Archived posting to the Leica Users Group, 2004/02/22

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Subject: Pixel resolution for 8x10 was: Re: [Leica] Reasons to use film
From: Jonathan Borden <jonathan@openhealth.org>
Date: Sun, 22 Feb 2004 10:05:24 -0500
References: <499B7781-6503-11D8-8D1F-0003938C439E@btinternet.com>

On Feb 22, 2004, at 1:49 AM, Frank Dernie wrote:
>  Does one often need/fully exploit the potential of 35mm film on a 
> Leica? I only exploited the full potential in the darkroom on my 
> biggest prints, most of the time the resolution superiority was just 
> wasted on a print of only 10x8".

It is generally excepted that 360 ppi is a reasonable maximal printing 
resolution, that is increasing printing resolution beyond this does not 
generally yield better prints. Assuming an 8x10" print, that is 10 
megapixels. Consequently, although 8x10s can look fine with 6 
megapixels, the optimal resolution for 8x10 is 10 megapixel (assuming 
zero cropping).

Thats for an unmanipulated image, if you are going to run USM etc. on 
the image it is a good idea to start with a higher resolution -- to 
minimize the introduction of digital processing/blocking artifacts. 
That is why I scan at ~40 megapixels.

The other issue is the difference between shape and distribution of 
pixels vs. film grains. Rectangular pixels when enlarged are not 
pleasing to the eye. Film grains have a more irregular shape and more 
random spatial distribution and when visible are *much much* more 
pleasing. That's why photoshop filters exist to *add* the appearance of 
film grain to digital images, and why it is often recommended to *add* 
gaussian noise to a digital image ... this "randomness" (which is a 
characteristic of film) reduces the appearance of digital "blocking" 
artifacts.

Enlarged film grain is very often not a terrible problem -- that is why 
folks like Tri-X and can accept 35mm enlargements of 16x20 or greater.

On the other extreme, if you need to be convinced about the potential  
benefits of higher resolution, look at a good 8x10 contact print (i.e. 
from an 8x10 negative). As much as I like my Leica, these 8x10s have a 
characteristic look that cannot be equaled in smaller formats. I can't 
explain the neural physiology or physics behind it, but it just *looks 
different*.

Jonathan

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Replies: Reply from "animal" <s.jessurun95@chello.nl> (Re: Pixel resolution for 8x10 was: Re: [Leica] Reasons to use film)
In reply to: Message from Frank Dernie <Frank.Dernie@btinternet.com> (Re: [Leica] Reasons to use film)