Originally posted by losecontrol And still this shows why you don't need a 20mp camera. It's all about the distance.
It is true it is
mostly about viewing distance.
With that size to see the full picture one could not view it from a few inches or even a few feet away - one really would have to stand back.
However with us photo nuts walking closer is likely to happen - again with that kind of size - the distance is going to much greater than a few feet or for a normal handheld size print.
There has been a long standing contention that says if one can print for the largest handheld print that can pass very close scruntiny - eg: nose to paper - then any larger print at correspondingly larger viewing distance will be fine -
so again it's the viewing distance.
The normal "correct" viewing distance is supposed to be equal to the diagonal of the print - and the closest optimal distance for the human eye is supposed to be about 25cm or 10 inches. That's why the long standing critical print size has been 10x8 (diagonal = 12.8")....
(
EDIT to Add - actually strictly speaking a 10" diagonal print is 8x6 )
So the theory is that if one can print to 10x8 at critical "quality" - then anything larger will be OK (again caveat at normal viewing distances).
Of course again this breaks down if one goes very close to the print - (changes the viewing distance) - and for camera nuts - this may not be adequate...... but for most people this is OK.
200ppi has been held as a mark of quality for digital prints - so a 10x8 is a mere 2000x1600 pixels = 3Mp - that maybe why Canon produced their first dSLR at 3Mp level the
Canon EOS D30 (not to be confused with the 30D).....
However these days with more Mp this printing density has raised to 300ppi - which is close to the critical 6lp/mm print resolution (= 305 ppi) especially for smaller prints like 6x4 or 7x5 -
if one extends this 300ppi to 10x8 - then that's 3000 x 2400 ....
hello 6Mp (OK not quite, but close enough for jazz....)
That is why the rush of dSLRs was when it reached 6Mp
(eg: first Canon Digital Rebel)
(
EDIT to Add - actually strictly speaking since a 10" diagonal print is 8x6 that pixel count at 300ppi is only
4.32Mp!!!)
So "in theory" anything 6Mp and above should be able to handle almost "any amount" of enlargement - as that 12mp enlargement demonstrated (17 x10 metres) -
worst case 6Mp should be able to get the same quality for half that size (10x 8.5 metres) right? -
I would hazard to guess that most of us would be quite happy with that.....
EDIT to ADD
The video has not been available for a while now from the USA (and reported as not viewable from the UK either)
I uploaded the .flv video for anyone who wants to view it -
Link