1/25th 1/50th etc shutter speeds is the way to go.

But I may be mistaken, of course. This is why, when overcranking with "PAL delivery" in mind, I never go higher than 50 fps (even though this only gives me 50% slowmo) - and of course, only use the "50Hz" shutter speeds.

Andy Wilkinson
September 7th, 2009, 05:55 AM
Yes of course...sorry if it came across wrong...and especially for anything shot in-doors under fluorescent light where it's doubly important to use 1/50 (or 1/100) and certainly not 1/60 or 1/120 if one wants to avoid strobing effects (in a 50 Hz AC current country).

Ofer Levy
September 7th, 2009, 05:55 AM
Andy,

I guess Ofer's dilemma is more between the 1/50th (compatible with PAL, or 50 Hz area's framerates, display refresh rates, etc), and 1/60th (as more "compatible" with his overcranked fps material BEFORE slowdown).

My bet is that if delivery is 25 fps on a PAL (HD)TV of 25/50/100 Hz refresh rate, the 1/25th 1/50th etc shutter speeds is the way to go.

But I may be mistaken, of course.

Hi Piotr, perfectly put - thank you! Thanks for the input Andy (-:

Cheers,

Ofer

Piotr Wozniacki
September 7th, 2009, 06:00 AM
...and especially for anything shot in-doors under fluorescent light where it's doubly important to use 1/50 (or 1/100) and certainly not 1/60 or 1/120 if one wants to avoid strobing effects (in a 50 Hz AC current country).

Well put, too, Andy :)

A very important consideration!

Steve Phillipps
September 7th, 2009, 11:46 AM
I wouldn't use 1/50th, I'd use 180 degree shutter which is 1/120th. This is what the Varicam is generally set on, certainly with BBC settings, always 180 degrees. I tried shutter off (ie 1/50th sec) shooting 720/50P with the PDW700 and it looked too blurry.
Steve

Buck Forester
September 7th, 2009, 12:17 PM
What I do in these kinds of scenaries is shoot in various modes/configurations and see what I like best upon review. That's how I learned photography and it's how I'm learning videography. It's not always the fastest method but you really get to know your camera and how it performs with different settings so you can nail what look you want on a shoot.

Ofer Levy
September 7th, 2009, 12:30 PM
What I do in these kinds of scenaries is shoot in various modes/configurations and see what I like best upon review. That's how I learned photography and it's how I'm learning videography. It's not always the fastest method but you really get to know your camera and how it performs with different settings so you can nail what look you want on a shoot.

Thanks for the input Buck. Of course I try different ways. However, the thing is that my eyes can sometimes get the wrong impression and when it goes to broadcasting some problems can emerge that I could not see.
I also like to hear experienced people - this is a very good way to save time and heart ache....(-:

Cheers,

Ofer

Bob Grant
September 7th, 2009, 05:18 PM
If shooting 50p/60p to deliver 50i/60i from my experience a 180deg shutter can give a result that may still look a bit stuttery. I've yet to try this however I suspect shutter Off might be the best solution as that's the only way to get 1/50 at 50fps.

Steve Phillipps
September 8th, 2009, 04:04 AM
If shooting 50p/60p to deliver 50i/60i from my experience a 180deg shutter can give a result that may still look a bit stuttery. I've yet to try this however I suspect shutter Off might be the best solution as that's the only way to get 1/50 at 50fps.

Seemed to work OK for Planet Earth! All the Beeb Varicams are set with 180 degree shutter (called Half in the Varicam menus).
Steve

Ofer Levy
September 8th, 2009, 04:36 AM
Hi guys,
Thank you for the input!
I actually got some footage taken at 720 60p 1/60 so will work on it and post it tomorrow.
All the slow motion clips on my website were taken in 180 degrees.

Cheers,

Ofer Levy Photography (http://www.oferlevyphotography.com)