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Contax 24~85N

 
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jjlphoto



Joined: 17 Jan 2007
Posts: 102

PostPosted: Thu Apr 12, 2007 6:22 pm    Post subject: Contax 24~85N Reply with quote

Contax 24~85N? Ok- Any comments on that lens? I've the Canon 24~70/2.8L. I can see the benefits of the Contax lenses I already own, how about this one? (Lens arsenal below)

Canon EF- TS-E 90/2.8 + Macro 50/2.5 + 24~70/2.8L + 70~200/2.8L
Leica R- Macro Elmarit 60/2.8
Contax CY- Distagon 21/2.8 + Distagon 28/2.0 + PC Distagon 35/2.8
Contax N- Planar 85/1.4N + Makro-Sonnar 100/2.8N + Vario Sonar 17~35/2.8N
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MomoInu



Joined: 15 Aug 2006
Posts: 68
Location: Santa Fe, NM

PostPosted: Fri Apr 13, 2007 11:42 am    Post subject: Re: Contax 24~85N Reply with quote

jjlphoto wrote:
Contax 24~85N? Ok- Any comments on that lens? I've the Canon 24~70/2.8L. I can see the benefits of the Contax lenses I already own, how about this one?


Well, unless you need the extra half-stop or so of speed of the Canon 24-70, I would be swapping it for the Zeiss 24-85. No hesitation.
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jjlphoto



Joined: 17 Jan 2007
Posts: 102

PostPosted: Fri Apr 20, 2007 12:16 am    Post subject: Reply with quote

How about the polarizer- is a standard thickness one okay, or do I need the "slim" style?
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conurus
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Joined: 15 Aug 2006
Posts: 795
Location: Vancouver, Canada

PostPosted: Sat May 05, 2007 4:22 am    Post subject: Reply with quote

The Contax UV filter is 5.5mm thick. Your polarizer can be at least that thick without vignetting.

To increase quality control, I began testing customers' lenses wide open. In the process I am astonished at the quality of the 24-85. This is just a random sample, not cherry-picked or anything. Sharpness and color saturation are set to 3 in DPP. This zoom is the strongest in the middle of its zoom range but I am posting the two ends instead.

All these tests were performed using AF. 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.



394V3467.JPG
 Description:
24mm
 Filesize:  314.62 KB
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EXIF Information  Details
Camera make  Canon Camera model  Canon EOS-1DS
ISO  100 Focal length  24mm
Shutter speed  1/1000 seconds Aperture  f/3.5

394V3467_100center.JPG
 Description:
24mm 100% centre
 Filesize:  479.45 KB
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394V3467_100center.JPG

EXIF Information  Details
Camera make  Canon Camera model  Canon EOS-1DS
ISO  100 Focal length  24mm
Shutter speed  1/1000 seconds Aperture  f/3.5

394V3467_100edge.JPG
 Description:
24mm 100% edge
 Filesize:  456.43 KB
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394V3467_100edge.JPG

EXIF Information  Details
Camera make  Canon Camera model  Canon EOS-1DS
ISO  100 Focal length  24mm
Shutter speed  1/1000 seconds Aperture  f/3.5

394V3477.JPG
 Description:
85mm
 Filesize:  418.36 KB
 Viewed:  37681 Time(s)

394V3477.JPG

EXIF Information  Details
Camera make  Canon Camera model  Canon EOS-1DS
ISO  100 Focal length  86mm
Shutter speed  1/500 seconds Aperture  f/5.0

394V3477_100percent.JPG
 Description:
85mm 100%
 Filesize:  1.2 MB
 Viewed:  37681 Time(s)

394V3477_100percent.JPG

EXIF Information  Details
Camera make  Canon Camera model  Not available
ISO  100 Focal length  86mm
Shutter speed  1/500 seconds Aperture  f/5.0

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jjlphoto



Joined: 17 Jan 2007
Posts: 102

PostPosted: Sat May 05, 2007 2:13 pm    Post subject: Reply with quote

conurus wrote:
The Contax UV filter is 5.5mm thick. Your polarizer can be at least that thick without vignetting.


That's good to know as the availibility of the front threads on standard polarizers makes it more usable on other lenses I have that use a 82mm hood screwed on front of the polarizer.


(I hope that was my lens used in the tests Laughing )

Thanks for the tests!
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norton



Joined: 28 Apr 2007
Posts: 4

PostPosted: Sun May 06, 2007 3:23 am    Post subject: Reply with quote

These look very nice indeed. Thanks for the info.
What about the vignetting, though? Are you using a filter here?
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conurus
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PostPosted: Sun May 06, 2007 6:25 am    Post subject: Reply with quote

Yes, there is vignetting at 24mm wide open. It makes no difference if a filter is used or not and you need to stop down to fix that.

From what I read from Erwin Puts, there is usually a design trade-off between vignetting and edge/corner sharpness. Vignetting can be corrected in post-processing, but corner sharpness cannot. In my personal opinion, I wouldn't worry so much about vignetting as I would edge/corner sharpness.

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jjlphoto



Joined: 17 Jan 2007
Posts: 102

PostPosted: Sun May 06, 2007 1:27 pm    Post subject: Reply with quote

conurus wrote:
Yes, there is vignetting at 24mm wide open. It makes no difference if a filter is used or not and you need to stop down to fix that.


I would think that typical wide angle use is stopped down, as I have yet to do any good work with one at wide open. I tried some and it looked wierd, like the lens was not sharp. It's just not the same as say a 200 at wide open. I did see on shot of a joshua tree shot with the canon 35L at wide open, and it looked interesting, but in general, my tastes are for a deep plane of focus with wide angle subjects.
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norton



Joined: 28 Apr 2007
Posts: 4

PostPosted: Sun May 06, 2007 4:45 pm    Post subject: Reply with quote

I should have been more specific... I actually meant on the 85mm shot, there seems to be a little vignetting. I was just wondering if this is consistent with what you normally see. I agree that fixing it is simple, just curious as to what to expect. I'm not much of a zoom guy, so I have little personal experience. I gotta say that this lens looks pretty attractive to me, for some reason, while Canon's zooms do nothing at all for me.
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conurus
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Posts: 795
Location: Vancouver, Canada

PostPosted: Sun May 06, 2007 8:59 pm    Post subject: Reply with quote

Anyway, yes, this is jjlphoto's lens.

There is no vignetting at 50mm, barely noticeable vignetting at 35mm, noticeable vignetting at 70mm and 85mm, and significant vignetting at 24mm.

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jjlphoto



Joined: 17 Jan 2007
Posts: 102

PostPosted: Sun May 06, 2007 11:32 pm    Post subject: Reply with quote

Sometimes vignetting can be confused with uneven illumination. I find that many lenses when shot completely wide-open are "hot" in the center with the edges deepening down.
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