I'm planning to shoot stuff to slow down in Twixtor. The slow motion doesn't need to be that much, maybe +50%. And I plan to do it in 1080 30p. Should I use then faster shutter speed like 1/120 instead of "normal" 1/60 ? How far you can go until it looks bad?

I have GH2, I could also use 720 60p but I don't like the idea of resolution loss.

@Sangye First: You must be young. Two: You must play videogames on a regular basis ;o)

@oophus: Yes, as long as your shot contains mostly non-overlapping linear motion, postprocessing for motionblur works sufficient enough.

As soon as you run into a mixed motion shot, with linear/nonlinear motions overlapping, artifacts will creep in.

You'll need all those overlapping motions in different image layers, then it'll work. That's why I mostly tell ppl not to rely on 'the fx guys' to fix something in post, if they could get it easily right in the first place.

1 minute, on set to change a filter, can save a few days of postprocessing hell.

But that's just me, maybe I got to picky over the years ;)

I would say the obvious reason for using NDs is consistency.

If you expose with the shutter speed, motion will be rendered in a wide variety of different ways throughout the film. If that's your stylistic intent, then fine, but it definitely calls attention to itself in a way that could throw even the average viewer out of your film.

It's not really the 180 degree shutter that's sacred, it's maintaining a single fixed shutter speed throughout the film. THAT is why we use NDs.

I was about to post

it's filming 101

Then I saw @viicharris had just beaten me to the post, pointing our the elephant in the room.

Thanks. I thought we'd all suddenly gone to la-la land !

@Sangye

I do, and it is a serious question.

If you've made some novel discovery, let the world know. Show us your shutter speed trick, your perpetual motion machine or whatever. Honestly, do you get off on wasting others' time?

@cde clearly maintaining a fixed shutter speed throughout a film is not what is necessarily done these days. Action scenes will have the gladiator-saving private ryan- no motion blur action thing happening and then it will change for mellower scenes depending on the effect desired.

I don't know if motion blur really is something natural to human sight, maybe someone has read that somewhere but I was taught that it's just a convention we have become accustomed to because it was something created by film cameras and technology. It's similar to how people didn't like watching The Hobbit at 48 fps because it looked too much like a soap opera on TV, or how HDTV's can show material that looks really 'fake' to our eyes because the old technology has shaped our expectations.

@Alienhead Yes, but in films where the technique is used, it is usually to call attention to itself for stylistic effect in a few key sequences, usually action. The majority of the film is shot with one fixed shutter speed. If one were to follow Sangye's technique and expose with shutter speed, then the rendering of motion would be wildly different throughout thefful., and not for any stylistically appropriate reason.

@Cde agreed. I think Sangye's idea is interesting and makes me imagine the possibilities that a faster shutter speed may offer, but it's not practical to change it around for most situations, not at this point anyway.

@goanna check out some films that use the fast shutter technique such as the ones already mentioned.

If the convention of shutter angle is required for the job, then stick to it. Otherwise I think @Sangye has a completely valid point. This parameter is like f-stop, sensor characteristics, lighting etc just another tool for chosen aesthetic. Very frequently used in high dynamic scenarios. But also has it's justification in others, if it supports the overall aesthetic of the work.

Actually GH2, as well as all the low and middle class camcorders, gives unnatural motion blur no matter what shutter speed is choosen, i.e. it's very far from the motion blur of the cinema cameras and movie productions. I've tried ReelSmart Motion Blur plug-in which in my opinion is the best popular for that purpose. If you adjust its settings right, then the footage becomes completely different, very close to the feel of the movie productions. Even if it's not graded. A really big positive difference!!! The only inconvenience is that this plug-in takes a lot of time for processing... very slow.

When I shot with Lumix 7-14 at day light, I prefer set fast shutter instead close aperture to 16-22, because MFT lenses not sharp at very closed aperture. That lens can't attach filter in front. Otherwise, wide angle make picture with less motion, and the problem with motion blur not really visible. After S 1/100 all shutter numbers look the same, there is not really difference from 1/100 to 1/2000, so if you have no time for instant shot, and you know that the scene will be with restrained motion of objects, you can use highspeed shutter, but if you see any electric lights in frame, maximum possible shutter can be only 1/100 at 50Hz countries and 1/120 at 60Hz of electricity.

For serious projects I try to avoid it and film at 1/50 with filters, of cause.

Yes, let's see the footage. I want to see how to get the jerks out of a shot where the shutter isn't open long enough to get all the movement in, how the codec manages to compress all those sharp frames and how the work in post is able to interpolate objects into the missing positions which never got recorded.