HPX250: What Are P.A.P. Filters?

David Saraceno

David Saraceno

Moderator
Staff member
Okay, I'm lost.

I have seen references to P.A.P.Filters in a number of posts relating to the 250, and I can't find references to them in the manual, nor on line?

I would appreciate it if someone could indicate what they are and how they are used with the 250.

Thanks
 
The 250 has two settings, Type 1 and Type 2. You get at the menu by holding in the DISP/MODE CHK button and then pressing the menu button; it adds a new menu at the bottom of the list.

P.A.P. stands for something like Progressive Advanced Processing. In a quick nutshell, it's two ways to approach noise reduction. In Type 2, which is the factory default, it's using standard frame-based noise reduction and results in an ISO of about 320. If you switch it over to Type 1, the camera gets twice as sensitive and a lot cleaner, because it employs a new type of noise reduction, which is temporal ("3D") noise reduction. It examines not just the frame it's working on, but several frames before and after it, analyzing what it considers noise and vacuuming it up. As a result the image gets substantially cleaner, and then they can gain the camera up another 6dB and it's still cleaner than Type 2.

But there's a side effect. Type 1's temporal (time-based) noise reduction can introduce some artifacts in the video. The HPX370 guys found it, they called it "micro-jitters" or "micro-jello", where you could see some ghosting or trailing and some odd patterns in the background especially on patterns.

So, for safety, they ship it with Type 2. But if you're comfortable exploring type 1, and you don't see the artifacts, you can really get a quite cleaner picture and twice the sensitivity out of it.
 
Barry's on the money. The Type 1 processing is great for when the camera's locked off on the tripod since most of the artifacts that seem to arise from temporal NR have to do with motion, assuming here that the hardware can't keep up. This results in:

1. Ghosting, where contrasty objects seem to double in the same frame during fast panning or zooming.
2. Smearing, where very fine detail is removed by the NR during motion as it is considered noise by the aggressive processing.
3. Noise trails, where the processing doesn't manage to remove the noise fast enough and leaves a trail of noisy area behind moving objects.

That's it in a nutshell.
 
Is the PAP setting something that can be assigned to a scene file, so that a turn of the knob is all that's needed instead of going into the menu?
 
I've shot PAP1 quite a few times with my 250 and have yet to see any artifacts at all. I was wondering if Panasonic made any tweeks to the PAP1 when designing the 250?
 
Jim Simon said:
Is the PAP setting something that can be assigned to a scene file, so that a turn of the knob is all that's needed instead of going into the menu?
Click to expand...
No. In fact the camera needs to power down and back up in order to switch between the two PAP modes.
 
is there a video showing the difference between PAP1 and PAP2 under good light and low light?
 
dxl said:
is there a video showing the difference between PAP1 and PAP2 under good light and low light?
Click to expand...

I do remember seeing something but I couldn't find it. I use PAP1 now almost always unless I am shooting outdoors in bright light and handheld. Otherwise PAP1 lets me keep the f stop very low for a sharp picture. Here is what Barrys book gives spec wise (p215). PAP2 is close to ISO 320 and PAP2 is 640 ISO , so its almost 2xs as sensitive (Progressive Advanced Processing so its not just bumping up the ISO). Its a great tool to have with the push of a button without adding gain noise to your picture. Try it and you will see.
 
I was wondering about the argument of a 10 bit codec in a camera with a small chip set such as the HPX250. Those extra 2 bits as I understand it only encode the grain that much better and thus making the 10 bit codec rather unnecessary. Barry; do you think that it pays of to use the PAP 1 setting, as it removes the noise and thus making the 10 bit codec more effective?
 
Funny that Panasonic has deliberately cloaked the PAP-1 feature behind a hidden menu. It's almost like they are saying "don't try it until you really know the camera well."

I hope it doesn't cause any PAP-smearing to the image :) (sorry, couldn't help it)
 
KINOKS said:
I was wondering about the argument of a 10 bit codec in a camera with a small chip set such as the HPX250. Those extra 2 bits as I understand it only encode the grain that much better and thus making the 10 bit codec rather unnecessary. Barry; do you think that it pays of to use the PAP 1 setting, as it removes the noise and thus making the 10 bit codec more effective?
Click to expand...

Your math is wrong.

8 bit = 256 levels of gray.
10bit = 1024 levels of gray.

Big difference.
 
I had some noise issues in PAP1 on a bright outside shoot where I forgot to turn to PAP2. ND filter was maxed and iris was somewhere around 6. I got a LOT of noise in dark moving areas and thought the cam had a technical fault. One has to exrecise these setting switches to be able to fully take control of the 250 when one has to be fast and get the best shot.
 
I was shooting PAP1 in a dark auditorium yesterday with +6 db. The footage looked quite good for what it was. No noise. Very happy with the 250.
 
timbook2 said:
I had some noise issues in PAP1 on a bright outside shoot where I forgot to turn to PAP2. ND filter was maxed and iris was somewhere around 6. I got a LOT of noise in dark moving areas and thought the cam had a technical fault. One has to exrecise these setting switches to be able to fully take control of the 250 when one has to be fast and get the best shot.
Click to expand...

That's not necessarily PAP1. I was shooting the annular solar eclipse with pretty much the same settings. ND all the way, fast shutter speed and closed down the iris. Lots of noise in the dark areas. Backed off the ND one and opened up the iris some and noise was gone.
PAP was set to default.
 
mcgeedigital said:
Your math is wrong.

8 bit = 256 levels of gray.
10bit = 1024 levels of gray.

Big difference.
Click to expand...


I know how much shades of grey an 8 bit or 10 bit picture has. It wasn't what I was referring to. There is an argument that a 10bit codec doesn't really pay of in a small chip camcorder. As I understand it all that extra headroom is more or less wasted on encoding the grain in the picture that much better than an 8 bit codec does. In a camera like the HPX250 an 8bit 100Mbit coedc would probably be better then a 10bit 100Mbit codec. This could be tested with an externall recorder or something...

Small chip camcorders have lots of grain compared to bigger chip camcorders.

A 10 bit codec should have a much wider bandwidth than only 100 Mbits.

http://www.dvinfo.net/forum/archive/index.php/t-466803.html

So seeing as the PAP 1 eliminates much of the noise via temporal filtering it would be logical that the 10 bit codec would be utilised better. But the question is
does the PAP1 degrade the picture in terms of fine detail that much more than PAP 2 that it again negates the use of 10bit. Hope I was clear...
 
You must log in or register to reply here.
Back
Top