Why does all 7D footage look

T

Tameside

Well-known member
like its about to go jello-vision any moment and in deed does when you move the camera? It seems inappropriate for any motion situations? That must be a real pain to work around?

Any tips?
 
That is one of the problems with all the DSLRS. But you need to use a tripod or some type of shoulder support. Some way to keep the camera steady.
 
Tameside said:
like its about to go jello-vision any moment and in deed does when you move the camera? It seems inappropriate for any motion situations? That must be a real pain to work around?

Any tips?
Click to expand...

The 7D (and the 5D...and some extent the RED ONE and the EX3...) have this problem because they use a CMOS sensor instead of a CCD sensor.

The CMOS sensor has a virtual vertical electronic shutter which passes over the frame as a way of reading data off of the chip, whereas most CCD sensors have global shutters, which capture the entire frame at the same time. In essence, it takes a small amount of time for the entire frame to be read out, from top to bottom, on the 7D. If there is a significant amount of change in composition (motion, for instance, or a strobe light) a temporal artifact will be created - vertical objects like street poles may lean a bit and solid flashes of light may appear as bands across only a part of the screen.

As the readout time on CMOS sensors increases, the effect should disappear to some extent. For example, the upcoming RED EPIC reads the sensor in 5µs, in comparison to the average film shutter exposure time of 4µs. RED ONE is currently at ~13µs.

In my opinion, the extremely light weight and small form factor of the camera also adds to the problem. Even the smallest of movements are easily translated into noticeable jitters in the footage when holding it - heartbeats, breathing, neuromuscular instability, etc.

The best way to fix the appearance of Jello is to stab stabilize the camera - add weight to it in some way, put it on a rig or a glidecam, or mount it on a tripod or slider. This adds much more control to the situation and really makes it look much better.
 
When we shot our short film (see my sig), we didn't even try to avoid it or work around it. It was only noticeable in one shot, which was an extremely shaky hand-held-while-walking shot.

Just know what the limitations are and what to look out for. Not a big deal.
 
When the OP asks why does it always look like it's 'about' to go jellovision, I will say one thing from my experiences on the GH1...when I'm just getting ready or looking around with the LCD screen on, it always seems wobbly or about to be wobbly as hell. Maybe it's just that I slow down when I start recording, or maybe something with the way it previews, but anyways, usually, once I hit that record button and get into a shot, it settles down enormously.
 
Did some steadicam work today and no jello what so ever. If you know the limitations of a camera you can avoid much of these things. You can't shake a 7D like a beanbag and expect it to look good.
 
I am surprised we are still asking this question.
The trick is to shoot so there is no jello.
Use tripods, dollies, cranes or a brace.
I mean , how hard is that ? Why would you shoot otherwise ?
 
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