Motion Blur While Shooting Video With 6D

[Haitham Lawati]

The achieved results of any video footage shot with Canon 6D are amazing. There are few drawbacks and blemishes that appear in some occasions, as this entry level camera stays far way behind the ultimate performance of any advanced cinematography camera. One of the heartbreaking blemishes that occur in this camera and worth to be discuss is the motion blur.
When I set the camera on 24 fps, I know that the ideal shutter speed would be 1/50 sec in order to create a very swift motion blur which, ultimately, achieves the pleasant cinematic look.
Despite 1/50 sec of shutter speed set on this camera, very severe and undesired motion blur still appears in some shots particularly when there are moving objects, which ruins the scenes and gives a feeling of cheap shots. If the shutter is slightly increased, say to 1/60 sec, flicker starts occurring in the scene. It is also worth noting that when sharpness is increased in Picture Style, the motion blur becomes more crisp and further ruins the scene.
Does anyone have any opinion in this regard and kindly advise us on how to mitigate the motion blur and come up with pleasant results?

[Haitham Lawati]

Any one to reply my inquiry ?

[Jon Fairhurst]

The ASC has some recommendations for panning and such. To generalize, you can pan slowly or extremely quickly, and you can track moving objects. The problem area is with medium speed objects (or background) that the eye and camera do not track.

The fastest pan you should do will take seven seconds from edge to edge of the screen. At that point, you start to see 24 fps judder. On the other hand, if you are tracking somebody running down the street, don't worry about the background motion - the audience will be looking at the runner and they aren't moving across the screen at all.

Whip pans are fine as they are disorienting and quickly over. (Though rolling shutter can make whip pans ugly due to tilt.) It's the medium speed, non-tracking pans that are a problem.

There's another case that can be a problem: moving objects in the background. Let's say you're filming on the side of a road. With a long lens near the road, the cars will whip by. With a wide lens and some distance, the cars will crawl by. Somewhere in the middle, you can get into the problem zone, which is excessive blur and judder. Solutions would be to make the shot tighter or wider, or to put an actor in the scene to draw the attention of the audience.

Video testing is an age old problem. We often get a camera and shoot handheld in the house, yard, and street and wonder why it doesn't look like a Hollywood movie. 24 fps is especially tough as it requires control of motion. It's even tougher if we don't have a story, actor, or action to follow in the scene.

...and then there's art direction, lighting, costumes, makeup, fog, grading, etc.

These days, I think camera motion control is a bigger challenge than the camera - and cameras with rolling shutter only compound the issue.

[Haitham Lawati]

Thank you very much for your response. Your post was very informative and helpful. However, my inquiry has not been clarified completely. In order to make my inquiry more understandable, I have uploaded an image illustrating the motion blur that appears while a character passes the camera. The video footage was shot at 24 fps and the shutter speed was set to 1/50 sec which I assume to be the ideal speed for video shooting and despite these attributes the motion blur keeps on appearing prominently every time a character makes a movement. Can you please help me in this regard and find a proper solution for this issue?

http://s12.postimg.org/u9xxfqo7x/Motion_Blur.jpg


host images

[Jon Fairhurst]

Rather than motion blur, I'm seeing frame blending. Note the "ghost" image at the leading edge of his shirt.

Are both the camera and the editing system set for 24 fps?

(Also, because the walking person is near the camera, he will also be slightly blurred due to shallow DOF.)

Once you remove the frame blending, the result should be much improved. :)

[Haitham Lawati]

Thanks for your reply. What you have mentioned is true. The ghost effect that appears in the shirt is a result of frame blending and I have no any idea how to disable this effect in Edius and Premiere because I have never experienced this issue with other cameras such as HDV. I will be thankful if you guide me on how to disable it in both of the NLEs.
By referring to the raw footage, the ghosting effect is not prominent but I can still experience some motion blur particularly in the t shirt. How can this be further reduced ?

[Jon Fairhurst]

The 6D shoots a true progressive format, so fortunately, you do not need to deal with interlaced fields. That should make things fairly easy. In Premiere, I would ensure that the project and the render are at 23.976 fps, progressive scan. I've never used Edius, but I assume that it's a similar situation - set the project to 23.976 progressive and render at 23.976 progressive (or at whatever the settings are for your footage.)

Regarding additional blur, you can shoot with a faster shutter speed, but then you risk judder. As I mentioned before, the walking person is also blurred due to moderately shallow focus.

Artistically, I'm not sure about the intent of the shot. If the audience is to focus on the weightlifter in the background, then why is somebody walking across the frame in the foreground? If the subject is the man in the foreground, then why is the camera not tracking him? In fact, if we are to watch the man in the background, the blur on the foreground person is desirable. You could also light the weightlifter bright and the foreground man dark to tell the audience where to look.

I've seen shots where a director has two actors standing still on a busy sidewalk, talking. The crowds walk quickly by them. This shot only works with tight framing, a long lens and shallow focus. The long lens makes the crowd move quickly across the frame. This fast motion and shallow depth of field make the crowd almost invisible while the actors are pin-sharp. This is very effective for showing that the characters are in their own, little world, ignoring everything around them.

In your case, you have a wide lens, so the man is passing by at a moderate speed. He is not so blurred to be ignored, but not so sharp to draw audience attention. As I say, the intent is not clear.

It is very important to compose shots and motion specifically for 24 fps, large sensor work. The key is to direct the attention of the audience to the subject and away from secondary parts of the image. This is why many documentaries are shot at 50 or 60 fps with medium- or small-sized sensors - both motion blur and focus blur are reduced, so the scene doesn't need to be so carefully composed.

I hope that this is helpful. :)

[Ervin Farkas]

As far as Edius goes, frame blending per se cannot be turned off during editing... IF - and this is the key - IF you set everything right.

If your footage is 23.98 fps, make sure you start an Edius project with the frame rate set to 23.98 fps. The only time Edius will do frame blending is when there is a difference between the source footage frame rate and project frame rate. You will only have the frame blending vs nearest frame option to choose from when you export to a different frame rate than your project settings.

[Haitham Lawati]

Thank you all for the support, your replies were very informative and helped me better understand some technical aspects related to video shooting with DSLR and overcome the issues which I recently addressed. After better understanding, a few more inquiries arise:

First: When shooting video, what is the criterion for determining the appropriate shutter speed? How do I know the amount of shutter speed I need for any particular shoot in order to reduce the motion blur and give more sharpness for any moving object in the scene?

Second: When shooting indoor and under artificial lights, the camera screen shows flickrs if, at any instant, the shutter speed is dialed above 50 fps. This blemish does not appear when shooting outdoor under daylight. What is reason behind this phenomenon?

[Jon Fairhurst]

In 50 Hz countries, you should also be able to shoot at 1/100 and avoid flicker under lights.

The reason for this is that some lights (especially fluorescent lamps) increase and decrease their brightness along with the sine wave of the incoming voltage. Well, it's actually a "rectified sine wave" as the light doesn't go negative when the voltage goes negative. Both negative and positive voltage create positive light. That's why 1/100 will work for 50 Hz lighting. The camera isn't sync'd with the light but it captures a full cycle of light output from dark to bright to dark.

Regarding shutter speeds, 1/50 is the normal compromise between stutter and blur. Switch to 1/100 if you want less blur under 50 Hz lighting. 1/250 will give you virtually no blur for normal, human motion. Of course, a hummingbird or race car speeding right next to the camera will blur even at 1/1000, so it all depends on the speed and direction of the motion, speed and direction of the camera, and the focal length of the lens. With a DSLR, you can do a test, take a still image, and zoom in to see the exact effects.

But with a higher shutter speed comes stuttering. This is fine during a hectic action scene but would be distracting for normal human interactions.

As mentioned, you can reduce blur by increasing the shutter speed or by changing the motion of action or the camera of the length of the lens. By managing the motion in the frame, you reduce the need to go for a faster shutter speed and you reduce the possibility of stuttering.

If you want fast action, less blur and less stuttering, you probably want to shoot and playback at 50 fps like a TV camera, rather than like a cinema camera. This gives more a a documentary look (some say a "soap opera" look) but might be what you seek.

[Marius Pavel]

The 6D features both automatic and full manual exposure controls in video recording mode giving both beginner DSLR video shooters and the seasoned advanced amateurs or pros ease of use and customization, respectively.