How important is keeping the front element clean?

[jett]

Normally I try my best to protect all of my lenses but...I'm thinking of getting an inexpensive collapsible lens (like an FSU) and just transporting the lens without a lens cap, hood, or UV filter. I'd get an elmar hood when the lighting that is harsh...this is what I do with my Retina IIIc.

Well this is my plan but I'm wondering if anyone shoots with moderately scratched up and dusty front elements? I believe that imperfections on the rear elements are worse than front elements. I'm not going to intentionally abuse this lens but since I don't plan on protecting it much, then I'd imagine the front element to get a little banged up with time.

 

[thegman]

I used to have a Summicron with a completely scuffed up front element, did not seem to affect picture quality at all. Unless it's a very valuable lens, then I tend not to bother lens caps etc.

 

[segedi]

The rear element appears to be far more important when it comes to affect on an image. I still tend to use caps, hoods and filters though.

 

[Roger Hicks]

With a good lens hood, or in any situation there's no harsh light striking the front element obliquely or a light source in shot, the main thing you see is a slight loss of contrast. BUT, if there's a light source in shot, or sun glancing across the front element, contrast loss can be enormous.

Cheers,

R.

 

[JohnTF]

I repeat myself, but, I gave a friend a Tamron zoom for a Nikon, some wide range lens, and the lens was dropped without its filter on to a rock which produced a 40mm very deep gouge, about 1mm across. Actually, I suspect a jealous friend did it on purpose, never saw a lens so abused.

Before having the element replaced, we shot a test roll in to the late afternoon sun, -- with chrome and glass reflections, and generally everything you could do at various focal lengths.

Results were we could find no evidence in the prints, -- conclusions were that while unsightly, you could tolerate a few scratches in the front. There is the old trick of filling in a ding with black ink, but lens was headed back to Tamron to replace the "Grand Canyon size" defect.

I should have asked for the old element back when I sent it to Tamron, bill was $100 back then.

I don't recommend this treatment, but with any older lenses, I generally avoid cleaning too much-- if I am at the shop, I hand it off to someone who has cleaned a lot of lenses-- seems to me more lenses are scratched while cleaning with what's at hand than by accident in use.

If you do not know if you have a modern hard coating, ask someone who does know, you should be able to clean modern hard coated lenses with a little care. Some older lenses are well known to be easy to scratch, am sure folks here know which ones are.

I used lens cleaner on a 60's Omega enlarging lens and it dissolved the coating.

A good lens hood does double duty, it also absorbs impacts, and helps with contrast and flare.

Scratches any where will grossly lower sales value often to silly levels, you might get a real winner of a lens cheaply with light front cleaning scratches.

Regards, John

 

[skibeerr]

I have cleaned some lenses when I was younger (about two years ago)
I went about it like this,

-blow of dirt.
-remove further dirt with a very soft brush.
-clean lens with a lint free paper cloth drenched, really drenched, in meth alcohol
work softly in a circular motion from centre to sides.
-dry with a fresh paper cloth same motion.

I had good results this way.

Now I dont bother any more.

 

[Sejanus.Aelianus]

I keep ultrawides as clean as possible, because the front element isn't too far outside the depth of field , even at f8.

Apart from that, just brush off the dust with a clean soft brush.

 

[johannielscom]

fat fingers and smears might impair contrast far more and even cause rainbow artifacts on the image, but just dust? I never bother with that.

Keep the sun away from the front element while shooting and you'll be fine most of the time. Or, software will fix low contrast.

YMMV!

 

[Highway 61]

Good metal lens hoods always are on the lenses ; lenses caps always are at home, in a drawer.

Even on travel. Dare I say, especially on travel !
There is nothing worse than missing a good picture because you had the cap on the lens and either forgot to remove it (while using a RF camera) or didn't have the time to remove it before the scenery vanished.

As soon as you don't throw metallic things in the photo bag there is no risk of damaging the front elements if you don't take the lenses caps with you.

Good multicoated UV filters can reassure you in a dusty environment of if you like cleaning the lens very often with your shirt, handkerchief, or tie.

Unproperly wiping dust off a lens surface can scratch the lens and affect the photos more surely than leaving the harmless dust where it is.

This is why they invented compressed air.

The only solid thing which should be in contact with a lens surface is a very soft martle hair brush. Those designed for womens' cheeks make-up (blush) are great and cheap.

In case of stains (fingerprints, raindrops, else), only a microfiber unwoven cloth moistened with Eclipse (or isopropylic alcohol) should be used.
Paper towels (even those marketed for cleaning lenses) must never be used ! Same with cotton woven tissues, even very soft : there always will be dust particles in them...

There used to be an old saying : "Keep the lens clean, but don't keep cleaning the lens". 😉

 

[Roger Hicks]

. . . There is nothing worse than missing a good picture because you had the cap on the lens and either forgot to remove it (while using a RF camera) or didn't have the time to remove it before the scenery vanished.

. . .

In case of stains (fingerprints, raindrops, else), only a microfiber unwoven cloth moistened with Eclipse (or isopropylic alcohol) should be used.
Paper towels (even those marketed for cleaning lenses) must never be used ! Same with cotton woven tissues, even very soft : there always will be dust particles in them...

. . .

Para 1: Yes there is. Finding you've run out of film!

Para 2: No. Chamois leather is much more effective -- including the chamois leather on a LensPen -- and for moisture/solvents it is perfectly acceptable either to breathe on the lens or to use ethyl alcohol or a proprietary lens cleaning solution. Or even pre-moistened lens wipes.

Where do your "dust particles" come from? For that matter, I have read a number of Hollywood camera operators who have said that nothing beats well-washed cotton cloth made from an old T-shirt.

You are making the common mistake of generalizing from your own experience/beliefs and saying that there is no other way of doing things. Also, chucking lenses into a bag with no front cover is a great way of getting dust on the front elements or even fingerprints when you are pulling them out.

Cheers,

R.

 

[Highway 61]

Where do your "dust particles" come from?

From everywhere out. Come on. Unless you store your Hollywood used T-shirts balls in a sealed bag after they come off the laundry (provided that they were washed/rinsed with demineralized water).

I wonder where you read that I wrote that there is no other way of doing things.

And with good photo bags you don't "chuck" lenses in them, but properly store them in the inserts which are designed for. Storing the lenses upside down with the rear caps on helps not putting one's fingers on the front elements, especially when the lens hoods are on.

The key is the lens hood, I might not have been clear enough there. This is either the cap, or the hood. Handling lenses without front caps and without hoods isn't something I'd do.

Anyway - good appetite Roger, cheers too. 😉

 

[Roger Hicks]

From everywhere out. Come on. Unless you store your Hollywood used T-shirts balls in a sealed bag after they come off the laundry (provided that they were washed/rinsed with demineralized water).

I wonder where you read that I wrote that there is no other way of doing things.

And with good photo bags you don't "chuck" lenses in them, but properly store them in the inserts which are designed for. Storing the lenses upside down with the rear caps on helps not putting one's fingers on the front elements, especially when the lens hoods are on.

The key is the lens hood, I might not have been clear enough there. This is either the cap, or the hood. Handling lenses without front caps and without hoods isn't something I'd do.

Anyway - good appetite Roger, cheers too. 😉

Highlight: "only a microfiber unwoven cloth moistened with Eclipse (or isopropylic alcohol) should be used." This accounts for my perhaps slightly aggressive response, for which I apologize, but it simply isn't true. Likewise the stuff about paper lens-cleaning tissues.

And... um... I have quite a lot of quite good bags (Frances used to cover bags for Shutterbug, and manufacturers are generous with samples). We do, in fact, chuck lenses into the spaces between the dividers. Some good bags, too, don't have dividers: my favourite small Billingham, for example.

I fully take your point about cotton cloths, and I do not endorse the practice. On the other hand, given the price of movie lenses, I can't help wondering if the rest of us are being a bit overly cautious in eschewing their advice.

Your point about lens hoods is also well made, and I quite agree; but I tend to take the best of both worlds, by using OpTech Hood Hats over the sop of the lens hood: http://www.rogerandfrances.com/subscription/review optech shower cap.html

Oh: and thank'ee for the "good appetite" -- I've just finished a light lunch of oeuf brik with a kir on the side. It must have been your good wishes that made it taste so good!

Cheers,

R.

 

[sevo]

Where do your "dust particles" come from? For that matter, I have read a number of Hollywood camera operators who have said that nothing beats well-washed cotton cloth made from an old T-shirt.

One thing many people mix up are old and new lenses - some optical glass is pretty soft, and so were early coatings, and many rules for lens cleaning date back to these days (and still apply when cleaning ancient lenses). Modern hard coatings are so hard that they even are applied to non-optical glass (shop window panes and the like) to make it more scratch and vandalism resistant - being overly paranoid about cleaning them is hardly indicated.

While a clean tumble-dried T-shirt won't do as well as the regular tool of choice of the motion picture and electronics industry (lint-free cotton cleaning rag - strictly speaking made from viscose or Tencel - which most people in the industry use almost like disposables) it does the job, at least when it comes to removing the grease - and any lint it leaves behind can be blown/brushed off.

A problem with expensive lens cleaning cloths (or lens pen tips) is that we tend to use them much too long to recoup the investment - if you re-use one cloth for dozens of cleanings, you would probably fare better with a roll of disposable kitchen towels. The one real risk of doing significant damage across all your lenses are bits of grit that got embedded into a cleaning cloth that sees long-term use.

 

[tempest68]

I learned this summer just how much I do like hoods because of choosing not to use one while on vacation. I was using my Canon EOS 3 w/24-70mm and my wife had her Nikon 1 J3 w/10-30mm, neither one sporting a hood. We were experiencing a heat wave, which was naturally causing us to perspire a lot. Needless to say we both had issue where we accidentally got perspiration on the front of the lenses. I'm certain that just using a hood would have greatly reduced the chance of that happening. Unfortunately I left the hoods at home 5 hours away. So even after the first day, I couldn't do much to prevent it from recurring.

I'm typically concerned about not starting the day with dust or smudges on the front element. So I use rocket blower and or lens pen before leaving the house. Then I take the lens pen with me (especially for a few lenses I don't have hoods for). I don't worry about dust accumulated while out, but any smudges drive me insane!

 

[yossarian123]

I wouldn't worry about the dust. I tend to just let the front elements on my lenses accumulate dust until I accidentally stick my thumb on the glass. Dust is cool but the thought of a finger print with oil gives me the willies so I'll clean it.

And I'll always have a lens hood on. Like mentioned above, stray sunbeams kill more shots than dust or cleaning marks.

 

[Stdon]

I'd far rather use a clean cotton Tee than any paper product especially out of the kitchen which are abrasive enough that they are used in the metal finishing business. Paper towels are used as a final polishing for fine molds for castings.
There are too many busy theories about cleaning lenses.

On a side note lensrentals.com posted photos recently taken with a lens with the front element totally cracked through and splintered. Only result was a slight loss in contrast and a tendency to flair when shooting into a bright light. Otherwise the images were fine.

 

[Rob-F]

"How important is keeping the front element clean?"

Not important enough to justify continual wiping, which will cause more harm. Only clean it when you can do so properly.

 

[noisycheese]

+1 on what Rob-F said.

I have read stories of people who were so obsessed with a clean front element that they have actually rubbed off the front element lens coatings over time. Not very smart, IMHO.

My approach has been to clean front and rear lens elements as little as absolutely possible. I will go months - sometimes years - between cleaning lens elements with a microfiber cloth and lens cleaning solution. There's very rarely any real need to "wash" your front element, even less for the rear element.

The main cleaning issue I face is dust, not smudges, smears or water drops. When I have dust on my front element, I will use a can of photographic (oil free) canned air. That removes the dust about 99% of the time.

If a particle of dust is really stuck and the canned air doesn't remove it, I will use a horse hair lens cleaning brush. That removes it the other 1% of the time.

 

[Godfrey]

I once had a Nikkor 135mm tele that had a somewhat scuffed up front element. Cost me $20. It was amazingly sharp if I kept light from hitting it obliquely, was most useful as a portrait lens for the softness it showed wide open.

G

 

[jsrockit]

With a good lens hood, or in any situation there's no harsh light striking the front element obliquely or a light source in shot, the main thing you see is a slight loss of contrast. BUT, if there's a light source in shot, or sun glancing across the front element, contrast loss can be enormous.

This is my experience too. It can be quite beautiful to use the flare and low contrast to your advantage. However, when you don't want that... it sucks to be stuck with that type of look.

Then again...

http://www.lensrentals.com/blog/2008/10/front-element-scratches