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Tamron SP 500mm F/8 Mirror Model 55BB: This later version
SP 500mm F/8, introduced in 1983, is an optically revised version of the
original model 55B lens first introduced in 1979. The major optical design
change is the switch to a constant thickness meniscus main mirror in order to
reduce close focusing spherical aberration. The change in the main mirror
design also necessitated changes for the two smallest lenses located within the
middle of the optical design. This model 55BB also discards the earlier model's
detachable tripod mount and the set of four filters for B&W photography.
The later model 55BB is also readily distinguished from the original model by
its diamond knurled rubber focus grip and the lack of the locking screw used on
the earlier model 55B's built-in rotating tripod mount ring. Thus this lens
does not feature any built-in tripod mount whereas the original lens
featured a detachable tripod mount.
We haven't had the opportunity to compare both optical versions
since the fact that the optical design had changed slightly completely escaped
our attention until now. Nevertheless this is now a high priority on our list
in order to answer two questions: Which lens is sharper across the field for
distant subjects? Which lens is sharper for tele-macro work? It may turn out
that the earlier version is slightly superior for long distance photography
while the later version likely is somewhat superior for tele-macro work. Why do
we say this without having compared these two lens versions? Because at least
in the early 1980s Tamron, unlike many other competitors, was NOT known for
introducing revised lens designs that offered inferior overall performance.
This is because Tamron was still trying to increase consumer acceptance and
market share by offering improved optics.
Please see the 55B link for our review and Modern Photography's
test results of the earlier version of this lens.
Lens Specifications:
| Lens Model |
55BB |
| Focal Length |
500mm |
| Aperture Range |
f/8 |
| Angle of View |
5° |
Optical
Construction
(Groups / Elements) |
4 / 7 |
| Min. Focus from Film
Plane |
66.9" (1.7m) |
| Macro Mag. Ratio [w/2X
Converter] |
1:3 [1:1.5] |
| Filter Size |
30.5mm (rear), 82mm (front) |
| Diameter |
3.3" (84mm) |
Length at
[w/Nikon mount] |
3.4" (87mm)
[3.6" (91.5mm)] |
| Weight |
21.0 oz. (595g) |
| Lens Hood |
Screw-in type, retractable. |
| Accessory |
Accepts SP 2X tele-converter #01F. Supplied
with lens hood, case. |
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