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Some Questions on Cleaning a Lens
#19
[quote name='wim' timestamp='1324485002' post='13978']

Hi Frank,



Ok, not just about lens pens, but cleaning with tissues, and filters <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='Big Grin' />.



My experience with lens pens is that they are extremely good at speading grease all over the lens surface. IOW if your lens has some grease on it, don't use them. And never ever touch the bristle hairs with your fingers, or other body parts <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='Big Grin' />. In short: I don't use them. I don't need a brush to get grease on a lens surface, or spread it around <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='Big Grin' />.



If you want to use lens tissues, it really becomes quite involved when it comes to using these. If you don't want to damage lenses with these, you really need to do the following:



Use a good blower to blow away any particles from the lens.



Tear of a very narrow strip on one end, so that the lens tissue edge is no longer sharp, but "woolly". Roll the lens tissue up, quite compactly, so that you get a little lens tissue cilinder, with a brush type side on one end.



Moisten the brush end with a tiny drop of cleaning alcohol or surgical alcohol (easier to get than "lens cleaner fluid" and essentially the same thing). Clean the lens with this by wiping of the lens surface with a gentle motion starting at the center and spiralling towards the edges.



Dry the lens surface with another, dry lens tissue "brush".



Done.



I was taught this by a Leitz microscope specialist who had done special training courses in cleaning equipment including lenses from camera lenses to expensive microscope lenses <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='Big Grin' />.



As to microfibre cloths: generally they are safe to use, but you have to be very carefully which ones you select. They should have no additives, and should be of the finest quality. Those which are sold wet, and that includes wet lens tissues, are known to do havoc with lens coatings under certain conditions (remove part of the coatings!), especially when they are a little older and (partly) dried out. And the rougher micro fibre cloths can still scratch lenses.



As to the use of UV or protection filters, I'd suggest a good filter, multi-coated, preferably scratch resistant like the newer Hoyas, or the B+W MRCs. Personally I use B+W MRCs, and I am currently switching to their latest incarnation, the nano-MRCs. These are so transparent, that you really need to look three times to see whether they have any glass in them, and they have the advantage of being slim filters with threading at th efront as well, unlike the standard B+W slim filters.



The use of filters is always a matter of debate and personal preference, but when one uses them with dslrs, it is important to use an excellent one: film only reflects 2-3% of light, a sensor from 40 to 60%, and with a not so good filter and light reflected of the back of the filter this may cause severe haze and therefore contrast loss, or even worse. And this always happens under difficult lighting conditions, exactly when you want to shoot <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='Big Grin' />. Excellent filters: no problems.



Personally I use filters because they do protect lenses - I have experienced a few incidents myself where the filter protected the lens from stuff from penetrating into the mechanism. Furthermore, a friend of mine happens to be the owner of a camera store, and he gets 2-3 damaged lenses per week, with and without protective filters, in about the same proportion as he sells them. With filters, it normally only requires removing the broken filter, a little cleaning, and mounting a new one. With those without a filter, most need to go back to the manufacturer. He thinks this is not so much caused by the glass in the filter, athough that certainly helps with mud, greasy fingers and a dog's wet nose, but more because of the extra rigidity the filter ring provides to the lens at its most vulnerable end.



Oh, and filters are generally a little easier to clean than lens surfaces <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='Big Grin' />.



Kind regards, Wim

[/quote]



I concur with Wim.

I used brushes, which in the end only turned into grease spreaders, and I couldn't even clean them even with alcohol.



- So, first use a strong (not the small weak ones) blower (like rocketblower). However, be careful, I have a good black one, but also a bad blue one that due to properties of the rubber seemed to be flaking blue rubber like crazy - it because a particle blower. A good blower will not leave any dust. And as mentioned, medical syringes could work too, would give a very strong blow.

The blowing removes any loose dust, the more you can remove the better, because some of the dust can be hard-grained, sand-like things that, once cloth or paper is used, can scratch the glass.



- in the second step I use a clean microfiber cloth, with some breath to remove resilient spots. If they don't come off, I use a tiny bit of lens cleaning fluid,

followed by a bit more breath and cleaning (it tends to never completely evaporate without residue, even the one from Zeiss)



I have seen some abnormalities on 30 year Hoya coated filters at the edge after a couple of years, presumably damages to the coating.



A simple way to clean the filters is take them off, wash them under running water with a little of liquid soap, followed by careful drying.
  


Messages In This Thread
Some Questions on Cleaning a Lens - by frank - 12-20-2011, 01:33 PM
Some Questions on Cleaning a Lens - by frank - 12-21-2011, 02:14 AM
Some Questions on Cleaning a Lens - by frank - 12-21-2011, 09:16 AM
Some Questions on Cleaning a Lens - by popo - 12-21-2011, 12:31 PM
Some Questions on Cleaning a Lens - by wim - 12-21-2011, 04:30 PM
Some Questions on Cleaning a Lens - by frank - 12-22-2011, 10:57 AM
Some Questions on Cleaning a Lens - by mst - 12-22-2011, 11:30 AM
Some Questions on Cleaning a Lens - by frank - 12-22-2011, 12:32 PM
Some Questions on Cleaning a Lens - by frank - 12-22-2011, 12:34 PM
Some Questions on Cleaning a Lens - by mst - 12-22-2011, 01:32 PM
Some Questions on Cleaning a Lens - by frank - 12-22-2011, 02:21 PM
Some Questions on Cleaning a Lens - by frank - 12-23-2011, 11:29 AM
Some Questions on Cleaning a Lens - by wim - 12-23-2011, 11:38 AM
Some Questions on Cleaning a Lens - by frank - 12-23-2011, 11:45 AM
Some Questions on Cleaning a Lens - by wim - 12-23-2011, 12:55 PM
Some Questions on Cleaning a Lens - by Guest - 12-23-2011, 11:55 PM

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