GH3 GH3 1/48 shutter @ 24p?

I really don't get why you all are giving him such a hard time on the nuances here...

1. When anyone says 24p, you know what they really mean. Do you give your clients a hard time when they say 1080/24? Seriously? lpowel, you know better! Come on guys..

2. You don't have to be a freak of nature to 'notice' 1/48 vs 1/50. If you are shooting the 'wrong' type of lighting, this can be the difference between a rolling lights and proper lights...

Example: We shot for a documentary/promo/tv series which requested 1080/25. There was a scene in which we were filming a control room at a factory. The used some old TVs and a bunch of computer monitors and a variety of LED lights all over the place. At 24P (shutter speed of 50) most of the screens looked great. BUT, we were filming at 25fps! So the result in 25p was rolling computer screens and TV screens. We had to shoot at a shutter speed of 40 to make it work with the general LED lighting, and I went around to all of the computer screens and adjusted their refresh rate to match our format. The TVs, however, are all NTSC and I could not alter their refresh rate.. They are TVs. So we had vertical rolling TV screens in the shot, which I could not alter.

IF the GH2 has syncro scan this would not be an issue. Never was an issue on my HMC150 or dvx prior to that. I love my GH2s dearly, but this is the only serious issue I have with them. Maybe Panny will have some feature to fix this... Maybe a firmware update can solve it...
 
PopcornFlix said:
Bruce: yes, I know the history of cinema cameras.

I disagree with your aesthetic analysis. I find that the motion blur rendered by a 180-degree shutter is unique and more desireable than that of a 172.8 degree shutter. The GH2 is one of the very few digital cameras that will shoot at 24p but not at 1/48, since that combination renders a recognizeable "film look" to the video footage.
Click to expand...

None of the Canon DSLR's had 1/48th of a second or Nikons that I know of. Even if they had 1/48th you wouldn't be seeing the effect of a 180 degree shutter as there is no "shutter" operating on our Canon DSLRs, or GH2s. The sensor is being scanned electronically not mechanically. And 24fps with 1/48th (if we had it) does not by itself render a "film look". This comes from a combination of things, many of them not physically tangible. Lighting, composition, camera movement, lens imaging characteristics, set design, DPs sense of vision, and more.

The "Holy Grail" of 24fps for the "film look" is about to change big time. "The Hobbit" is being shot in 48p, several producers are planning to shoot their next "blockbuster" in 60p. Theatres in recent years have been projecting each frame of 24fps films twice to reduce the flicker effect which some people can see, and it gives some folks headaches. So what we've been seeing is 48fps.

With conversion to digital projection that game has already changed. There is no mechanical blocking of the film gate while the next frame is being pulled into position so that resulting "flicker" effect at any frame rate is gone.

The goal of all this is to "smooth" and even totally remove the mechanical flicker. I usually wait for DVDs to come out but I went to our local theatre (now converted to digital for most screens) recently to see "2016: Obama's America". Much of the archived footage had to be at 24fps, and I don't know what the digital stuff was shot at. But there was absolutely NO FLICKER of any kind, it was all extremely smooth. And the the previews of coming attractions looked worlds "smoother" than I expected.

PopcornFlix said:
Different people have different levels of visual acuity, and different artistic tastes. Allow me to enjoy mine.
Click to expand...

Of course, didn't mean to offend you in any way.
 
I noticed when I watched Prometheus the nagging "this doesn't look like film" thought was constantly in my head. It was all too clean and didn't feel like film at all, though it was projected at 24fps.

Go figure.
 
Last edited:
Chris Adler said:
I noticed when I watched Prometheus the nagging "this doesn't look like film" thought was constantly in my head. It was all too clean and didn't feel like film at all, though it was projected at 24fps.

Go figure.
Click to expand...

Why would you want anything else for a sci fi film, especially if it's set in the future?
 
HotConductor said:
When anyone says 24p, you know what they really mean. Do you give your clients a hard time when they say 1080/24? Seriously? lpowel, you know better!
Click to expand...
The OP asked a question about a precise distinction in shutter speeds at a precise framerate. And if you must be that precise, the answer is no, the GH3 doesn't record at either 1/48-sec shutter speed or 24fps. But of course, for practical purposes you're right, and there's no point in being pedantic about it.

As for the "180-degree shutter" effect, I'm not going to say it's a myth, only that digital cameras are incapable of reproducing it, not even the ones whose shutters can operate at precisely 1/48-sec. The cinematic magic is not solely in the numbers, it's a property of the film camera's mechanical shutter as well.

As most probably know, the shutter in a film camera was a revolving disc, with a 180-degree pie-slice cut out of it to admit light. When synchronized with a 1/24-sec frame rate, this produced an exposure of approximately 1/48-sec duration. The reason it was not precisely 1/48-sec is because the leading and trailing edges of the shutter were naturally smoothed by motion blur of the revolving disc. While the esthetic nature of this effect could be debated, the technical effect was to reduce the temporal aliasing of the sampling window, which can definitely influence the perception of stuttering and motion discontinuity.

A digital video camera uses a completely different type of shutter to expose the sensor to light. These electronic shutters open and close virtually instantly, producing a sharp transition between darkness and light with each frame. In addition, the notorious "rolling shutter" effect produced by MOS sensors adds another layer of digital distortion to the image. A large part of the clinical look this produces is due to the temporal aliases created by the electronic shutter, regardless of whether the frame rate is precisely 1/48-sec or approximately 1/50-sec.

This digital motion stuttering can be quite noticeable at the low frame rate of 1/24-sec, particularly when viewed at the uneven monitor refresh rate of 60 fields per second. While I agree with most that film looks great displayed in a theater frame-doubled at 48fps, I think video looks esthetically much smoother when shot at 30fps.
 
Last edited:
lpowell said:
As most probably know, the shutter in a film camera was a revolving disc, with a 180-degree pie-slice cut out of it to admit light. When synchronized with a 1/24-sec frame rate, this produced an exposure of approximately 1/48-sec duration. The reason it was not precisely 1/48-sec is because the leading and trailing edges of the shutter were naturally smoothed by motion blur of the revolving disc.
Click to expand...

I'm very susceptible to this. The motion of objects on screen shot with DSLR's really bothers me. It feels like video motion, even at 24p. With everything else going great these days such as sharpness/resolution, control over DOF, decent dynamic range, etc. This feels like the last thing that needs to be done to really push the full classic film-look many of us have been trying to achieve.

I'm curious if there is a way we could add a mechanical shutter in a similar fashion to the rotating ground glass 35mm adapters of a few years ago. Or if there is some way software could be used to convert/mimic this effect after the fact.
 
Jim Simon said:
That doesn't obviate the need for technical competence, though.
Click to expand...

That's not how that idea is presented, by and large. Besides, that's not a legitimate comparison. Some people like the way The Bourne Supremacy looks, some people are interested in high frame rate cinematography. It's not an issue of competence, it's an issue of particular taste which is solely related to a technical matter.

You can't say that shooting The Hobbit in 48fps is a mark of technical incompetence. That's completely off the mark.
 
Well, it would've been an entirely different movie. For me, not necessarily more entertaining. Then again, some are able to tell the difference between 1/48 and 1/50 shutter, some have no problems with comprehending 4 frame cuts ;)
 
Gary Huff said:
Doesn't matter what it looks like, I thought "content is king"...right? right?
Click to expand...

Re: 'film look' reliant on 24 fps... it keeps some people with a ready excuse as to why they never make films worth watching... it's not 'true 24 fps', or 'the shutter wafting across the film plane left artifacts that can't be done in digital form, so therefore I can't produce a film'... etc...

It is with some irony, that many of these beliefs about what is the 'film look' were considered defects, and years of technology improvements were made in film and cameras to 'get rid of them'... grain size shrunk, shutters that worked more reliably, lens improvements with coatings and better lens shaping to eliminate defects etc...

Then introduce a technology that eliminates many of the 'sensor/capture' side defects, albeit introducing some new ones... and now someone can't make a film because it doesn't have all these 'defects' of yesteryear...

I personally can't seem to make films because I can't organize and get a group together long enough to make a short film... but I'm working on that... but I doubt that the group formation doesn't happen because there's a wyrd 'knife edge/motion effect' missing on my DSLR shutter that was present in a Film film camera...

And I pretty sure these days not as many people have been subjected to crappy 8mm 'Real(tm)' Film film clips to know that Film is not some sort of 'holy thing that disallows crap to be made', and that goes for 16mm film as well... and from Ed Wood and Ted V. Michels, I can believe that crappy 35mm films could be made just as easily... although with 35mm film the expense of making crap probably was out of most would be film maker's price range...
 
Jim Simon said:
That doesn't obviate the need for technical competence, though. The Bourne Supremacy would have been A LOT more entertaining with proper lighting, a tripod and cuts that lasted more than 4 frames.
Click to expand...

I agree... with the Wife carping about shaky cam at every shot, I couldn't enjoy the film at all...

They are very well made. You may not like how they were made, but there was no lack of skill and technical expertise.
 
Last edited:
j1clark@ucsd.edu said:
It is with some irony, that many of these beliefs about what is the 'film look' were considered defects, and years of technology improvements were made in film and cameras to 'get rid of them'... grain size shrunk, shutters that worked more reliably, lens improvements with coatings and better lens shaping to eliminate defects etc...
Click to expand...

I would also add that it strikes me that certain people's idea of a "film look" also stems from their childhood of watching their beloved films on low resolution basic cable/VHS presentations and crappy projections in cheap theaters.
 
Gary Huff said:
I would also add that it strikes me that certain people's idea of a "film look" also stems from their childhood of watching their beloved films on low resolution basic cable/VHS presentations and crappy projections in cheap theaters.
Click to expand...

Speaking of 'crappy projectors in cheap theaters'...

We got the Bluray package for the Indiana Jones series.... Talk about innumerable 'errors' that were missed for years with the normal Film film distribution. The Wife was yelling at me about the 'out of focus shots' right and left on "Raiders", she walked out of the IMAX presentation, due in part to her perception of the 'transfer quality', and due in part because of a very badly setup IMAX projector, and probably a wyrd delay in the audio...

Anyway, on looking into it, there were a number of focusing errors that were 'known' to exist in the 'Raiders' negative, and those were pretty much carried into the transfer.

Upon recollection, I don't ever recall seeing any of those errors while watching the original presentation way back when... not even after years of VHS or heck even the DVD transfers...

But with the 'new and improved' transfers and Bluray HD... wow... what a mess if I were to pixel peep...

Oh, yeah, no question all of the Indiana series were shot on film... 24 fps, etc. etc. etc...
 
You must log in or register to reply here.
Back
Top