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Lens focus The place to talk about your camera's glassware.

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Old 23rd February 2008
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Is this an illusion?

Hi there folks. Glad to contribute to a UK based forum!

Here's a lens theory conundrum. I recently bought a Tamron 35-70 f3.5 zoom and modified an Adaptall/Konica mount for my E400. A lengthy job but I got it working. It looks good on the camera and performs rather well. I did a short review on another forum

http://www.fourthirdsphoto.com/vbb/s...ad.php?t=21841

However in pursuit of perfection I dismantled the Adaptall mount yet again and inserted a 0.4mm shim to move the whole lens forward. This was to minimise the past-infinity focus problem. It now parfocal, it retains its focus as you zoom. Excellent so far!

What I find is that the lens now seems to produce very slightly better results - as if it has been placed in its optimum design position.

Now if this was a prime lens I would put this down to my imagination, but because its a zoom lens and they react in strange ways to things like extension tubes, I just wonder if this improvement has some real basis in physics??

For info, some other lenses I have used or converted are: Hexanon 28mm, 40mm, 50mm, Vivitar 28mm Nikon 50mm and 100mm. I have a web page showing some basic lens tests on many of these if you are interested..
http://www.snaar.co.uk/lenses/index.html

Best regards

Pete
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Old 23rd February 2008
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Re: Is this an illusion?

Pete,
I've used the OM adaptor to mount my OM lenses on the E-System body and have obtained some mixed results. I'd really like to know if the Konica Hexanon lenses produce better/worse pictures than the Olympus equivalent?

Have you done this comparison?

Has anyone else???
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Old 23rd February 2008
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Re: Is this an illusion?

Hi there Graham

I have looked around various legacy lens sites these last few months and I can't say I have seen any direct Hexanon/Oly comparisons. I know that Brian Moseley (to be found on the DPreview forum) has tried an awful lot of Hexanons and he may have a foot in both camps..

I do have some personal observations from my experiences with legacy lenses, and I have heard these comments aimed at OM lenses as well:

Old lenses may have better physical construction but in general they struggle to match the quality of modern Zuiko pro lenses (or even kit lenses sometimes). Maybe this is because the pixel pitch on modern sensors is so much tighter than film grain.

I have found that lenses tuned for maximum sharpness (e.g. the Hexanon range) tend to produce a pale coma around highlights wide open. They often exhibit odd Bokeh as well. Both of these spherical abberation effects improve radically as you stop the lens down. Thus the "legendary" Hexanon 40mm f1.8 is not that brilliant wide open, but its a different lens altogether at f2.8 and f4

I live in hope of finding the perfect legacy lens set for my E400. The Vivitar 28mm f2 is pretty good (buy ugly to look at!) This Tamron 35-70 is showing promising signs. Finally, there is the Nikon E 100mm f2.8 - the only legacy lens I am happy to use wide open :-)

Regards

Pete
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Old 23rd February 2008
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Re: Is this an illusion?

Tell me more about your ideal legacy lens set up, Pete. Is it sharpness or compact size you're after? Assuming a bit of both, you might be interested in:

Mir 1B 37mm f2.8
Nikkor 50mm f1.4 AI
Pentax Takumar 55mm f2
Carl Zeiss 135mm f3.5 Sonnar
Nikkor 180mm f2.8

All of them are, I think, as good wide-open as the lenses you mentioned.
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Old 23rd February 2008
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Re: Is this an illusion?

Yes, an interesting lens list there!

I have used Nikkors in my film days and I already have a Nikon to 4/3 mount, and I have a fair idea of the good ones and the poor ones.

Zeiss is unknown territory for me but I gather they have a good reputation.

I tried a SMC Takumar 50 1.8 (?), and I found it only about as sharp as the Nikon E 50mm wide open, but it certainly got sharp beyond f5.6

The Mir is a complete unknown however.

I guess I would like to end up with an old style 3 lens set up. A wide (so 17mm would seem to be a candidate, a short zoom (the Tamron 35-70 does very well for that, but I would like to try the Tamron SP 24-48) and I guess my Nikon E 100 fulfills the long end. Compact, sharp, inexpensive are the key words ;-)

(I should point out I am not a complete Luddite: I use the 14-42, the 40-150 and the amazing 11-22 Zuiko lenses when I feel the need for AF...)

Pete
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