Newsgroup: it.arti.fotografia
Titolo: zoom Sigma o Nikon

Debbo comprare uno zoom luminoso 80-200 circa e ho un grosso dubbio.
Premesso che posseggo una nuova Nikon F100, sono infatti indeciso tra uno
zoom originale come l'80-200 f2,8 ED New (quello con il collarino per il
treppiede) ed il Sigma 70-200 f2,8 APO HMS.
Le 150 carte di differenza non rappresentano una variabile, così come per me
non é una variabile il fatto che un domani per il Nikon mi daranno due
palanche in più rispetto al Sigma.
Punto sulla qualità e la solidità.
Intenzionato all'inizio a comprare subito il Nikon, mi é venuto il dubbio da
quando ho letto giudizi sperticati sul Sigma ed ho sentito che molti
professionisti lo usano  in quanto ritengono che sia addirittura di qualità
migliore rispetto al Nikon.
C'é qualcuno che mi può aiutare ?
Grazie
Marco

...

So che il Nikon e' una gran bell'ottica, e in quanto a solidita' i nikon di
quella fascia sono eccellenti (io avevo quello one-touch). Il Sigma
denuncia all'MTF un calo alla focale massima, che il Nikon non ha. Il
valore aggiunto del Sigma potrebbe essere la messa a fuoco a ultrasuoni,
sempre che per te la velocita' in AF sia un valore, ma andrebbero provati.
Non fidarti dei "si dice..." spesso sono interessati o sponsorizzati. Credo
siano un ottimo acquisto entrambi. Se resti deluso puoi sempre cambiarlo.
A proposito: come va l'F100?
Saluti
Vitantonio Dell'Orto

 C'é qualcuno che mi può aiutare ?
Io ho trovato questo (usando la Nikon list; puoi consultarla per essere
piu' completi al 
http://www.listquest.com/lq/search.html?ln=nikonl
)
==============================
Date: 12-Jan-1999 03:17:59 
Subject: 80-200/f2.8D vs. Sigma 70-200/f2.8 APO EX HSM [v04.n190/18] 
Thomas;
I ran some tests on a Sigma 70-200 HSM vs. my Nikon 80-200 F2.8
that might help you with your decision. Testing method as follows:
Shot as listed from F2.8-F11 and at focal lengths of 200mm and 80mm.
Target was a colored newspaper and results were printed on 8X10 paper
@ 16X enlargement. Film was Kodak Royal Gold ASA 25 to take film
grain out of the equation. Shots were all made on the same roll of film,
mounted on a heavy tripod and shot with an electronic release. The
results refer primarily to sharpness, as that was my main concern. This
method is not scientific but darn practical.
@200mm
Identical @F2.8
Nikon slightly better @F4
Identical @F5.6, 8, 11
@80mm
Nikon obviously  better at all aperatures.
The autofocus of the Sigma was nice and smooth but didn't feel any
faster than the Nikon on my N90S (I've always wondered why a motor was
necessary for autofocus after using the current 80-200). The Sigma seems
to glide into focus while the Nikon seems to slam into focus. The
Sigma's manual focus overide is a great feature, while the Nikon's a
real pain to switch from auto to manual focus. This is the main reason I
was considering the Sigma, but the loss in sharpness at the short end
was too much to make the change. I do use the Sigma 300mm F4 lens and
it's tack sharp, so I'm not a Nikon only shooter.
              Hope this helps!
              Don Cooper
=============================================
Date: 12-Jan-1999 14:37:00 
Subject: Re: 80-200/f2.8D vs. Sigma 70-200/f2.8 APO EX HSM 
dear Thomas
I have the Nikkor AF 180, I've used extensively the Nikkor AF 80-200 and
I know the older 70-210 non HSM sigma zoom.
I don't like very much Sigma lenses in general because of their build
quality.
The old 70-210/2.8 is a solid and sharp lens but it has a diminutive and
clunky aperture ring and giving is slight price advantage over the Nikon
I do not suggest you to buy it.
The Nikkor AF 80-200/2.8 D "n" is a very good lens: focuses fast AF with
the F5 and decently with others AF bodies (F90x, F70 and F4); very good
contrast and sharpness in almost all light conditions even wide open.
Probably sharper than the OLD sigma wide open.
Both share the same disadvantage: heavy weight and bulk.
If this is a major issue for you or you don't really need a zoom go for
the 180: it is a wonderful lens, very sharp at all apertures and
distances and sharper than the zooms at least at wide apertures. AF is
not so speedy but it is relatively lightweight and small.
hope this helps
           Massimiliano Marchetti
           web page: 
http://www.geocities.com/SoHo/Gallery/8043
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