View Full Version : Shutter Setting - Degrees rather than Speed?
Scott Webster
11-16-2007, 05:07 PM
Is a 'degree' setting going to be a selectable option on the camera or will it always be a shutter speed display?
dalemccready
11-17-2007, 08:57 AM
yeah degrees would be great personally
Greg M
11-17-2007, 09:04 AM
Red has stated this would be added in later software versions. I thing features are top priority right now.
David Mullen ASC
11-17-2007, 09:27 AM
Personally, it's just me, but I find it more confusing to label shutter controls in terms of degrees of shutter angle in a camera without a mechanically spinning shutter.
Everyone has to mentally convert 24 fps w/ a 180 degree shutter angle to 1/48 and it gets even harder when you start talking about 32 fps with a 150 or 171 degree shutter angle, etc. What's wrong with selecting the actual shutter speed, like 1/50, 1/100, whatever, for an electronic camera? Seems simpler, more direct.
Using shutter angle terminology for a camera with an electronic shutter seems like a odd holdover from film camera technology.
Greg M
11-17-2007, 09:46 AM
You will have the option to select either way...but it would help w/ metering for some of us old farts
David Mullen ASC
11-17-2007, 10:04 AM
All my meters usually input shutter speed rather than angle, so it hasn't been an issue. I always hate those calculations when shooting under 60 Hz or 50 Hz lighting where you have to figure out the shutter angle to use in order to get a 1/60 or 1/50 shutter speed at the frame rate you are using...
Joseph Mastantuono
11-17-2007, 12:55 PM
The reason I could see about applying shutters angles rather that simple speeds is when you get into variable speeds.
at 12fps, 1/48 is saving private ryan land. but at 48fps you're looking at a bit of motion blur. The advantage of angles is that you have to do a little less math in your head... Unless like david said, you're using a meter that doesn't do angles.
Brook Willard
11-17-2007, 08:31 PM
I'd love it if the interface just displayed both... degrees and duration.
Degrees makes more sense to me in certain situations. For example:
Set the shutter to 1/48th.
Enable Varispeed at 48fps.
The shutter speed will still be displayed as 1/48th... which would be 360 degrees at 48fps. What the camera doesn't tell you is that it's scaling that 1/48th exposure to 1/96th [180 degrees] with the frame rate change from 24fps to 48fps.
This is the same with all Varispeed modes. It will still display the 24fps shutter speed no matter what speed you're shooting. Nothing like a physically impossible 1/48th displayed shutter at 75fps! :)
Matt Redmond
11-17-2007, 09:09 PM
Using shutter angle terminology for a camera with an electronic shutter seems like a odd holdover from film camera technology.
But what other way is there to currently describe an exposure ratio? It maybe an odd holdover, but if there is no replacement for what it does, then it's still a necessary holdover.
Hz deals with cycles per second, so the only thing your shutter time is relative to is a second. This has its benefits (filming computer monitors - or consistent exposure regardless of frame rate). It also has its draw backs...
No matter what your frame rate is, if your shutter is set to 180 degrees then you know your frame is being exposed for HALF the length of time than if there were no shutter, and your motion blur is going to be exactly how you expect it to be no matter the frame rate.
BOTH are very important and neither can be left off the Red. There are things which each do well, and there are things each fall flat on.
There is no clear winner, so just give us both :)
Stuart English
11-17-2007, 09:13 PM
In fact the Exposure Time parameter is stored as microseconds internally, what the UI displays is just a "feel good" value - we could do % if desired ::unsure:
More seriously, we have planned on angles as well as 1/xx sec as inputs, but we are working on other things in the UI at the moment.
Its also fair to say that the 1/xx format seems to have been very well accepted right across the spectrum of users.
(Yes we do need to fix the feedback of shutter speed when in VariSpeed)
jbeale
11-17-2007, 10:29 PM
Nothing like a physically impossible 1/48th displayed shutter at 75fps! :)
Just for fun... I don't think any cameras now existing actually do this, but 75 fps with an (effective) 1/48 shutter speed is not a meaningless concept. 1/48 sec is about 21 milliseconds. So... let's say you have a superfast camera that does 1000 fps with 1 millisecond duration each frame (eg. 360 shutter).
Now, if you want to generate 75 fps at 1/48 from that, you can do it. Frame one is the average of exposures 1-21. Frame two is the average of exposures 13-33, and so forth. Each frame is 21 msec long (1/48) and they are 13 msec apart (75 fps). With the effective exposures overlapping, you would get plenty of motion blur / ghosting and I don't know why you'd ever want it, but it's possible. In theory, anyway.
Brook Willard
11-18-2007, 12:22 AM
The funny thing is that when I wrote that post I thought to myself "I wonder if anybody's going to prove me wrong here?" - knowing full well that frame accumulation could make a 1/48th shutter at 75fps.
You get the prize!