Iloca
Carpal \'Tunnel
Reged: 06/12/2005
Posts: 3712
Loc: Northern Ireland
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Olympus seemed to go to a great deal of trouble attempting to deliver light to the sensor as close to 90deg as possible. Their stated reasons for doing so include reduced vignetting, increased sharpness edge to edge and reduced 'crosstalk/spill' from one photosite to the adjacent sites which should reduce fringing.
Recent tests in AP have mentioned that 'fringing' is indeed present when using the kit lenses on the E-410/510 and 420/520. I'm not sure if fringing has been mentioned in tests of FF/APS-C cameras but if it hasn't then it has to be assumed that it isn't present.
Likewise I've seen very little mention of either improved edge sharpness on 4/3rds models or reduced edge sharpness in FF/APS-C models.
Any views?
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Benchista
Wich Tyler
Reged: 11/08/2000
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Loc: Everywhere and nowhere, baby
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Certainly it was an issue with APS-C cameras and lenses - must admit I can't remember the last time I read about it, though. I know Canon has significantly improved its main kit lens from the fairly poor 18-55 to the rather respectable IS version, and I suspect other manufacturers have done similar things. FF does suffer a little from reduced edge sharpness, particularly with wideangles, which are the least telecentric.
And you must remember that ALL the manufacturers have been making their lenses more telecentric, just that most haven't made it an issue, as they still have several that are not.
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Nick
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Light and Shade II - the new blog
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Iloca
Carpal \'Tunnel
Reged: 06/12/2005
Posts: 3712
Loc: Northern Ireland
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I assume it's more of an issue if you're using older lenses. I could compare try to compare an OM 24mm with an E-System lens but I don't have anything thats directly comparable so I'm not sure how relevant it would be. Comparing a prime with a zoom isn't ideal, I need someone to give a an E-Zuiko 50mm 
You mention that the others are now making their lenses with telecentricity in mind, perhaps that would explain why the new? Nikon 14-24mm f/2.8G ED AF-S NIKKOR seems surprisingly big. Admittedly it's 2.8, the other lens I'm thinking of is the Zuiko 7-14 f/4 which as you may have mentioned in the past wasn't exactly the last word in miniaturization
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Mi Vid Iloca
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alanS
Dr Dust
Reged: 30/09/2005
Posts: 3402
Loc: Up North, England.
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At least it's now widely admitted that there can be issues when using lenses designed years ago on DSLR's. It's not s long ago that some were insisting that nothing needed to be done to the already existing designs.
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Alan's defence lawyer claimed that "Booze played no part in his typo's."
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LargeFormat
old hand
Reged: 24/10/2006
Posts: 977
Loc: Buckinghamshire and Cumbria
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Do you think the design of the sensors themselves might have helped. In particular the microlenses to the photosites have, allegedly, improved. Certainly Canon with the EOS 1D III made a lot of it.
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Benchista
Wich Tyler
Reged: 11/08/2000
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Loc: Everywhere and nowhere, baby
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I'm sure it's critical, actually.
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Nick
www.nbrphoto.com
Light and Shade II - the new blog
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Iloca
Carpal \'Tunnel
Reged: 06/12/2005
Posts: 3712
Loc: Northern Ireland
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So how do Microlenses work? Are they offset over the photosite at the edges of the sensor to re-align the light rays, delivering them to the sensor at closer to 90deg?
If that is the case how does that work when lenses of different F/L are used, I assume that the wider the lens the more the light needs to be 'bent', if so wouldn't it in theory need to be optomised for each lens.
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Mi Vid Iloca
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daft_biker
Action Man!
Reged: 11/10/2006
Posts: 6976
Loc: Doon the glen
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I've heard folk elsewhere on the net talk about fringing as chromatic abberations. Is that right? Can there be a number of causes of fringing?
I know I've had little bits of fringing on my Canon 50/1.4(designed for film I assume)....mostly from brake levers on bikes that catch the sun. I think I've used the kit lens for the 40D(a 17-85) twice for quick snaps so don't really know if it does it or not!
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Andrew (BSRIPN) ... Pics.
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Iloca
Carpal \'Tunnel
Reged: 06/12/2005
Posts: 3712
Loc: Northern Ireland
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I assume they're one and the same but really I'm not sure. I never really noticed it on my shots probably because I wasn't actively looking for it (you need to view at 100% don't you?  )
I did notice it though when I tried an OM Zuiko 300mm f/4.5 on the E-3 (or was it E-1) and it was pretty bad, like a coloured halo (think of 'Ready Brek Kids')
That reads like a contradiction, I didn't notice it but I did notice it. You know what I'm getting at though 
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Iloca
Carpal \'Tunnel
Reged: 06/12/2005
Posts: 3712
Loc: Northern Ireland
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Done a quick test earlier using an OM Zuiko 200mm f/4 and E Zuiko 50-200mm f/2.8-3.5 I've linked to 2 Full Size crops, (be warned the file size is slow to load) Both were taken at f/8. I've named them A and B. Without looking at the exif can you tell which is which?
Image A, Click for Big
Image B, Click for Big
I don't see a lot of difference but it occurred to me that with the OM lens I'm only using the center of the image circle anyway, also as it's a 200mm it should be less affected than a wide angle lens with regard to Telecentricity. That said I've previously noticed it pretty bad fringing on a 300mm OM lens.
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Benchista
Wich Tyler
Reged: 11/08/2000
Posts: 36432
Loc: Everywhere and nowhere, baby
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Quote:
I don't see a lot of difference
I can't see any - both say "THIS PHOTO IS CURRENTLY UNAVAILABLE".
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Nick
www.nbrphoto.com
Light and Shade II - the new blog
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Iloca
Carpal \'Tunnel
Reged: 06/12/2005
Posts: 3712
Loc: Northern Ireland
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You give up to easily
Sorted Now 
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Mi Vid Iloca
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Benchista
Wich Tyler
Reged: 11/08/2000
Posts: 36432
Loc: Everywhere and nowhere, baby
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Quote:
You give up to easily
Sorted Now
Nope.
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Nick
www.nbrphoto.com
Light and Shade II - the new blog
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Iloca
Carpal \'Tunnel
Reged: 06/12/2005
Posts: 3712
Loc: Northern Ireland
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Well?
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Mi Vid Iloca
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Benchista
Wich Tyler
Reged: 11/08/2000
Posts: 36432
Loc: Everywhere and nowhere, baby
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Yes! That works now. Now all I have to do is actually look at them...
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Nick
www.nbrphoto.com
Light and Shade II - the new blog
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beejaybee
Marvin
Reged: 18/07/2007
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The OM 200mm f/4 is a honey, isn't it! I've noticed that the 300mm f/4.5 has quite a lot of "blue bloat" (uncorrected longitudinal chromatic aberration) even on film cameras ... photographing a star field is a really severe test of any lens.
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Iloca
Carpal \'Tunnel
Reged: 06/12/2005
Posts: 3712
Loc: Northern Ireland
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It is and thats what encouraged me to get the 300mm. Ironically I got the 300mm to use on the E-1 rather than the OM until I saved up for the EC-1.4 to use on the 50-200. 
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Mi Vid Iloca
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El Sid
Going potty
Reged: 14/04/2003
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Loc: Sussex-by-the-Sea
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I reckon B is the OM lens. There seems to be little or no fringing on either but B is a touch sharper which I'd expect from a prime lens, even an old one...
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Nigel
Completely BSRIPN 
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daft_biker
Action Man!
Reged: 11/10/2006
Posts: 6976
Loc: Doon the glen
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Quote:
I reckon B is the OM lens. There seems to be little or no fringing on either but B is a touch sharper which I'd expect from a prime lens, even an old one...
Same here...I think B is the old lens but I haven't gone pixel peeping! I'm only going by the thuumbnails!! I think the colours in A look like they have come from a more modern lens for digital. The colours in pic B look drab in comparison.
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Andrew (BSRIPN) ... Pics.
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Iloca
Carpal \'Tunnel
Reged: 06/12/2005
Posts: 3712
Loc: Northern Ireland
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The OM lens is actually 'A'
Not too bad for an oldie, I actually rate the 50-200 as a sharp lens but there's not much difference apart from about £650
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Mi Vid Iloca
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