800 TV lines resolution

G

Gugulino

Active member
As everybody knows the AF100 has only 800 TV lines of resolution. I asked myself, if it is then better to shoot in 720p. Should the picture look sharper than in 1080p?

Thanks!
 
What makes you say that? The BBC test measured 680 lines, not 800. In my experience, 720p looks a tad bit richer (more pixel detail for a fixed data rate), but 1080p looks cleaner, especially if you need to do in-image cropping down to a 720p delivery format. I regretting shooting an event in 720p when I really needed more lens reach than I had. I scaled the image up to get better framing, at the cost of a lot of softness. Had I shot 1080p, I would have only needed to crop, not scale.
 
I did some tests comparing how much detail the AF100 had compared to Canon 5Dmk2 and 5Dmk3. I found they were on par with eachother. Unless you need 50p I don't think 720 will be better than 1080. Maybe the image will loose even more when downsampled.
 
If I remember correctly, Barry Green said that the camera has 800 TV lines resolution.

Could it be that the picture looks cleaner after downsampling to 720p?
 
The 800 lines comes from the claimed specifications from the Panasonic factory. They said the camera was designed to a specification of 800TVL. In my measured tests I think I came up with more like 700.
 
If I have my PMW-F3 in 720p mode it's more detailed than the AF100 in 1080P mode so I can't see 720p on the AF100 to be an improvement over 1080p, but hey I can be wrong...
 
Gugulino said:
As everybody knows the AF100 has only 800 TV lines of resolution. I asked myself, if it is then better to shoot in 720p. Should the picture look sharper than in 1080p?

Thanks!
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800 TVL (vertical resolution) is about as good as 1080p HD gets for any single chip under $10k video camera. You are talking about optical resolution off a chart at the end of the signal chain after the lens, sensor, in camera processing, and recording.
 
Ok, I understand! It is more a measurement technique to measure the optical resolution, than the resolution of the output. I thought that the raw output picture has 800 TVL and is then down or upsized to 720p or 1080p.
 
I think the LPF is tuned to 800 lines but the chip and signal processing inside the AF101 can't really reach that high. I've even tried using external recording and frankly there's little to no gain doing that. It is an underresolved camera and the loss of detail can be severe.
 
Osslund, how many TVL has your PMW-F3? Perhaps Panasonic had to under resolve the camera, to prevent aliasing, moiree etc.
 
I haven't measured it but it's much higher and Sony claims 1000 lines which I have no doubt is somewhere near that. I never miss detail on the F3 as I did with the AF100.
 
Osslund said:
I haven't measured it but it's much higher and Sony claims 1000 lines which I have no doubt is somewhere near that. I never miss detail on the F3 as I did with the AF100.
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With significant aliasing according to the BBC camera test. 800-850 lines clean is as good as 1080p gets. Any more and you will get aliasing. This is true of the format regardless of camera.
 
alaskacameradude said:
Really? So the EX1 has aliasing???
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Of course it does. Just not enough to be a problem, as they tuned the OLPF about right on the EX1.

Whether a camera "has" aliasing or not, is usually never the question, as they pretty much all do. The question is "how much". And that can be optimized with proper sensor design.

Here's the quote from Adam Wilt's review of the EX1:
Sony claims 1000 TVl/ph (TV lines per picture height) resolution, and I see that on the test charts. There's a bit of aliasing past that point, but not so much as to be problematic. Picking an optical low-pass filter for a sensor is always a tradeoff: ensure attenuation at the sampling frequency and you risk losing too much high-frequency information; keep that sharpness and risk distracting aliasing and moir©. Sony seems to have split the difference finely; if I boost the detail setting the aliasing becomes apparent, but at the default setting (detail 0), or with detail off (roughly equivalent to detail -30) it's hardly visible on the test charts-and in the real world it simply isn't a problem.
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Barry_Green said:
Of course it does. Just not enough to be a problem, as they tuned the OLPF about right on the EX1.

Whether a camera "has" aliasing or not, is usually never the question, as they pretty much all do. The question is "how much". And that can be optimized with proper sensor design.

Here's the quote from Adam Wilt's review of the EX1:
Click to expand...

Barry, if I read that quote right, Adam is saying that aliasing turns up 'after' 1000 lines not 800.
 
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