Test: Zeiss 24-85 on Canon

conurusconurus Registered Users Posts: 15 Big grins
edited May 6, 2007 in Cameras
To maintain autofocus, auto aperture diaphragm and EXIF, you can of course go with the manufacturer's lenses, or you can go with the Contax N series converted to EF mount

For example, the Zeiss Vario-Sonnar 24-85 has a reputation of an excellent "knock around" lens. It has great colour, little distortion at 24mm, and great performance across its zoom range. Here is a 24mm sample, Canon EOS 1Ds, wide open, DPP sharpening=3.

394v3467_541.jpg

100% crop centre
394v3467_100center_183.jpg

100% crop, edge, wide open not as good as centre, but not bad at all.
394v3467_100edge_154.jpg

85mm is just great.
394v3477_146.jpg

100% crop
http://support.conurus.com/files/394v3477_100percent_282.jpg

Note: all these tests are done with autofocus. As you can see in the 85mm 100% crop wide open at f/4.5, autofocus is extremely accurate. I took two pictures with AF but both of them focused equally accurately. The exact center, which is where the AF point is, is the plane of the crane and the boat, but you can see the roof just a bit in front is starting to get outside of the depth-of-field. (Please click on the 85mm 100% crop to see what I am talking about.)

Mechanical quality is outstanding, with a predominantly metal construction, although most samples have a zoom creep problem. It will slowly zoom itself back to 24mm if the lens is pointed upwards.
Bo-Ming
conurus - world's first independent lens mount conversion with autofocus and auto aperture

Comments

  • ziggy53ziggy53 Super Moderators Posts: 24,131 moderator
    edited May 5, 2007
    Thanks for posting these. I see that there is good detail in the last image, 85mm, 100% crop, but I wanted to see if I could discern pixel and sub-pixel detail.

    I hope you don't mind, but I added a custom curve to increase contrast, and then two USM applications of 20, 25, 0 and 100, .5, 0. I took a 640x480 crop from the horizontal center and a little high.

    I think the results show a nice amount of detail, with no halo, even at the sub-pixel limits. (See the radio mast and whip antenna.)

    I think this lens is a very good match for your system.
    ziggy53
    Moderator of the Cameras and Accessories forums
  • SeefutlungSeefutlung Registered Users Posts: 2,781 Major grins
    edited May 5, 2007
    So how does this compare to the Canon 24-70? And what is "wide open"? on the Zeiss? How quickly does this lens focus when compared to a Canon of equal aperture?

    Gary
    My snaps can be found here:
    Unsharp at any Speed
  • ziggy53ziggy53 Super Moderators Posts: 24,131 moderator
    edited May 5, 2007
    Seefutlung wrote:
    ... And what is "wide open"? on the Zeiss? ...

    Gary
    conurus wrote:
    ... wide open at f/4.5, ...

    I had to look for it too.

    Good questions. thumb.gif
    ziggy53
    Moderator of the Cameras and Accessories forums
  • conurusconurus Registered Users Posts: 15 Big grins
    edited May 5, 2007
    This is a f/3.5-4.5 lens, sorry for not being clear. Postprocessing has always been my weakness, so thank you for fixing my image up!
    Bo-Ming
    conurus - world's first independent lens mount conversion with autofocus and auto aperture
  • ziggy53ziggy53 Super Moderators Posts: 24,131 moderator
    edited May 6, 2007
    conurus wrote:
    This is a f/3.5-4.5 lens, sorry for not being clear. Postprocessing has always been my weakness, so thank you for fixing my image up!

    Technically, I oversharpened the image and it is too contrasty. The method I used is mostly to show the ability of an image to resolve edge information at the sub-pixel level without the edge halo that results when there is not enough lens resolution for USM to accurately process.

    The test does not demonstrate edge or corner acuity nor does it compare against the Canon competitive products, which might be interesting.

    Thanks for the clarification on the f rating for this lens.
    ziggy53
    Moderator of the Cameras and Accessories forums
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