---- Original Message -----
From: "Moose" <olymoose@xxxxxxxxx>
> On 5/25/2010 6:28 PM, C.H.Ling wrote:
>> You are lucky, 5D II has very bad red channel noise, this one shot at
>> ISO160
>
> It's been years, so I don't remember details. I read someone who claimed
> that the intermediate ISOs on the 5D were noisier than the primary ones.
> So I checked, and it was true of mine, as well. So, 160 is noisier than
> 200, 320 noisier than 400, and so on. Since then, I've only used the one
> stop series starting with ISO 100.
>
> I have no idea whether the same might be true of the MkII, but it might
> be worth checking.
>
Since discovered the pattern noies problem of 5D II, I have checked all low
ISOs, don't see 100, 200, 400... are better than any intermediate ISOs.
>> , try to convert it with PS red filter. There are lots of noise and
>> artifacts everywhere, image is totally non usable:
>>
>> http://www.accura.com.hk/temp/IMG_4865.JPG (4.5MB)
>>
>
> I disagree, at least for this particular image. The problem is easy
> enough to see. However, I don't like what the red filter does to the
> mural, so wouldn't want to use it there anyway, And it doesn't do
> anything of use to me on the rest of the buildings. If I use it
> judiciously on sky only, it does a nice job, with only a couple of areas
> of subtle mottling which are easily corrected. There is trouble in the
> couple of spots where the red channel is already blown in the brightest
> clouds, but that's an exposure/processing problem, not the fault of the
> filter process.
Here is another image at ISO 100. straightly converted from RAW with DPP, no
sharpen and no NR.
http://www.accura.com.hk/temp/IMG_2587.JPG
The sky looks terrible with red filter under CS4 and there is no blown out
red.
>
> It's also possible to get the sky effect using other tools after a
> straight B&W conversion. In the English idiom, there's more than one way
> to skin a cat.
>
I just wanted to point out that software filter does not always works. Of
course you can always touch up the faulty parts but I prefer the save my
time for other things. In this case I prefer a real glass filter.
> I can certainly see that there would be other sorts of image where the
> red channel problem would not be so easy to get around.
>
> Thanks for helping me resist the MKII. ;-)
I had seriously thought about switching back to the original 5D but
sometimes I really need liveview for critical focusing and 21MP is very
useful for lens test.
C.H.Ling
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