PDA

View Full Version : For Those Who Are Concerned About "Frame Judder"



basspig
10-03-2008, 08:51 PM
My wife and I stopped in to a Blockbuster store this afternoon (she was bored and looking for something to watch over the weekend) and right where the walk in traffic diverges into the different areas of the store, there was a huge PlayStation display with a 42" Sony Bravia monitor, playing a Blu-ray disc "Pirates of the Caribbean."

While my wife looked around at the selection of movies, I studied the cinematography on this film. There were some pan shots on board the ship, and the thing that stuck out at me was eye-disturbing frame judder. I remember thinking just at that moment, "This sure beats the heck out of the theory that the EX1 has a lousy motion quality," which we've heard variations of from a number of new users over the past 6 months.

It also bore out my belief that the camera has little to do with the "motion quality" as it were; it is purely a matter of shutter dwell angle.

As far as image quality, I noticed halos around the edges of the ship's masts on an outdoor shot, suggesting that the picture underwent quite a bit of unsharp masking with a rather large radius setting. It looked a bit "video-ish".

Another thing I noticed was that the indoor scenes on board ship were extremely grainy and that grain was not a nice 'filmic' grain--it seemed like it was made up of macroblock noise, which made it something I would reject if it came out of my render farm. The picture was rather quite noisy.

And finally, and this is a neutral comment, color grading was very evident, particularly on the indoor scenes. Lacking was blue tones; the picture was dominated by yellows and oranges. It reminded me of one of the Magic Bullet looks that I see often here with graded EX1 footage.

After looking at that movie on Blu-ray, I feel even better about the images I get from the EX1.

PS: My wife didn't find any movie worth renting, so we left empty-handed.

I, Filmmaker
10-03-2008, 09:17 PM
I rented the EX1, and I really didn't like the LONG GOP. And the rolling shutter showed up with camera flashes and quick pans. In all honestly, I truly DIDN'T like the motion i was getting. And I really tried to remain completely objective. I mean man, lock down the camera and film an interview and its gorgeous. But go handheld and do some quick panning and man, it made my fiance dizzy. (I wasn't even pushing it to the limit, I just did a relatively fast pan, and the telephone poll in the shot moves like a blade of grass in the wind. Bendy, and jello-y. So I decided to go HPX.. BUT all these issues are arrising with the HPX's lens, and wobble, and such.

To each his own

Stevet
10-03-2008, 10:08 PM
Mark,
I'm sure Blockbuster's Sony Bravo LCD playing "Pirates of the Caribbean" had it set with the factory defaults. I'm sure you will find "sharpness" was on during that movie playback.

That would explain why the movie had harsh edge sharpness.

As far as motion. 24P 1/48 (180 degree) shutter in these video cameras is nothing more than that. Anyone can throw the footage on a timeline ans inspect ALL 24 frames at 1/48 th shutter.

It's absolutely amazing how many try to read beyond basics.

Now CMOS shutter artifacts are there if you fling the camera about. That's for sure.

We're still woking with the EX1 cameras. The image quality is absolutely excellent. We have no interest in anything else at this point.

One thing for sure, we are interested in RED Scarlet. Everyone's going to add this to their tool kits, at that price. We're also interested in the Nano and XDR drives to capture 4:2:2 1920x1080P.

Jim Arthurs has recently demostrated how clean the EX1's 4:2:2 SDI out. Very clean signal and great for keying.

basspig
10-03-2008, 11:57 PM
Yes, I was thinking the same thing about the Bravia's settings. That aside, the film WAS noisy. And the jutter on the pans was almost seizure-inducing.

A 180º shutter is pretty slow and tends to blend frames and take the edge off judder. When shooting with a 22.5º shutter, the frames are highly discreet and lack the motion blending that tends to melt them together in a pan shot, so the judder is quite obvious.
I think 180º is great for narrative work though. The audience doesn't need a razor-sharp pan shot--they just want to see continuity between the shots.

CMOS artifacts are a special case: certain types of shot situations may present objectionable artifacts. I find that particularly apparent with rapid flash sequences like those seen in fireworks. Overcrank footage makes these things easier to spot.

As for the Scarlet, it's a whole new workflow, it's proprietary, and I'm pretty certain it's not very portable with a very long battery run time. It will probably be more of a studio camera, tethered to a bevvy of hardware for recording.

The thing I like about the EX1 is that it replaces a van full of gear that I used to need 20 years ago. I love the freedom and I don't feel so bad about doing a competitive rate because my work is so much reduced.

I have a downloaded Quicktime file somewhere of a test with SxS and SDI signals compared. Subtle differences at normal viewing distances, but indeed, SDI takes it beyond scrutiny. Where SDI gains ground is in keying fast-moving subjects.

TimurCivan
10-04-2008, 12:11 AM
out of the box dispalys are set up with most settings set to 11.....

once you dial them back down to normal levels most LCD TV's offer a relatively good picture.

moldcad
10-04-2008, 02:04 AM
Regarding the grainy low light scenes Basspig has mentioned. Most of the BluRay movies I ever watched on my 50" plasma, and some of the HD movies being broadcast by HBO HD I have here, were much worse in this department than my own EX1 productions displayed on the same screen, with the same settings (BTW. being the absolutely most neutral ones). It beats me why.

Stevet
10-04-2008, 09:06 AM
TimurCivan is right.

I've have YET to see any set that did not have its factory default settings cranked - Contrast, Sharpnes, Chroma, ect...

This will add and boost noise levels. It's amazing the difference of a properly calibrated set.

moldcad
10-04-2008, 09:39 AM
Quite coincidentally, I just watched the Pirates on HBO HD - the Bravia you've seen it on, Basspig, must have been set in a totally wrong way; the broadcast version is marvellous!

But I intentionally put my Panasonic back to the "Factory settings" - and what I saw was a complete mess; over-saturated colours, stretched and noisy blacks, over-exaggerated edges...

Carl Marxx
10-04-2008, 10:19 AM
Bass Pig, most of the Blue-ray commercial disks are streamed in 14+ to18mbps with high compression, they used to give the stream rates on the back of the jacket, but I think thay have stoped that. Lower stream rates give more time. I have seen both 14.8 and 18Mbps, and you can see a clarity there. If you author a the blue-ray disk, use the 25Mbps option and the results are much better. The stream on the blu-ray disk is close to 40MBps Max, but I have not seen the program to write that speed for any hand-out version, yet! Note: the nice think about archiving clips on a blur-ray data disk is that you can run easily HQ clips directly at the 35Mbps rate without errors: i.e., you can do your editing directly from the disk if you need too. --- Carl Marxx

Jon Neely
10-04-2008, 07:55 PM
if you have a PS3, just hit triangle and it will show the bit-rate and compressor used on the HUD.


Jon

basspig
10-04-2008, 09:47 PM
Carl, that's interesting about the low bitrate on Blu-ray commercial discs. They must be using h.264 encoding, because 14-18mb/s would be barely adequate for 720p, much less 1080p.

I have looked at the bitrate monitor (my Sony BDP-S301 has this feature on the Display button, just like my first DVD player in 1998 had) and looked at a few BD movies' rates and they generally bottomed out in the teens but went much higher on complex scenes.

I typically encode with an avg br of 25 and a max of 35 in h.264 and that gives me over 3 hours of high quality content on a single layer BD-R.


About the Bravia, the picture, despite the sharpness being cranked up, assuming factory defaults, was still not all that crisp in terms of actuall DETAIL. It reminded me of a 1440x1080 picture stretched to 1920x1080. Looked okay, but I would have to rent it and see it on the reference monitor to really evaluate. Most of my BD titles that I own are okay, but not extraordinary on clarity. Lots of film grain. That said, they DO make a vast improvement over DVD. But I'm not losing any sleep over commercial BD movie quality. I'm pleased that we can equal or exceed the quality of picture that passes for "perfect" on BD commercial movies. :)

Noel Evans
10-04-2008, 10:00 PM
I have a Bravia - best units on the market at the moment by a long shot IMO. I watched POTC not so long ago and on mine it looked great. I have xbr that has 24p True Cinema, which is the latest version. Your video store may have an older model bravia that isnt 1920x1080 thats had a good deal of use.

TimurCivan
10-04-2008, 10:27 PM
about judder....

I saw something today that practically stoped me in my tracks and made me feel all weird. Apparently the new Samsung displays have some kind of motion estimation circuit, that "fills in" the gaps between 24p frames... and it makes 24p content move like Video... its DISTURBING and causes lots of articfacting, the guy who owned the set thought it looked "Amazing and clear"....

Sigh.....

Jon Neely
10-04-2008, 11:03 PM
that why I bought one of the old sammys on sale, 52'' and has great picture.


Jon

DCSensui
10-05-2008, 03:14 PM
One thing for sure, we are interested in RED Scarlet.

Scarlet is being rethought. No telling how long it will be when the working version hits the market. Meanwhile the market and state of the art will change as usual.

http://www.scarletuser.com/showthread.php?p=21391#post21391

As for judder, it can be seen at the theatres in Hollywood movies, depending on the rate of panning. I remember seeing that while watching a movie when I was in high school, and that was a LONG time ago!

Carl Marxx
10-05-2008, 03:25 PM
Carl, that's interesting about the low bitrate on Blu-ray commercial discs. They must be using h.264 encoding, because 14-18mb/s would be barely adequate for 720p, much less 1080p.

I have looked at the bitrate monitor (my Sony BDP-S301 has this feature on the Display button, just like my first DVD player in 1998 had) and looked at a few BD movies' rates and they generally bottomed out in the teens but went much higher on complex scenes.

I typically encode with an avg br of 25 and a max of 35 in h.264 and that gives me over 3 hours of high quality content on a single layer BD-R.


About the Bravia, the picture, despite the sharpness being cranked up, assuming factory defaults, was still not all that crisp in terms of actuall DETAIL. It reminded me of a 1440x1080 picture stretched to 1920x1080. Looked okay, but I would have to rent it and see it on the reference monitor to really evaluate. Most of my BD titles that I own are okay, but not extraordinary on clarity. Lots of film grain. That said, they DO make a vast improvement over DVD. But I'm not losing any sleep over commercial BD movie quality. I'm pleased that we can equal or exceed the quality of picture that passes for "perfect" on BD commercial movies. :)

A lot of releases use extended footage and special "back-of-the-Scene" footage to sell them to the public, so there is alot more of video on the disk than just the featured movie. I have seen personally on the early releases 14-to 18MBPS specifications on the back of the package. As far as the compression: I can't remember what they use; but the Blue-Ray player are capable of decoding long GOP and H.264 and up to 39Mbps if I remember in the manual. You know, Blue-Ray players are very fussy and the early players, which I've seen stores use, can produce noisy video if you look closely. -- Carl

basspig
10-05-2008, 05:03 PM
The setup was a recent addition to the store. A Sony Playstation 3 was driving it. Perhaps that was the culprit.
The video that was showing appeared to be the main feature, not a bonus section, as it went on uninterrupted and looked to be the movie itself. I would have loved to pop in my demo reel for a good comparison, but I didn't have it with me.

Re: judder, I remember actually being distracted by it in a movie I'd seen in a theater in the late 1970s. It was some science fiction or futuristic military flick--heck, maybe even a Bond movie, and there was a pan through some dimly-lit control room, something like a war room or mission control center, and there were all these consoles with CRTs in them that the camera was doing a truck shot across in the near-field, and the judder was somewhat disorienting and annoying and I remember that distraction better than the film, to this day some three decades later.

Stevet
10-05-2008, 05:12 PM
I've been viewing Blu-ray videos I've made with the EX1 and they are excellent. I see no addional noise when viewing on my 50" Pioneer plasma using a PS3.
In fact, at times they look better than store bought Blu-ray.

basspig
10-05-2008, 11:43 PM
Same thing here. Hollywood's got nothin' on our Blu-ray discs. :)

Have some shots of nature scenes that have spectacular, rich colors, where every frame looks like a photograph, on BD-R. The 24p footage just looks tremendous. I encode everything with h.264 at a generous BR and it looks nearly indistinguishable from the master footage. No noise, breathtaking dynamic range, and rich, "Fuji Velvia" colors.

'Time for me to take another tour of area HDTV retailers and test my latest BR-R demo reel.......

EIREHotspur
10-06-2008, 09:22 AM
Great tips here guys.
EX3 settings and options are a real minefield.
I copy and paste all the great tips into a Word Document for quick recall.