Unanticipated Flaring Objects

muddykneesmuddyknees Registered Users Posts: 181 Major grins
edited August 24, 2004 in Technique
Yesterday I took this view from inside a barn looking out onto a substantial expanse of clowdy bright sky (Rebel kit lens 28mm end, 1/40s, f/20, ISO 200)

(This is my first attempt to upload an image - hope it works!)

In attempting to darken the highlights and lighten the shadows using photosho's highlight/shadow dialog, not only did I "enhance" the visibility of dozens of light spots in the dark areas, but also dark spots in the light areas - the first time I've noticed this phenomenon!

So, now I'm curious about the optical explanation for all these spots under the contitions of this photo, and, of course, how in the future I can avoid or minimize or at least anticipate such a proliferation of UFO's.

Gary

Comments

  • zero-zerozero-zero Registered Users Posts: 147 Major grins
    edited August 24, 2004
    That is caused by droplets of water on the front element. Looking at the mist in your pic, it's not difficult to guess where they came from. You probably didn't see them before taking the pic because they become more obvious as the lens stops down for exposure.

    Lens cap on till you take the pic is the only cure you need. Wouldn't you wish all problems in life were as easy to solve? :D
  • wxwaxwxwax Registered Users Posts: 15,471 Major grins
    edited August 24, 2004
    Yeah, sure looks like water on the lens. Shame, that's a pretty scene and a nice shot. Thanks for the tip, Z-Z.
    Sid.
    Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam
    http://www.mcneel.com/users/jb/foghorn/ill_shut_up.au
  • pathfinderpathfinder Super Moderators Posts: 14,694 moderator
    edited August 24, 2004
    wxwax wrote:
    Yeah, sure looks like water on the lens. Shame, that's a pretty scene and a nice shot. Thanks for the tip, Z-Z.
    I remember reading somewhere something by Galen Rowell about shooting in inclement weather- which he did a lot of - he talked about actually using a UV filter overr his lens in the rain and then wiping it with a chamois just before taking the shot. But he had been out in the rain all day long! This is more extreme than most of us will need I hope. Better to just keep you equipment dry in the first place. Unless you are using a Nikonos of course.
    Pathfinder - www.pathfinder.smugmug.com

    Moderator of the Technique Forum and Finishing School on Dgrin
  • muddykneesmuddyknees Registered Users Posts: 181 Major grins
    edited August 24, 2004
    zero-zero wrote:
    That is caused by droplets of water on the front element. Looking at the mist in your pic, it's not difficult to guess where they came from. You probably didn't see them before taking the pic because they become more obvious as the lens stops down for exposure.

    Lens cap on till you take the pic is the only cure you need. Wouldn't you wish all problems in life were as easy to solve? :D
    OH! Of Course! Duh!

    I guess I had been ignoring that slight drizzle on a warm day, and totally forgot about it afterwards!

    I'm amazed I never noticed this before - I've taken lots of pictures in the rain or spray from falls or surf - I guess the results in those situations were just so obviously lousy that I just never bothered looking more closely like I did this particular time.
  • muddykneesmuddyknees Registered Users Posts: 181 Major grins
    edited August 24, 2004
    pathfinder wrote:
    I remember reading somewhere something by Galen Rowell about shooting in inclement weather- which he did a lot of - he talked about actually using a UV filter overr his lens in the rain and then wiping it with a chamois just before taking the shot. But he had been out in the rain all day long! This is more extreme than most of us will need I hope. Better to just keep you equipment dry in the first place. Unless you are using a Nikonos of course.
    I remember seeing a film crew using a portable hair dryer to warm their lenses at the tropical exhibit in the Hall of Flowers (greenhouse) in Golden Gate Park. My own lens was hopelessly fogged up, although I was trying to warm it by cupping my hand over the lens cap.

    What, by the way, would be the appropriate approach for surf-spray, with salt crystals presumably forming on the surface? It seems that just using Eclipse fluid on a Pec wipe would risk scratching the coating because the salt would not be readily soluble in methanol. Seems one should rinse the surface with distilled water first?

    (Actually sea salts are probably softer than glass - recalling what I learned in Geology Lab - and certainly the stray quartz grain is more of an issue when taking your camera to the beach.)

    Gary
  • GREAPERGREAPER Registered Users Posts: 3,113 Major grins
    edited August 24, 2004
    muddyknees wrote:
    I remember seeing a film crew using a portable hair dryer to warm their lenses at the tropical exhibit in the Hall of Flowers (greenhouse) in Golden Gate Park. My own lens was hopelessly fogged up, although I was trying to warm it by cupping my hand over the lens cap.

    What, by the way, would be the appropriate approach for surf-spray, with salt crystals presumably forming on the surface? It seems that just using Eclipse fluid on a Pec wipe would risk scratching the coating because the salt would not be readily soluble in methanol. Seems one should rinse the surface with distilled water first?

    (Actually sea salts are probably softer than glass - recalling what I learned in Geology Lab - and certainly the stray quartz grain is more of an issue when taking your camera to the beach.)



    Gary
    For the most part, it is not the glass you have to worry about scratching. Its the multilayered coated on the glass. Most of todays lenses are multicoated.
  • wxwaxwxwax Registered Users Posts: 15,471 Major grins
    edited August 24, 2004
    muddy, that was interesting, your comment about a crew shooting in a greenhouse. I've seen videocameras steam up after getting water in the lens housing during hurricane type weather. And one time in Alaska, my photographer Kent made the mistake of bringing his camera indoors. When we went back out, at zero F, all the moisture on the lens instantly turned into a thin coating of ice. Took him a while to get sorted out!
    Sid.
    Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam
    http://www.mcneel.com/users/jb/foghorn/ill_shut_up.au
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