It is not the codec, it is the onboard computer!

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philiplipetz

Veteran
Here are the symptoms of "codec problems" the GH1:

1. IQ suffers when image becomes complex
2. Movement degrades IQ
3. At least one report that audio suffers when IQ suffers
4. Lowering resolution to 720p from 1080p improves IQ
5. IQ suffers when using m4/3 lenses that trigger onboard distortion correction
6. Kit lens IQ is much better in still tests than in video tests
7. Panasonic AVCHD implementation at 13mbps in other cameras can be better than 17mbps in GH1
8. Several informal reports that AVCHD data rate drops when presented with kit lens and complex images

Panasonic knows how to make good AVCHD codecs, what is happening is that the onboard computer is insufficient to handle all the tasks that are thrown at it, and so it is programed to DELIBERATELY reduce the AVCHD quality when it is stressed. This allows it to put out something. Unless it reduced IQ there would be dropped frames when the computer fell behind.

If this is true then requests for a firmware upgrade are futile unless you are willing to forgo one of the automatic features. However, dpreview shows that the kit lens is not very good when tested on a camera without internal distortion correction, a camera without the onboard computer. This suggests that the Panasonic cannot turn off lens correction to improve IQ, AVCHD will improve but lens performance will suffer. Clearly, Panasonic is committed to onboard lens distortion correction so they cannot retreat from that path.

It appears that the lens team presented the computer team with a lens that required more correction than the computer team had allocated. They had to ship and the result was deliberately degrading the image at times.

Still I am seriously considering purchasing a GH1 and using only my FD lenses, but I will await the GH2 eagerly. The only firmware upgrade that may work is if they somehow figure out a way to use the onboard computer chips more efficiently. Not easy to do. I really hope I am wrong as I want a miraculous solution.
 
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That is a great summary. Great post.

I agree with every point and have also seen that mud is worse when using the kit lens. The miscommunication between the lens team and the electronics team is also very plausible.

Mud is definitely less bad with my manual lenses from Canon & Zeiss.

Firmware fixes can help by making the software optimised, thus saving on CPU time but I think this is one river which is too big to bridge.

Maybe try lowering the bitrate to 13 from 17 and see if this results in a less stressed CPU at all times. You may see a slight lowering of peak IQ but a more even and consistent picture with highly detailed scenes & lots of movement?
 
philiplipetz said:
This suggests that the Panasonic cannot turn off lens correction to improve IQ, AVCHD will improve but lens performance will suffer. Clearly, Panasonic is committed to onboard lens distortion correction so they cannot retreat from that path.
Click to expand...

Is lens correction disabled using manual lenses?

If not, they could realease a firmware that disables this function (and others) shooting without the kit lens

Regards

Gary
 
Couldn't you just set the camera to "shoot without lens" function, but still use the kit lens?

(I'd try it but my camera is on loan at the moment.)
 
Neither is a good option, because the lens correction needed for the kit lens is quite dramatic. Unless you want a load of barrel distortion, there is no way Panasonic can engineer a 14-140mm lens without using electronic distortion correction.

The shoot without lens function doesn't disable the kit lens auto functions, it just allows the camera to keep shooting when the kit lens isn't attached.
 
Yeah but you don't have the camera either. I haven't seen problems with my GH1. If you hold it like an average consumer would hold the camera and expect to see Spielberg like images then the problem isn't the camera. There are a lot of people like that. Why not wait til you actually get to play around with one first? All images in any camera can be broken. Some people will tell you all this negative stuff about it but I think they might just need to look at their composition instead. Either way I wish you luck on your future endeavours what ever camera you do decide to choose.
 
Distinction

Distinction

There are two different kinds of "codec problems". One is the mud that everyone talks about when you whip the camera around with the kit lens. Personally, I haven't seen mud since I started using nikkors and/or the kit lens with autofocus off. But there is another problem even with tripod shots and that is most definitely a bitrate problem. With 8 bit compression you always get banding and macroblocks. The higher the bitrate the less offensive these are. That's the sole reason the 7D is interesting to me.
 
Why it matters that it is the computer and not the codec

Why it matters that it is the computer and not the codec

There is no need to flame me because I do not have a GH1 in my hands. I have had it on preorder at three places for many months. Many people look to DVXuser to find out what the pros think about technique and gear. It is as much an educational resource as community of pros.

There is a very real human need to feel good about your decisions and I do mean to threaten anyone who has a GH1. It is a great camera.

The key is to make films, not pixel peek.

I have been eagerly awaiting the results of Illya Friedman's demonstration of a
GH1 film projected onto large theater screen. He was supposed to do this at the DVexpo yesterday. If that is positive then the doubts about the GH1 should be put to rest.

So why did I write this post? Everyone is complaining about the wrong thing. It is the computer, not the codec. Perhaps there is a functional reason that 1080p was disabled in the GF1.

If we know that it is the capacity of the onboard computers we also can trust that the codec problems will go away in the next version of the hardware. This makes it easier to buy into the Panasonic m4/3 system than if we thought that Panasonic could not produce a capable codec.

There are so many advantages to the m4/3 system and the GH1; longer recording times, smaller size, EVF while filming, flexible LCD viewfinder, and the ability to use the highest quality lenses from almost any source. All of these things suggest that it is Canon and Nikon who will have to change, not Panasonic.

If we can trust the codec when it is allowed to run without being deliberately throttled then we can enjoy our GH1s, knowing how to work around their limitations, while confidently expecting that all of our gear will work marvelously well on the GH2 that will have faster computer chips that allow the full potential of Panasonic's codecs to be expressed in our films.
 
I didn't see anybody flaming your post. I think that was a misunderstanding. I think for what you want to do with the camera, same as me, it is fully capable. I think you will find too often there are certain people here who attack the camera when they should be looking into their composition. Those are the people I can't understand because they seemed to have missed the point of filmmaking. It isn't the camera that makes one good. Back to the camera itself I have not found so many problems with it like certain people will claim. Sure you can break it but take into consideration the technology we have here. This isn't film so we don't have to wait to see if the image went bad. We can view it instantly. Now of course viewing it on your LCD isn't exactly recommended for looking for problems but it does have an HDMI out. Sure it isn't live, but there is no reason somebody couldn't get a shot then review on a monitor and then adjust lighting, exposure, composition, and camera movement then shoot again to fix a problem they might encounter. Keeping notes of all the problems that might happen is a must to save time later. I would use the hell out of the camera before jumping right into shooting to become familiar.

And in the end, for me, it is all about story. There are ways around the camera's problems and we are talking about a $1500 camera that has image quality beyond anything only a few years ago. So the camera isn't going to make up for story or composition but it is a good thing to know the work-arounds. What makes finding the work-arounds tough is going through all the negative bashing about it, again not directed at you.
 
Maaan I was telling for ages that the hardware is not strong enough but people like commanderspike wouldn't believe me :Drogar-Evil(DBG):
 
I checked some of the footage from last weekend where I got some stunning shots and some mediocre. I found one clip, of the mediocre ones, that had clear mud and they all where shot with a Nikon 35/2.0D lens.

So even with this lens we will have mud. This was no serious issue since the clip itself was so bad. My fault for shooting this bad...
All the clips where I had shallow dof where stunning! The GH1 really likes to have it shallow and it seams the cpu don't have to deal with to much detail.
 
There is an onboard computer revolution about to happen with all manufacturers. Recently a Canon rep said that the DIGIC IV chip was designed for stills with live view but the DIGIC V chip will have a core designed around real time codec encoding. Only then will DSLRs move from being still cameras with stacked still images and become true video cameras. ALL current DSLR chips are designed for still images. In the GH1 we see it as mud but in the 7d it seems to be moire and aliasing. All symptoms of forcing live view feeds into a chip that then has to encode them. Much more efficent to encode the frames as they are imaged. Then the compromises that lead to degradation can be gone.
 
The GH1 likes shallow DOF because blurred backgrounds are less detailed. Just using shallow DOF will not stop mud if something else stresses the onboard computer. Know how to baby it and marvel at the stunning results. It is harder to encode poorly shot film
 
I must have a GH1 from the magical batch because I have no "mud" problem with 1080p, unless of course I whip it around like a crazy person just to see how it reacts. And yes I am shooting with the kit kens with a camera that I am holding in my hands now. If you are a good cinematographer you will have absolutely no problem whatsoever with it because you would know how to properly shoot. I hate to repeat the point but unless you are really good as a shooter you will continually have problems, and not only because of "mud". People have to learn how to shoot properly first then go out and get the GH1.
 
I got a question. Is the GF1 and GH1 have the same hardware internal? I notice the Venus Engine HD aka Venus Engine V is used on both. However, they decided to implement a AVCHD LITE codec for that one. Do you think that Panasonic pushed the limits of the VENUS Engine a bit too much for the GH1? Possibly a good upgrade would be an option for AVCHD Lite?
 
Sorry, but how can anybody make ANY conclusions about ANY product first, without knowledge of the REAL engineering of such product and second without actually having such product in his hands. It is amazing, just amazing. The very first thing with the GH1 is that you have to actually know how to shoot anything properly with any camera then you have to actually go out and shoot something worthwhile with it. I just went out a couple of hours ago and shot some more foliage, traffic, people walking the streets at 1080p and guess what? No problems. I did smooth pans, tilts, the whole thing and everything looks fine once again. Please, once you have the camera in your hands and actually shoot something with it then report your findings. It is an amazing disservice to everybody here informing on something that you really have no knowledge of first hand.
 
John, suggesting that we cannot learn from other people's experience is absurd. Letting other people elevate the state of knowledge is the basis of human civilization. Shared experience, group memory, is what makes us human. It would be absurd to state that the camera feels horrible if I had never handled it, but it is NOT absurd to summarize the experience of DOZENS of other people and use that as the basis for my statements. That is what we are taught to do in school.

Please base the rules of conduct in this forum on the same rules that are commonly used in daily life. Are you saying that we cannot have an opinion on the President because we have never met him? Are you saying that the only people who can decide our political fate are the people who actually handle the day-to-day details? Of course, you are not saying anything that absurd. Yet, your suggestion that the only people who can comment on the GH1 are owners is equally wrong. You are a senior member of this forum and I respect that but I also respect the many people whose experience I summarized in the post that opened this thread.

As a ex-CEO of many software companies I have some knowledge of how the demands of hardware are handled by stressed computer programs, and I recognized that pattern in many posts of our fellow DVXuser group. Yes, I do not have the internal schematics of the design, but then nether did the team that hacked the Canon 5dMkII and they used their past experience to guess how the camera was programmed. I was told, but do not know if it is true, that many of them never handled or owned the 5dMkII yet their guesses where still valid.

By your standards I should say that you have no right to question my conjecture because you are not a computer geek. I disagree, you have every right to say whatever you want . But please recognize that the best way for the community to grow into the highest standard is by building on the experience of others to create new and better things. That is why we gather together in a virtual community; that is community.
 
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