Archived posting to the Leica Users Group, 2000/03/19

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Subject: Re: [Leica] 35mm versus 120
From: john <bosjohn@mediaone.net>
Date: Sun, 19 Mar 2000 08:57:07 +0000

Rick Dykstra wrote:
> 
> Hello LUG.
> 
> Look, Leica prints will be sharper until I buy a Hasselblad, OK?
> 
> To be a little more serious (but not too much more), when I take a portrait
> I'm using the format vertically. The neg is 36mm high, compared to, what,
> 56mm for the 'blad.  Now that's a 1 to 1.55 ratio.  Sure, the neg area is
> 3.63 (rounded) times bigger, but for a head and shoulders portrait, its that
> 1 to 1.55 ratio that makes more sense.
> 
> So, a 'blad will use 1.55 times more film area for something that will be
> shot vertically on 35mm (provided the width of the subject fits within the
> 24mm neg width).  And this is true of the portraits I take - not too many of
> my subjects have heads that fat. The same applies for a horizontal group
> shot.
> 
> Now, the other variables.
> 
> An M camera vibrates less (so I'm told - I've only ever dry fired a 'blad,
> in a dream factory called Phototime in Melbourne, Australia.  Sounded like a
> lot of stuff moving around in there, and it didn't feel steady in my hands).
> 
> M lenses are generally faster, which can mean using higher shutter speeds,
> to obvious effect.  Or slower film, again, an obvious advantage.
> 
> 35mm lenses provide greater depth for the same field of view (don't they?),
> an important handheld photography factor.  We're chipping away at that
> ratio.
> 
> Now factor in some of Erwin's MTF comparisons, the M is now neck and neck
> with the 'blad.
> 
> Add a pinch of my own unashamed bias, and, hey presto, Leica wins!
> 
> When I'm allowed to spend 1.55 fortunes on a Hasselblad system, I will
> recalculate the proof provided above to ensure that the two systems come out
> equal, measured across a range of applications.  And each system will win in
> it's respective specialisation.  I'll be doubly happy!
> 
> Regards
> 
> Rick (I'm convinced and that's all that matters) Dykstra
I don't understand why you used the figure 1.55, I figured on the basis of a
6x4.5 negative the medium format negative is three times larger, 6x4.5=27
2.4x3.6=8.64 27/8.64=3.125 or so. 6x4.5 gives an aspect ratio between 4x5 and
2x3, fatter than your 35 mm but skinnier than 4x5.  This gives me three times
the negative area to work with. Sharpness is not the only issue. The larger
negative should be able to produce
smoother tonal transitions and more discernible shades of gray or hues of
color, finer grain, and more detailed images given the same final print size. 

The other parameters you mentioned, however, are important, so the gap may not
be as wide as the figures above show, but bottom line, the medium format
negative should produce a sharper, more detailed print, all other things being
equal. But of course they are not. Incidentally no one has mentioned the fact
that the demands on the enlarging system, especially the lens are much greater
enlarging 12 times as opposed to four times. Any gains in sharpness of the
Leica lenses on the camera given the same negative area, may be lost in the enlarger.
John Shick