Other: X70 Shutter Angle Problem

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skimmel

Well-known member
Hi, just got a PXW-X70. I want to set shutter angle to 180. But, if I set it, say with a 30p setting, and then I change to 60p, the shutter angle changes on its own to 360.

I really just want shutter angle to remain at 180 degrees no matter what I'm recording. Is there a way to set it to stay at 180 degrees?

Thanks.
 
This is a well known feature of Sony cameras. Round these parts it's known as the shutter bug and persistent lobbying by members here managed to get Sony to write it out of the FS7 firmware.
 
That explains why I hadn't seen it before -- my other camera is an FS7. I don't understand the reason that it does this and why it can't be fixed.
 
It's not a bug and it is not going to be "fixed" because the camera was programmed that way on purpose. Sony thinks 1/60 (or 360 degrees, if you prefer) ought to be the default shutter speed for 60P. That's fine if you don't agree, but that's the way they make their cameras, so you'll have to spend a couple of seconds to override it. In this case, I happen to agree with Sony.
 
Doug Jensen said:
It's not a bug and it is not going to be "fixed" because the camera was programmed that way on purpose. Sony thinks 1/60 (or 360 degrees, if you prefer) ought to be the default shutter speed for 60P. That's fine if you don't agree, but that's the way they make their cameras, so you'll have to spend a couple of seconds to override it. In this case, I happen to agree with Sony.
Click to expand...

Thanks Doug. Can you educate me on this? What is the benefit of 360 degrees for 60p vs 180 degrees? I am just about to shoot my first event at 60p and would like to get this right.
 
Well, let me ask you this first: What are you going to do with the 60P footage in post? What exactly is your workflow? What is your final delivery output format going to be? Where will it be viewed?
 
Was just about to add that! I plan to shoot 60p, deliver at 30p. Some, but not all, footage will be slowed down 50%.
 
I don't have a theoretical explanation for this, but just watching my own 50p footage I find it better looking with 360 deg shutter, so I for one approve of Sony's decision to make it default for 50/60 fps, as Doug said already. Please remember that the golden "180 degrees shutter" rule applies mainly for filmic stuff (24 fps, or for making life easier to European shooters - 25 fps in PAL area). High framerates of 50/60 fps are mainly intended for achieving that more video-ish, "out-of-the-window" look and feel. Just a personal opinion, though.

Piotr
 
This is not an argument about aesthetics or what is technically right, a professional level camera should not be changing settings for the user. Professionals do not need this level of wet-nursing.
 
I agree in that I'm also strongly against any technical device trying to wet-nurse me, but don't think it's just a mistake by Sony; it must have been implemented for a reason.
 
skimmel said:
I plan to shoot 60p, deliver at 30p.
Click to expand...

See, that's the issue right there. Today there are not very many places where you can actually output, play, or deliver 1080/60P footage. So what often happens in post is that the 60P gets downconverted to 30P by allowing the NLE to drop half the frames. So, let's just ignore the fact that you have captured twice as much data and therefore have clips that are twice as big without any visual benefit in post. Of course, as you say, you can easily convert 60P to slow-motion so that is one benefit, but how often is that going to happen? And I'd rather shoot S&Q Motion when slo-mo is needed.

The issue that is more important than just wasted data is that the shutter speed won't look right if you had shot 60P @ 1/120 (or 180 degrees). After your NLE dumps half the 60 frames per second, you'll be left with 30 frames per second. And unfortunately those 30 frames will have been shot with 1/120 shutter speed which is too fast for normal-looking video. You will end up with the equivalent of a 90 degree shutter.

I believe Sony chooses 1/60 for 60P because they know that dropping frames is likely to happen in post -- and also because they are still stuck in a 60i mindset.
 
Thank you Doug. That makes sense. For the event I was shooting -- a swim meet -- I need to be able to switch between normal and slow motion frequently in the video I produce for them (e.g., start a dive in normal speed, slow down as the swimmer enters the water, and speed back up again when the surface from below the water).

So, for the first swim meet, I shot at 180 degree and, as you said, the normal speed footage on a 30p timeline looks very choppy. I will mostly use the footage for slow motion.

Any suggestions for a compromise shutter angle? Thanks again.
 
Why don't you just shoot at 1/60sec shutter speed ? That is what I do all the time shooting 60P and 60i anyway. Shutter angle is a leftover from film cameras. There is no mechanical shutter on a modern electronic camera just the time the sensor is collecting light before data is sent to the buffer. That way you can control the image blur independent of frame rate. In my mind 30P is slow for a fast moving sport especially as resolution is now increasing making every fine movement obvious on high resolution screens.
 
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