Reading mode: Light Dark

7D Movie - motion best shot at slow shutter speeds

Go to last post
P

parna

Forum Enthusiast
Messages
259
Reaction score
0
Location
Stawell, Victoria, AU
Can anyone please explain why this is so?

Manual on page 153 says

"When shooting a movie of a moving subject, a shutter speed of 1/30th sec to 1/125th sec is recommended. The faster the shutter speed, the less smooth the subjects movement will look."

thanks

peter
 
with a faster shutter speed per frame, the action is 'freezed' more and when played successive will appear jerky or jittery opposed to having the action blurred in each frame. if you recorded/played the movie at a higher framerate (like 60 FPS) you would see less of the affect.
 
It's pretty simple - the longer the shutter is open, the more motion blur is captured in the exposure, and the more a moving object will overlap from frame to frame.

Very short shutter speeds can produce a strobe-like stuttering jerkiness of motion, as in certain sequences in "Saving Private Ryan".
 
Usually, when filming with a video camera, the standard shutter speeds are 1/48 for 24p film and 1/60 for 30p or 60p/i.

Faster shutter speed can be good for fast action sports or for someone that wants to extract a frame from the video.

But some blur is usually needed to give a natural aspect to a movement. They did that when filming the firsts Star Wars episodes for their stop motion animations. There was a motor in the objects that introduced a small amount of blur during each exposure.

--
Sylvain

http://www.primeaumedias.com
 
I'm in the same position you are. I took some video of a Hercules aircraft flying over this afternoon. When I viewed it on my computer it was brutally choppy. Realized I had the shutter a wayyy off the recommended settings :(
 
So what does it look like when you shutter speed is too long? Say... 1/12s or 1/6s with 24p. Any examples you can point me to?

I'm thinking about special effects already :)
 
Actually, upon recording several more videos...I've come to notice that I am getting the choppiness in each clip. When I watch the movie on my 7D, it's totally fine. When I view it as a .MOV, it shows lots of stutter.
Any ideas?
Shooting 1920 x 1080, 24fps.
 
Julio said:
So what does it look like when you shutter speed is too long? Say... 1/12s or 1/6s with 24p. Any examples you can point me to?

I'm thinking about special effects already :)
Click to expand...
Homer Simpson moment...

24 frames/sec means slowest exposure is 1/24... :^O (DOH!)
 
it could be your playback on the computer. h264 is a pretty CPU intensive codec. i noticed slight jerkiness on the playback of 720/1080 24p fullscreen on my laptop, though when i played the same video on my playstation 3 is was perfectly smooth.
 
Julio said:
So what does it look like when you shutter speed is too long? Say... 1/12s or 1/6s with 24p. Any examples you can point me to?

I'm thinking about special effects already :)
Click to expand...
This will gives a blurry strobe effect. Some video cameras can go at these speeds.

--
Sylvain

http://www.primeaumedias.com
 
Minimum shutter speed for 1080 on this camera is 30, for 720 and 480 it's 60. Some video cameras do have the ability somehow to have a slower shutter speed than the frame rate. I think the effect would be very motion blurred and ghostly.
--
Primary equipment:

30d, EF-S 10-22, 17-55 f/2.8 IS, EF 50 f/1.4, 70-200 f/4.0L IS, EF 70-200 f/2.8L with broken AF, 580EX, and an HP B9180
 
I can't even play back the clips posted on the web from the 7D without them stuttering.

It really is time for me to put a new system together. Alas, this machine has served me so well for so long. It's a true friend.

But it's just not up to today's demands, I guess.

--
Jim H.
 
I agree with the other poster who mentioned that it's probably your computer and not the shutter speed. I was trying to view a 1080p video on my Core2 duo machine at work and it stuttered a lot. You might have luck with a different viewer and the proper codec's. I was using Quicktime to view and I've always had issues with high-res video with QT.

The choppiness due to shutter speed will be very consistent and only show during action. Choppiness due to playback shows more as hickups, where it jumps every once in a while.
--
Primary equipment:

30d, EF-S 10-22, 17-55 f/2.8 IS, EF 50 f/1.4, 70-200 f/4.0L IS, EF 70-200 f/2.8L with broken AF, 580EX, and an HP B9180
 
I will record another video and view it with a different program, as Quicktime is still choppy as the Atlantic in November.

Any suggestions as to which would be a suitable replacement for viewing .MOV files?

Also, here are a few shots I took over the past little while with the 7D. I'm no pro, and I'm still mucking around with the settings.
http://www.flickr.com/jeffrogerson
 
skrubol said:
Minimum shutter speed for 1080 on this camera is 30, for 720 and 480 it's 60. Some video cameras do have the ability somehow to have a slower shutter speed than the frame rate. I think the effect would be very motion blurred and ghostly.
Click to expand...
They would have to take shorter exposures under the hood and blend them together in the output. IOW, out-frame 4 might be frame 3, 4, and 5 blended; out-frame 5 is 4, 5, and 6 blended, etc.

--
John

 
If you don't have a video card with good H.264 decode acceleration, then you'll probably want a fairly recent computer, say with dual-core or very fast single-core to be able to view 1080p24 H.264 perfectly smoothly.
ffejnosregor said:
I will record another video and view it with a different program, as Quicktime is still choppy as the Atlantic in November.

Any suggestions as to which would be a suitable replacement for viewing .MOV files?

Also, here are a few shots I took over the past little while with the 7D. I'm no pro, and I'm still mucking around with the settings.
http://www.flickr.com/jeffrogerson
Click to expand...
--
Everything Apple - http://everythingapple.blogspot.com/
 
changing the playback app from QT probably won't improve your playback. unfortunately, you may need a bump in hardware.

alternatively, you could recode your movies into less compressed files either through a different (less efficient) codec or h264 at a lower bitrate. so what you'd be doing here is trading the dense/high-bitrate file for a slower bitrate with larger file size. if you're not that familiar with recoding, might be able to just direct burn to a DVD (MPEG-2) with an app that does the recoding within that step. typical MPEG-2 bitrates should playback perfectly fine even on modest machines.
 
its best to freeze the frame, and editing program will let you disolve or use other effects between them. Pros will crank up the lights, and with the 7D crank up the iso and to keep it at 1/30 or faster.

el mariachi used a single camera, but effectively used freeze frames when the camera angle was being changed. Some still pictures may be best used instead of in the 7D, since the 8fps will be better at the slow speeds anyway and may have fewer rolling shutter artifacts.
skrubol said:
Minimum shutter speed for 1080 on this camera is 30, for 720 and 480 it's 60. Some video cameras do have the ability somehow to have a slower shutter speed than the frame rate. I think the effect would be very motion blurred and ghostly.
--
Primary equipment:

30d, EF-S 10-22, 17-55 f/2.8 IS, EF 50 f/1.4, 70-200 f/4.0L IS, EF 70-200 f/2.8L with broken AF, 580EX, and an HP B9180
Click to expand...
 
You must log in or register to reply here.

Keyboard shortcuts

f
Forum
m
My threads
Mobile site
About
Editorial content
Cameras & Lenses
Community
All content, design, and layout are Copyright © 1998–2025 Digital Photography Review All Rights Reserved.
Reproduction in whole or part in any form or medium without specific written permission is prohibited.
When you use DPReview links to buy products, the site may earn a commission.
©GPS Media - Guides, Products, Services.
Back
Top