Originally posted by sammie Recently purchased a K7
I just came across the Imaging Resource review of the camera. So, mostly good stuff I guess, but one thing that I worries me about about the review is the camera's inability to render the red leaf fabric details like all the other cameras can. Instead of rendering any detail whatsoever, the fabric is completely blurred. No other camera does this. What's going on?
First I think this is a really good call and observation.
JPGs have a difficult time rendering in the red - the lossy compression seems worst in red - anyone can easily see this for themselves by saving in JPG with increasing compression.
However I believe most APS-C dSLRs all have this problem to an extent.
I think the crop shown was at ISO1600 or above - this is intrinsically pretty noisy for an APS-C sensor - it is actually pretty amazing the image quality that modern dSLR are capable of extracting.
But let us see some actual examples and comparisons all crops from Imaging-Resource sample test shots -
First establish a baseline -
All crops still have their EXIF data attached
At ISO200 -
as one can see the K7 does pretty well against the 12Mp
FULL-FRAME Nikon D3S at its true base ISO.
Of course the details are destroyed by ISO1600 for the K7 -
but it is not alone -
compare to the top of the line APS-C dSLRs Nikon D300s and Canon 7D -
yes, the Nikon and Canon are a bit better - but really nothing to write home about - especially if one compares these to the baseline shots at ISO200 above -
by ISO3200 both the Nikon and Canon look pretty bad too:
Actually the K7 at ISO800 is still pretty respectable for this patch -
all this means is that there is probably a "leap" in noise at and above ISO1600 -
and unfortunately Pentax strategy in its JPG appears to sacrifice more in the red area.....
However what really surprised me was this:
I think the K7 uses the same Samsung sensor as the Pentax K20D - look how much detail is retained in that same red area even at ISO3200!
The K20D ISO200 crop is included for a base reference.