GH2 crop mode downsides?

roei z

roei z

Veteran
i would be glad for some other opinions on the matter.
yesterday i tried to shoot indoor footage at 650 iso 24p.
looked pretty well on regular mode,
but when using the crop mode, apart from bigger noise pixels and a bit less sharpness,
which are the logical differences (that can even look nice and 16mm like),
i noticed that even at minor lowlight situation i get ugly unusable mud.
am i doing something wrong, or we can say that crop mode in lowlight can get dangerously muddier very quickly ? (NOT like the regular mode)

could someone could also test or address this from his recent experience ?

thanks :)
 
no, i'm talking about the tele mode which lets you use a native 1080 res of the sensor without downscaling.
it's a new feature, nothing to do with the natural 4/3 crop. that way you can have x5 tele from any lens attaches (300mm = 1500mm)
without losing quality.

however, i wanted to hear some opinions on how well it can actually perform in lowlight vs the "regular" mode..
 
It's very useful mode but quite grainy at high ISO's. Other than that it generally looks fine to me and haven't noticed any obvious mud of course it will depend on the source material.

Couple of my own tests:

Lower light:
 
At the moment I'm using the Panasonic 14-45 (very good lens just not great for low light), 20mm f1.7 (excellent sharpness in the center), 45-200 (very good for the price and great build. The coffee video was all shot with an Olympus OM 50mm f1.8 via adaptor and the video at the gardens was shot with the 45-200 and I think there is a shot in the there with my 14-42 (which I've replaced with the 14-45)
 
your videos indeed look good, so it's weird, how come i get mud at certain shots... can you tell your findings on when it does get muddy on your shots?
it must get it at some point or another. just to be exact, thanks.
 
bradleysteenkamp said:
It's very useful mode but quite grainy at high ISO's. Other than that it generally looks fine to me and haven't noticed any obvious mud of course it will depend on the source material.
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Good vid - but worra lotta messing about for a cup of coffee :happy:

Philistines like me just take a spoonful of instant, and away we go.....
 
I wonder what other variables might be in play since the shots of the train and the ultra-closeup of the beans look fabulous and the second, closer shot of the blue bag looks really bad.
 
stoneinapond said:
How so?
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Severe shake. Shouldn't be shaking that much even if it was handheld. And since the wider bag shot, which I'm guessing was shot without the crop mode, is rock solid, I wonder what's going on...

Sorry to be picking apart your piece, Bradley. Everything but that one shot looks fabulous. It just makes me wonder what's going on and if maybe something about the other shots masks the problem?
 
roei z said:
i would be glad for some other opinions on the matter.
yesterday i tried to shoot indoor footage at 650 iso 24p.
looked pretty well on regular mode,
but when using the crop mode, apart from bigger noise pixels and a bit less sharpness,
which are the logical differences (that can even look nice and 16mm like),
i noticed that even at minor lowlight situation i get ugly unusable mud.
am i doing something wrong, or we can say that crop mode in lowlight can get dangerously muddier very quickly ? (NOT like the regular mode)

could someone could also test or address this from his recent experience ?

thanks :)
Click to expand...
In extended crop mode you are essentially using a sensor as large as that of a compact point and shoot camera. With those cameras, when using anything beyond ISO 200, you have to accept a loss in quality, regarding noise as well as resolution. So it seems to me, your experience is more or less what I would expect in extended crop mode.
 
But smaller overall sensor size doesn't equal more noise, smaller individual pixels equal more noise. The compacts have more noise because they squeeze 12-14 million tiiiiiiny pixels into that area. The pixels on the GH2 don't get any smaller, you're just using less of them. It shouldn't cause different noise (or anything else except FoV, for that matter) characteristics, just as switching from FF35 to APS mode on a Nikon D3 doesn't.

The answer must be that the GH2 sensor is ALWAYS bad at high ISOs but most of the time this is hidden by downsampling. If this isn't the case, my second guess is it's a software bug that can/needs to be fixed.
 
figured this is the case.
but i was unsure because of the video posted here which looks pretty good. he claims the crop mode is mud-less and clear, even in lowlight.
he didn't get back to me with info on his higher ISO experience.

so now i'm even more confused :)
 
Lee Saxon said:
But smaller overall sensor size doesn't equal more noise, smaller individual pixels equal more noise. The compacts have more noise because they squeeze 12-14 million tiiiiiiny pixels into that area. The pixels on the GH2 don't get any smaller, you're just using less of them. It shouldn't cause different noise (or anything else except FoV, for that matter) characteristics, just as switching from FF35 to APS mode on a Nikon D3 doesn't.
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I think you're walking on thin ice with those statements. The D3X with its smaller pixels doesn't have more noise than the D3 at low and medium ISOs if you're comparing them at the same print size. Because the (slightly more noisy) 24Mpix of the D3X need less "enlargement" than the (slightly less noisy) 12 Mpix of the D3 to reach the same print size.

And yes, it's overall sensor size that matters because sensor size is limiting the amount of light and thus the number of photons that reach the sensor. The larger the sensor the more photons fall on it at any given exposure. Obviously, if the sensor is twice as large, twice as much light falls onto it if you expose both at f4, 1/50s. The more photons available, the less amplification needed. The less amplification, the less noise.

Switching from FF35 to APS mode on a Nikon D3 does not change noise if you compare them on your monitor at 100%, but it does increase noise if, again, you're comparing them at the same print size. A 40x60cm print from a D3 FX exposure is less noisy than from a D3 DX exposure at the same ISO.

OTOH, the D3 does produce cleaner images than the D3X above 1600ISO. So there seems to be a limit for pixel size at any given ISO (edit: if you want good quality). And small sensor compact cameras with 12 or 14Mpix are beyond that limit at anything but their base ISO.
 
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