| Specifications |
| Optical Formula |
12 elements in 8 groups |
| Aperture Range |
f/4.5-5.6 ~ f/32-38 |
| Number of Aperture Blades |
9 |
| Minimum Focusing Distance |
1,50m |
| Maximum Magnification |
|
| Maximum Diameter |
72mm |
| Length |
155mm |
| Filter Size |
58mm |
| Weight |
605g |
| The front element rotates |
| Internal zoom |
| comes with front cap, rear cap |
|
| Build |
| This lens wonīt win the price for the best mechanical lens of Pentax but the plastic which is used for the
outer shell gives a much better impression then those of some other manufactures.
Surprisingly at this lens it isnīt the focus tube which has some play but the focus ring itself.
The zoom ring is big, works smooth and without any play. Over all I find the build quality acceptable, not
outstanding but also no big complains. |
| Optical |
| The lens hasnīt the best reputation under the Pentax users. In my opinion this has two reasons.
First due to the high price of the FA version they expect to much from a slow consumer grade zoom
lens and second the use of this lens without a tripod and a lens hood, which is both essential for this lens.
The lens has 12 elements in 8 groups and even at a cloudy day the contrast without a lens hood falls visible.
In my opinion this lens shouldnīt be sold without a lens hood. Wide open the lens is a bit soft especially over 250mm.
2 stops down it is good over the whole range but this means f11 at 300mm, so donīt even think about handheld.
1/500s shutter speed is a must at this focal length. The lens produce some vignetting wide open at all focal length.
It increase from the short end to the long end but even at 300mm it is only noticeable at a clear blue sky.
It has very minor pincushion distortion over the whole range but this is barely of interest because it isnīt a classical focal
length for architecture work. |
| Handling |
| I find that the lens feels very comfortable. With the wide zoom ring you can change the focal length very easy
and due to the internal zoom system the length and balance of the lens doesnīt change.
While the focus ring is, wide away from the zoom ring, at the front end of the lens you canīt change the focal length
and manual focus without putting the hand forth and back. The auto focus speed is quite slow and due to the slow
f5.6 at the long end it hunts sometime in wildlife use. The front element revolves - making the use of graduate and polarizing filters somewhat of a pain. |
| Compatibility |
| As you would expect I have not had any compatibility problems with the two cameras I've used it on so far. A Pentax MZ-5 and a Pentax MX. |
| Conclusion |
| I find the quality of the lens quite good for the price of the F version.
But you must have in mind that you have to use a tripod over 200mm even if the lens feels good handheld.
And while using a tripod you can stop down to f8 to increase the optical performance. And donīt forget the lens hood. |
| © 2000-2002 Andreas Busse |
