Sacrilege!!! You dare question the superiority of primes?
HAR
----- Original Message -----
From: "Joseph Tainter" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: January 25, 2001 1:57 PM
Subject: Primes vs. Zooms: Unusable Sharpness?
> The quote below came up on rec.photo.film+labs. It brings up
something
> I've often wondered about, to wit:
>
> If most films can resolve less than most lenses, and most
scanners can
> resolve less than most films, why are prime lenses considered
superior
> to good zooms? It would seem at first glance that the extra
lens
> sharpness of a prime would not translate into extra image
sharpness.
T-Max 100 can quite happily resolve close to 100 lppm in normal
shooting situations. Most prime lenses are hard pressed to hit
60 lppm in normal conditions, and the best zooms will likely be
not much higher than 50 lppm. A bad zoom may be as low as 30
lppm (those are the ones with the word Minolta on the lens bezel
<G>).
So, the problem to me is that the person who wrote the post to
rec.photo.film+labs is passing incorrect information.
There is also more than mere resolution to think about. Lens
flare, contrast and bokeh to name a few are qualities where
primes tend to be better.
Primes also tend to have better colour correction and suffer
fewer optical abberations than zooms, especially long range ones
that go from wide angle to telephoto.
William Robb
>
> I use several zooms for, of course, their convenience, but
also have
> three primes that I use often.
>
> This isn't meant to start a flame war. I've seriously wondered
about
> this for some time.
>
> Thanks,
>
> Joe
>
> "If you use film, the only thing you will be testing is the
film itself
> since film see only about 10 to 20% of the resolution the lens
will see.
>
> "An example: A typical f4 lens will have about 500 lines per
millimeter
> with noon daylight summer sun. Most picture type ASA 50 to
400 films
> will record betweent 50 to 100 l/mm from this 500 l/mm image o
r about 10
> to 20%.
This is a false statement. There is a huge difference between
measurable aerial resolution and what the lens will actually
project onto the film.
>
> "Special aerial recon films can do up to about 350 l/mm or
60+% but ASA
> ratings are down under 10."
Hmmm, I want to see manufacturers specs on that one. I bet he is
taking the 1000:1 TOC measurment rather than the 6:1 TOC
measurement.
William Robb
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