beejaybee
Marvin
Reged: 18/07/2007
Posts: 5274
Loc: Really Here In Name Only
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Olympus Zuiko Digital ED 50mm f/2 Macro lens scores 91% in AP Test!!!!!!
Surely some mistake 
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londondailyphoto
newbie
Reged: 15/12/2006
Posts: 25
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Shame they didn't add a bokeh score, too, might have edged the Nikon then.
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Ham
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zuiko
Olympian...
Reged: 19/06/2006
Posts: 444
Loc: Norfolk.
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An interesting thoughtful article on four macros from different companies that were all excellent quality and each had there own ideas on how to achieve a sharp image. Geoffrey states that Olympus use firmware to correct lens aberrations to great effect, though he stated some purist may have ethical doubts about image purity.
David
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" ENCEFFC!" "ENNSEAEFFSEA!"" ENNCEFFC!" "ENNCEEFC!"
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Photocracy
The Great Pretender
Reged: 18/11/2006
Posts: 737
Loc: Sunny South Coast
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I have this lens and I often leave it on the camera for general use because it is so incredibly good. I haven't seen the article yet but, as Ham suggested, a bokeh comparison would almost certainly result in even more praise. As well as general use, it's also an excellent portrait lens. I was a little disappointed that it was a mainly plastic build, but to be honest this should not detract from it all. It is still built very finely indeed and weather sealed too.
The most unusual thing about this lens is the concave front element. I read somewhere that this is a superior way to construct a lens, but is rarely done due to expense and vulnerability to cracks. Apparently, the smaller 4/3rds format is an advanatge here as a smaller amount/diameter of glass is needed to achieve the same thing. This reduces both costs and vulnerability to cracking making concave lenses a more viable proposition for 4/3rds. Maybe this has something to do with it's great performance and what will probably become known as it's legendary bokeh.
The only other concave lens I know of is the 50mm 1.8 Carl Zeiss Ultron on my Zeiss Ikon Icarex camera and Ivor Matanle mentioned one other somewhere, but I can't remember what it was.
Edited by Photocracy (22/06/2008 12:41)
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Malcolm_Stewart
Carpal \'Tunnel
Reged: 11/07/2005
Posts: 2732
Loc: Milton Keynes, UK
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Quote:
...The only other concave lens I know of is the 50mm 1.8 Carl Zeiss Ultron on my Zeiss Ikon Icarex camera and Ivor Matanle mentioned one other somewhere, but I can't remember what it was.
Canon's early FD 35 f2 breechlock had a concave front element.
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Malcolm Stewart
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Repton
Mr Test Shot
Reged: 05/07/2005
Posts: 1796
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s'cuse me ignorance but isn't the 35mm macro concave too?
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beejaybee
Marvin
Reged: 18/07/2007
Posts: 5274
Loc: Really Here In Name Only
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Quote:
Geoffrey states that Olympus use firmware to correct lens aberrations to great effect, though he stated some purist may have ethical doubts about image purity.
I can't see the point of quibbling; surely the point is that it's the combination of lens, sensor and software which results in the recorded image.
Of course, not all cameras - not even all four-thirds cameras - have the same sensor or software, so the characteristics of the lens are still very important. And software cannot create information that is not resolved by the lens, or captured by the sensor - though any artifacts of the image capture processing will be recorded in the image, which may be the point that Geoffrey was trying to make.
However ISTR the corrections applied by the Oly software are limited to vignetting and distortion; provided the lens does not have particularly appalling characteristics in these respects, these corrections will not generate significant artifacts, nor will they affect resolution, colour correction etc. to any significant extent. The most likely side effect of these corrections from an image quality point of view would be to push up the noise in the lightened corners of an image when correction for significant vignetting is applied.
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Iloca
Unregistered at user's request
Reged: 06/12/2005
Posts: 3800
Loc: Northern Ireland
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Quote:
However ISTR the corrections applied by the Oly software are limited to vignetting and distortion; provided the lens does not have particularly appalling characteristics in these respects, these corrections will not generate significant artifacts, nor will they affect resolution, colour correction etc. to any significant extent. The most likely side effect of these corrections from an image quality point of view would be to push up the noise in the lightened corners of an image when correction for significant vignetting is applied.
The software correction for 'Vignetting' as far as I can tell is called "Shading Comp" and is user selectable, (Off/On) As such I suspect it doesn't apply to RAW files and equally doesn't apply unless you use Olympus software. In that respect it's similar to "Noise Filter" which can be set to Off/Low/Standard/High but again only works if shooting jpeg or on RAW files converted in Olympus software. Converting RAW files in 3rd party software effectively means the noise filter if Off. My guess is that the same applies to vignette correction. I can't find anything about 'Distortion' in the camera menu but it does appear as an option in Olympus Master when working with jpeg.
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Mi Vid Iloca
My Flickr Gallery
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zuiko
Olympian...
Reged: 19/06/2006
Posts: 444
Loc: Norfolk.
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No quibbles here or from Mr C. I think he was addressing the point that there is a greater emphasis on in camera processing rather than in the design of the lens. Some people may think this this is not the way to go about obtaining a sharp image. A bit like playing cricket in pyjamas. Its just not done. 
David.
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" ENCEFFC!" "ENNSEAEFFSEA!"" ENNCEFFC!" "ENNCEEFC!"
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RogerMac
Hotshoe Shuffler
Reged: 25/03/2007
Posts: 542
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As Iloca says vignette correction is menu selectable and the default - at least on the E500 E510 and E3 - is OFF.
All of the manuals contain a warning about using it at high ISOs typically:
Quote:
In some cases, the edges of the image may be shadowed due to the properties of the lens.
The shading compensation function compensates by increasing brightness at the dark edge
of the image. This function is especially useful when a wide-angle lens is used.
x Notes
• This function is not available when a teleconverter or an extension tube is attached to the
camera.
• At higher ISO settings, noise in image edges may be conspicuous.
I must say that I have tried hard to see any vignetting or visible distortion on my 50mm f2 and failed. I have spotted some distortion on the consumer grade lenses
Edited by RogerMac (22/06/2008 20:07)
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