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01-23-2007, 08:25 PM   #1
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An interesting difference: M and DA 40mm

I came accross this when doing lens tests for the other thread, and it really puzzled me.

Have a look at the attached images- the M 40mm seems to have a smaller angle of view than the DA, suggesting that the DA is actually more of a 38/39mm.

The optical construction must be slightly different, since the minimum focusing distance has also change between the two lenses. Anyone have any details on this? The first pic was taken with the M, while the other with the DA.

BTW, I used a tripod and MLU for both shots...

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01-24-2007, 12:17 AM   #2
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Hi Mo, the 2nd pic definitely has a wider view than the first one. Da version seems to produce brighter image there too.

For some reasons, I prefer the M version
01-24-2007, 07:05 AM   #3
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Interesting. Close focus could be changed by one lens having a longer helicoid than the other. This would not change the optical formula. When companies measure focal length they get a +- 5% range. That way they don't end up with things like a 22- 111 focal length. Now it is looked at as neat for some strange focal lengths. Look at 31, 43, 77 Limiteds.
thanks
barondla
01-24-2007, 07:17 AM   #4
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Were they both set to focus at the same distance?

01-24-2007, 08:48 AM   #5
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Yes, both were set to focus on the same subject (infinite focus) manually w/ AF confirmation.

Thanks for the info, barondla

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01-24-2007, 02:56 PM   #6
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Mo, which one has truer color rendition? On my monitor, the M seems to have much warmer tone than DA. Or maybe the DA is much cooler?
01-24-2007, 03:17 PM   #7
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QuoteOriginally posted by clm Quote
Mo, which one has truer color rendition? On my monitor, the M seems to have much warmer tone than DA. Or maybe the DA is much cooler?
Yes, that's the question I had too. Which has the more accurate color.
01-24-2007, 06:00 PM   #8
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I believe the camera used a different white balance (I didn't shoot in RAW), so I'll have to test that again later.

From my experience, though, the DA seems to do a better job of that.


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