100 lppmm * 36mm = 3600 lpp35mm frame long side. Now, Niquest says that we must sample at more than twice the information rate to reconstruct the highest frequency and currently (in communications) this generally means a sampling rate of about 2.5 or so times this highest frequency when using VERY good low pass filters. This implies about 9000 tri-color pixels are required along the 36mm side. Likewise, 6000 tri-color pixels are required to sample the 24mm side. The total is then 9000 x 6000 = 54,000,000 pixels or 54 megapixels. Now this is assuming tri-color pixels. For different resolution equivalents, we have the following:
40 lppmm = 8.6 mp = 34.6 mb raw @ 32 bits per pixel 50 = 13.5 mp = 54.0 mb raw @ 32 bits per pixel 60 = 19.4 mp = 77.8 mb raw @ 32 bits per pixel 70 = 26.5 mp = 105.8 mb raw @ 32 bits per pixel 80 = 34.6 mp = 138.2 mb raw @ 32 bits per pixel 90 = 43.7 mp = 175.0 mb raw @ 32 bits per pixel 100 = 54.0 mp = 216.0 mb raw @ 32 bits per pixel 110 = 65.3 mp = 261.4 mb raw @ 32 bits per pixel
Note: with a little thought, you will realize that the number of required number of pixels remains constant regardless of the sensor size for the same quality photograph.
My conclusions:
For most use 40 lppmm is entirely suitable.
If you want the very best (equal to using say, Provia 100F or Tech Pan film or better, the very best lenses, solid tripod, controlled lighting and critical focusing) you still need film and you will need it for a long time.
Average consumers don't care because they don't blow their photos up to 3x5 feet, don't ever crop and are used to accepting the quality of a $4 throw away one shot p&s camera. Digital processing is within the consumers' capabilities and gives them a feeling of "control". Many pro's, especially PJs and wedding photogs will drop film also and go to digital to save money and time. The money is in the volume and therefore in the average consumer. Film outlets and film choices will dwindle. We'll all be forced to digital for most work because of this. Our shiny new digital cameras will have a tech life of about three years just like computers. Eventually, after 10 years, what was the very best digital camera when it was purchased will command a price of $25 on ebay, about the price of a Russian Leica copy.
Bonus: for some years to come, your digital cameras will not require the very best lenses to work to the best of their capabilities.
Drawback: You will need a newer, more capable computer and larger communications bandwidth every three to six years.
Just my opinion...
Regards, Bob... ------------------------------------------------ "A picture is worth a thousand words, but it uses up three thousand times the memory."
From: "Rob Studdert" <[EMAIL PROTECTED]>
On 15 May 2005 at 8:38, Bob Blakely wrote:
Ain't film wonderful! the grain is entirely random! No anti-aliasing filter
required! FYI, anti-aliasing filters are not like the ubiquitous UV filter. By
their nature, they must add minor, shall we say, distortions to perform their
function.
Film grain is just like natural dither, it affects the captured image to more
or less degree depending upon the film type and format or film area. AA filters
in digital systems should be matched precisely to the sensor in order to
eliminate aliasing distortions and to provide a natural fall off of resolution.
AA filters don't introduce distortion they should eliminate it by band limiting
resolution, they don't introduce artifacts like the essentially random nature
of grain in film. From the perspective of distortion and accuracy in image
recording if resolution was equal I'm sure I'd prefer a digital system over
analogue film in 9 out of 10 scenarios.
