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Thread: Spots from gas?

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    Default Spots from gas?

    Something has me puzzled. Both of my Olympus (digital) zoom lenses have marks on their front elements similar to those that would be caused by small droplets. The marks are not dull but shiny: they reflect light. Both lenses are carried or stored, one at a time and usually without caps, in a cheap Chinese bag. My film camera lenses have no such marks. Nor do the Zuiko Digital 35/3.5 and 25/2.8, which are not kept in the bag for any length of time. I do not use protective filters.

    I wonder if the lenses have a fancy soft coating which is reacting chemically with something in the atmosphere. I assume that the material of the bag is chemically inert -- does not let out gas or fumes -- but I can't be certain of that. Haven't noticed any effect on images, but who knows what migth happen if these little spots grow in number or when they are repeatedly sought to be cleaned off.

    There is much muck in the air of this city. It could be reacting directly with the coatings, or it could be causing some part of the bag to let out fumes which then react with the coating.

    The coatings that Canon and Nikon used in the 1950s were pretty much indestructible. I understand that Zeiss coatings were as good. Early Leitz coatings were fragile and I have no knowledge of the later ones. The soft coatings that came in the early 1970s, at least in Canon lenses, may have been marginally better optically, but they seem to have been made up without keeping life spans in mind. Canon "SSC" coatings were more fragile than "SC" ones, which in turn were not durable when compared with earlier hard ones.

    With film cameras, from the 1960s, I did not use protective filters. I did get one for the expensive and vulnerable looking zoom for my first digital three years ago; but I stopped using it when I saw the difference between photos taken through it and those taken without it on.
    Mukul Dube E-3, ZD 14-54, ZD 35, ZD 25, ZD 18-180, FL-36, ME-1, Bower SFD 926o; Sony A7 with kit zoom and 24, 35, 50, 55, 85 and 105 manual Nikkors Flickr

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    Default Re: Spots from gas?

    Have you tried cleaning them with a LensPen? I'm guessing they will wipe right away. Simple and easy.

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    Default Re: Spots from gas?

    I doubt its a soft coating, but what won't wipe off with spit and a lens cloth will probably be removed with a Lens Pen.

    Steve

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    Default Re: Spots from gas?

    Thank you both. A lens pen may well be a good remedy, but unless the cause is identified a remedy will be needed repeatedly.
    Mukul Dube E-3, ZD 14-54, ZD 35, ZD 25, ZD 18-180, FL-36, ME-1, Bower SFD 926o; Sony A7 with kit zoom and 24, 35, 50, 55, 85 and 105 manual Nikkors Flickr

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    Default Re: Spots from gas?

    There should be one easy remedy; and that is to use the lens cap when lenses are in the bag.

    If you don't have lenspen nearby, you could try a clean soft cloth dampened with water and a drop of dish cleaning liquid )the kind for washing dishes by hand). That should also remove a lot of different type crud.
    flickr | "God made the integers; all else is the work of man" - Leopold Kronecker

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    Default Re: Spots from gas?

    Quote Originally Posted by payasam View Post
    Thank you both. A lens pen may well be a good remedy, but unless the cause is identified a remedy will be needed repeatedly.
    Only you can know what the small droplets were, sap from a tree maybe, somebody sneezed maybe, insect droppings maybe...???


    Steve

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    Default Re: Spots from gas?

    "spots from gas" - um, do you mean like when I get light-headed, somewhat dizzy, and see spots before my eyes when I see an ad for a new tripod in a photography magazine?
    Rich
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    Default Re: Spots from gas?

    Lots of the textiles used in a camera bag could offgas various compounds that could in turn deposit on glass, but I'd be surprised if they were the cause of your issue. More likely is that the lenses were moved abruptly from warm to cold environments, allowing dew to condense and result in water spots.

    I have seen the chemical cause too, though, where a lens has been stored for a long period of time (years) in a case whose components (especially foams and rubbers) are breaking down.

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    Default Re: Spots from gas?

    Thank you, tomsi42. After I clean the lenses -- that's assuming I can remove all traces of the little marks -- I shall begin to cap them when they are not to be ready for immediate use.

    The idea of something from the fabric or foam occurred to me, acme, because I can think of no other cause. As I said, it could be plain atmospheric pollution also. Abrupt changes of temperature can be ruled out.
    Mukul Dube E-3, ZD 14-54, ZD 35, ZD 25, ZD 18-180, FL-36, ME-1, Bower SFD 926o; Sony A7 with kit zoom and 24, 35, 50, 55, 85 and 105 manual Nikkors Flickr

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    Default Re: Spots from gas?

    I just did a quick check/look at two lenses which i have with me right now..12-60 and M14-42.(will check the rest later at home in the evening).
    The M14-42 which does not have any protective filter had patches (not spots) ... shiny-reflective-rainbow colored reflections..no adverse result to the picture.wiped it gently in circular fashion with a spectacle cleaning cloth..the marks went off after some (many) wipes.
    considering that i'm from the same environment as you, i thought my situation might be exactly the same...one thing though..the 12-60 which has a UV glass in front is spotless (checked by unscrewing the filter).
    hopefully your situation is the same as mine. perhaps the lens coating attracts some stuff from the local atmosphere..and the past few days has been quite moisture laden...I've noticed such marks even on my computer monitor screen..but they get a regular wipe because it stares me in the face.

    Regards.

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    Default Re: Spots from gas?

    Thank you, Raj. If you don't face the same problem as me, the cause of my spots must be something other than the air of the city. I shall have to go about this systematically, ruling out one thing after another.

    David, your words are reassuring in that you speak of the toughness of coatings. My spots cannot be spittle, because no one else uses my cameras and I must have stopped blowing at lenses 45 or more years ago. I'm still hunting for pure alcohol, as the water in the 70 per cent stuff sold by chemists creates difficulties.
    Mukul Dube E-3, ZD 14-54, ZD 35, ZD 25, ZD 18-180, FL-36, ME-1, Bower SFD 926o; Sony A7 with kit zoom and 24, 35, 50, 55, 85 and 105 manual Nikkors Flickr

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    Default Re: Spots from gas?

    Quote Originally Posted by payasam View Post
    David, your words are reassuring in that you speak of the toughness of coatings. My spots cannot be spittle, because no one else uses my cameras and I must have stopped blowing at lenses 45 or more years ago. I'm still hunting for pure alcohol, as the water in the 70 per cent stuff sold by chemists creates difficulties.
    Look for anhydrous isopropyl alcohol (or isopropanol) at an electronics supply house. It's mostly harmless around plastics (and people) and will eventually soften most oil based contaminations.

    If the isopropyl alcohol doesn't work, water spots do regain likelyhood. Either moving from cold weather outdoors to warm indoors, or air conditioned indoors to warm outdoors can do it. They show up because atmospheric contamination dissolved in the water is left as a residue when the dew evaporates, creating a thin film that affects the properties of the anti-reflection coatings. The actual optical consequence is very small, but they do look ugly. Depending on your environment, they can have a chemical makeup not too dissimilar to cement, which often makes them hard to remove safely. Rather than rubbing very hard consider using a little saliva (as has been suggested), or an enzymatic cleaner like Purosol.

    Anyway, maybe I'm wrong on the source of your spots, but the extra information probably won't hurt.

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    Default Re: Spots from gas?

    Seems like licking the objective lens after a shot of Absolut Vodka is the way to go.

    The more lenses and spots the more fun it gets!

    Cheers, Jens
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    Default Re: Spots from gas?

    Quote Originally Posted by jebir View Post
    Seems like licking the objective lens after a shot of Absolut Vodka is the way to go.
    Anhydrous ethyl alcohol would be even better than isopropyl. But it tends to be expensive or difficult to get in undenatured (and hence clean-evaporating) form because people tend to drink the stuff!

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    Default Re: Spots from gas?

    Quote Originally Posted by acme View Post
    Anhydrous ethyl alcohol would be even better than isopropyl. But it tends to be expensive or difficult to get in undenatured (and hence clean-evaporating) form because people tend to drink the stuff!
    Well, it wouldn't be fun at all to clean the lenses using my method with anhydrous ethyl alcohol (it burns your mucosa in no time - I know) - but it can at least be made much better than IPA if diluted to about 40%. Absolut Vodka is a premium undenaturated quality product from my home town that already has that strength - I'll have to try it.

    Well - well... being at my son's place, I realize that don't have any lenses to clean and not even any Absolut Vodka. So I'll just go ahead and try out some alternate cleaning solution. I think I'll see how fun it can be when Ouzo meets ice water and saliva.


    Cheers, Jens
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    Default Re: Spots from gas?

    Thank you, acme. Yours is the kind of reasoned explanation I was after: and with regard to the nature of the spots, you may well be right. If I run out of saliva I shall get my dog, Pappu, to contribute some.

    Jens, I gave up drinking alcohol eleven years and one month ago, and there is no likelihood of my using it to dilute my saliva (unless that is done in vitro). I have, in addition to the usual rum, whisky and vodka, a bottle of arrack sitting around, brought by a friend who came from Kerala. This product is not terribly different from the coconut feni of Goa.
    Mukul Dube E-3, ZD 14-54, ZD 35, ZD 25, ZD 18-180, FL-36, ME-1, Bower SFD 926o; Sony A7 with kit zoom and 24, 35, 50, 55, 85 and 105 manual Nikkors Flickr

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    Default Re: Spots from gas?

    davidh202: "Sometimes the only thing that will remove these spots is a little spit on a piece of lens tissue."

    Worked brilliantly. Thank you.
    Mukul Dube E-3, ZD 14-54, ZD 35, ZD 25, ZD 18-180, FL-36, ME-1, Bower SFD 926o; Sony A7 with kit zoom and 24, 35, 50, 55, 85 and 105 manual Nikkors Flickr

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