Originally posted by Greg Wilson
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Purple lines showing up in my pictures.
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And there are other points of view. Surely that is not hard to understand?
My post #12 was for general information for those interested,not for an argument.Purple fringing is a result of CA ,but CA is not the only reason.
Plenty is written on the subject.My quote on post#12( my link was RS) was taken direct from the last link given in post #14.Also try:
http://www.wrotniak.net/photo/oly-e/e300-fring.html
http://www.pictureline.com/newslette...plefringe.html
Jordan.If you have photoshop you may want to try:
http://www.outdooreyes.com/photo26.php3
http://www.bytephoto.com/tutorials/c...berrations.php
Greg
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Originally posted by Greg WilsonAnd there are other points of view. Surely that is not hard to understand?
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Perhaps his search also netted 1500 results and, like you, got bored of copying?
Actually I believe you guys are talking around each other here. Purple fringing is a result of both chromatic abherration or sensor saturation. I've noticed in many of my shots that areas of high contrast (the back of a dark vertical stabilizer always shows it) that there will be a hard line of purple about 2 pixels wide immediately against the back of the tail, a very consistent hard line. This would lead me to believe that its the lens defect, in particular my 75-300 (at the end of the summer this night job is gonna buy me some L glass goshdangit, but I digress) which is notorious for CA. I believe it's the lens because the purple fringe is very consistent to the line it's against.
On the other hand, I also see light purple, almost bluish "clouds" flaring up in areas where lots of glare is apparant, in particular the leading edges of wings where the glare is very harsh, whereas the area immediately next to it under the wing is a bit more subdued. I believe this is the sensor phenomena as I've never seen this type of thing on film, though I have seen Chromatic abherration.
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Originally posted by E-Diddy!On the other hand, I also see light purple, almost bluish "clouds" flaring up in areas where lots of glare is apparant, in particular the leading edges of wings where the glare is very harsh, whereas the area immediately next to it under the wing is a bit more subdued. I believe this is the sensor phenomena as I've never seen this type of thing on film, though I have seen Chromatic abherration.
Film LATTITUDE is the ability for a film to record an image even under less than ideal lighting. The print process allows us to extend this lattitude with additional processing as we convert from a negative to a positive.
So if latitude is to be considered to be the entire range of exposure that a film will handle, so + and - 3 to 4 (or more) stops for many films covers the range from deep, dark black to whitest of white and experience shows that even that whole range isn't really useful in some instances.
The over and underexposure tolerance of negative and slide films, is due partly to the manufacturer's decision on how to rate the "speed" of the film within the ISO standard. As you well know, digital sensors have no where near the latitude of film under even the best circumstances, thus the phenomena you see in your photos. It is a well documented occurance.
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