rasiel Posted January 13, 2008 Share Posted January 13, 2008 i went out for a debut of my d300 w/ 85mm f/1.4d lens. when i got home i noticed on this shot that the edges of high contrast exhibit really high fringing. what's going on? ras<div></div> Link to comment Share on other sites More sharing options...
tonybeach Posted January 13, 2008 Share Posted January 13, 2008 Did you use NX to convert from RAW or shoot this in JPEG? I see no real detail in the snow which leads me to suspect that you overexposed the snow and then dialed it back using exposure compensation. This looks like it could be blooming (purple fringing) rather than CA per se. There is a good explanation of what may be going on in this shot here: http://www.photozone.de/Reviews/Nikkor%20/%20Nikon%20Lens%20Tests/220-nikkor-af-85mm-f14d-review--test-report?start=1 Some overexposure and perhaps longitudinal CA may also explain what happened. Link to comment Share on other sites More sharing options...
lex_jenkins Posted January 13, 2008 Share Posted January 13, 2008 That looks like the purplish fringing peculiar to digital sensors in general, not specifically the type of CA that some lenses suffer from. However, digital camera do seem to have a knack for emphasizing lens CA. Some folks argue that purplish fringing *is* CA, but it's due to the sensor design itself. I suppose that makes sense. But if you can't duplicate the CA using the same lens on a film camera, it isn't CA due to a lens flaw. Link to comment Share on other sites More sharing options...
arthuryeo Posted January 13, 2008 Share Posted January 13, 2008 Guys, <p> This CA problem on the Nikkor 85mm/1.4AFD is a well known problem. When the image has high contrast edges (like the one you have), it is the easiest to reveal this CA problem. <p> The lens was released almost a decade ago and there're no ED elements in there. So, please be gentle with your critique. It's due for an upgrade with more current optical technologies, which now cost a fraction of its costs a decade ago. <p> <img src="http://d6d2h4gfvy8t8.cloudfront.net/4213763-md.jpg"> <p> Look at the edges of the whiel signs on the fence in the background. Link to comment Share on other sites More sharing options...
arthuryeo Posted January 13, 2008 Share Posted January 13, 2008 If you are so annoyed by it, stopping the lens down a little (like f/3.2), the CA should go away. Link to comment Share on other sites More sharing options...
vivek iyer Posted January 13, 2008 Share Posted January 13, 2008 What about the other aberrations at f/1.4? Link to comment Share on other sites More sharing options...
walterh Posted January 13, 2008 Share Posted January 13, 2008 We could trade - I got the f1.8 version .-P IQ seems superb to me at least for the two people- lots of detail. BTW: High contrast edges are not good targets for testing CA because several effects will be involved. Try BW stripes ore something similar where dynamic range fits into the histogram. Link to comment Share on other sites More sharing options...
rasiel Posted January 13, 2008 Author Share Posted January 13, 2008 i forgot to mention that, yes, i did overexpose a full stop. you pretty much need to on snowfields unless you want gray snow. on the other hand this is a straight jpeg with no PP at all. and i did step down the lens to f2.5 ras Link to comment Share on other sites More sharing options...
harvey_edelstein1 Posted January 13, 2008 Share Posted January 13, 2008 A bit of wit and wisdom from the late Herb Burt Keppler. "If you don't need a superfast lens (f/1.4, f/1.2) buy the slower (f/1.7, /1.8, 2), which will probably be cheaper, of as good or better quality, and far superior for getting good sharp close-ups." (Modern Photography, January 1980) I have this lens since the days when asa 400 was just so so, and like it stopped down 2 stops and appreciate its speed when I really need it. www.Photozone.de has a review on it that explains all the various types of CA specs. Their verdict is mixed, I hope Nikon does an update like they did with the 105mm vr macro, some ED glass and asph could improve this nicely made lens, and AFS could make it focus faster. Given today low light sensitive digital sensors, Keppler would probably get the 85mm f1.8 instead and save money. Link to comment Share on other sites More sharing options...
rolubich Posted January 13, 2008 Share Posted January 13, 2008 My 85mm 1.8 show the same amount of purple fringing. I found a PS action that correct it in a very easy way, just one click. Have a look here: http://www.shaystephens.com/ca-ps.php I tried to correct the picture you have posted and purple fringing has completely gone. I will try to post a crop of the corrected picture. Roberto Link to comment Share on other sites More sharing options...
kelly_flanigan1 Posted January 13, 2008 Share Posted January 13, 2008 Re<i>It's due for an upgrade with more current optical technologies, which now cost a fraction of its costs a decade ago</I><BR><BR>Rare Optical glass is still expensive, oil is, health care is. The only thing that might be cheaper is to have the lens made in China with very low labor costs. Link to comment Share on other sites More sharing options...
arthuryeo Posted January 15, 2008 Share Posted January 15, 2008 Here's one at f/3.5, CA seemed to be well under control. <p> <img src="http://d6d2h4gfvy8t8.cloudfront.net/6842235-lg.jpg"> Link to comment Share on other sites More sharing options...
aaron l Posted January 16, 2008 Share Posted January 16, 2008 At 1.4 and 1.8, my 85 f1.4 has purple at high contrast edges, so I just stop it down a bit. These can be corrected in PS after the fact. Link to comment Share on other sites More sharing options...
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