Purple Menace

Discussion in 'Photography Forums' started by Pete Delaney, Jun 1, 2005.

  1. Pete Delaney

    Pete Delaney
    Well-known Member

    Joined:
    Mar 14, 2005
    Messages:
    3,212
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Lincolnshire
    Ratings:
    +653
    :confused: Ok I'd like to let off a bit of steam.....until today I was really happy with my 17-85mm F4-5.6 IS USM lens. However, I have now discovered that a particularly nice hand held shot I took looking up a rocky gorge suffers from Chromatic Aberation. If I had wanted to print the image above A4 size then the purple fringing would become noticeable. It is the classic edge of dark tree against a sky background that has caused the effect.

    Questions:
    I don't really know if all wide lenses suffer to some extent or not, if so do you think I should live with it?
    I have only had the lens a few weeks, it is in showroom condition with all the packaging, do you think London Camera Exchange will take it back for an exchange?
    I would perhaps look at the 17-40 F4L as it is not much more expensive than my lens, what would you guys' suggest :rolleyes: my other lens is a 70-200F4L with 'no-snags' so far :)
     
  2. seany

    seany
    Banned

    Joined:
    May 1, 2003
    Messages:
    2,997
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    61
    Location:
    Manchester city
    Ratings:
    +1
    It is a common problem with wide angles along with flare, i think every wide angle is going to show it at some point. It all dpends just how much your going to put up with.

    Can't say i noticed it much when i had the 16-35
     
  3. Zone

    Zone
    Moderator

    Joined:
    Jun 24, 2001
    Messages:
    6,754
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Barnsley
    Ratings:
    +2,459
    Usually contrasty backlit subjects are the cause, no real answers for you I'm afraid but have you tried correcting it using PS, there's an article here that may help.
    As you've said though up until now you have been really happy with it, so personally I'd give it a second chance, I'd actually be trying to recreate a similar shot to see if the fringing occurs easily or not, if not then I'd live with it :)
     
  4. Pete Delaney

    Pete Delaney
    Well-known Member

    Joined:
    Mar 14, 2005
    Messages:
    3,212
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Lincolnshire
    Ratings:
    +653
    Here it is, what do you think? This represents the top left hand side of the picture the tree is the furthest object away and hence is a little soft, plus the image was a hand held shot at 0.3 secs to make the water falls look creamy. Oh and F22 at 17mm.
     

    Attached Files:

  5. Zone

    Zone
    Moderator

    Joined:
    Jun 24, 2001
    Messages:
    6,754
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Barnsley
    Ratings:
    +2,459
    How much of a crop is that? Its definately fringing but also a pretty easy shot to recreate, I'd be tempted to take a whole batch of similar shots and have a look at the results.
     
  6. Pete Delaney

    Pete Delaney
    Well-known Member

    Joined:
    Mar 14, 2005
    Messages:
    3,212
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Lincolnshire
    Ratings:
    +653
    It's 100% crop, other similar images do not show the effect. Perhaps I will only very occasionally get this happening. I think I will ring LCE tomorrow and see what their advice/customer service is like. If they will exchange for me then I may well go for the 17-40mm F4L. I think this may bug the hell out of me. Once you know it's there it gets under your skin. This lens was well over £400 so I was expecting better. On the other hand I have taken some beautiful shots with this lens..... :confused:

    Pete.
     
  7. Pink Fairy

    Pink Fairy
    Member

    Joined:
    Dec 5, 2004
    Messages:
    239
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Location:
    Watford
    Ratings:
    +32
    It's a doddle to clear up in Photoshop, and if it's not a frequent problem it would be easier to just learn the simple technique to remove it's distracting presence.
    Andy
     
  8. Pete Delaney

    Pete Delaney
    Well-known Member

    Joined:
    Mar 14, 2005
    Messages:
    3,212
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Lincolnshire
    Ratings:
    +653
    Ok heres a small sample of the image post processing (thanks Zone) :) The CA was on the side of the darkest tree....top left of picture.

    EDIT: Rang LCE this morning and they came up trumps :thumbsup: I am exchanging the lens for a 17-40 F4L USM. I am hoping that this new lens will prove to be better quality and therefore will produce less CA and sharper images. I realise I lose the very valuable image stabilisation of the old lens but I felt that the 17-85 lens was more of a compromise lens and not as dedicated as the 17-40 or primes (obviously). Thanks to LCE for great customer service :thumbsup: I hope this exchange was the right thing to do!

    Pete

    PS Customer service is worth the extra.....the whole peace of mind thingy; I wonder how you would get along doing this with 7DayShop? :rolleyes:
     

    Attached Files:

Share This Page

Loading...
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice