120 is of course a general term for the format.
And I even shoot Medium Format, using an old 6x6 TLR.
And your objection is irrelevant. Especially since I was dealing in
generalities (Otherwise I would have specified Emulsion and format
versus specific digital cameras)
-Adam
J. C. O'Connell wrote:
I think someone needs to tell you that you cant
calculate resolution of a sensor required to
match "120" film because there is not a single
120 film format. there is a whole bunch: 645, 6x6 6x7 6x9 6x12
and 6x17 formats all in wide usage by 120 film users. I hate to say it
but that oversight gives you away as not really
knowing very much about medium format at all...
That's OK you wont need to know as its dying away
along with 35mm soon. But "120", that's really not
a format....and you cant calculate unless you specify
which specific format on the 120 film you are trying to match on digital.
JCO
-----Original Message-----
From: Adam Maas [mailto:[EMAIL PROTECTED]
Sent: Monday, September 19, 2005 11:07 PM
To: [email protected]
Subject: Re: Pentax K 2.5/200mm
Note you're assuming that resolution scales linearly with sensor size.
It doesn't, although it's not that far off.
Note that I also did not say that the 17MP can exceed 120, and your own
math shows that it can match it under the same 'average' conditions that
I quoted for 6MP.
So your math doesn't prove your point. Since it suggests that 27-43MP
will exceed 120 and 17-26MP will match it. And the latter was exactly
what I asserted. Since the resolution scales slightly slower than the
sensor size (And this is primarily a lens limitation, not a film one)
it's fairly easy to consider 17MP a match for 120 in general.
-Adam
Mishka wrote:
120 film has at least 2.8 times (645) or 4.3 (67) the area of 35mm film
per shot.
10MP * 2.8 == 27MP != 17MP.
10MP * 4.3 == 43MP != 17MP.
6MP * 2.8 == 16.7MP ~ 17MP
6MP * 4.3 == 26MP != 17MP
the simple kind.
and, yes, MF lenses are every bit as good as 35mm (comparing
best to the best and mediocre to mediocre)
so according to your own numbers, 17MP is the lower bound on 120
format(s) -- the smallest one (645) under average conditions. this is
again, according to your own post.
in other words, "17MP" is bullshit.
mishka
On 9/19/05, Adam Maas <[EMAIL PROTECTED]> wrote:
I suspect you are misunderstanding me.
Here it is again. Under average conditions, 6MP about equals the best
35mm films, 8MP will do a little better. Under ideal conditions ~10MP
equals 35mm. The conditions affect the resolution of the film more
than it does the resolution of digital, which doesn't tail off as
quickly as film resolution does under poor conditions (Grain size
varies, sensor site size is fixed, combine with the linear response of
digital sensors and digital has advantage under poor conditions that
disappears under ideal conditions). Note that this is for APS and FF
Bayer sensors of traditional design (I'm not getting into the Foveon
and Fuji sensors), the little sensors in most Prosumer P&S's do not
fare as well (6MP DSLR's generally outperform 8MP Prosumer cameras for
resolution)
A 17MP camera can match the resolution of 120 film in most cases, as
proven by teh Canon 1Ds mk II.
Mishka wrote:
do the math (the simple kind: multiplication and division)
mishka
On 9/19/05, Adam Maas <[EMAIL PROTECTED]> wrote:
They do not contradict at all. When used under ideal conditions,
35mm film is still exceeded by a 10+MP sensor (All other things
being equal and using glass of sufficient quality). 17MP can match
120 film.
-Adam
Mishka wrote:
Those are mutually contradictory statements. Both cannot be true at
the same time.
mishka
On 9/18/05, Adam Maas <[EMAIL PROTECTED]> wrote:
It takes 10+MP to exceed 35mm film under idea; conditions, and as
the 1Ds mkII has shown you can match 120 film with 17MP.
