On 4/22/2012 7:16 PM, steve harley wrote:
on 2012-04-22 14:03 P. J. Alling wrote
A 24mp sensor gives a liner dpi improvement in a 13x19in print of
lets see,
(carry the one divide by 19), 50 dpi. For that I expect that a raw
file will be
roughly four times the size of a K-5 file and 90% of the time the
improvement
imperceptible at a normal viewing distance. It's worse if you view
your images
on a computer screen.
weird math
a 24 megapixel image file, given the same effective compression, would
be just under 1.5 times the size of a 16.3 megapixel K-5 file
the linear improvement should be sqrt(1.5) or about 22% improvement
assuming the sensors are proportioned the same; to express this as
dpi, start with the K-5's output of 259 ppi across the 19 inch output
size you mention (4928/19); a 24mp sensor of the same proportions
would give you 318 ppi, or 59 greater "dpi"
I rounded somewhere and came out 9 dpi short. That's a noticeable
difference? Also square roots are not necessary, and possibly wrong, it
assumes that the photo sites are square which may not be the case,
however you can look up the actual numbers, they are published and
simply divide the length of each side by the dimension you wish to print
to find the linear resolution. The math is very simple. I have no way
of knowing if the 24mp file is going to be 4 times larger but I do know
that the K-5 file is roughly twice as large as a K20D file, those
numbers are published. True the K20D has 12 bit color depth and the K-5
is 14,. but compression is a funny thing. You never know how it's going
to be implemented.
--
Don't lose heart! They might want to cut it out, and they'll want to avoid a
lengthily search.
--
PDML Pentax-Discuss Mail List
[email protected]
http://pdml.net/mailman/listinfo/pdml_pdml.net
to UNSUBSCRIBE from the PDML, please visit the link directly above and follow
the directions.
