How clean is clean enough for lenses?

<p>So today I finally got around to maintaining my camera friends...a good dusting and operations check, as well as cleaning any lenses that may have needed it (shooting fall colors along the blue ridge parkway in NC in a few days). I used all the most common techniques, old t-shirt and breath, microfiber, solution and tissue, lenspens, all with varying degrees of success. Maybe it was just because I had a better than usual light setup for this evening, but I felt like either I could have gotten a little better result, or I was getting to the point that I was splitting hairs and being overly critical.</p>

<p>So what does everyone else consider "clean" for lens surfaces?</p>

<p>I'm sure mine are good enough, I was taking images that had no noticeable impact from dirty lenses before I started this whole job, and the lenses look 100 percent better after cleaning. I'd love to hear how everyone else feels about lens cleaning, their methods, and its importance.</p>

<p>Thanks!</p>

<p>Justin</p>

<p>For me, clean means no marks at all - and no grease. I use Pentax microfiber cloths, which I buy on e-bay in bulk. I use only one side (the side with printing on it) to clean lenses, thus reducing the transfer of finger grease to lenses. I use a given cloth for a relatively short time and then wash it - the cloths I have are made of a thick black material and will wash plenty of times with a mild detergent at 40°C.</p>

<p>I look them over almost every time they come out of the bag, and if I see something on the glass I clean it off, but I don't worry too much about it. I've used some lenses that looked pretty nasty to me, and never really seen any issues in the photos. Check out these articles: http://kurtmunger.com/dirty_lens_articleid35.html and http://www.deansphotographica.com/deans_of_idaho/old_stuff_pages/dirtylenstest/dirtylenstest.html</p>

<p> </p>

<p>As long as there's no liquid/grease/oil on mine (including fingerprints, obviously), I don't mind a little bit of dust. I just wipe anything off with my tshirt, unless it's serious — then I use a blower and cleaning fluid with lens tissue.</p>

<p>My 2 cents, A small amount of dust take less then 1% of surface area and make the lens 1% less good, meaning no big deal. A big botch of grease or hazy oily coating effects a lot more area, meaning bad news.</p>

<p>I have had conversations with my local camera repair shop about dust and marks on lens elements, and internal dust in my newer zoom lenses. From these conversations, dust and marks on a rear element is more of an issue than on the front element. Of course with digital, we're always trying to keep any dust from transferring from the lens to the sensor. Internal dust in zooms is more common, due to the air movement created while zooming. Zoom slowly, and keep your camera bags clean. I always like to carry a bulb blower in the field for my lens cleaning. Blowing dust off a digital camera in the area of the lens mount before changing lenses should reduce dust transfer to the sensor.</p>

<p>In reviewing Nikon lenses on <strong><em> </em></strong> http://www.naturfotograf.com/index2.html Bjorn Rorslett discusses how he likes to shoot into the sun, and the importance of a very clean front element, and the frequent use of a hood when shooting into, or near the sun.</p>

<p>Like others, I don't worry about a bit of dust, but I do clean my lenses squeaky clean whenever I detect any haze. I also sometimes knock the dust off of my camera with a big sable brush before changing lenses, and that's often when I knock any dust off of the lens surfaces as well. And as Christopher discusses, the lens does need to be pretty clean whenever sunlight hits the front element. Brightly illuminated dust against darker backgrounds can be problematic, particularly when shooting at small apertures. </p>

<p>Otherwise, dust has only a small adverse impact on the contrast, and haze has a much larger adverse impact, hence why it looks hazy. Anyone who wears glasses knows this (or at least should).</p>

<p>My number one rule is always put a "haze" filter on each, and every lens I own. Keeps errant fingers off the coated surfaces, and God forbid you drop the lens, some times the filter will take most of the impact (assuming it lands just right). The flat surface of the filter is much easier to keep clean than the delicate front element.</p>

<p>Trust me, you cans spend thousands on a phenomenal 35/1,4 and another 75 clams on a b+w haze filter to protect it, but when you have a decent coating of dust on the filter, it's going to look like it flared, even when back lit.</p>

<p> </p>

<p>you could probably throw a bag of flour on a lens and it wouldn't degrade IQ. That being said, I still clean my lens often by blowing off dust with a rocket blower, but I'm not as particular about it as I used to be.</p>

<p>Salt spray can corrode the lens. Dog drool and dog snot can be hard to work through. Beyond that, I'm liberal on being a slob with the equipment. I'm with the bad breath and a T-shirt cleanup plan.</p>

<p>Mud and rain have got to come off of there. Rain can be a problem because the cloth will get wet. I know; but, once there is more than a drop of water on the cloth it just smears around. A pet peeve, I guess. Just use another corner of the T-shirt.</p>

<p>One day I'm going to become a spokesman for an expensive camera line just to scare the hell out of purists.</p>

<p>Threads like this crack me up..I think it has more to do with your personality type than the optical results. If you are Anal,you'll clean every tiny speck, if you are best described as "Artistic",you won't care.<br>

A Pro photographer of my acquaintance ,shooting studio-based portraits,routinely left his med/format lenses uncovered,sitting upright,until the front elements looked like ashtrays.<br>

Challenged by me as to the disgusting state of his optics,his reply was that his clients liked his results :that a sharp,glare free portrait did not sell well.<br>

I had to buy a Zeiss Softar #1 to get a similar effect..</p>

 

<p>Lens cleaning borders on obsessive-compulsive behavior, witnessed in this thread. The fact is, dirt, even grease rarely affects the image unless you are shooting against a strong backlight. There's no real excuse for getting grease on the lens, but dust is unavoidable. If you must clean, then do it with due diligence.</p>

<p>Optical glass and coatings are relatively soft and easily scratched. It's wise to remove any visible dust with a brush or blower before proceeding. If there are spots remaining, you have to use something which will dissolve those spots without harming the lens or mounting. Salt is best removed with distilled/deionized water. For everything else, use a cleaning solution designed for camera lenses. In particular, there must be no oil* or silicone in the solution, since that affects the anti-reflective coatings. Use a lens tissue or clean microfiber cloth (used only for lenses), dry or moistened with cleaning solution. Wad the tissue up and brush, don't scrub, and don't touch the moist area with your fingers.</p>

<p>The best way to keep dust from digital sensors is to keep your lenses dust-free around the mount and rear elements. If you shoot in a dusty environment, or one with water spray, protect the lens with a filter of some sort.</p>

<p>* The solution can be contaminated with oil if your skin touches the tissue or (particularly) the solution in the bottle. If cleaning leaves an oil slick (streaks) on the lens or filter, you know where it came from. This is especially true with pure alcohol, as used for cleaning digital sensors.</p>

 

<p>I think you'll find this an interesting web page. Caution contains serious lens abuse!<br>

http://kurtmunger.com/dirty_lens_articleid35.html</p>

 

<p>God, how many times has that "dirty lens" article been cited?! You realize it's for entertainment purposes only, right? It's like the oft linked "repair" method for the yellowed Takumar 50/1.4 (the one that involves a very large tool and a sturdy "workbench.")</p>

<p>I'd love to see the tests replicated at f/11 or so. There would be parts of the broken lens images that would be well beyond recognition.</p>

<p>Also consider what would happen with the masking tape images. The bits of masking tape are approx 1/10 the front element dia (just eyeballing it), which corresponds to f/4.5 at 85mm. Each bit of masking tape would result in a complete eclipse of some part of the frame at f/45 (not going to happen, obviously), but also a 0.2 stop decrement at f/16 and a 0.1 stop decrement at f/11. I think those might be noticed as dim spots in the frame!</p>

<p>Any idiot can stick masking tape on a lens and proclaim it functional, but that doesn't mean it's so.</p>

<p>Again, dust doesn't matter a whole lot, unless sometimes at small apertures with sunlight lighting it up. Haze on the lens matters a lot, robbing the image of contrast.</p>

<p>But anyone who prefers to work with dirty lenses, feel free to do so.</p>

<p>For me Yala wild life zone was not a place to maintain your lens clean, being in a jeep with red soil flying all over he place, my Nikon D3X and the 300MM F2.8VR urned to be all reddish in colors and I was scared to have any of them damaged, nothing I could have done at the moment but kept shooting, only when I returned to the hotel started to clean them and that was very hard to get rid of all that red dust.<br>

Now I bought special camera and lens covers from b&h which can protect my camera and lenses for my next trip next week to Sri Lanka again.</p>

<p>For me Yala wild life zone was not a place to maintain your lens clean, being in a jeep with red soil flying all over he place, my Nikon D3X and the 300MM F2.8VR urned to be all reddish in colors and I was scared to have any of them damaged, nothing I could have done at the moment but kept shooting, only when I returned to the hotel started to clean them and that was very hard to get rid of all that red dust.<br>

Now I bought special camera and lens covers from b&h which can protect my camera and lenses for my next trip next week to Sri Lanka again.</p>

<p>Rashed, whatever you do, just don't shoot with any lens in that environment that doesn't have internal zoom and focus. Otherwise the lens will expand and contract, drawing dusty air through the camera into the lens. (Don't ask me how I know this!)</p>