Shutter on/off
 

Whoops! Accidentally turned my shutter off(on my EX1r) - which got me thinking... Why would someone want to turn their shutter off?

As I pretty well always shoot 50i I almost always have the shutter Off as this is the only way to get the correct shutter speed of 1/50th Sec. To me the question would be 'why would anyone turn the shutter on?' as you're wasting 1 stop of light.
Even when shooting 25p I find the extra motion blur from a 360deg shutter not objectionable and the extra stop of light can be very handy. This however is an option to exercise with caution if fast motion is involved as you may or may not like the outcome.

Agree. I shoot 25P and in general have the shutter off. The motion blur is desirable for smooth motion. Fast motion? How fast? But good for cars in traffic & people walking. And as Bob says, the extra stop is useful.

Thanks. The video I shot (24P) did look ok and when I played with the on/off, I noticed the extra light with shutter off. Maybe this will come in useful. I did notice that birds wings looked worse than normal though (as you said), due to their speed. I also did a timelapse before I noticed and it looked just fine - that might be a good application if I need more light.

Shutter off for low light situations or when shooting interlaced (as shutter off is 1/50 or 1/60)

If shooting 25p, 1/25 (shutter off) is a little low and most motion will blur. If using 50p you'll be OK in most situations with it off.

Last year I had been shooting in low light (at 25p) and then had to immediately go outside to get some footage of a passing train. In the haste I forgot the shutter was set to off. The footage looks OK but on a train going at 70mph, all detail was lost. Shot still works but I was kicking myself because its not how I wanted the shot to look.

Usually, if shooting progressive, I shoot 1/50. It gives the best balance of motion and detail on the captured image. Sometimes retaining detail on the image is more important than smoothness. I've shot quite a few videos of high speed machining processes and clients demand detail. So I trade off the image looking "natural" for a high shutter speed.

This is something that has never been clear to me. I generally shoot my EX1R at 60i at 1/60th sec. In this case, does it matter if the shutter is on or off?

I disagree entirely with the guys saying it's fine to shoot with shutter off, that would be 360º degrees shutter or 1/24 shooting 24p, or 1/25 shooting 25p.

I hate that motion blur, plus I've never ever seen that look in any hollywood movie or tv show EXCEPT for Public Enemies, where sometimes the subjects looked like ghosts when they moved around a fixed frame.

Be sure to make tests and be convinced that you like what you see before shooting anything really important with shutter off.

Just my opinion, have fun.

Well of course you must always test rather than just accept what someone tells you. However let me assure you that turning the shutter off does not give you ghostly images. You have to shoot accumulated frames to get that. There are times you want detail in the frame, but to get detail with fast motion means small shutter sector, little motion blur and motion jerkiness at 24/25 fps. You must always test.

I certainly will continue to shoot with shutter at 180 degrees, but it was an interesting (though unintentional) experiment.

For my 50i shooting, unless I am looking to create a "stutter shutter" look or similar, I operate with my shutter "off". Although technically it is not off, the option has been switched off.

I shoot shutter off when shooting 30p or 24p in lowlight situations. This is to gain an extra stop of light.

For 60i/60p or in better lighting conditions I am shooting 1/60 for the 60 modes and 1/48 or 180º angle for the 24p modes.

if you are using artificial light, you should allways turn shutter off, otherwise you'll get some flickering or darker steaks marching slowly through your image.

Bad advice.
Maybe shutter is a problem in Germany, but not in NTSC areas. Over here, shutter can (and should) be used in 99.9% of all shooting situations regardless of whether the lighting is artificial or natural. Personally, I never turn the shutter off unless I'm in a very dark location and there's very little motion.

I had always been a little nervous of shooting "shutter off" due to motion blur potential. I mostly shoot 1080/30p and find the light loss in progressive vs. interlaced a bit of a problem when I shoot conference work in natural (low) light. I now have no hesitation to flick the switch to shutter off. in low light When there is minimal movement in the shoot, the "shutter off "setting is ideal (for me anyway) since I can keep the gain setting to "0" or to at least a low number setting - without compromising picture quality. The look of gain is worse, to me, then a slight increase in motion blur. I doubt I'd ever use shutter off for anything where there would be considerable movement in the frame.

Ian

I have begun recording in 720 50p - Now I do not use the shutter anymore. When I recorded in 25P I used the 180 degree shutter. Played back on CRT monitor it looks stuttering but on an LCD screen you got a great result. I believe that the LCD screen gave a lag to the material so it did not stutter.
Who have CRT screens theese days - except from us !

I absolutely agree.
There's no light loss concerning the dynamic range (signal/noise assuming a white-noise signal) when switching from interlaced to progressive in a low-light situation (actually the dynamic range of progressive is higher than the dynamic range of interlaced in bright situations). In interlaced-mode there's an operation before interlacing from 60p to 30i happending which accumulates every two successive lines (so the pixel-values of line(y) of the output is line(y)+line(y-1) of the input, in other words filtering each frame with the kernel [1, 1]^T), probably to cope with that interlaced-flickering without decreasing the noise-level (to artificially degrade the value of the camera?). Of course you could in principle (when ignoring/compensating that non-linear gamma stuff) apply that operation to the "darker" progressive shots in post to get the same result, but of course the temporal resolution is gone.
So to conclude: When switching from progressive to interlaced (in low-light situations, when reasonable gain-settings would differ by 6dB between interlaced and progressive assuming aperture and shutter speed are fixed), the dynamic range stays the same, the light-sensitivity increases at the expense of vertical resolution and of course the temporal resolution increases (with costs of additional vertical resolution drop+aliasing while movement).

Bottom line:
If you need 30p/25p and it gets dark, don't play with the interlaced-mode, but increase the gain value, because you will still capture more picture information than in interlaced-mode.

Hey guys, Doug is a guy you should all take some advise from. He has been at this for a long time and is an expert in his field. I agree impliedly with his call here. Unless you're shooting in an ambient light situation where there's no lighting other than a couple of 60 watt bulbs for light, That's about the only time to turn the shutter off. Exposure is a combination of , iris, ND filter and shutter speed and gain if absolutely necessary.

It's not a good sign if even simple things in life like shutter-speeds already leads to delegation of judgement.
That's an improper rule of thumb. The question is not, if the shutter should be off or on, but which is the shutter-speed I want to use. Shutter off effectively just means, to select the slowest possible shutter-speed, which is 1 divided by the framerate.
My experience is that a shutter-speed of 1/50s or 1/60 looks in general most natural/inconspicuous. So when shooting with 50 or 60fps, turn the shutter off, if you want to get natural looking motion blur. If you shoot with 24 or 25fps, use a 180°-shutter.
It gets interesting if you shoot with 24 or 25fps and have a low-light situation. My rule of thumb for that situation would be: If there's just very little motion and you would need a lot of gain to get the exposure right, turn the shutter off. If there's a lot of motion or you would just need a small amount of gain, leave the shutter on.

Definitely shutter-off for groundglass 35mm adaptor work. My personal preference for direct-to-camera imaging.

Didn't mean to appear judgmental, just agreeing with Doug. Yes, I turn the shutter off on occasion when shooting in dark situations where there's not much in the way of motion. Sounds like you have the same convictions. But yes, the question is not whether to turn the shutter on or off. It's choosing a shutter speed optimal to the shooting conditions and as a creative choice. I guess if your shooting in the dark most of the time you're going to need to use the lowest shutter speed most of the time, which is off. The irony here is, this thread wouldn't even exit if the shutter function had no off and simply started with the lowest scan rate possible for the selected frame rate.

Yes, I like that Sony gives me some technical insight by not abstracting the shutter controls just into selecting resulting shutter speeds, but also let me turn it on and off. But I guess Sony overrated the technical comprehension of some of its customers when sourcing this control out.

Interesting that people are expressing such strong views on this question. I wonder how many have actually given the matter any serious assessment. The correct answer is that which you find by your own testing and evaluation. I've run my own tests for a variety of situations (including passing traffic) and find that shooting 24/25P shutter "off" does not give strange effects and I prefer the greater motion blur for its impression of smooth motion. However if shooting at higher frame rates or need to process with stabilisation routines, it is a different matter. I have no problems with people disagreeing, but I am interested in their evaluation criteria. Might be some correlation with complaints about jerky motion at 24fps.

Besides that I don't like the heavy motion blur with 1/24s shutter speeds, what do you think about the finding that almost every hollywood movie is shot with a 180° shutter?

That isn't a persuasive argument, and anyway not entirely true (shutter angle is varied as required). However a film camera cannot have 360 shutter (the shutter must be closed while the film is advanced). I've shot a lot of film, so I'm aware of the related issues. The golden rule is test and assess. What other people (including highly experienced DOPs) suggest is your starting point, not your commandment. Your conclusion is that "off" results in too much blur; that's right for your use.

Sometimes they use faster shutter-speeds to make a scene look more stressful, but (almost) never slower. Could you give me one example of a hollywood production which uses in any scene a slower shutter-speed than 1/48s (@24fps)?
Why don't they shoot digitally? Do you think that some esoteric arguments regarding picture quality are more important to them than price performance ratio and less restrictions on workflows and shutter-speeds? I'm not an insider, but I guess that most major productions today are shot digitally.
That's right, but my personal experience regarding shutter-speeds perfectly matches with what I find in todays big commercial productions. I have no problem with your preference for slow shutter-speeds, but you have to put up with that I think your opinion is an outlier.

Since shutter speed is set for a specific shot you cannot make a statement that a film is shot at a particular shutter speed. Obviously 180 shutter is the most common opening for a film camera, and you specifically have no idea what shutter settings are used for any digitally photographed feature film. That most features are shot digitally is incorrect, as you could have easily determined. But this is quite pointless and irrelevant. I leave you to hold your views.

Yes, I can. Shutter speeds are easily recognizable (at least for me). I watched many movies (like many of us) and they are in most cases very near to 1/48s (of course I can't differenciate between something like 1/46s and 1/50s).
Again, yes I do. Give me any random scene of any random movie, and I bet that it was recorded with an 180°-shutter. (Btw., it's very easy to measure the shutter-speed of a shot afterwards if there's enough motion and resolution.)
I'm sorry, I edited my last post while you wrote your last. But again: What's the argument for shooting in film? And no, it's not pointless: If most movies would be shot digitally, restrictions concerned with celluloid-shooting would have a low relevance concerning this discussion.

The basis of 180 shutter is in film, not video. But I'm pleased you spend your time trying to measure shutter speeds of feature films; keep it up wasting your time. You have rather lost the plot.

You go around my question: Why would todays hollywood prefer shooting 180° film over 360° digital, if 360° would look better than 180° to the majority?
I don't have to measure it, because I can see it. But if you doubt it, we can measure it.

Sorry I have to disagree with this, IMO when shooting in interlace mode there is no need for shutter most of the time it's only when shooting progressive that shutter becomes more useful and even then I wouldn't use it 99.9% of the time.

I should have been more clear and made it a point to say "when shooting PROGRESSIVE". I guess I made the mistake of thinking that was obvious. I haven't shot any interlaced video since 2006, but I guess there are still some people holding onto that old technology.

Anyway, you are missing the whole point of my original post. The person I was responding to stated that shutter should only be used when shooting under "natural" light. Certainly you must disagree with that ridiculous statement.

Sorry, didn't know you haven't shot interlaced! We still shoot in that "old" technology over here in the UK as a lot of Broadcasters insist on it.

I do agree that progressive does need shutter a lot of the time whether lit or unlit.

"Sorry, didn't know you haven't shot interlaced! We still shoot in that "old" technology over here in the UK as a lot of Broadcasters insist on it."

That's news to me, I always produce Progressive material these days, it results in cleaner frames and is easier for doing green screen work.

When I first purchased the EX3 I tried all the frame rates and hated the 720p 24fps look. Now two years later I shoot all my material on 24fps. 720 for my DVD output and 1920x1080 for broadcast material. (Getty, BBC etc)

Yes I do know why progressive can be better, but some of the production companies I work for ask for 50i even when shooting HD.

Interested that you shoot 24 fps and not 25 fps - is that for compatibility with film or easier export to NTSC areas?

Cheers

24fps is for Easier export to North America etc and Getty prefer this frame rate too.

NTSC DVDs will play on 98% of UK players. PAL will not play on the majority of US players (not sure of the figures for this)