On Fri, 23 Mar 2001 11:48:05 +0100, you wrote:
>Hi,
>
>anybody know what the quality of the new sigma 300 or 400 tele apo macros
>is, especially
>compared to the Pentax 300 f4 and 400 f5.6 lenses.
>
>Will a Pentax 1.4S teleconverter work on the sigma lenses?
>
>Anybody how can help me choose a versatile telelens, I'm not sure if 300 or
>400mm is the
>better choice.
I like the M* 300/f4, and F* 300/4.5, better than Sigma AF APO Macro
400/f5.6. I've owned all these lenses. But the M* 300/4 (optically and
mechanically identical to the A* version except for the A button on
the aperture ring) is not a lens that is easy and fast to focus.
Add a TC to a 300/f4 or f4.5, and you have a 420mm lens. Without the
TC, the 300mm focal length is just fine for many purposes. So with a
300/4 plus TC you get two good lenses in one.
The same could be said for a 400mm and TC, but if the 400 lens is a
slow f5.6, adding a TC makes for a really slow f8 lens.
The advantage of a 400mm plus TC exists if the 400 is f2.8 - less so
if the 400mm is already a slow f5.6.
As to quality, my Sigma APO Macro AF 400/5.6 was just fine optically.
No complaints at all. I would expect the same fine optical quality
from their APO Macro AF 300/4.
I've heard the manual focus versions of the Sigma 400/5.6 lens is not
as good as the AF APO Macro.
For me, the best 300mm lens is the Pentax F* 300/4.5, the one with the
tripod mount. It gets really better if you also own an A* 200/4 Macro,
because you can put the smaller tripod mount of the 200mm on the 300m.
Or maybe one could buy the 200 Macro mount as a replacement item, and
use it on the F* 300/4.5.
As for teleconverters, the newest AF teleconverters from Sigma and
Kenko should work fine. My older AF Kenko 1.5x works good. But - I do
not like the bokeh of the F* 300/4.5 and TC (it becomes f6.3) when
shooting wide open.
If I were on a budget and wanted to buy new, the Sigma APO Macro 300/4
plus its 1.5x AF TC would be very tempting.
I am in the middle of a roll using my new K-series 200/2.5. I tried
the Pentax 1.7X AF Adapter on it, and it autofocuses beautifully -
giving me an AF lens of 340/f4.2. That's getting close to the AF 400/4
or 400/4.5 dream lens I would like to have. I'll be interested to see
the optical quality of the slides from the 200/2.5 and AF Adapter in a
week or so.
--
Happy Trails,
Texdance
http://members.fortunecity.com/texdance
http://members1.clubphoto.com/john8202
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