Flickering when move the camera at DVinfo.net

Go Back   DV Info Net > JVC ProHD & MPEG2 Camera Systems > JVC Everio GZ-HD and GZ-HM Series

JVC Everio GZ-HD and GZ-HM Series
JVC's Everio Series 3CCD High Definition MPEG2 camcorders.


Reply
 
Thread Tools Search this Thread
Old August 8th, 2008, 08:43 AM   #1
New Boot
 
Join Date: Sep 2007
Location: Darzo (TN) Italy
Posts: 7
Flickering when move the camera

Hello,
I shot with HD7 quality 1440 CBR, convert files TOD to HDV 1080i50 25 fps and edit video on FCP 5.1.4. I have to do a normal video DVD PAL, but I would like use HD7 to have the HD input quality. I export HDV 1080i50, edit on FCP using QT conversion for DVD Studio Pro.
I export to QTfile using:

Compression: None
Depth: Millions of Colors+
Quality: Best
Dimension: 1024x576

the video output on DVD shows flickering in scenes who presents a movement of the camera. The OIS is active and the movements are no quickly but the flickering seems a constant with HD7 when shooting without tripod.
Anyone have the same impression and maybe know some way or tricks to reduce this problem?
Thanks, Costantino from Italy

Last edited by Costantino Briani; August 8th, 2008 at 10:12 AM.
Costantino Briani is offline   Reply With Quote
Old August 8th, 2008, 11:47 AM   #2
Regular Crew
 
Join Date: Jul 2008
Location: New York NY
Posts: 35
Hi Costantino

Glad to see another HD7 user. Welcome!

I must say the OIS on the HD7 is not the best. The HD6, several Sonys and Canons have a better system. I hate to say it, but even my old Canon ES3000 HI-8 has a better OIS. I learned after the second day of use to turn off OIS on the HD7 and keep it off.

I don't know, the flickering you describe sounds like it may be the OIS.

I described it as a stuttering or smearing that could be seen. If the scene or talent is motionless for a second and then moves, or if the camera is steady and moved slightly, the image stutters, smears or blurs. Any motion seems to throw the OIS off for a moment as it tries to re-align the image. That is why I always use a tripod, mono stick or shoulder mount and keep OIS off.

Since I do not use FCP or render to PAL I do not know what the settings may be doing to the video.

What you can try is to shoot a few seconds of video with OIS off and do the same edit/conversion you did before. If the final result looks OK, then you know it was the OIS.

Only use OIS only when it is necessary, the rest of the time keep it off.

Let's see what happens!

Best Regards.
Manuel Correa is offline   Reply With Quote
Old August 8th, 2008, 02:43 PM   #3
New Boot
 
Join Date: Oct 2007
Location: Toronto, ON
Posts: 15
Monostick or Shoulder mount

Hey Manuel,

I did not know the OIS would actually make your movie look worse.... This is interesting. Can you share your experiences/model of the mono stick and shoulder mount that you use, and how do you find the HD7 works with these?

Thx!
Adrian Vargas is offline   Reply With Quote
Old August 8th, 2008, 03:31 PM   #4
New Boot
 
Join Date: Sep 2007
Location: Darzo (TN) Italy
Posts: 7
Quote:
Originally Posted by Manuel Correa View Post
Hi Costantino

Glad to see another HD7 user. Welcome!

I must say the OIS on the HD7 is not the best. The HD6, several Sonys and Canons have a better system. I hate to say it, but even my old Canon ES3000 HI-8 has a better OIS. I learned after the second day of use to turn off OIS on the HD7 and keep it off.
...
Hi Manuel

Thanks for the kind reply. I'll try to use camera without OIS I hope this is the right way.
I think is not a FCP setting issue but just a HD7 problem about OIS or something else.

Usually I use a tripod with the camera motionless but in some rare cases I'd like do a wavy and slow movement as free hand and this cause the flicker.
If I do it with the cheap Canon MVX300 I have no problem.
I'll let you know thanks!
Costantino
Costantino Briani is offline   Reply With Quote
Old August 10th, 2008, 08:36 AM   #5
Regular Crew
 
Join Date: Jul 2008
Location: New York NY
Posts: 35
Quote:
Originally Posted by Adrian Vargas View Post
Hey Manuel,

I did not know the OIS would actually make your movie look worse.... This is interesting. Can you share your experiences/model of the mono stick and shoulder mount that you use, and how do you find the HD7 works with these?

Thx!
Hi Adrian

Nice to meet another HD7 user.

OK, a few things first. I won't go into a long dissertation on OIS. Saying OIS will make a video worse is not exactly correct. It is the "way" it is used that may cause a video to not look its best.

There is a difference in behavior between OIS being ON or OFF. The problem with the HD7 OIS is its implementation. That is why I said compared to other manufactures, Canon and Sony for example, they achieve close to 95% stability in most of their hand held cameras. I should mention that it is Canon who is credited with the first OIS system, I believe.

Overall, the HD7 does a good job of removing exaggerated movement. If you have movement that covers a large range of motion, the OIS is OK. For example, if you are running or shooting from a moving vehicle, the OIS produces a better picture under these conditions than with OIS OFF.

What causes it to fall short is with small, smooth, tiny movements when hand holding. This type of movement seems to trick the HD7 OIS to a degree. This appears when OIS is ON and you are mounted on a tripod, or if you pan or move the camera very slow and you are trying to keep the image stable as well. The elements are either slow to respond or keep moving once you stop the movement, which in turn causes the very motion you are trying to eliminate.

These are the conditions where I see frame stutter, image blur, flickering, artifacts, trailing, what ever you want to call it. MPEG compression may also be playing a factor in this, I am not sure. That is why I say if you are able to hold the camera steady yourself or have it mounted on a tripod, you should always keep OIS OFF.

No long dissertation? Right! Too Late!

As for the mono stick, I use a Manfrotto 561B. I find the HD7 works well with this unit. Because the release plate allows a camera to be positioned forward or back, you can achieve a good balance. The head on the 561B has a smooth tilt and a handle which can be repositioned. The head itself does not pan, instead a fluid base is used on this model which incorporates three small feet. I like the stability this provides me.

Some don't like it. The complaint being that the base is to stiff or that the drag on the base can not be adjusted. Others don't like the feet at the base. It is a little heavier than others, Gitzo and Monostat for example. But I find the 561B to be a very good and well built stick.

Shoulder mounts are another matter. I looked at various units and was not impressed by most. Either they were uncomfortable, flimsy, or very expensive. The DIY route didn't offer much either. I could not see myself going somewhere looking like I brought half the Home Depot hardware department with me.

The system I decided upon was from Cavision. They are based in Canada and should be easily available to you. I couldn't remember the model# on a previous post, but going over my papers it is the RS-1580. I chose this because it is well built, comfortable and configurable. This unit comes with 300mm rods that some may find too long. If you are not going to use a hood/matte box or eyepiece shade, then 200mm or 250mm rods might be better depending on the camera setup and what you are anticipating down the road.

For me, the way I have my camera set up it is fine. It is not cheap in construction or cost. As a support system, I felt it gave me the most bang for the buck. I can carry the camera on this system much better and longer than trying to hand hold the camera alone.

Although smaller cameras are great because of reduced weight, the ability to keep them stable is the flip side of the coin. I still have and use my Panasonic 456u to this day, a shoulder mount video camera. I do regret selling my JVC X3 however, but that's another story.

I hope that answers your questions and keep in mind that my statements are “in my view”.

Look forward to hear from you again.

So, tell us, what's in your bag of goodies?

Best wishes to you!
Manuel Correa is offline   Reply With Quote
Old August 13th, 2008, 12:26 PM   #6
Major Player
 
Join Date: Feb 2008
Location: Lancashire UK
Posts: 496
Thanks for the Dissertation Manuel, I learned something handy there, about the big movements being better with OIS turned on. So far I've simply turned mine off and ignored it, but I shall remember your wise words sir.

Ta very much

Avey
Wayne Avanson is offline   Reply With Quote
Old August 15th, 2008, 10:16 AM   #7
New Boot
 
Join Date: Sep 2007
Location: Darzo (TN) Italy
Posts: 7
Flickering when move the camera

Hi,

about flickering issue on first post, I have tried with OIS off on the camera some shots with HD7 mounted on a Manfrotto 501HDV Pro Fluid Video Head.

In the pano movement the flickering is clear too.

You can download samples wide-angle(chairs back or the flank of the wall on the right)
http://www.el-en.it/zcos_folder/test_1.mov
http://www.el-en.it/zcos_folder/test_4.mov

Samples zoom tele
http://www.el-en.it/zcos_folder/test_3.mov
http://www.el-en.it/zcos_folder/test_5.mov

Maybe this camera can be used only motionless...!? I'm not be able to understand if and where I mistake!
Kind Regards
Costantino Briani is offline   Reply With Quote
Old August 16th, 2008, 02:52 AM   #8
Major Player
 
Join Date: Apr 2007
Location: NJ, USA
Posts: 339
Quote:
Originally Posted by Costantino Briani View Post
Hi,

about flickering issue on first post, I have tried with OIS off on the camera some shots with HD7 mounted on a Manfrotto 501HDV Pro Fluid Video Head.

In the pano movement the flickering is clear too.

You can download samples wide-angle(chairs back or the flank of the wall on the right)
http://www.el-en.it/zcos_folder/test_1.mov
http://www.el-en.it/zcos_folder/test_4.mov

Samples zoom tele
http://www.el-en.it/zcos_folder/test_3.mov
http://www.el-en.it/zcos_folder/test_5.mov

Maybe this camera can be used only motionless...!? I'm not be able to understand if and where I mistake!
Kind Regards
Yes, I did notice flicker on back of chair! But when I run your clip in WMP it was not visible, but it was clearly visible in PowerDirector's window! I run same in PowerDVD Ultra but flicker was not there! I am using HD7 one & half year now but never seen this kind of flicker on my any of videos? Huh!

Can you upload original .TOD file of same? I have not seen rest two clips, and I have question for you, why you use 4:3 mode for recording? Why you are not using 16:9 mode!

Kaushik
Kaushik Parmar is offline   Reply With Quote
Old August 17th, 2008, 01:09 PM   #9
Regular Crew
 
Join Date: Jul 2008
Location: New York NY
Posts: 35
Flickering when move the camera

Quote:
Originally Posted by Costantino Briani View Post
Hi,

about flickering issue on first post, I have tried with OIS off on the camera some shots with HD7 mounted on a Manfrotto 501HDV Pro Fluid Video Head.

In the pano movement the flickering is clear too.

You can download samples wide-angle(chairs back or the flank of the wall on the right)
http://www.el-en.it/zcos_folder/test_1.mov
http://www.el-en.it/zcos_folder/test_4.mov

Samples zoom tele
http://www.el-en.it/zcos_folder/test_3.mov
http://www.el-en.it/zcos_folder/test_5.mov

Maybe this camera can be used only motionless...!? I'm not be able to understand if and where I mistake!
Kind Regards
Hi! Ciao Adrian

Speranza che state facendo bene. Ho esaminato I vostri video e posso avere una ragione per la quale osservano quel senso.

OK! My Italian is not so good. It has been some time since I had to write in Italian. So, if you don't mind, I will continue in English.

Now that I have seen the videos, I believe I can tell you what is happening and why. I should first mention a few things. Please keep in mind that this is my opinion and I can be totally wrong. I am not an expert, but I try to learn and understand what I must work with. If someone else can correct or clarify anything I say, I am all ears and will gladly listen.

What must be stated here is that despite all the codecs that are in use, none of them is actually lossless compared to uncompressed content. No matter what you are considering, audio or video, compressed content can not duplicate the original exactly, it is only an approximation of the original. A recording that is done digitally and sampled at a ratio of 1:1 is an exact copy. Anything less can only be a close representation of what the original was. Our willingness to accept compression is what it is all about. It is the degree of acceptance that becomes the real question, it is the bottom line that drives all of this. For the manufactures and public, it is a question of what is good enough to be passable or acceptable.

OK! Now that the preamble is finished, this is what I see and can say.

Part of this has to do with MPEG2 compression and the HDV format. First we must understand the MPEG2 frame structure and Long GOP. A video is broken down into what is called a GOP, Group Of Pictures. Within this GOP there is a sequence of I, B and P frames. With MPEG2, a GOP starts with an I-frame which has no reference to any other frame. This is followed by several P and B frames which are referenced to other frames and used to predict motion across the GOP before the GOP begins again. The GOP structure varies depending on frame rate. The frame order is a 6 frame GOP for 720 24p, 25p and 30p, a 12 frame GOP for 1080 25p and 720 60p, and finally a 15 frame GOP for 1080 24p,30p, and 60i.

“DV” uses “intra-frame” compression while “HDV” uses Long GOP “inter-frame” compression. In DV, each frame is complete. Each frame has all the information needed for a decoder to recreate the frame. With HDV however, only the I frames are complete. In order to decode other frames it must analyze other P and B frames in the GOP. The longer the GOP, the more video compression is possible. It should also be noted that all HDV video compression is both spatial and temporal, and that temporal compression is greater in 1080i HDV video than in 720p HDV video due to the use of a longer GOP.

This compression does come at a cost however in terms of artifacts that can been detected. These artifacts can be seen when there is a lot of motion in the frame. It is the limitation of compression. Under most circumstances, the Long GOP has the benefit of saving space with minimal loss in quality. It is however susceptible to artifacts when too much changes in the span of just a few frames. Dropouts within a frame can wreak havoc with inter-frame compression and affect multiple frames since other frames may be referencing that very frame.

These artifacts can be seen if you know what to look for and look closely. An image that does not move in an MPEG2 video will compress very well and show no artifacts. While a scene with complex rapid motion may show signs of picture breakup, not just on one frame, but may affect several frames. This is where inter-frame compression can drop the ball, because by design, it requires dependency upon previous and subsequent frames. Because MPEG2 reduces file size by approximating data and storing only the differences between one frame and another, the result can be what is called macro-blocks, MPEG Blocking, combing, even noise or a stutter or jump within a frame. Keep in mind that this dependency can also become an issue when editing HDV, because a decompression and re-compression of the entire frame group must occur at edit points and/or during transitions as well.

To further aggravate the situation, we have what is called Horizontal Aliasing. I believe 1/5 inch CCDs do not sample images enough in the horizontal plane, and therefore they do not create enough information as to the detail of the image. Because of this, vertical content can appear to stutter, block, jitter, flicker, it has been described many ways. If the image in front of the camera moves horizontally across the sensor or the camera is panned across this same plane, vertical lines appear to grow and shrink as they move. The vertical lines of the chair or wall now looks blocky, as if the image is falling behind and catching up with the sequence of motion. If, like myself, you are used to seeing video shot in SVHS or BetaCam SP for example, the artifacts of compression become noticeable and annoying.

Is there a way to reduce these effects? I do not have a complete answer, it is marginal at best. It is possible, mostly by changing the format of the recording, that is, to record in a format that uses a smaller GOP, 720 24p, 25p and 30p for example, if the camera can be switched. Unfortunately, the HD7 records only in 1080 60i which is the
long GOP.

Another, is to experiment with the workflow. Changing parameters and/or the order of how you decompress, edit, re-compress, render HDV can make a difference. I do not have a formula as to how and what to use, it is a situation of trial and error to discover what works best. I wish I could give you exact steps, but I too must try different things, and it can be frustrating.

Deinterlacing the video can remove the combing artifacts but the price you pay is in reduced vertical resolution. Video shot in interlaced format can be converted to progressive as a post production process, but again at a cost. How well the conversion is done is dependent upon the software and how complex the footage. In addition, the conversion can be time and hardware consuming depending on the output resolution. Nothing is free in this world, no matter what we are told.

One final thought. Oh boy! I can hear it now, “When are you going to get off the soap box! ! OK! OK!

Another consideration is in Quicktime. As I understand it at present, version 7.4.5 of the Apple lossy intermediate codec lacks the transcoding and generational quality of some other codecs. I has been passing around that 7.4.5 and possibly the current version of Quicktime does not play well with HDV because of a glitch or programming error in the coding of the codec. I do not have exact information on this matter.

I see the videos play back in Quicktimes .MOV format. Are these artifacts visible if you render to .AVI or use another program to view the videos? Do they appear in the original footage, the FCP preview, or when the video is rendered? Just some questions to get the brain cells moving, OK!

I may have missed other factors at play here or be totally off base in what I have said. If anyone else wishes to chime in, all the better. As I said, I too am learning every day and encourage anyone with more information or corrections to post.

Hope to hear from you again. Bye!

Speranza di sentire ancora da voi. Arrivederci!
Manuel Correa is offline   Reply With Quote
Old August 21st, 2008, 05:48 PM   #10
New Boot
 
Join Date: Sep 2007
Location: Darzo (TN) Italy
Posts: 7
Quote:
Originally Posted by Kaushik Parmar View Post
Can you upload original .TOD file of same? I have not seen rest two clips, and I have question for you, why you use 4:3 mode for recording? Why you are not using 16:9 mode!
Kaushik
Hi Kaushik,
Upload .TOD is too large size file but there was the flicker yet. Of course I filmed 16:9 if you download file and use QuickTime Player you can see correctly, if you see 4:3 maybe use some Window Media plugin.
Thanks.


Quote:
Originally Posted by Manuel Correa View Post
Hi! Ciao Adrian

Speranza che state facendo bene. Ho esaminato I vostri video e posso avere una ragione per la quale osservano quel senso.

OK! My Italian is not so good. It has been some time since I had to write in Italian. So, if you don't mind, I will continue in English.
...
Hi Manuel,

sorry for late reply, I was out for some days and don't worry about your Italian maybe my English is worse...

Your deep analysis is very interesting, alas I'm not able perhaps to get all the meanings but the sense of your post is clear.
About your question the artifacts were visible in original TOD, with other codec too and in the FCP preview.

I'm reading some comments, on the italian forums too, about the HD7 OIS issue. Many of these relate the trouble for get image stabilized when the camera is moved or handled. Someone say that the lense of the camera is too large to be stabilized ohter people are unconditional "this camera is a fraud!" because JVC not tested this model accurately because they want show to market a fullHD consumer before than competitors...

I don't know what the truth but surely there's something that's not good though we can try different parameters and codec or what you want.
Sure the best result with HD7 is if the camera is motionless on tripod, at most you can zoon or move from up to down slowly, the problems start when move panoramic so the vertical line flicker.

As you wrote on your preamble all the question also depend of the degree of acceptance, in fact in the same forum I found enthusiastic and hostile comments about HD7.

Just today I filmed for about one our and at the first look the TOD seems better than my sample files, maybe today the light was more diffuse and minor contrast was on the scene, anyway I let you know what about after conversion and compression process.


Thanks and best regars!
Costantino Briani is offline   Reply With Quote
Old August 22nd, 2008, 02:32 PM   #11
Regular Crew
 
Join Date: Jul 2008
Location: New York NY
Posts: 35
Hi Costantino

I'm so sorry. I was so concerned about getting the Italian right, I put Adrain's name on the post instead of you. Shows you what a knuckle head I am. Also you must pardon me, because sometimes I get too involved in the technical aspect of things and I go too far.

I'm sure you got the meaning of what I was saying. As for the lens being too big to stabilize, I don't know about that. There are other cameras with bigger lenses or more elements that are stabilized, Canon for example.

Is this camera a fraud? I personally don't think so. Could things have been done better, Yes. Did JVC make a mistake, Yes. I think what you said about being first on the market with a consumer HDV unit was JVC's driving force. I hope they learned a lesson. Despite some of the good things about the HD7, it is the negative things that have hounded the camera to this day. The camera may not have lived up to the expectations most people were looking for in a camera that cost $1200.00 street price when it was released. Add to this that the HD7 is not really a point and shoot camera, but was marketed that way, didn't help. The problem many were having with the .TOD extension, the initial Sharestation troubles and misinformation just made it worse.

A friend of mine told me, never by the first year release of a car. Why? Because they are in such a rush to get it out, their may be a few bugs in it. Wait another year or two . As they get the complaints and hear what the customers don't like or doesn't work, they will fix it the following year. Most of the time it does seem to work that way. This goes for electronics and, it appears cameras as well.

I think if you play around with some of the settings both in camera and during edit and conversion, you will find the right spot. I too must play around to get things just right. Let us know how you make out.

All the Best to you.
Manuel Correa is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > JVC ProHD & MPEG2 Camera Systems > JVC Everio GZ-HD and GZ-HM Series

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 10:40 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network