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Vario-Sonnar 70-300/4-5.6 wide open at 300mm
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Leo



Joined: 23 Nov 2006
Posts: 24
Location: Toronto, Canada

PostPosted: Sat Jan 06, 2007 2:10 am    Post subject: N70-300 Test image Reply with quote

It is so exciting to get the mount and the mount works well in 70-300. As mention, the focus action is not very well in 300mm end.

Here is the comparison between a fixed focal lenght lens with N70-300.

It seems that the performance of N70-300 is not very well in this range. However, the lens has great improvement at F8



compare.jpg
 Description:
compare between OM300 and N70-300 at 300mm end. Canon 10D
 Filesize:  62.42 KB
 Viewed:  50440 Time(s)

compare.jpg

EXIF Information  Details
Camera make  Not available Camera model  Not available
ISO  Not available Focal length  Not available
Shutter speed  Not available Aperture  Not available
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Leo



Joined: 23 Nov 2006
Posts: 24
Location: Toronto, Canada

PostPosted: Sat Jan 06, 2007 2:14 am    Post subject: N70-300 test image 2 (Macro) Reply with quote

However, the greatest thing of this lens is its macro, as the old VS70-210 f/3.5. I try to take the pic at full opened aperture. Not bad


macro_small.jpg
 Description:
Macro at f5.6
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macro_small.jpg

EXIF Information  Details
Camera make  Canon Camera model  Canon EOS 10D
ISO  200 Focal length  152mm
Shutter speed  1/125 seconds Aperture  f/5.6
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Leo



Joined: 23 Nov 2006
Posts: 24
Location: Toronto, Canada

PostPosted: Sat Jan 06, 2007 2:16 am    Post subject: N70-300 test image at 130mm Reply with quote

It is another example.


N70300_130_45_small.jpg
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N70300_130_45_small.jpg

EXIF Information  Details
Camera make  Canon Camera model  Canon EOS 10D
ISO  200 Focal length  130mm
Shutter speed  1/350 seconds Aperture  f/4.5
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mOnAmis



Joined: 14 Sep 2006
Posts: 29

PostPosted: Sun Jan 07, 2007 12:07 pm    Post subject: Reply with quote

Is that OM300 a Canon lens or an Olympus?
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Leo



Joined: 23 Nov 2006
Posts: 24
Location: Toronto, Canada

PostPosted: Sun Jan 07, 2007 1:12 pm    Post subject: Reply with quote

Oh.... OM300 means Olympus 300mm f/4.5 Sorry...

And the above comparison is the actual pixels count without resizing.
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mOnAmis



Joined: 14 Sep 2006
Posts: 29

PostPosted: Sun Jan 07, 2007 4:03 pm    Post subject: Reply with quote

Do you have any shots t f8 or higher?
I agree the makro function on this lens is quite good.
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MomoInu



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

PostPosted: Mon Jan 08, 2007 10:41 pm    Post subject: Reply with quote

Leo wrote:
Oh.... OM300 means Olympus 300mm f/4.5 Sorry...

And the above comparison is the actual pixels count without resizing.


Hi Leo,
At what aperture was the comparsion images made?

From Zeiss' published MTF's the VS 70-300 is weakest at 300mm, but I would have expected it to be a little better than shown in your comparision. Is that level of performance repeatable?

I haven't converted my VS 70-300, as it was the lens that I used the least. I perhaps should do so just out of curiosity to see how it performs. I could compare it to the Canon 300 f4L IS, which I recently acquired. I wouldn't expect it to be as sharp as the Canon fixed-focal length lens, but I would expect it to excel in other aspects of image quality.
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Leo



Joined: 23 Nov 2006
Posts: 24
Location: Toronto, Canada

PostPosted: Tue Jan 09, 2007 10:54 am    Post subject: Reply with quote

Hi,

I did the comparison at the max aperture setting, OM300 was set at f/4.5 and N70-300 was set at 5.6.

I do need someone to verify if it is the fact or the lens is faulty. I have very high expectation on this lens too.

By the way, I will try take the digital photo with f/8 setting. I had deleted the file so I need to re shoot again.

Regards,
Leo
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MomoInu



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

PostPosted: Tue Jan 09, 2007 4:10 pm    Post subject: Reply with quote

I think you will find that the 70-300 Vario-Sonnar is best between 70 and 200mm, and probably optimal around 150mm. Wide-open it could be that weak at 300mm, but it's worth another try or two to make sure we have it right.

In the mean time, here is another sample with the 24-85mm Vario-Sonnar on the 5D. Captured at 24mm, f11 and .5 sec.



24-85_50_Comparison_4-try1.jpg
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 Filesize:  1.52 MB
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24-85_50_Comparison_4-try1.jpg

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Camera make  Not available Camera model  Not available
ISO  Not available Focal length  Not available
Shutter speed  Not available Aperture  Not available
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conurus
Site Admin


Joined: 15 Aug 2006
Posts: 795
Location: Vancouver, Canada

PostPosted: Tue Jan 09, 2007 9:26 pm    Post subject: Reply with quote

Hi Leo,

I think you told me that my mount was 0.2mm too thick when you installed it to your 70-300. I guess your mount thickness is 1.60mm and there is only 1 shim inside the lens, and it is 0.30mm thick?

Please confirm. Thanks!

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I am a bird and I uncovered the E, EF and N-mount communication protocols!
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Leo



Joined: 23 Nov 2006
Posts: 24
Location: Toronto, Canada

PostPosted: Wed Jan 10, 2007 2:28 am    Post subject: Reply with quote

Hi,

Yes... the thickness of the N-mount is 1.6mm and there is only one shim in it and it is 0.3mm

Leo
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conurus
Site Admin


Joined: 15 Aug 2006
Posts: 795
Location: Vancouver, Canada

PostPosted: Sat Jan 13, 2007 5:40 am    Post subject: Reply with quote

Leo wrote:
Hi,

Yes... the thickness of the N-mount is 1.6mm and there is only one shim in it and it is 0.3mm

Leo


Ok I will admit fault here - sorry for this issue. The conurus mount is made thicker than the original Contax N mount because you would remove some shims to tune the film-to-flange distance to be as close to 4.00mm as possible.

However, in your case, even after you have removed all shims, it is still 0.20mm too thick. It is like always having a 0.2mm extension tube all the time. For a wide angle, this would have been a disaster, but for a long telephoto, especially since the lens would focus beyond infinity because of AF, this is far less of a problem. I am not sure if it is the reason behind the unsatisfactory performance at 300mm. But in any case, it is my responsibility to fix it.

I tried turning the mount thinner in my home shop, but the result was not very good. I was not skilled enough to make the thickness even, so I cannot fix it myself. However, I just spoke with my machine shop and they seemed to be willing to make the mounts thinner for me using a surface grinder, so I am going to pay them to make some of my mounts thinner. This machine shop is amazing - they can make the mount's thickness so even around the whole ring that any slight uneveness is almost unmeasurable. However, they are also very very slow. Please use your 70-300 like this for the time being and I will send you a thinner ring by mail when it is ready.

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Leo



Joined: 23 Nov 2006
Posts: 24
Location: Toronto, Canada

PostPosted: Sun Jan 14, 2007 11:44 am    Post subject: Reply with quote

Hi Thomas,

I am so glad that what you are doing and I must need to give a big thank to you.

I do think it is a natural process to make a third party accessories and the products will become better and better with sufficient feedback from users. I feel very happy that you take my advise so seriously. I sent you a PM since I just want to report the case, not to public and so you can improve your products. Since you will help the user to convert the lens afterwards, I don't think it is a problem.

I have hand-grinded the mount and it is now in right thickness. So I took the pics in the best status of the lens.

A Big thanks to you..

Leo
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Leo



Joined: 23 Nov 2006
Posts: 24
Location: Toronto, Canada

PostPosted: Sun Jan 14, 2007 11:51 am    Post subject: Reply with quote

Here is the test of my N70-300 at 300mm with different aperture setting.


n70-300_test2 copy.jpg
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n70-300_test2 copy.jpg

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ISO  Not available Focal length  Not available
Shutter speed  Not available Aperture  Not available

n70_300_test copy.jpg
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 Filesize:  63.28 KB
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n70_300_test copy.jpg

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ISO  Not available Focal length  Not available
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MomoInu



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

PostPosted: Sun Jan 14, 2007 2:50 pm    Post subject: Reply with quote

Leo wrote:

I have hand-grinded the mount and it is now in right thickness. So I took the pics in the best status of the lens.


Do you have the capability to do that accurately? As far as I know, there is no way to do that evenly or accurately "by hand".

You really should wait for conurus to send you the thinner ring. At least you can be sure that it, accurate, even and perfectly flat, all of which is important to get infinity focus right.
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