your werent talking in generalities you specifically mentioned 17MP as matching "120 film" which cant be done because "120 film" isnt a format. If you meant 6x6 but said "120 film" that's one thing but you cant say you were being general when you spouted 17MP. sorry that does not compute. jco
-----Original Message----- From: Adam Maas [mailto:[EMAIL PROTECTED] Sent: Monday, September 19, 2005 11:22 PM To: [email protected] Subject: Re: Pentax K 2.5/200mm 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. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>> >>>>> >>>>> >>>>> >>> >>> >>> >>>
