Announcement

Collapse
No announcement yet.

Purple lines showing up in my pictures.

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by Greg Wilson
    Read the quote again!!!!! It refers to purple fringing not CA.
    I only needed to read it the first time. Purple fringing is the end result of CA. Surely that is not that hard to understand?

    Comment


    • #17
      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
      My contribution to JetPhotos

      Comment


      • #18
        Originally posted by Greg Wilson
        And there are other points of view. Surely that is not hard to understand?
        Like I said, my search netted over 1500 results, yet you don't seem to understand. What he is seeing is the result of poor optics (cheap lens), also known as CA, visible as purple fringing.

        Comment


        • #19
          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.


          Comment


          • #20
            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.
            You probably will not either. As you know, film has a much higher lattitude then a digital sensor.
            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.

            Comment

            Working...
            X