The difference among f/stops on modern lenses with excellent coatings is (supposedly)
exceptionally small. Some zoom lenses may show differences when used with slides and
compared side to side with primes by someone with an exceptionally critical eye, I
suppose. I'll bet that even this us usually too small to be of any concern.
Your Dad's old Speed Graphic may not have been multi coated, but it was coated and
probably has only 4 elements. The difference is marginal, and it doesn't matter. It
mattered even less in the day of the old Speed Graphic. The film of the day was B&W
print,
wide latitude and often the printing sucked by today's standards anyway...
Thank you for failing to properly attribute quotes. - and this from a group that is
probably zealous about copyrights and proper tribulation of their photo work!
Sheesh!
Regards,
Bob...
-------------------------------
"In the carboniferous epoch
we were promised perpetual peace.
They swore if we gave up our weapons
that the wars of the tribes would cease.
But when we disarmed they sold us,
and delivered us, bound, to our foe.
And the gods of the copybook headings said,
'Stick to the devil you know.' "
--Rudyard Kipling
From: <[EMAIL PROTECTED]>
> OK folks, I hear what you are saying.
>
> Now, tell me how interchangeable lenses are used along with those fancy hand held
>light
meters. When you take out your Pentax Spot Meter, do you adjust it every time you put
a
different lens on the camera? Oh, the T-value for that lens is 1/2 stop better than
this
one?
> (I'm serious here, not pulling your leg!)
>
> If I take out my Dad's old 2x3 Speed Graphic and the GE meter hand held lightmeter,
>it
says shoot at this f stop/speed. It doesn't say much about T-values for the lens. Is
the
difference that marginal that it doesn't matter?
>
> Regards, Bob S.
>
>
> > Note: The lenses of almost all motion picture
> > cameras use T-stops (measure of light
> > transmission). At one time in the industry,
> > before the excellent coatings of today and
> > when the lenses of these cameras were mounted
> > on turrets, there could be a significant
> > difference between an f/stop and a T-stop and
> > between one lens and another. Even with the
> > advent of zoom lenses, the problem continued
> > when shooting scenes with several cameras
> > using different lenses. You might detect the
> > difference on the silver screen because you
> > would be seeing the results side by side and
> > in time and overlapped. I've read that the
> > human eye can detect a difference of about 1/3
> > stop and some films exaggerate this (high
> > contrast films). Photographs are not usually
> > viewed as same scene side-by-side, and even
> > when they are, the change doesn't take place
> > overlapped in 1/30th of a second. In a print,
> > or adjustment of a slide for the printed page,
> > it may be nearly impossible to detect small
> > differences that might be obvious on the
> > silver screen. Some camera lens makers publish
> > the maximum T-stop of their lenses. The f/stop
> > and T-stop of a pinhole camera are the same.
> >
> > T-stop determines light transmission accurately
> > and DOF and diffraction closely.
> > F/stop determines DOF and diffraction accurately
> > and light transmission closely.
> >
> > Mirror tele's throw everybody off. When they
> > say they're f/8, what do they really mean?
-
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