ISO 1600 low light performance

commanderspike

commanderspike

Carbonite Member
I shot this last night http://www.vimeo.com/5744461 (details in the footage forum: http://www.dvxuser.com/V6/showthread.php?t=178315)

A few striking things I found:

ISO 1600 is almost noise free for well exposed shots.

With a Zeiss F1.4 lens the camera's maximum brightness at 1/30 is the same if not a little bit better than what the human eye sees.

720p gives the same detail on a 50 inch screen as 1080p :huh:

This is a complete reversal of my shooting technique so far. I attempted to underexpose slightly, have ISO no higher than 800 and stick to the 1080 24p mode for extra resolution.

All in all very pleased with the GH1 & lens adaptability, and even though my Zeiss 85mm F1.4 has scratches in the front coating they don't affect the picture. Look for the bargains which are less than pristine and by with confidence :beer:
 
Underexposure has always been the rule for video cameras, you always wanted to protect your highlights and aim for a little underexposure. Not necessarily so with the GH1. Underexposure can lead to banding, and underexposing 1600 ISO footage is simply horrible. Properly-exposed 1600 is so clean, noise-wise, that it's really exceptional for someone used to shooting on a 1/3" video camera. But you don't want to go underexposing 800 or 1600 ISO footage.

The lower the ISO, the more the camera tolerates underexposure. Underexposed 800 or 1600 leads to blocky muddy soft footage with flat colors and general unpleasantness.
 
Spot on Barry. With an old DVX100 I had 'excitable' even in bright areas of the picture in low light, and underexposing would dampen this affect.

With the GH1 it's the opposite. Feed it enough light at ISO 1600 and the image is quite simply amazing.
 
Barry_Green said:
Underexposure can lead to banding, and underexposing 1600 ISO footage is simply horrible.....Underexposed 800 or 1600 leads to blocky muddy soft footage with flat colors and general unpleasantness.
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Thanks for chiming in on this Barry. I had heard some reports on this but nothing definitive.

Btw, you had JDS's GH1 for a while didn't you? I'm assuming you put it through the wringer? Does this mean we can expect a GH1 Book soon?!? :D
 
commanderspike said:
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ISO 1600 is almost noise free for well exposed shots.
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But, why would you like to go to 1600 ISO if you already have well exposed shots!!!

I think the only reason you would like to up the gain/ISO is when you do not have a well exposed shot and you want to capture a shot in the light that is inadequate.
 
Examples like these are why I disagree that the MKii is all that "faster" than the GH-1. The fact that you're able to shoot wide open without worrying about the image going to shallow hell is plenty excuse to employ fast glass.

I haven't been using my lenses above F3.4 ~ 4 on the MKii which renders the lowlight advantage useless.

Nice clean footages. Thanks for sharing.
 
720p gives the same detail on a 50 inch screen as 1080p
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On a 42" screen I see a lot of difference if the scene is a general view. Take some footage of a street scene in 720 then in 1080 and look at the car number plates. I find they are legible much further away in 1080. Stuff like chain link fences in the distance can quickly show up the difference, imho. For closer shots, admittedly the difference is less.
 
Having now taken some footage in 720p of a child playing indoors, I have to say that having forgotten that I'd not set the GH1 to full high definition, I didn't notice any need for more detail in those shots. I guess I'll simply use the right definition level for the particular shot to be taken, in future - FHD for wide/detailed, SH for closer.
 
During the day I've been shooting everything Iso 100 (outdoor) and usually try to (when shooting in a situation where i get to add more light) not go abpve iso400. Is there a reason to shoot higher than 100 in outdoor daylight?
 
Is there a reason to shoot higher than 100 in outdoor daylight?
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If you want high shutter speed and/or deep DOF - which for filmic look you probably don't but for other purposes you might.
 
Yeah that was what I was thinking...usually in daylight you have leeway to stop down or use high shutter, and in fact often need to w/o NDs. Indoor I would usually add light before considering raising ISO (if it's an option.)
 
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