@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.

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.

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.

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

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.

I've never seen a frame of film with evidence of a shutter once the camera is rolling (and they shout "Action!"),

What I do see in the posted shots of stuttering GH2 are frames where the stated exposure time is greater than the actual exposure. When I get back from this bush trip I will try to reproduce the error and then post some still shots.

I became obsessed with the strobe issues on the GH2 (especially when panning) accompanied by an annoying flicker. I live in PAL land so I used the HBR 25frame and also the 24P, and tried a lot of the hacks, nothing worked, filters, Screen resolution refresh rate, turning off I.R, all manner of shutter speeds etc..decreasing sharpening, tried all types of conversions and viewing as well ...Plus I read countless forums on everything from 120hz screen refresh rates (not many people have those anyway) to what type of media player to view thru (most people dont have those either)...so your clip will still judder when others view it .

However my trusty old TM700 at 1080/50P does not do this at all, but if the footage is converted to 25P then it is not as smooth, so frame rate definitely helps a lot regardless of the arguments against frame rates.

Then a little while back I read here the suggestion to shoot at 29.97 all the time

http://www.hdvideopro.com/technique/miscellaneous-technique/help-desk-did-i-judder.html

So I switched my cam to NTSC, set the shutter to 50 (for lights in PAL land) and 60 as well...and lo and behold the problem was 99% FIXED. No more obvious flickering (day or night), and very little strobe effects AWESOME!! Try it ....do some A/B's you will see a big difference, and the best part is I can use 29.97 for just about everything, even tho I live in PAL land, so for me anyway the problem is solved...no more 24P or 25P.

IMHO Cinematic look (24P) simply does not work that well on current digital CMOS cameras unless its absolutely still or very close, its not a Cinema look, its more of an epileptic fit inducing look if you do any panning...29.97 has made my life with the GH2 a lot less problematic!

Cheers

@feha Hi...yes I converted back to 25p on a video conversion editor and also in Vegas Pro 11.0. Both looked significantly choppier (anyone could spot it, no trained eye needed), mind you there was not the flicker that 24P gives as well (regardless of the many hacks and settings I have tried).

Today I did an indoors pan across a metallic blue Strat (I did many outdoor nature tests too) Anyway although the GH2 was handheld and not panned that smoothly on the Strat pan, the quality and general smoothness of that video filmed in 29.97 was $%### GREAT!! I was over the moon!! No Strobing!! No Flicker!! filmed at 29.97 1080P (HBR) in NTSC with the Panasonic 20mm F1.7 lens, ISO 400, Ap 4.0 and the shutter can be at 60 for 180% shutter or 50 for lights in PAL land. The result was great!! So for me anyway I will stay at 29.97 all the time from now on.

I did try the 720P 50/60P settings much earlier with various hacks where they were upsized to 1080p they were good too, but personally I could see they were ultimately enlarged to 1080P and (to my eye anyway) they seemed to lack the resolution that the 1080P 29.97frame rate gives. I guess the bottom line is that the 29.97 is the fastest universal frame rate that the GH2 does at 1080P, and it works...who would have thought an extra 5 or 6 frames could make such a difference, but they do. The added bonus is Youtube, Vimeo, BluRay etc... appear to accept the 29.97 rates, so I will stay there all the way from now on. I also just read that LPowell shoots mainly in that rate as well, he described it as less problematic LOL!! Very true!! Cheers

@Astro problem is, 30p does not translate into the correct cadence if inserted into 24p timeline in post... Also, 30p usually does not span on the card, yet 24p does, allowing very long recordings - especially with @Ralph_B 's Sanity v5.

Hello, i'm new here. Bought my GH2 last week after doing countless research on the quality, and of course, i never read anything on the strobing issue before noticing it on the cam :s At first i thought i was a moron for setting a too high shutter speed, but then i verified and it was 1/50 for 24p. So i installed firmware 1.1, and the 25p gave the same strobing. So i tried various patches here (thanks for the great work btw), but still same issue.... I read up there that Splash Pro Ex solves the issue in Motion2, and i just tried it....it does work. (it's not as fluid as 50i, but then of course the point of 24p is to be less fluid-ish i guess).

So, could someone now give advice on the workflow ? - My objective is to produce both documentaries are fiction films (to be sent to festivals, via DVD, and shown on internet, maybe sold to TV).

Which editing program (windows compatible) do you suggest ? Should Splash PRO EX be applied before editing or after ? (sorry if this could offend the more experienced here, i have very limited knowledge of workflow) For PAL people, is 24p or 25p the most compatible mode (for dvd export and internet) ?

And any recommendation on the patches ? (noobish as i am, i tried 4 different ones, and forgot which one is on my cam :D ), for now i use SanDisk extreme class 10 30MB/s, which patch works best on it ?

Thanks in advance :)

@mo7ies : thanks for your quick answer, but i get the same excessive strobing at any shutter speed (ok, slightly reduced at 1/25, but still enough to become epileptic). It becomes fluid with Motion2 on the Splash pro ex, but some flickering appears on the most contrasty zones (panning with the black frame of my computer screen against a very light yellowish wall). (ps : i pan with and without stabilizer, with arms, waist, or on a spinning office chair, but none of these affects the strobing). thanks for the tip about the sanity patch and the card. I'm waiting for better lenses too (ordered panasonic 25mm, for now i have only the kit 14-140 which reaches its limits very rapidly when shooting indoors).

With 1/25 shutter, i get acceptable movements in travelling, if i don't go too fast and avoid very contrasted stuff... now i'm waiting for my new video tripod for more serious testing. I'll have to find dollys, cranes and so on (a guy i know has a self-made crane, 4m high).

And today i benefited from a brief heavy rain episode to push the camera. Resolution is awesome, i can clearly see the rain drop traces against a dark wall that is like 50m away from me. The patch that i still don't remember went to 51 Mb/s for that. Looks awesome. (and will look better when i use a tripod).

@mo7ies - thanks for these posts. Coming from half a lifew of using film, I'm amazed at how much you can slow the shutter speed down and maintain excellent results. I have the Pana 25 1.4 and yes, it's sharp as a rat turd, and with that comes the strobing and the frizzle shite that pulses over contrasty zones. o reduce stutter, I've been trying out the vari setting with 80% then playing it back at 24 with a 25% speed up in Avid. It works okay, havent' tried synch sound though. (there's no sound in vari mode.; I'll bet that new 12-35 is going to give us that really sharp "problem too" Might have to try shooting through panty hose, If I can nab some.