Re: [OM] Birds, Bokeh, and DZes

[Chuck Norcutt]

After posting this note I accidentally stumbled across the following 
link on DPReview which illustrates that downsizing really doesn't do 
very much in practice to reduce noise.  It would if noise was random but 
in the case of digital cameras with Bayer patterns sensors it's not.

Check it out
<http://blog.dpreview.com/editorial/2008/11/downsampling-to.html>

To quote the main point: "The mathematical theory may tell you that 
downsampling works but it won’t if your noise grains are any larger than 
one pixel (and they nearly always are from a camera with a bayer color 
filter array)."

Chuck Norcutt


Joel Wilcox wrote:
> Either downsizing or just the fact that the image is small.  Even with
> high ISO images I don't detect much noise until about 50% pixels,
> which is a pretty large image were it to be printed at that size.
> Thanks for looking.
> 
> Joel W.
> 
> On Sun, Jan 4, 2009 at 9:20 PM, Chuck Norcutt
> <chucknorcutt@xxxxxxxxxxxxxxxx> wrote:
>> Oooh!  I like that.  I don't see any noise but downsizing tends to get
>> rid of it.  But I'll take your word.
>>
>> Chuck Norcutt
>>
>> Joel Wilcox wrote:
>>> I've been looking among recent photos for images that show the bokeh
>>> qualities I like when working with the DZ 50-200.  Here's one that's
>>> possibly serviceable:
>>>
>>> http://www.flickr.com/photos/99378213@N00/with/3168574152/
>>>
>>> (You can force a larger image and better background by clicking the
>>> slideshow icon.  Sorry for inflicting Flickr.)
>>>
>>> I don't expect it to knock your socks off, but the bokeh is reasonably
>>> pleasing to me.  It seems to me that 150mm is a fairly sweet spot,
>>> with aperture in the range of 5.6 to 8, or even wider if the subject
>>> doesn't require too much DOF.  This image was shot horizontally but
>>> cropped vertically to produce an image that seemed somewhat more
>>> interesting to me.  It was shot at ISO 800.  I didn't use NR as it
>>> didn't seem to me to need any.  Your sensitivity may vary.
>>>
>>> I've always sort of felt that bokeh is something managed and planned
>>> for every bit as much as it is a quality associated with a lens  At
>>> any rate, I tend to blame myself for jittery backgrounds (which has
>>> probably saved me from drifting into Leica-land).
>>>
>>> Joel W.
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