The attack and decay area of a mechanical shutter, which is completely out of focus, is very different from the sharp edges of an electronic shutter. All else being equal (speed, display etc., no compression) this will be the sole reason for a perceptual difference. As I mentioned before, the Tessive filter tries to cure this.

An interesting observation: with HDRx on the RED cameras (using "Magic Blend") it looks a bit better, since that is introducing some softness to the trailing edge of shutter.

GOP compression will introduce additional temporal artifacts, only intra compression is free of these. That said, some of the low GOP settings here at VK's are very good in that respect.

And the "hula dance" is probably RS, right.

Roberto and others here - Thanks for all this. It is a VERY valid topic. I only recently started shooting digital. I have a gh2 and a few sharp lenses, mainly the pana 25mm 1.4. I always love slow pans, crane moves and or dolly work. In 35mm film, it was possible to move through a jungle or rainforest panning and tilting very slow (well within mathematical specs covered in asc manual). Never had I a 24fps/180 degree shot exhibiting the same strobbing and/or "farkle" (great term!). This summer I used a Red Epic and Zeiss superspeeds. There was less of that effect, but still some. The bottom of the frame seems to do a little hula dance during slow pans. Could that be the rolling shutter? However, when I shoot the same thing with the lens out of focus (same shutter speed) it seems to tame the effect. I wouldn't be surprised if a diffusion filter might help. It's been so long since I've used those. Now I will do some fiddling with 40, 30 shutter speeds. For those of us who have spent decades using film cameras are very aware of exaggerated (blurring) effect caused by using shutter angles greater than 180. I do believe that it's a twofold problem 1, rolling shutter, 2, lack of the natural attenuation of a rotating mechanical shutter. And yes, monitors and video cards might play a role too. If there is a way to solve this in-camera (not in post) we all would be delighted. Thanks again! Bill

with Motion2 turned all the way up, all of our 24p GH2 mts footage plays perfectly

It would be nice if we all had players with that kind of error-correction. But the stuttering is still there, especially if the individual frames are not blurred as with the several examples of downloadable mts files posted on Vimeo.

You should be able to test your shutter speed yourself, using a high-quality, belt-driven vinyl record turntable which has speed adjustment and either has those black & white markings on the side, or else you add your own as in the picture. First you calibrate your record player using an incandescent light source. Next, make a good strong mark on the turntable. (radial will be good, we'll be measuring angles here). Finally, shoot some video of your rotating turntable using only available light. Record the blurred angle (measured with a compass, protractor, a pair of scissors....)
The rest is mathematics.

@Mr_Moore

Just yesterday, completely by accident noticed heavy strobing and judder in a scene in Life of Brian (1979)

Since your post I have finally got hold of a DVD of this movie - (and it's still as much fun to see as it was in 1979- thanks for the reminder).

No, I don't see any strobing on that particular scene, but I do see stutter in other scenes. Most of the DVD looks very good. But there is also occasional strobing, chromatic aberration, light-level flickering and more, all associated with what I reminds me of the early "Hopping Patch" CRT telecine copies we got for broadcast back in the early 80's. This was before anyone had a [Betamax], TV was pretty terrible - and 24>25 fps (PAL) conversion was brutal or else ignored. It all goes with the 1970's look, really, along with the frequent zooms!! ;-)

What disappoints me is how hard it was to get a copy at all of this classic, let alone a re-mastered Blu-Ray, which would be a better reference to the original.

-Not that it would be a faithful image! Lately, even colour films from the 1940's are being re-mastered with such grain-free fidelity and smoothness that I imagine there will have been all kinds of interpolation and other stuff applied.

A looks a bit smoother to me - (but I'd rather see a steady camera shooting a side-view of steadily moving traffic).

If I were you, mo7ies, I'd also be using 1/30 if it works.

1/30 is supposed to produce too much blur on barely moving subjects when you don't want it - (but after all, plenty of users are reporting shutters not doing what they're supposed to do; "not blurring at all" seems to be a big one).

Until some real tests are done with spinning test charts, we don't know if 1/30 is really 1/30 anyway.

@mo7ies did i miss something..? why didn't you try 1/40?

I'd like to see a comparison of stuttering footage with long GOP settings and then same subject with short GOP settings, everything else unchanged.

In my experience, syncing to the power line frequency is only necessary if you have hmi's, fluorescent, or street lights. Tungsten won't make a difference. But, it's not always something that will show up on a monitor so it's good to play it safe. I would not use a 1/30 for general shooting. There will be a lot of motion blur and to me it's borderline smearing. @mo7ies I don't think there's a lag as you describe. If you imagine a sensor 25 pixel rows high, each row is turned 'on' for the time that the shutter speed is set to, in sequence, one pixel row per millisecond. If you could see a visual representation it would look like a crowd doing the wave at a stadium. I think the subtle skew from normal camera movement tricks your brain into thinking the straight line should start 'there', but then it pops up just a little bit over to one side or the other, and we can interpret it as strobing. And it's not just straight lines, it's any shape. Of course I could be totally wrong. :)

More info on lighting flicker to be found on threads like "Shooting 24p in 50Hz electricity system countries" http://www.personal-view.com/talks/discussion/1444/shooting-24p-in-50hz-electricity-system-countries-/p1

@LPowell "The electronic shutter is triggered at the start of each frame and as long as its duration is not longer than the frame rate, the shutter remains open for the same amount of time, regardless of frame rate. "

Yes, but the same shutter will produce different angle on different framerates, thus affecting motion blur - will it not.

That's why for 30p we need 1/60 shutter to get the "normal blur" look = 180 deg shutter.

And for 24p (what we are discussing here) 1/48 shutter which we approximate with 1/50 on GH2, for the same "normal blur" look = 180 deg shutter.

Except, we still seem to get the strobe effect and NOT a normal blur look, as discussed above.

So as a compromise, methink we should use 24p with 1/40 shutter generally, and then apply Force Motion Blur effect in post, selectively, to the troublesome-looking shots.

BTW, I'm not a huge believer it using 1/60 shutter for 60Hz light - because without also synchronizing the Phases, the two frequencies (shutter vs light pulsation) will still produce artifacts, IMHO. But this is for a different discussion, I guess :)

Now, I assume you are talking about 30p recording with 1/60 shutter, correct?

I was mostly concerned about the 24p recording - in which case do you think 1/30 shutter is universally appropriate or not?