On Wed, 05 Mar 2003 16:36:33 -0000, Bill Tuthill
<ca_creekin@yahoo.com> wrote:
>Alan Browne <alan.browne@videotron.ca> wrote:
>>> Although I retain very little faith [in] Pop
Photo SQF numbers...
>>>
>>>
28mm 50mm 80mm
>>> 2.8
C F C+
>>> 4.0 B+ B C+
>>> 5.6
A A A
>>> 8
B+ A A
>>> 11
B+ A A
>>> 16
B B+ B+
>>> 22
C+ C+ B
>>>
>>>
28mm 50mm 70mm
>>> 2.8
C C C
>>> 4.0
C C C
>>> 5.6
C C+ C
>>> 8
C C+ C+
>>> 11
C C+ C+
>>> 16
C C+ C+
>>> 22
C C+ C+
>>>
>>> The 28-70/2.8 was able to produce B+ quality
11x14 enlargements
>>> stopped down, and C+ quality 16x20 enlargements
at all apertures.
>>
>> Do you happen to have comparable data for Minolta,
Canon and Nikon?
>Here are new-style SQF grades for the Minolta
24-105/3.5-4.5 D, which
>appears to be better (if you believe SQF) than the
Tokina 28-70/2.8.
>But note: Chasseur d'Images found more softness at 105
than at 70.
>
> 24mm 70mm
105mm
> 3.5 C+
> 4,4.5 B C+
B
> 5.6 B C+
B
> 8.0 B C+
B
> 11.0 C+ C+
B
> 16.0 C+
C+ B
> 22.0 C+ C
C+
> 27.0
C C+
>
>At all apertures the 24-105 D produced A quality 11x14
enlargements
>at 24 and 105mm, and B+ quality at 70mm. Grades for 16x20 were:
>
> 24mm 70mm
105mm
> 3.5 B
> 4,4.5 B+ C+
B+
> 5.6 B+ B
B+
> 8.0 B+ B
B+
> 11.0 B+ B
B+
> 16.0 B B
B+
> 22.0 B C+
B
> 27.0
C+ B
>
>Sorry, I did not record SQF scores for similar Canon or
Nikon lenses.
With all of these, what does any given "grade"
mean?
Is there any indication of corner performance compared
with center? I consider a lens soft at a given stop
if the corners are soft, regardless of center
resolution. If the lens is not at least acceptably
sharp over just about all of its image area, it is
not a sharp lens for me...