What does 'shutter off' exactly mean?

Baluardo

Baluardo

Well-known member
hello everybody,

I am a newcomer in the F3 world, still trying to figure out some basic concepts.

- What does exactly 'shutter off' mean? Let's say I am shooting 1080p25. What would be the exposure time of every frame?

in the Z1, it would basically mean auto shutter, but evidently it is not the case in the F3, since it does not change exposure automatically, unless I set auto shutter from the TLCS menu. I have just noticed that switching the shutter 'off' gives more brightness compared to putting the shutter in manual mode, at 1/33, or 1/50. Does this mean the exposure time is 1/25 sec?

thanks for helping, I don't find the manual (otherwise very good) very clear on this point.

ciao,
Andrea
 
Yes, if shooting 25P with the shutter off, I've always assumed it's effectively 1/25th exposure time. Obviously this can get a little smeary with fast moving subjects so 1/50th (or 180 degrees) shutter tends to work a little better for most looks. With the F3 you also have the option of a shutter time which is longer than the frame rate. So setting the slow shutter in the camera-set menu for, say 4 frames would give the effect of a 1 second exposure!
 
i think you're confusing shutter with frame rate.

i don't have an f3, but i believe the default shutter (off) at 24p is 1/48th.
 
We were talking 25P, but in any case, 1/48th at 24P is 180 degree shutter which you can dial in as normal. Turning the shutter (off) will result in a brighter picture as the F3 switches to 1/24th or zero shutter. I don't think I'm confusing shutter with frame rate, it's just they're effectively the same if you turn the shutter off?

As Andrea has noted in his OP, it gets brighter when he turns the shutter off!

P.S. I'm puzzled why, without owning an F3, you would assume shutter (off) meant a shutter speed of 1/48th?
 
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Ahh, but are you saying you can't turn the shutter off on the EX3?
If you're shooting 24P and the shutters still running at 1/48th with the shutter switch (off), then this sounds like you've got it set to "full auto" which I think is determined by the 'TLCS' setting. I'd be surprised if you can't turn the shutter off as this would severely restrict the EX3?

Anyway, to return to the O/P, you can turn the shutter off on the F3 and it becomes equivalent to the frame rate.
 
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Nate Weaver said:
No.

It's 1/24th with shutter off, in 24P.

Would be 1/25th at 25p.
Click to expand...

This is correct. (I've used all of the mentioned cameras.)

The reason they call it "Shutter OFF" is because it is effectively a 360-degree shutter - it emulates this electronically.

In a film camera, the degree of the shutter is determined by how much of a circle the shutter covers per moment the frame of film is behind the lens. A 180-degree shutter is a semi-circle; a 90-degree shutter is 3/4 of a circle, leaving only a 1/4 of the circle unobstructed at any moment that frame of film is behind the lens, thus giving you an exposure that is 1/4 the frame rate.

Therefore, for a 360-degree shutter, there is no shutter! The entire 360 degrees of the circle is unobstructed by the shutter, exposing the film for the entire time it is behind the lens, giving you an exposure that is equal to the frame rate - 24fps is 1/24 exposure with a 360-degree shutter.

Hopefully this graphic will help -

Moviecam_schematic_animation.jpg

EDIT: Forgot. No animated gifs in the forum. Click here for the real image in motion - http://upload.wikimedia.org/wikipedia/commons/a/ad/Moviecam_schematic_animation.gif
 
Thank you all guys.

Only thing I was wondering: since movie cameras usually shoot at 180deg (=1/48th sec), would keeping 'shutter off' (1/25th or 1/24th) make it look less 'filmic'?

ciao,
Andrea
 
Baluardo said:
Thank you all guys.

Only thing I was wondering: since movie cameras usually shoot at 180deg (=1/48th sec), would keeping 'shutter off' (1/25th or 1/24th) make it look less 'filmic'?

ciao,
Andrea
Click to expand...

I personally tend to find questions about what makes something "cinematic" or "filmic" vague and misleading - the medium is just that is - a medium, but every Director and DoP takes the format in their own direction.

Shooting at 180deg is the norm - it's a happy medium between motion blur and light sensitivity. If you shoot fast motion at 360deg the difference will be obvious, but if there's little or no motion the difference may be difficult to detect.

Ultimately, what are you shooting, and who do you want to emulate/mimic?
 
Baluardo said:
Thank you all guys.

Only thing I was wondering: since movie cameras usually shoot at 180deg (=1/48th sec), would keeping 'shutter off' (1/25th or 1/24th) make it look less 'filmic'?

ciao,
Andrea
Click to expand...

It can, but you raise the age-old debate, "What does 'filmic' look like?"

If the subjects aren't moving very quickly, you can shoot with a different shutter than 180-degree, and most people won't notice. Also note that a great deal of fight/action scenes are shot with a 90-degree shutter to sharpen the images (reduce motion blur), which creates a more visceral feel, and is more similar to how your eye would perceive it, if it were happening in front of you.
 
thanks.
We are in pre-production for a series of scientific promotional/documentalist clips, and I am evaluating the possibility to shoot some parts in a docu-drama style, using a film camera look. Motion will be definitely slow. I will run some tests with our new F3 and will see..

thx all
:)Andrea
 
Even with a film camera we used to (occasionally) vary the shutter for different effects. Because running with a camera often produces a ton of blur a shorter exposure will sharpen it up. Because of all the 'live' cop shows this choppy effect is now culturally perceived as intense and live.

The opposite, as was said, is a longer exposure lets in more light but blurs more. If there's not much motion it still looks good, but a lot of motion looks smeary.
 
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