Friday, March 23, 2007

Joeshp And Mery Dresses

28mm vs Canon 17-40mm Zeiss Jena

Zeiss Distagon 28mm 2.8 vs Canon EF 17-40mm 4 (first impressions)

Preliminary considerations:
The camera used for comparative testing and 'a Canon 350D Mail to a tripod, set to ISO 100 and used in the 350D Av
Unfortunately, adopting a pentamirror and not a prism, which makes it, because of low light 'Line of Fire (already' small in itself) making it difficult to manual focus, especially with lenses less than 50mm depth of field and where the 'rather large. For the Distagon
and 'used a Contax adapter ring / Eos generic Chinese manufacturing thickness of about 1.55 mm (as measured with rating).
The Focus in this case and 'took place in manual and wide open.
As for the Canon 17-40mm, having previously tested the accuracy of fire and the absence of front / back focus of 'objective, the focus and' arranged by AF.


In using the Distagon and you 'noticed an obvious overexposure of about 1 stop, which strangely enough, not changing the aperture remained constant, but increased by about 1 / 3 stop of each aperture' closed 5.6 . As for the focusing of
to infinity, the tests carried out have proved disappointing, making think of a problem with an adapter too often.

The first comparison test between the two objectives has shown a striking superiority 'of the Canon compared to the Zeiss.
Hence, returning to the problem of the thickness of the adapter, I wanted to experiment by reducing the thickness from 1.55 to 1.50, 1.40, 1.30, 1.20.

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Going from 1.55 mm to 1.50 mm is beginning to have an improvement, but 'that the yield to 1.40 mm lens makes a leap in quality' in bringing clarity to overcome the Canon . Beyond
respectively 1.30 and 1.20 mm in the end, the benefits begin to decline and begins to demonstrate a significant increase of chromatic aberration on the green.
doing various tests, I noticed that the results were quite erratic, which would give the winner first and then again the Distagon Canon, hence the decision to make 4 shots every time redoing the fire, the Distagon.
In the image of fire-proof and 'very clear difference in yield given by imprecise focus, in fact proof' C 'and' been particularly sharp, unlike the other three.
Proof 'C', compared to the Canon, is more 'engraved, so' as the image of testing with the bricks.

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Currently, these first tests conducted on the reduced size 1.6x Distagon give a slight advantage over the Canon, but that 'turns out to be more usable, given the practical' natural lens, and thanks to the repeatability 'steady results in terms of sharpness.
Regarding the first consideration of the color rendering, colors denote the Zeiss' colder than the Canon.
Tests will be repeated, however, will come not just 'have a professional invoice Adapter Contax / EOS and possibly a FF camera, where the Distagon should give their best.

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