Rick Posted March 27, 2016 Share #41 Posted March 27, 2016 Advertisement (gone after registration) Water droplets especially can cause damage depending on whether they contain anything other than water (salt) and whether they are promptly removed or left to dry. Chemical damage is just as bad as physical damage. Maybe salt would damage the coatings. I don't know. I do know that salt doesn't damage the coatings on spectacle glasses. Do you have any credible source you could post that states salt damages the coatings on modern Leica lenses? I've never had water damage any of my modern Leica lens coatings. I'd love to see someone (Ming) test lenses for salt and chemical damage. Now that would be a worthwhile blog post! Could you specify what "chemicals" you believe we might commonly get on our lenses that would cause damage? Sounds nasty. Rick Quote Link to post Share on other sites More sharing options...
Advertisement Posted March 27, 2016 Posted March 27, 2016 Hi Rick, Take a look here Ming Thein on filters. I'm sure you'll find what you were looking for!
Exodies Posted March 27, 2016 Share #42 Posted March 27, 2016 And Ming could end his article with links to condiment suppliers 2 Quote Link to post Share on other sites More sharing options...
pgk Posted March 27, 2016 Share #43 Posted March 27, 2016 Maybe salt would damage the coatings. I don't know. I do know that salt doesn't damage the coatings on spectacle glasses. Do you have any credible source you could post that states salt damages the coatings on modern Leica lenses? Well, spectacle coatings are very different to lens coatings I would imagine - most specs use plastic lenses so I'd doubt that the coatings are at all similar. And no, oddly enough I haven't actually carried out a test on modern Leica lens coatings . However I can confirm water and seawater damage on mineral glass as underwater lens ports suffer from this (the areas affected oxidise and develop a cloudy sheen) if not dried properly. In over 35 years of professional photography I've never found a problem using protective filters on my lenses. The idea that they decrease optical quality has been a recurrent one throughout that time. If there was any significant impact on optical 'quality' I'm sure it would have been well and truly demonstrated by now. I stand by my assertion that its negligible. 2 Quote Link to post Share on other sites More sharing options...
NB23 Posted March 27, 2016 Share #44 Posted March 27, 2016 Nobody knows for sure the probable cause(s) of chronic fatigue syndrome and it is certainly not a 'norm' … and to suggest it's caused by air poisoning is pure conjecture. Fact is, people are living longer than their forebears so in most 'normal' environments all the alleged poisons are not having a detrimental affect on our longevities - unless you smoke tobacco, drink too much alcohol, or consume too much sugar and red meat. dunk I was only giving an example. And cancer is definitely becoming the norm. Quote Link to post Share on other sites More sharing options...
flyalf Posted March 27, 2016 Author Share #45 Posted March 27, 2016 The use of filter for protection is a double edged sword. As Thein says: "However, for every tale of ‘my lens was saved by the filter’ – I’ve seen an equal number where a cracked filter resulted in bits of very abrasive glass scrubbing the front element and necessitating in replacement anyway; at very least, the coatings are going to be toast. And now instead of replacing just the hood or front element, you’ve paid for the filter, too. The one exception to this is when you’re shooting in unfriendly environments – sand, water, mud, sea spray; I’d rather my filter get sandblasted than my front element." Personally I use a filter on my "street" lens (35/1,4) when in cities. The IQ is affected, but I'm not to happy with having the fine gravel-like dust on my front lens, so I chicken-out with a UV filter. 2 Quote Link to post Share on other sites More sharing options...
EoinC Posted March 27, 2016 Share #46 Posted March 27, 2016 Ming may experience the advantage of not using a filter because the KL climate is very different to that of e.g. London (where he used to live). In KL there are frequent heavy rains which clear the atmosphere - probably leaving it crystal clear late in the day - thus optimising imaging and maybe exacerbating the noticeable difference between using or not using a filter. dunk I spend a very large part of my time in KL (Lately it's been 5 days per week). The air can be just as dirty / hazy as anywhere. During the last round of Indonesian slash and burn activities, KL air was atrocious. Crystal clear days are not that common. 1 Quote Link to post Share on other sites More sharing options...
Rus Posted March 27, 2016 Share #47 Posted March 27, 2016 Advertisement (gone after registration) For users of older lenses such as the Summicron 50 collapsible, which has a softer glass for its front element, a good protective filter is perhaps a safer move than letting the lens "go commando"~ XD 1 Quote Link to post Share on other sites More sharing options...
Rick Posted March 27, 2016 Share #48 Posted March 27, 2016 And Ming could end his article with links to condiment suppliers Right, like popcorn? Rick 1 Quote Link to post Share on other sites More sharing options...
Exodies Posted March 27, 2016 Share #49 Posted March 27, 2016 Harsh Quote Link to post Share on other sites More sharing options...
Rick Posted March 27, 2016 Share #50 Posted March 27, 2016 Well, spectacle coatings are very different to lens coatings I would imagine - most specs use plastic lenses so I'd doubt that the coatings are at all similar. And no, oddly enough I haven't actually carried out a test on modern Leica lens coatings . However I can confirm water and seawater damage on mineral glass as underwater lens ports suffer from this (the areas affected oxidise and develop a cloudy sheen) if not dried properly. In over 35 years of professional photography I've never found a problem using protective filters on my lenses. The idea that they decrease optical quality has been a recurrent one throughout that time. If there was any significant impact on optical 'quality' I'm sure it would have been well and truly demonstrated by now. I stand by my assertion that its negligible. Not really. The type of coating used to protect the surface is very scratch resistant and can even be a quartz type coating. Can you point to a resource that shows there is a difference in these advanced type of coatings? Rick Quote Link to post Share on other sites More sharing options...
pgk Posted March 28, 2016 Share #51 Posted March 28, 2016 Not really. The type of coating used to protect the surface is very scratch resistant and can even be a quartz type coating. Can you point to a resource that shows there is a difference in these advanced type of coatings? Rick Spectacle lens coatings are anti-reflect but marketed primarily as being scratch resistant (that's what the sales staff tell me - then they add that you should only use special cleaning fluids as detergents can damage them which is of course absurd or perhaps water droplets too can cause damage ?). Camera lens coatings are primarily intended to reduce reflections and flare and are multi coatings all of very carefully controlled thickness - or should that be thinness? I would expect camera lens coatings to have far tighter specifications and as far as I can remember are vapour deposition coatings but I may now be wrong. I haven't checked this all out (can't honestly be bothered) but the base requirements are very different so I would expect the coatings themselves to be different and that the scratch resistance of camera lens coating to be important but not as important as their optical qualities. If Leica thought that filters degraded the images from their lenses I would have anticipated a statement to this effect. Quote Link to post Share on other sites More sharing options...
pgk Posted March 28, 2016 Share #52 Posted March 28, 2016 Actually this is another classic example of a thread whereby theory and carefully controlled practice can show subtle nuances of difference. In the real world such nuances are entirely irrelevant but many are hung up on the goal for ultimate technical perfection. Why is it, I wonder, that many require technical perfection when image content is actually a far more important consideration most of the time? Of coursed technicality is often important but rarely as important as it is often made out to be. 3 Quote Link to post Share on other sites More sharing options...
MarkP Posted March 28, 2016 Share #53 Posted March 28, 2016 ...because technical perfection is easier to achieve than image-content perfection (myself included).... 4 Quote Link to post Share on other sites More sharing options...
sdk Posted March 30, 2016 Share #54 Posted March 30, 2016 It's nice when you get both technical perfection and interesting content for a photo. Why not strive for both, even if the combination isn't easy? 1 Quote Link to post Share on other sites More sharing options...
Rick Posted March 31, 2016 Share #55 Posted March 31, 2016 Spectacle lens coatings are anti-reflect but marketed primarily as being scratch resistant (that's what the sales staff tell me - then they add that you should only use special cleaning fluids as detergents can damage them which is of course absurd or perhaps water droplets too can cause damage ?). Camera lens coatings are primarily intended to reduce reflections and flare and are multi coatings all of very carefully controlled thickness - or should that be thinness? I would expect camera lens coatings to have far tighter specifications and as far as I can remember are vapour deposition coatings but I may now be wrong. I haven't checked this all out (can't honestly be bothered) but the base requirements are very different so I would expect the coatings themselves to be different and that the scratch resistance of camera lens coating to be important but not as important as their optical qualities. If Leica thought that filters degraded the images from their lenses I would have anticipated a statement to this effect. Spectacle coatings are designed to be anti reflective. Other coatings are meant to be scratch resistant. Some of the coatings are combinations of the two and even offer hydrophobic properties and repeal oil. Leica camera lenses have antireflective coatings. They also are designed to be extremely scratch resistant. For Leica, the anti-scratch resistant properties are very important and Leica touts this fact. At a Leica event the Leica presenter took out a green Scotchbrite pad and rubbed the front of the 21mm Summilux to demonstrate how tough the coatings were. He passed it around and I could see no scratches. So, I believe the anti scratch property of their lenses is pretty important to Leica. Rick Quote Link to post Share on other sites More sharing options...
FlashGordonPhotography Posted March 31, 2016 Share #56 Posted March 31, 2016 At a Leica event the Leica presenter took out a green Scotchbrite pad and rubbed the front of the 21mm Summilux to demonstrate how tough the coatings were. He passed it around and I could see no scratches. Rick And yet, i managed to permanently mark the front element of a 135 APO in an afternoon by walking with it face down in a new camera bag. the lens cap popped off and the result was a large blemish in the middle of the front element. Gordon Quote Link to post Share on other sites More sharing options...
MarkP Posted March 31, 2016 Share #57 Posted March 31, 2016 It's nice when you get both technical perfection and interesting content for a photo. Why not strive for both, even if the combination isn't easy? I fully agree. I was just replying to pgk's rhetorical question? Quote Link to post Share on other sites More sharing options...
pgk Posted March 31, 2016 Share #58 Posted March 31, 2016 It's nice when you get both technical perfection and interesting content for a photo. Why not strive for both, even if the combination isn't easy? I think most would agree. The question is whether filters degrade image 'quality' and I have found little evidence to suggest that it does from my own testing. In some circumstances it will but these are rare in my experience - but of course if you are shooting images of specific types then it may be a factor - I would not use a filter for higher magnification macro images - I have to use a planar, mineral glass port underwater and there is degradation of corners as a result (and no solution so I'm stuck with it). So in some circumstances filters will cause 'quality' loss. BUT, in most images I still honestly think that the loss is so little as to be indistinguishable so discarding a filter and allowing debris, dust and potentially scratches on the front element to degrade images seems to me a higher risk - and filters are easy to clean and cheap enough to replace if damaged. As an aside, would you leave your camera body lying around with the body cap off because you can clean the sensor easily enough? Most people would not even though sensor cleaning is accepted as part of digital camera ownership. To me sensor and front elements should both be treated with reasonable care. 2 Quote Link to post Share on other sites More sharing options...
jmahto Posted March 31, 2016 Share #59 Posted March 31, 2016 I use lens cap for complete protection. Quote Link to post Share on other sites More sharing options...
jmahto Posted March 31, 2016 Share #60 Posted March 31, 2016 Prev comment was tongue in cheek. In SLR lens the hood is generally deeper than tiny RF lens hoods and provide way more protection. This is why in SLR, I stopped using filters for protection. For RF and mirrorless lens, the hood doesn't protect against accidentally finger prints therefore I started out using filters along with hood. However, even if most of the times filter makes no difference, they do make a difference in tricky light situations, and worse, you will not know the negative effect unless you chimp heavily for flares/artifacts or after upload to computer. By that time it is too late. This is why I don't use filter when I am shooting something important where I will not get a second chance. Therefore the answer is "it depends" and you have to do your own test. Quote Link to post Share on other sites More sharing options...
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