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Wide Angle Comparisons...
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PostPosted: Thu Apr 03, 2008 10:40 am    Post subject: Wide Angle Comparisons... Reply with quote

Hi!

I have used this morning to "testshoot" my new Vivitar 3.5/17 in comparison with other wide angle lenses.

Part 1: Distortion

I think it shows that the Nikkor 2.8/24 is the best one here with almost no distortion, whereas the Cosina 3.8/20 is the worst of the three. The Vivitar 3.5/17 is rather OK for a 17mm lens and better than the 20mm Cosina.

For comparison reasons here the results of the AF-zoom Sigma 17-70:

Considerable distortion at 17mm (but not too bad such such a zoom lens) that almost vanishes at 23mm.

Part 2 will follow...


PostPosted: Thu Apr 03, 2008 10:58 am    Post subject: Reply with quote

Part 2:

That's the scene:



Performance wide open

Vivitar 3.5/17 at f3.5

Almost "dreamy". Wink

Cosina 3.8/20 at f3.8

Even worse.

Nikkor 2.8/24 at f2.8

Not bad for f2.8.

(AF-zoom) Sigma 17-70 at 17mm and f2.8


(AF-zoom) Sigma 17-70 at 23mm and f3.2




Performance at f5.6

Vivitar 3.5/17

Better, almost sharp.

Cosina 3.8/20

Still not really good but better than at f3.8.

Nikkor 2.8/24

That's pretty good.

(AF-zoom) Sigma 17-70 at 17mm and f5.6


(AF-zoom) Sigma 17-70 at 23mm and f5.6




Performance at f8

Vivitar 3.5/17

That's fine. Sharp enough for me.

Cosina 3.8/20

At f8 this lens is OK.

Nikkor 2.8/24

Not better than at f5.6 but not worse either.

(AF-zoom) Sigma 17-70 at 17mm and f8

It is interesting that the Sigma zoom lens gets a little worse at f8.

(AF-zoom) Sigma 17-70 at 23mm and f8



- So I think that the Nikkor-N.C 2.8/24 is the expected winner here and does not need to hide behind the modern Sigma zoom lens.

- The Vivitar 3.5/17 MC is quite a decent lens with a dreamy rendering wide open, otherwise fine.

- The Cosina 3.8/20 should only be used stopped down to at least f5.6, if not to f8.

- The Sigma 17-70 AF zoom lens performs pretty well compared to the primes. But then again that's an APS-C lens which are easier to design.

The results of the edge performances is very similar just with even bigger differences!


PostPosted: Thu Apr 03, 2008 11:45 am    Post subject: Reply with quote

nice test Carsten with logical conclusion.
Nikon is always up to his reputation.
You should show border performance.
When I checked the Leica 24 at center it was as good as the other, in border it was a lemon.


PostPosted: Thu Apr 03, 2008 5:15 pm    Post subject: Reply with quote

Excellent work !

I have a version of that Cosina I think, a Soligor 21/3.8 (T4), similar to a Vivitar 21/3.8. I've had it for my Exaktas, and now I'm using it on my K100D. It has a flare problem and its not too sharp, as you show. A pity, because it doesn't seem that there is anything wide enough to call wide on a K100D + cheap.


PostPosted: Thu Apr 03, 2008 6:45 pm    Post subject: Reply with quote

The Cosina is not a "bad" lens, it is just not as good as the others in this test.

BTW, this Cosina design has been sold as 3.8/19, 3.8/20 and 3.8/21 as far as I know. Confused


PostPosted: Thu Apr 03, 2008 8:08 pm    Post subject: Reply with quote

Interesting test, thanks for posting it. I agree that the edge results would also be useful to see, if you have time to post them.


PostPosted: Fri Apr 04, 2008 5:16 pm    Post subject: Reply with quote

great test, helps a lot!


PostPosted: Sat Apr 05, 2008 12:42 pm    Post subject: Reply with quote

Interesting tests and far more useful than most!


PostPosted: Sat Apr 05, 2008 1:06 pm    Post subject: Reply with quote

Very nice test, thanks alot!

I have a clear weakness for wide angle Nikon primes, so I´m not surprised about the result Wink

But it´s interesting to see how different the appearance of the whole picture depends on the lens used, even with similar aperture settings, dull weather and similar focal ranges.

By the way, have you tried the Sigma against the 17-85 IS? I would be very curious about your opinion.


Greetings
Benedikt


PostPosted: Sat Apr 05, 2008 1:39 pm    Post subject: Reply with quote

BenediktW wrote:
By the way, have you tried the Sigma against the 17-85 IS? I would be very curious about your opinion.


I have but just a little bit.
The Sigma is a little sharper, although there is nothing wrong with the sharpness of the 17-85.
And although the Sigma is not really good at avoiding distortion at 17mm, the EF-S is even worse. The problem with the Canon lens is that the distortion at 17mm is not a pure barrel but rather wavy, which makes it difficult to correct in pp.
Anyway, between about 21 and 40 mm the EF-S is fine and then it turns into a cushion distortion but not as bad at the barrel at 17mm.
For snapshots or street, I think the 17-85 is excellent due to the IS and the very fast and silent USM. It focusses extremely fast on the 40D, even much faster than the already quite fast Sigma.
The Sigma 17-70 opens up to f2.8-4.5, the 17-85 doesn't.
At the moment I will keep both and see which lens I am going to use more often.