Does the bitrate on the AF100 drop in lowlight?

Shooter said:
Your grader is absolutely correct. Protect the highlights. He should also advise..protect some detail in the shadows

But he is not telling you to abitrarily "under expose" them by cranking down on the aperture ( or ISO as some may propose)

He is telling you to expose them on the waveform correctly. They need to sit at a value that they should be or that you wish them to be. (that can be ..anywhere except in the clip zone or the ped)

Understand this: Any color or tone (incl. black) will become white if you over expose it enough. The converse is true also and any color / tone will become black if you under expose it enough.

May seem strange concept..but ..you need to light for black ( and expose for shadows as well as highlights and mids). It does not happen by itself. All cameras have a limited range of tone/levels.

BTW: Film Noir is not achieved by simply cranking down the exposure and it certainly is not shot with limited lighting. Exactly the opposite in fact.
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But, I haven't seen this kind of blocky noise in darker areas of frame on any other camera I have ever used, apart for slight occurrences in 5D footage. If the AF100 is especially sensitive in this regard it's worth knowing.
 
BTW: Film Noir is not achieved by simply cranking down the exposure and it certainly is not shot with limited lighting. Exactly the opposite in fact.[/QUOTE]

I had a blast lighting our Film Noir tribute.
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ten1.jpg


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taylormade said:
BTW: Film Noir is not achieved by simply cranking down the exposure and it certainly is not shot with limited lighting. Exactly the opposite in fact.
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I had a blast lighting our Film Noir tribute.
ten3.jpg


ten1.jpg


ten4.jpg
[/QUOTE]

One and two ...especially lovely. Nice work. What were these shot for?
 
Apart from the great shots.... say a friendly "thank you" to your costume-designer and the make-up / hairdresser. Good job on this part too.
 
So here is a fade to dark background grab.
I used noise clean settings without added detail coring. Looks pretty darn good.. but
You can see the breakup around the lightsource glow against the dark background. I figure this would be a situation that pushes the codec? If the nano can improve on this then that would be spectacular.

bpress
Norm2
-2 master ped
detail lvl -7
v detail -7
coring -7
iso400

 
Nothing wrong with the shot but it really is a situation that any camera or codec would struggle with. Including film cameras.

Shooting a light source ALWAYS exhibits this unless extreme control measures are taken. eg you could have exposed for the source light at 96-100% IRE and pumped up a separate key light on the guitar.

Your light source is also straight down the barrel so it is also flaring the lens with no way to cut it.

Actually ..I really like the shot ( although I am a bass player.. I really like instruments and alcohol in the same shot.)
 
Actually ..I really like the shot ( although I am a bass player.. I really like instruments and alcohol in the same shot
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haha for sure. glad you dig it.

I was doing tests earlier with CineD and NORM1 and just those settings alone introduce so much noise that I can understand how everyone freaks out early on. I'd love to use cine D in lowlight if the nano could reduce some of the noise(if it's codec noise)

Here's a shot with CineD and NORM1 with detailing at -2.




and here with the images correctly stretched.



 
I'm noticing that all the examples are from controlled light situations. What about when you're shooting in available light and you are doing the best you can? Usually to protect the highlights I do stop down as much as I can. It's worked with other cameras without the blocky noise, any tips on what to do with the AF?

I don't have the footage at my fingertips but have the camera and I can see the blocky noise in the black/grey gradients on a larger monitor (not on the LCD). Again this is with available light indoors, lit by a large window. So it's bright on one side of the subject, dark on the other. Looks perfect in the "lit" areas apart from a tiny amount of banding that's acceptable.

Those noir grabs look fantastic btw.
 
tipota said:
Apart from the great shots.... say a friendly "thank you" to your costume-designer and the make-up / hairdresser. Good job on this part too.
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This was an interesting project. The actors really liked the script I wrote and went into the shoot with amazing gusto. We shopped old clothes stores together and picked out the costumes - all authentic forties stuff. The actresses did their own hair and make-up, helping each other out before we rolled camera. I did the location scouting - St. Louis is an old town with lots of forties visual excitment. This film was truely a group effort on all levels.

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ten2.jpg
 
Okay so I couldn't get hold of the original footage that I was talking about, so I grabbed the camera, stuck the Lumix 20mm 1.7 on there and took a picture of our Lucy. I stopped down deliberately to show the chunky noise that was appearing in dark areas - or rather appearing to appear.

http://www.pleasedsheep.com/LucyAF101.bmp (bmp)
http://www.pleasedsheep.com/LucyAF101.tga (tga)

ISO200, at about f2. Lit from a large lounge window.

I will reiterate that I wouldn't usually shoot this underexposed but I just wanted to show the blocky noise, which with other cameras I didn't get no matter what. I've put it into two file formats to avoid errors when exporting the still frame.

And here's Lucy at ISO800 at, if I remember correctly, f1.7.

http://www.pleasedsheep.com/Lucy-Brighteraf101.bmp
Not as bad, but it's still there. It's like chunky noise/posterization.
 
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I don't believe the posterization in near-black areas of your sample shots is primarily due to a lack of bitrate. It's more likely caused by an inherent limitation of the sensor's low-light tonal range, further degraded by the 8-bit, 4:2:0 color sampling of the AVCHD codec. There simply isn't enough mathematical precision at such low illumination levels to accurately capture subtle color gradients. To achieve finely detailed dark areas, scenes like this need to be shot at higher exposure levels and graded down in post-production.
 
astigmatic said:
So here is a fade to dark background grab.
I used noise clean settings without added detail coring. Looks pretty darn good.. but
You can see the breakup around the lightsource glow against the dark background. I figure this would be a situation that pushes the codec? If the nano can improve on this then that would be spectacular.

bpress
Norm2
-2 master ped
detail lvl -7
v detail -7
coring -7
iso400

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Isn't +coring values to reduce noise? Maybe that's part of it?
 
Benjamin Eckstein said:
Isn't +coring values to reduce noise? Maybe that's part of it?
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coring is supposed to reduce noise caused by detail levels. Since I turned down the detail levels I turned down coring. I actually tend to keep coring down whenever I can because I don't like the look of noise reduction.
 
booth said:
Okay so I couldn't get hold of the original footage that I was talking about, so I grabbed the camera, stuck the Lumix 20mm 1.7 on there and took a picture of our Lucy. I stopped down deliberately to show the chunky noise that was appearing in dark areas - or rather appearing to appear.

http://www.pleasedsheep.com/LucyAF101.bmp (bmp)
http://www.pleasedsheep.com/LucyAF101.tga (tga)

ISO200, at about f2. Lit from a large lounge window.

I will reiterate that I wouldn't usually shoot this underexposed but I just wanted to show the blocky noise, which with other cameras I didn't get no matter what. I've put it into two file formats to avoid errors when exporting the still frame.

And here's Lucy at ISO800 at, if I remember correctly, f1.7.

http://www.pleasedsheep.com/Lucy-Brighteraf101.bmp
Not as bad, but it's still there. It's like chunky noise/posterization.
Click to expand...

I see the blocking in the first one. But honestly, at this low exposure I would expect something like that. All my previous cams except for the 7d wouldn't even capture data at that low light level. And the 7d would add it own type of artifacting like vertical banding. However, again, I wonder how direct 422 capture could improve things.

The second image looks darn crisp to me, what are your settings. On my monitor it's hard to see any blockiness. EDIT : I know it will be more obvious during moving playback.
 
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astigmatic said:
I see the blocking in the first one. But honestly, at this low exposure I would expect something like that. All my previous cams except for the 7d wouldn't even capture data at that low light level. And the 7d would add it own type of artifacting like vertical banding. However, again, I wonder how direct 422 capture could improve things.

The second image looks darn crisp to me, what are your settings. On my monitor it's hard to see any blockiness. EDIT : I know it will be more obvious during moving playback.
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It is there, just above her out of focus eye. The settings were stock scene file 1, but with Cine Like V, sharpness dialled down to -4 and Matrix Norm 2. Just try raising the brightness a tad, and yes on movement it is more apparent due to it constantly changing shape. Perhaps I'm being picky, after using the EX1 for two years I haven't seen this kind of thing. It does appear in 5D footage from time to time (I find on gradients of white more than anything). Unlike the EX1 I have no IR problems and no issues with the lens/backfocus, etc! ;)

mcgeedigital said:
I see nothing abhorrent in that iso 800 grab.
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I could work with it, it's just when it comes to grading it's a struggle. And if I use Neat, it does a great job with removing the normal noise but doesn't touch any kind of blocky noise.

But, as long as I know it's not a fault and it's just one of the cameras quirks I can work around it.

Thanks for the replies.
 
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