Highlight Clipping Seems to be the Main Concern

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powervideo

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This has been a real interesting time on the AF100 forum this past week. No-one can say there isn't passion surrounding this camera, but as mentioned elsewhere some of the commentary has been less than helpful to the debate.

Panasonic's invitation to bring those experienced DOP's to Japan really is to be applauded. I'm sure other manufacturers involve camera ops in their product's development, but probably not as spectacularly public like Panasonic has done here. The Japanese footage has been very useful but probably in hindsight should not have been released. Everyone has been dying to see footage (myself included), but releasing preproduction material has caused a premature debate and possibly unrealistic expectations for the sub-5K camera.

I've been a long time Panasonic user since 2000 with a D910 Pro50, then a SDX900 and now a GH1 (hacked) and Varicam (tape). I've always loved the Panasonic "look". To my eye, it is less video-like than some other manufacturers and produces lifelike natural skin tones and a more organic structure (some would call it noise).

One thing the Panasonic cameras, particularly the SDX900 and Varicam, have been able to do is to hold the highlights. But even more interesting to me is how well the low-cost hacked GH1 holds the high contrast detail. Just do a Vimeo search and look at some of the better GH1 videos and you will see the difference between the GH1 contrast-holding ability and the AF100, even with graded footage.

The level of highlight clipping is the most worrying part of the camera for me. Like Philip I use Magic Bullet a lot and even the most subtle MB effect can blow out the highlights without any trouble. If the detail is not there to begin with, then MB will kill it every time.

At the very least I hope there is still time for the engineers to at least match the highlight handling capability of the GH13. I know the AF100 units tested in Japan were still pre-production, but I would expect that the assembly lines will start rolling within the next couple of weeks if Panasonic is to make a late December dealer delivery. The problem would be if the clipping is inherent in the new sensor design, but I would think this is unlikely.

I think it will be a great little camera; very useful on commercials, music clips and corporates. I've prepaid for one, so my verdict is already in.
 
I took some downloads from vimeo at 720p compressed. Applied a simple curve adjustment in post keeping a lot of the "flattness" and with a little bump in the hi values you really don't notice the clipping as much.
 
The problem would be if the clipping is inherent in the new sensor design, but I would think this is unlikely.

Do you think it could be the codec clipping the highlight detail? Highlights as opposed to shadows contain the most detail information in an image so perhaps one way the codec compresses is to kill all that detail in the form of clipping. If so this could easily be tested (and cured) with an external recorder.

Do other AVCCAMs have similar highlight clipping characteristics?
 
Do you think it could be the codec clipping the highlight detail? Highlights as opposed to shadows contain the most detail information in an image so perhaps one way the codec compresses is to kill all that detail in the form of clipping. If so this could easily be tested (and cured) with an external recorder.

Do other AVCCAMs have similar highlight clipping characteristics?

I don't know enough about codec design, but my GH1 hack is AVCHD and doesn't exhibit the same blow-outs even in equivalent Cine-D settings - well equivalent as I can get them on the GH1. My GH1 records AVCHD at 60mbs so that may be influencing the quality result from the GH1.
 
This has been a real interesting time on the AF100 forum this past week. No-one can say there isn't passion surrounding this camera, but as mentioned elsewhere some of the commentary has been less than helpful to the debate.

I've been a long time Panasonic user since 2000 with a D910 Pro50, then a SDX900 and now a GH1 (hacked) and Varicam (tape). I've always loved the Panasonic "look". To my eye, it is less video-like than some other manufacturers and produces lifelike natural skin tones and a more organic structure (some would call it noise).

One thing the Panasonic cameras, particularly the SDX900 and Varicam, have been able to do is to hold the highlights. But even more interesting to me is how well the low-cost hacked GH1 holds the high contrast detail. Just do a Vimeo search and look at some of the better GH1 videos and you will see the difference between the GH1 contrast-holding ability and the AF100, even with graded footage."


Similar story for me on gear - my first Panasonic was the 910 DVCPRO50, then SDX900 - which I feel or at least for me is the best standard def camera ever made, and now 2700 Varicam + 7D. Yes - these pannys definitely hold the highlights - time will tell with the AF100. Jan helped with issues/advice since the beginning back in 2000 - from her enthusiasm you gotta think that they're onto something special here. Looking forward to seeing this play out.
 
Why don't you guys wait for some clips that didn't use cine-D, before empirically declaring that there's "a problem"?

Hear hear. And to add --- ok lets say Barry actually had a set on hand with lighting there'd be nothing but oooh's and ahhhh's
 
Hear hear. And to add --- ok lets say Barry actually had a set on hand with lighting there'd be nothing but oooh's and ahhhh's
There will be plenty of testing soon enough that will answer all questions. Highlights will be tested extensively. Sets and lighting will be put to use. There's no reason to rush to any manner of judgement.
 
Why don't you guys wait for some clips that didn't use cine-D, before empirically declaring that there's "a problem"?

I'm not saying it is a problem; it's a concern. It will only be a problem if it ships this way. A lot of clips besides the Japanese tests are showing this clipping in high-contrast scenes, but I'm not sure if they all have been shot in Cine-D. I'm confident that the final result will be fine; I'm just a little nervous until it's in my hands.
 
Same here, 2700 and 170 in our inventory. I tell clients that if they're shooting in controlled lighting situations and no wide shots, the 170 will do well, otherwise the 2700 is the way to go for resolving wider shots and handling big contrast. The tonality is so much better, ditto light sensitivity, although Filmlike 3 or Film-Rec will slow down sensitivity. Main issue I have with the Pansonic palmcorders is how highlights have hyper chroma which is typical of low cost video cameras--totally unnatural, not film like.

Obviously there is a huge price difference between Panasonic's high end 2/3" P2 Varicams and their lower end 1/3" cameras(although the HPX500 also exhibits the same super chroma highlights, even though more expensive and 2/3"). My hope with the AF100 is for better latitude than the 1/3" cameras, better sensitivity, lower noise, better highlight handling. So far the tests are inconclusive, although Barry measured very good latitude with an early prototype.

It's hard to compare 32 bit processing in a P2 Varicam to a $5K camera, but I expect a more sophisticated image than the HVX200A/HPX170 at the very least. If nothing else, DRS should provide better highlight handling than what I'm used to with our 170, since the 170 doesn't allow DRS in 24 or 30p. I continue to have faith in Panasonic, Jan and Barry and others who have shot with this camera, we just need to hang on a bit longer and all will be revealed.
 
I dunno. It seems to be a reasonable question especially since Barry is an expert on Panasonic cameras - no not this one - but previous models, and he had similar issues.

I think postulating theoretical hypothesis may generate pertinent experiments. Yes, I understand Barry's point about not blowing this out of proportion - especially since a problem may not even exist - but there is no harm if we remain rational and cool-headed.

One idea is that cine-gamma-D is the issue but perhaps it is reasonable to think that the codec is to blame if GH13 users don't have the same problem. Again, I would love to see if highlights blow out similarly recording externally at a higher bit rate.
 
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I took some downloads from vimeo at 720p compressed. Applied a simple curve adjustment in post keeping a lot of the "flattness" and with a little bump in the hi values you really don't notice the clipping as much.

to my knowledge the definition of TRUE CLIPPING is that it is 100% information loss. meaning there is ZERO data there that means there is NOTHING that can be done in post to restore that because you cannot restore what is not there. so if you're able to restore something in post then it wasn't clipped to begin with. but the clipping i'm seeing on af100 you will not restore in post because it is true CLIPPING, i.e. 100% data loss in selected area
 
to my knowledge the definition of TRUE CLIPPING is that it is 100% information loss. meaning there is ZERO data there that means there is NOTHING that can be done in post to restore that because you cannot restore what is not there. so if you're able to restore something in post then it wasn't clipped to begin with. but the clipping i'm seeing on af100 you will not restore in post because it is true CLIPPING, i.e. 100% data loss in selected area

Sure - you can't restore what's been clipped. The PaPa's luma curve can make the transition more smooth as the luma values approach 100%, but it won't restore what's been lost...
I believe Cine-D gamma is the problem. It is the first choice among Panasonic users who want film-like images and I think most footage we've seen so far was shot with it. I wonder what it's gonna look like with B-Press - I liked it on my HMC150...
 
Here are some clips from some of my GH1 shoots that had high contrast situations or strong whites. Most of the clips were shot with as equivalent to Cine-D look as I could get, with the sharpness and contrast at a minimum. None of the shots have been graded or had any optical effect filters or grads used during filming. Considering the limitations of the GH1, if the AF100 is no worse than these, I will be a happy man!

 
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For me the big question about highlight clipping is-"Is it the AVCHD codec". Although it can look great, it still has limitations (like all codecs).
I plan on using an external recorder recording at 140 mbps (Nanoflash is my preference) and comparing the 2 in a digital grade (more than likely Color) at CineFilm here in Atlanta.
I am trying to put this camera into perspective- large sensor, HDSDI out, plenty of lens mounts and a sub $5K price.
It will be wonderful when I get this in my hands.
 
to my knowledge the definition of TRUE CLIPPING is that it is 100% information loss. meaning there is ZERO data there that means there is NOTHING that can be done in post to restore that because you cannot restore what is not there. so if you're able to restore something in post then it wasn't clipped to begin with. but the clipping i'm seeing on af100 you will not restore in post because it is true CLIPPING, i.e. 100% data loss in selected area

the problem, i believe, that the majority of this section is attacking is the fact that the clipping is very harsh and noticeable because there is not much roll off. What I'm saying is adding the slight curve adjustment in post doesn't restore any information, it just makes the transition smooth and more "organic" without blowing out and making hyper saturated chroma.
 
Here are some clips from some of my GH1 shoots that had high contrast situations or strong whites. Most of the clips were shot with as equivalent to Cine-D look as I could get, with the sharpness and contrast at a minimum. None of the shots have been graded or had any optical effect filters or grads used during filming. Considering the limitations of the GH1, if the AF100 is no worse than these, I will be a happy man!


nice video. the shot at 42 secs is absolutely beautiful. Bang on exposure there. Many of your shots demonstrate the hilight or objects or scenery. Do you have any on skin tones, because that's what the majority of us are "complaining" or commenting on.
 
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