Cleaning a lens?
Hi All, I have done a search on this site about cleaning a lens and to my suprise didn't find any advice (mind you my eyes are going:( )
Using a lens cleaning kit from a photographic store...the pack of tissues and plastic bottle of 'squirt' often make marks on the front or rear element surface worse rather than better.
Any suggestions on what to get from the chemist to shift those stuborn stains? I geuss pure alcohol will be in there somewhere??
Denatured alcohol, micro cloth n a can of air.
I blow first (dry air or N2), then use a lens cloth or lens pen (first a soft brush then the felt end) and as a last resort use lens tissue plus spectral grade methanol. If the solvent is not high grade or if there is a good deal of oil on the lens to begin with, then you can have marks.
I'd definitely not use acetone or rubbing alcohol or low grade ethanol... or water ;)
P.S. If you do have a lot of finger oil on the lens, you might try one of those oil-removing skin wipe things. In my area you get a pack of 10-20 blue, thin sheets in a little pocket pack, they are meant to be used for wiping the oily parts of your face. Anyway they "grab" oil fantastically well and what minor powdery stuff is left can easily be brushed or blown off. These sheets can take oil off lenses and rc prints too. I don't know what's on those pads but my suspicion is that it is forensic technology- you can lift fingerprints very easily with them!
Thanks....No oil, just years of grimme
My best advice: DON'T!!
A lens can have an amazing amount of crap on its surfaces with NO apparent effect on the quality of the image. Every attempt - EVERY attempt - at cleaning will have a detrimental effect on the surface of the lens - the first to be damaged will be the coating, then the glass itself.
The saddest sight in all of photography is to me the once beautiful Leica or Hasselbled lens with a large translucent spot in the center of the firrst element, the result of "knee-jerk" cleaning.
Keep a "plain" (Skylight, UV, etc,) filter on the lens. Then, if you MUST clean anything, every time (read: anally) you can watch the translucent spot grow on the filter, and know you have preserved your "good" glass.
IF I decide that there is no other alternative - every year or two, or three -and I MUST clean the lens itself, I will use clean water, and surgical cotton, being careful to use as little pressure (read: awfully close to "none") as possible.
Ed, water is just about the very worst thing you can use on any lens. First of all, the lens surface will be hydrophobic, so water will not spread evenly, and moreover the [inevitable] contaminants in the water will immediately precipitate out onto the lens. Also, some of the AR coatings make this issue even more important. Finally, the most deleterious substance on your lens would be oil, against which water will do no good at all. If you must use water then you must also add surfactant or you will probably make matters worse.
That's why geek optics folks like me use spectral grade MeOH or EtOH with as much water removed as possible ;)
Since I am already being a contrarian in this post, permit me to also disagree with your assessment that a damaged Leicablad lens is the saddest sight in all of photography. To me the saddest sight in all of photography is a fantastic lens with a UV filter on it. IMHO a person who is willing to pay the bucks for fantastic lens should also be willing to take the risk of letting the lens do what it can, in all its naked splendour.... as the lens engineers (and indeed, God Himself) intended for it to be used.
I will now dismount my soapbox ;)
I have been amazed with the power of graphite. I use those Lens Pens (name brand, do not trust knock-offs). Here is my procedure. Use brush on pen to brush away dust particles (if necessary). Breathe on lens, twist cap of Lens Pen, open cap, and use the graphite pad to clean going in a circular motion from the outside inward. You can have a lens coated in finger oil and the graphite takes it right off without leaving cleaning marks or scratches. The pens need to be replaced after 100 normal uses or so. If anyone knows a better way to clean a lens (besides doing nothing at all), please let me know.
I also use methyl alcohol to clean glass (like quartz cuvettes), but never my optical lenses (the less liquids that could get inside the lens, the better). Also, I agree that UV filters for "protection" defeat the point in obtaining a quality lens.
Disclaimer: I do not work or have investments with Lens Pen or any of its subsidiaries, assuming there are any.
Lens cleaning solution, Kodak or Leland. Apply one drop to a wadded up tissue as per the instructions.
Ammonia used in the same manner all work well.
First rule: Don't apply liquid drops or spray directly to the elements. Apply it to the tissue.
It might be interesting to run a poll asking whether people leave a protective filter on their lenses or not. I think there only need to be the two choices, so setting up the poll would be easy. Maybe I will do it myself, if I can figure out how to do it!