How do folks keep large front elements clean?

[nsecomb]

I will apologise in advance for what will be a blatant demonstration of ignorance.  I thought of posing the question in the beginners section, but I doubt a beginner would be asking questions about the lenses mentioned here.

When handing a child a camera for the first time, one of the first requests is usually "don't touch the glass".

Many photographers put clear filters on the front of their lenses simply to protect the front element from damage or soiling.  I've always thought that these front elements had coatings on the exposed face and that using a cloth and fluid on them risked scratching, thinning or removing said coating if there is grit on the lens or cleaning cloth/tissue.

Yet there are several (quite expensive) lenses which are simply too big to carry a filter on the front, or the front element is so bulbous that a conventional filter can't be fitted.

I am curious as to how the pro's and enthusiasts who use such lenses go about cleaning these front elements when they inevitably have dust, rain, insects or parts of vegetation deposited on them by wind, gravity, contact etc.  Is it a case of using lint-free cloth and lens cleaning fluid only when things have built up a bit, and making concerted effort to keep the lens front capped, or out of the wind/dust when shooting?  Or is it just a fact of life that these lenses will have crap hit their front element during ordinary field use and you simply have to clean them as required, and hope that the front coatings don't get scratched or worn down in the process?

It's not uncommon in adverts for second hand sales of such lenses to see "the glass is clean / perfect".  I sometimes wonder how that could be for a lens which can't have a filter attached to the front, unless the lens was hardly ever used or the seller lives in an environment very different to mine, one where there is hardly any wind, dust or precipitation.


Sincerely, and in curiosity,

Nigel

[Marlyn]

My way.

Most of my Canon L leneses, including some big glass, do not have filters on them. I leave them 'bare' and clean as required.  The procedure I use which seems to work fine is this.

1. Lens Caps or Lens hoods.  Leave one or the other on your lens at all times. This stops an amazing amount of crap, especially on longer lenses. (longer hoods).  I often leave lenses in the bag, hood on, Cap off, for a quick change.

2. Cleaning.  Carry a good quality large cloth and a small blower.   Not one of the crap ones, something like a Gittos rocket mini.  Keep the cloth Clean, wash it regularly. (sink in hotels does just fine).  

   Whenever there is any crap on the lens, blow it off, and give it a gentle wipe with the cloth if it really needs it.   I generally use cleaning fluid only if something is stuck or smeared, and when I do, its the good stuff.  Don't use the crap in the $9.99 cleaning kits.   Bottle from your local Optomertrist or similar is good.  They all work, including just Isopropal alchohol,  I'm just not sure what some of them might do to the coating due to dodgy chemistry.

You mentioned this "Is it a case of using lint-free cloth and lens cleaning fluid only when things have built up a bit"....  Answer, defiantly not, and in fact the exact oppositie.  Clean anything off fast and regularly.  Apart from scratches, the biggest risk to the coating on the element is any form of Acid/Alkaline corrisive substance that can break it down.   This is contained in things like plant matter, grease, oil (including skin oils), etc etc.   If you come in from a shoot in the rain, clean the lens right away.

The coating is pretty tough if you look after it, but it does scratch.  Which is why blowing those granuals off first, and washing the cloth regularly is important.  

In a harsh environment, I put a UV filter on the lenses I can. (This is ones where I'm expcting a sand flying, or Mud flying such as rally or 4WD).   Dosn't happen much.

This is what I was taught, or figured out from experience,   YMMV of course.    To date I've only damaged one front element, on a 24mm TS-E. Tha was caused by putting it down in a bag without a lens cap or hood on, not noticing it was sitting on top of a battery and then driving a few 100 km with it like that.

Mark.


Edit: I should clarify something here. I'm pretty brutal with my lenses in the field, but find a little blower works wonders in keeping the crap off. The key thing here is, if it gets real junk on it, get it off fast, then you don't 'need' to wipe them very often at all.  A Little blow, a small wipe on a smear is it. Don't clean it 'just because', as every time you do rub it, you are making micro scratches.

[Ken Bennett]

I keep the lens hood on all my lenses, which helps a lot. But I'm very remiss in otherwise keeping them clean. When I do notice something, I'm just as likely to blow on it and wipe with my t-shirt as anything else. (Of course, I'm not a total idiot -- I won't wipe a lens that has sand on it, etc.) Maybe once a year I will get out some lens cleaner and wipes and a can of compressed air and do a thorough cleaning of all my lenses.

After 20+ years as a photographer, I've never noticed any problems with my lenses. The front elements are in perfect condition, er, with maybe some dust....

[Rob C]

I think that lenses that can't take filters carry their own death warrants.

Before I bought my ill-fated 24-70 Nikkor zoom I had played with the idea of getting the hot wide one instead (14-24 or something like that), but decided that all that doh rey me invested in something that can't take a filter is nuts; maybe some folks have a gentle insurance company.

I do not believe that cleaning a lens is safe at all - have you taken a close look at a filter through a magnifying glass after it has been used for a year or so? Though they too are coated, they are not able to resist damage, but they are relatively inexpensive.

Rob C

[fredjeang]

But then that leads us to the delicate filter protectors.
Actually, I do not use them any more but would be more than happy to know the good onces (brands) that do not degrade the lens performance.

Fred.

[Dustbak]

I rarely clean my front element. Have any of you ever tried what you need to do before something that is on your front element becomes visible? Most damage I have seen on front elements were cleaning marks.

Blow it clean (Giotto's rocket works nicely), wipe it only if your really need to but keep it to a minimum (once a year sounds about the right interval ).

[Marlyn]

{double post}

[Wayne Fox]

2. Cleaning.  Carry a good quality large cloth and a small blower.   Not one of the crap ones, something like a Gittos rocket mini.  Keep the cloth Clean, wash it regularly. (sink in hotels does just fine).  

   Whenever there is any crap on the lens, blow it off, and give it a gentle wipe with the cloth if it really needs it.   I generally use cleaning fluid only if something is stuck or smeared, and when I do, its the good stuff.  Don't use the crap in the $9.99 cleaning kits.   Bottle from your local Optomertrist or similar is good.  They all work, including just Isopropal alchohol,  I'm just not sure what some of them might do to the coating due to dodgy chemistry.

Agree with much of your post.  I only use a filter for effect, never as a protection device.  Lens Cap/lens hood are good, and I avoid additional glass surfaces that might degrade my image.

It is unlikely that a few small specs of dust on a large front element will have any visual affect on image quality.  But conscientious use of a blower frequently is the best tool.  Otherwise humidity will eventually make the dust stick so it can't be blown off.

The other enemy of lens is when a film deposit builds up ... beach shooting, dusty/windy conditions.  This overall haze is a definite problem and normally requires cleaning.

However, I personally never use Isopropyl alcohol, it is quite harsh.  The 70% diluted kind will most of the time leave smears.  I have used sensor cleaning alcohol however, which I believe is less harsh and it seems a sensor is probably more delicate than a lens element.

So I'm at a loss as to which is the best cleaner.  I'm not sure the stuff an optometrist provides is any better than the fluid from a reputable lens cleaning fluid such as Zeiss Lens Cleaner.  I have used Kodak Lens cleaning fluid for many years on the rare occasions I need a liquid cleaner without any negative issues that I'm aware of.

[PeterAit]

Agree with much of your post.  I only use a filter for effect, never as a protection device.  Lens Cap/lens hood are good, and I avoid additional glass surfaces that might degrade my image.

It is unlikely that a few small specs of dust on a large front element will have any visual affect on image quality.  But conscientious use of a blower frequently is the best tool.  Otherwise humidity will eventually make the dust stick so it can't be blown off.

The other enemy of lens is when a film deposit builds up ... beach shooting, dusty/windy conditions.  This overall haze is a definite problem and normally requires cleaning.

However, I personally never use Isopropyl alcohol, it is quite harsh.  The 70% diluted kind will most of the time leave smears.  I have used sensor cleaning alcohol however, which I believe is less harsh and it seems a sensor is probably more delicate than a lens element.

So I'm at a loss as to which is the best cleaner.  I'm not sure the stuff an optometrist provides is any better than the fluid from a reputable lens cleaning fluid such as Zeiss Lens Cleaner.  I have used Kodak Lens cleaning fluid for many years on the rare occasions I need a liquid cleaner without any negative issues that I'm aware of.

Lens manufacturers sell cleaners, for example Nikon lens cleaning fluid $4.95. It seems to me that you could not be safer than to use the mfg's own fluid. I never use filters simply for protection, but am pretty careful about using the cap and hood. I use a camel hair blower brush for lose stuff and the Nikon fluid with a piece of oft-washed cotton t-shirt when needed.

[NashvilleMike]

I am curious as to how the pro's and enthusiasts who use such lenses go about cleaning these front elements when they inevitably have dust, rain, insects or parts of vegetation deposited on them by wind, gravity, contact etc.  Is it a case of using lint-free cloth and lens cleaning fluid only when things have built up a bit, and making concerted effort to keep the lens front capped, or out of the wind/dust when shooting?  Or is it just a fact of life that these lenses will have crap hit their front element during ordinary field use and you simply have to clean them as required, and hope that the front coatings don't get scratched or worn down in the process?


Nigel

I'm firmly in the "no filter unless you have a specific need" school of thought; for me just using the lens hood offers reasonable protection in most cases and I accept the fact I'll need to clean the front element from time to time. My lens cleaning routine is pretty simple - for general dust and such I use a big rocket blower(like the Giottos that has been mentioned in other responses) and when I've been shooting in an environment (sea spray, etc) that needs a wet cleaning (or I need to get rid of fingerprints, etc), I use what I consider without question the best lens cleaner around, something called ROR cleaner, which stands for residual oil remover. I use it with a brand new or extremely clean microfiber cloth, typically a new one that I've reserved for a few lens cleanings before I toss it. I've used about everything else in terms of lens cleaners and this is the only cleaner I trust and have never seen it damage coatings or glass. I have used it regularly on my Nikon 14-24 without any fear. It's pretty amazing stuff. Lesser grade cleaners tend to leave marks, so I don't bother with them any longer.

-m

[Marlyn]

Agree with much of your post.  I only use a filter for effect, never as a protection device.  Lens Cap/lens hood are good, and I avoid additional glass surfaces that might degrade my image.

It is unlikely that a few small specs of dust on a large front element will have any visual affect on image quality.  But conscientious use of a blower frequently is the best tool.  Otherwise humidity will eventually make the dust stick so it can't be blown off.

The other enemy of lens is when a film deposit builds up ... beach shooting, dusty/windy conditions.  This overall haze is a definite problem and normally requires cleaning.

However, I personally never use Isopropyl alcohol, it is quite harsh.  The 70% diluted kind will most of the time leave smears.  I have used sensor cleaning alcohol however, which I believe is less harsh and it seems a sensor is probably more delicate than a lens element.

So I'm at a loss as to which is the best cleaner.  I'm not sure the stuff an optometrist provides is any better than the fluid from a reputable lens cleaning fluid such as Zeiss Lens Cleaner.  I have used Kodak Lens cleaning fluid for many years on the rare occasions I need a liquid cleaner without any negative issues that I'm aware of.

Wayne, I agree with you, and my post could proably have been better worded.  I also do NOT use Isopropyl alchol, and advocate using the best cleaner I can find.  (I also use the ZEISS Lens Cleaner),  however on a trip once I forgot it, and got a bottle from an optomerist which they use for cleaning the lenses in their equipment, and it worked just as well.    I find the cheap stuff from (insert any local camera/print shop) smears , and dosn't remove "grunge" nearly as well as the Zeiis or equiv.   Good fluid = less wiping to get it clean, IMO would lead to less scratching.  

As for what affects image quality.  Haze from general crap in the air, especially if your near the sea, and any kind of water directly on the lens.  

One other tip.   Saltwater can't be blown off, and should not be rubbed off either.   When cleaning off haze / seawater, I use these little bottles of distilled watter with the snap off tops (Come in most decent first aid kits),  and give it a really good wash first, just using the preassure of a small hole in the top and 'squirt'.   After its clear of junk, then its Cleaning fluid and a cloth.    
This may be overly paranoid, but I don't like the idea of wipeing element, even with cleaning fluid when it has been near saltwater, or sand, for fear of scratching it.

Regards

Mark

[AndrewKulin]

You did not say what type of photography interests you.  So if your interests lie in landscapes I was once told by a pro landscape photographer that they essentially keep a polarizing filter almost permanently attached on each of their lenses.  Provides the effect they want anyway for landscapes, and protects the lens.  And since it is on most of the time anyway, they then do not need something like a clear UV filter for protection which just adds another layer of glass to the light path.

[nsecomb]

You did not say what type of photography interests you.  So if your interests lie in landscapes I was once told by a pro landscape photographer that they essentially keep a polarizing filter almost permanently attached on each of their lenses.  Provides the effect they want anyway for landscapes, and protects the lens.  And since it is on most of the time anyway, they then do not need something like a clear UV filter for protection which just adds another layer of glass to the light path.

That's true Andrew, I didn't, because:
1) It hadn't occurred to me that what I shoot would be a factor as it was intended to be a general question.

2) I was working from the premise that most folks shooting outdoors would face similar hazards (with the exception of those shooting in wind-blown sand or salt spray, close to sporting events where there is plenty of mud flying etc.).

3) I have not purchased a lens that can't have a filter mounted on the front... I just ogle them ocassionally, looking at those on offer second hand with a mix of desire and a tinge of fear concerning the exposed front element being damaged while trying to clean it.

I photograph basically everything except products and people, much of it is landscape and nature.  The polariser approach unfortunately wouldn't work too well for me personally, if for no other reason than I own several lenses with the same thread size and only have one polariser to use between them... $250 per filter (77mm Circ PLR) really adds up quickly.  Still if a situation arose where it would work, I'd certainly give it a try (polariser without UV underneath).

I want to thank all those that have responded with how they approach this issue.  For those of that have never had the experience it is so useful to hear of experiences with this kind of issue before one considers purchasing such a lens.  Not that I expect I will any time soon, but maybe in a few years time I'll getter a faster long telephoto to replace my trusty EF f5.6 400mm, armed with the guidance conveyed above on how to protect and clean the front of it.


kind regards,

Nigel

[petermarrek]

I would never not purchase a lens because it might be hard to clean. Have used a 14-24 for over a year without cleaning it, a lot of the time on water including salt water. The only rule- keep the lens cap on when not looking through the lens.

[gullevek]

I rarely clean my front element. Have any of you ever tried what you need to do before something that is on your front element becomes visible? Most damage I have seen on front elements were cleaning marks.

Blow it clean (Giotto's rocket works nicely), wipe it only if your really need to but keep it to a minimum (once a year sounds about the right interval ).

I see smears when I shoot wide open in certain bokeh moments. Especially blue light. But normally I don't see any of the dirt at all. When it gets too dirty I just wipe it off with a soft cloth. Something like a cleaning cloth for glasses.

[tom b]

There was a previous thread on this topic. You can read the comments here:

http://luminous-landscape.com/forum/index....showtopic=32003

Cheers,

[schrodingerscat]

Some thoughts from a twenty five year camera tech -

Best protection is a lens cap. Can't believe the times I've been hiking on a very dusty trail and have seen cameras hanging on people with the lens, as well as the whole camera,  unprotected. Only takes a second to remove it.

Most modern filters are coated, and most "digital" filters are multicoated on both surfaces. These coatings are usually softer than those found on lenses.

Always blow off glass surfaces before wiping with anything. It is also advisable to always wet clean. If your breath won't work, use a liquid cleaner. Most techs use anhydrous isopropyl or lab grade methanol. Next best is a comercial lens cleaner. Products for eyeglasses are not recommended, nor is rubbing alcohol. Use either lens tissue or a micro fiber cloth(kept clean). Articles of clothing are a no-no.

One of the most damaging things to lens coatings are fingerprints. The acids etch the coating and the print becomes permanent. Remove as soon as possible.

If having a filter on the lens gives you confidence to clean it more often, a clean filter is beter than a dirty lens.

Don't forget the rear element, has more of an impact than the front.

Keeping it clean is better than waiting 'till it gets real ugly.

[Rob C]

Some thoughts from a twenty five year camera tech -

possible.

If having a filter on the lens gives you confidence to clean it more often, a clean filter is beter than a dirty lens.

Don't forget the rear element, has more of an impact than the front.

Keeping it clean is better than waiting 'till it gets real ugly.

Very good advice, if only because I agree with it 100%!

;-)

Rob C

[KevinA]

Very good advice, if only because I agree with it 100%!

;-)

Rob C

Rob I have the Sigma 12 - 24 mm which has a front element unsuitable for filters. It's not been a problem for me the glass is still good, that wide Nikkor zoom is one reason I would add Nikon to my Canons. If you need what the lens can do it's better to have it and live with the fear.

Kevin.

[Rob C]

Rob I have the Sigma 12 - 24 mm which has a front element unsuitable for filters. It's not been a problem for me the glass is still good, that wide Nikkor zoom is one reason I would add Nikon to my Canons. If you need what the lens can do it's better to have it and live with the fear.

Kevin.

Kevin, that all depends on how much fear you already have in your life; my bag is full and there's no room left for more!

Rob C