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Shutter Speed incorrect when shooting at 60fps

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Robert Muller

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Just wanted to know if anyone else had experienced problems when shooting 2k at 60fps.

When changing from 30 to 60fps, the shutter speed has not compensated fully, and the shutter angle has increased, giving a blurred/soft effect.. A bit like motion blur!

Thanks for any help with this problem.

Rob
 
I will ask the DIT, but excuse my ignorance, how does that effect the process?

Rob
 
Shutter Speeds

Shutter Speeds

Remember an electronic camera's shutter speeds behave opposite to what you are used to on film.

The camera shutter speed won't "compensate" for a change in capture frame rate - unless you select RELATIVE shutter mode.

i.e if it was at 1/48th sec at 24 fps and you select Varispeed at 48 fps it'll still be at 1/48th sec shutter speed.

Unless you change the shutter operation mode from NORMAL to RELATIVE......then it will be at 1/96th sec at 48 fps.
 
Robert Muller said:
I will ask the DIT, but excuse my ignorance, how does that effect the process?

Rob
Click to expand...

What you need to know is in the manual.

RELATIVE changes the shutter depending on your frame rate.

By way of example:

In the normal mode you set a shutter speed, say 1/48th of a second. That's it, the camera attempts to give you that shutter speed.

If for some reason you ask for a setting the camera can't deliver, it does its best and displays what it delivers on the EVF in red letters.

(normal operation, where the camera is delivering what the operator requests, will have shutter speed displayed in yellow letters.)

So, RELATIVE mode will do the math for you. From the build 17 manual:

Enabling Relative mode with 1/48 sec shutter at 24fps will mean 1/96 sec for 48fps, and 1/16th sec for 8fps. This achieves the same visual result as setting a180 degree shutter.
Click to expand...

So, its an attempt to set a virtual mechanical shutter- and I happen to think its mislabeled.

Instead of reading out ANY fractional shutter speed in photo style, RELATIVE mode should read what it intends, a shutter angle in degrees.

Then people who are trained to work in degrees get what they expect without any risk of confusing people trained to work in fractional seconds. People who work with both will get cued as to what techniques, or way of thinking, to use because of the change in units.

But I digress...
 
I never understood the concept of setting the shutter in angles. Can anyone explain to me how that works, and why it's used? Basic I know...
 
DEGREES

DEGREES

Instead of reading out ANY fractional shutter speed in photo style, RELATIVE mode should read what it intends, a shutter angle in degrees.
Click to expand...

You can do that too, in DISPLAY menu, set SHUTTER or STATUS (depending on firmware build) to DEGREES.

This option means the Shutter value reported in the Status Bar at the top of the UI will report Degrees......
 
Jonas Kvist Jensen said:
I never understood the concept of setting the shutter in angles. Can anyone explain to me how that works, and why it's used? Basic I know...
Click to expand...

180º is half of a complete turn, so it's half the exposure time.

24fps = 1/48th
60fps = 1/120th

360º shutter, exposure times equal the frame rate, 24fps = 1/24th.

However the math gets a little tricky (to figure out what the actual number in seconds is) but you get a mental picture quite easily. I also suck at math :).

It's semantics originated from film cameras, check the rotary disc shutter link that Martin posted.
 
What I find interesting is that my HV-20 will actually use a shutter speed longer than the frame rate. E.g. 24 FPS w/ a 1/6th shutter speed... pretty blurry but kind of cool too.
 
Shutter Speeds

Shutter Speeds

That says there is frame averaging going on... by definition you have to read the image once within 1/24th sec in order to have a 24 fps image...
 
Stuart English said:
You can do that too, in DISPLAY menu, set SHUTTER or STATUS (depending on firmware build) to DEGREES.

This option means the Shutter value reported in the Status Bar at the top of the UI will report Degrees......
Click to expand...

That's good to know, thanks.

Now my question is, why isn't it the default behavior?
 
Alexander Ibrahim said:
That's good to know, thanks.

Now my question is, why isn't it the default behavior?
Click to expand...

If it were the default behavior, then another group of people would want to know why it's not the other way around.. In terms of an electronic shutter system as the RED One has, I think shutter represented as angles is less fitting. Then again, I'm more from a photography and video background so I always think of shutter in terms of speed / exposure time rather than angles/degrees. To each their own, RED gives us the option to set either one. And relating one to the other isn't a big deal anyway when you need to.
 
The 180˚ shutter is one of the crucial elements to achieve that "much desired" film "look". Basically You are only exposing half of the actual time (so in 24 FPS the shutter would be 1/48). On the wast majority of shoots in Mexico on the RED ONE the DP's still prefer the shutter to be in degrees and most of the time at 180˚ with 24 FPS. The beauty of RED ONE is that You can "lock" the ratio, which in case of degrees will result in constant ˚ number whenever You change the FPS. Of course if You are displaying the shutter in time, it will always change to be 1 divided by double of Your FPS. So if You have set Your shutter to 1/48 at 24 FPS and You "lock it" and change Your shooting speed to 60 FPS, Your shutter will automatically be adjusted to 1/120...

This is also why most DP's prefer to see the degrees instead...

:devil: Peter
 
Peter Moretti said:
What I find interesting is that my HV-20 will actually use a shutter speed longer than the frame rate. E.g. 24 FPS w/ a 1/6th shutter speed... pretty blurry but kind of cool too.
Click to expand...

When the HV20 shoots at any shutter speed longer than the set frame rate, it lowers the actual frame rate. So, no, it is not shooting 1/6th second shutter speed at 24 FPS, it is shooting it at 6 FPS.
 
I did a ramp from 25 to 50 fps in normal mode with the display in degrees and the angle went from 180 to 90 and the image got darker. What's going on there?
 
Well, to maintain a 180 degree shutter the speed would change to 1/50 to 1/100.

If the shutter angle had changed from 180 to 90, in that case, it would change from 1/50 to 1/200. Not sure why this would happen (???).

What you could do was set the shutter to 1/50 and shoot both the 25 fps and 50 fps with the same shutter.
 
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