[Leica] Comparing film and digital resolution

[grduprey at mchsi.com (grduprey at mchsi.com)]

I use my retirement to make images and could care less about the technical 
stuff.

gene

----- Original Message -----
From: "Frank Filippone" <red735i at verizon.net>
To: "Leica Users Group" <lug at leica-users.org>
Sent: Saturday, April 12, 2014 11:21:07 PM GMT -06:00 US/Canada Central
Subject: Re: [Leica] Comparing film and digital resolution

Is this really correct?   A grain of film is a digital ( exposed or not
exposed)?  How would you then get differing grey levels in the same small
area?  All the grains in that area would all be exposed or not exposed....
Closer to the concept of printing.....

I believe that a grain sensor within film is in itself an analog item with
varying degrees of "greyness".

To your point, you are speaking of quantization levels not individual pixel
locations....... example.... Original D1 camera had 5MP of resolution.  That
meant there were 5milliion sensor locations.  Each sensor location is
recorded at (let's say) 14 bits of depth.   A D4 has 16MP of sensor
locations and it too is recorded  ( let's say) at 14 bits of depth......
The D4 has more resolution.  They have equal quantization levels.

Image receptors per square inch is independent of the depth to which those
sensor locations are measured.....  I only spoke of receptors per square
inch.....

Here we go again... too much retirement time.....

Frank Filippone
Red735i at verizon.net


But surely a single grain in film is either exposed or not, whereas a pixel
has, depending on the sensor, thousands of brightness levels. So they are
not directly comparable and it would require a big patch of film containing
thousands of grains to display the range of tones a single pixel is capable
of, though clearly a patch of pixels would be required to compare the
effect.



>________________________________
> From: Frank Filippone <red735i at verizon.net>
>To: 'Leica Users Group' <lug at leica-users.org>
>Sent: Saturday, 12 April 2014, 14:07
>Subject: Re: [Leica] Comparing film and digital resolution
> 
>
>Several years ago, I did the calculations based upon the molecular 
>particulate size of TMax100 film.? I picked that film because the 
>density data was available, and it was the most consistent particulate 
>size film available, and it was reputed to be the most consistent 
>homogenous density mix of crystals within the sensitive film layer.
>
>My assumption was that the TMax100 crystalline molecule was the 
>smallest discernible and quantifiable light capturing receptor.? 
>Therefore, the closest analogy to a digital sensor pixel.
>
>As I remember it, the particulate size, and therefore the effective 
>pixel density, was around 15MP per square inch.? The closest ( B+W 
>only) comparison is the MM.
>
>The MM is about 10MP per square inch.
>
>Based upon this, and for all practical purposes, digital sensor 
>technology resolution has caught up with chemical resolution.
>
>Too much time on your hands is a bad thing......you worry about things 
>that are purely theoretical.? This happened to me as well when I first
retired.
>Seems a pattern....
>
>Frank Filippone
>Red735i at verizon.net
>


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