Re: [Leica] Resolution vs. Contrast?

[Phil Stiles <stiles@s-way.com>]

A very interesting comparison. Back in the '60s we used to say the
German glass had the resolution, and the Japanese the contrast. The
"Leica look" was softer, but with more shadow detail. Photojournalists
were said to go for the "bright" images with Nikon (which is notorious
for needing to be stopped down.) This is enough dim memory, rumor and
innuendo for one day. I'll guess #1 is German and #2 Japanese. But like
the finish to wine, we know the proof of the pudding is in the Bokeh!
Thanks for posing this puzzle.
Phil Stiles NH USA

Peter Klein wrote:
> 
> Folks:  I'm currently comparing two older 85-90mm lenses, both
> approximately f/2.  To avoid prejudicing the discussion, I'm not going to
> reveal what brand(s) they are.
> 
> I shot the "newspaper taped to the wall" test with each.  This means
> shooting a double-page spread of the stock market quotes, with the camera
> on a tripod, placed so the newspaper just fills the frame horizontally.  I
> shot Kodachrome 64 at all stops, and viewed the slides with a portable 30x
> hand microscope.  Please note that I'm taking some real pictures with the
> lenses, too, but that roll isn't finished yet.
> 
> All this is crude, but it does give a reasonable idea of how each lens
> performs at that distance. The lower-case letters in a stock market quote
> are about 1mm high, and you can see three distinct lines in them (such as
> in the letter "e"). Reduce a 68 cm-wide double-page spread down to a 36
> mm-wide frame, a factor of 18.9, and these three lines in a mm-high letter
> reduce to less than .0175 mm each on film.
> 
> I encountered an interesting difference between the two lenses.  Wide open,
> lens #1 shows the smallest print quite blurred.  But I can tell that the
> characters are letters and numbers, and sometimes identify one.  However,
> the lines of the characters are very light and somewhat irregular in how
> dark they are.  In other words, the appearance of the print is very low
> contrast.
> 
> With Lens #2, wide open, the text is completely unreadable.  The space
> within individual characters seems almost completely filled in, such that a
> small "e" looks like a dot and a capital "E" looks like a rectangle.  But,
> though the characters are blurred beyond recognition, the outer edges of
> the characters are distinct, and the contrast between a character and the
> space around it is much more distinct than Lens #1.  In other words, Lens
> #2's image appears to be of lower resolution, but higher contrast.
> 
> Both lenses seem to have about equal resolving power at f/5.6 and narrower,
> but Lens #2 continues to have the appearance of better contrast at these
> openings.  Oddly, at a couple of stops in this range, both lenses show
> slightly more readable characters near the *edges* of the slide than in the
> center!
> 
> Now the fun part--which lens do you think might take better pictures
> (especially wide open), and why?  I'm curious how this crude but easily
> done test translates to "look."
> 
> --Peter