Equipment

Front Element Lens Protection Revisited

The internet is an interesting resource. Once you’ve put a reference up, it’s there forever. Over time, things may change, but that 10-year-old article doesn’t. A few weeks ago someone used some old articles I’d written (12, 3) as a reason why he doesn’t use protective UV filters. They claimed I had said there was no need to use UV filters.

That’s kind of what I said, but so compressed as to be inaccurate. What I really said was this:

  1. Evaluate the cost to benefit ratio of using a UV filter. Don’t use a $100 filter to protect a $100 front element.
  2. Evaluate the situation. If you are in a high-risk environment, use a filter to maximize your protection.
  3. Never, ever use a cheap $30 filter unless you don’t care about image quality.

But at that time (2010 to 2013) I wrote those posts, that meant I didn’t use UV filters very often because it usually wasn’t worth the money. Front element replacements weren’t that expensive, and high-quality UV filters were expensive.

A Bit About My Qualifications

As with every article I write, there will be three or four comments saying, “I’ve had 20 different lenses and never had this problem.” Good for you. I take care of around 20,000 lenses at any given time. About 15,000 of those never had a problem either. You do the math. So I write about the problems that occur so you can be forewarned about the problems that may occur with your lenses. Forewarned is forearmed.

We replace front elements in lenses for cosmetic reasons every day. Every. Damn. Day. Sure, they’re rental lenses and maybe don’t get babied as much as your lenses do. You may get lucky and never deal with any of this. But it’s always good to make an informed decision about what precautions you want to take. In this particular case, basing your decisions on 6 or 8 year old data can be a mistake.

Discarded front elements. Each bin has around 125 front elements and weighs 30 to 50 pounds each. Lensrentals.com, 2016

Discarded front elements. Each bin has around 125 front elements and weighs 30 to 50 pounds. Lensrentals.com, 2016

There Has Been a Big Change

When I wrote most of those articles I talked about above, front elements cost from $70 to $200, and good filters cost $70- to $140. Today highest quality UV filters cost from $70 to $120, even in 82mm size. But the cost of replacing front elements has skyrocketed.

I’ve always said to evaluate the cost-benefit ratio of whether you want to use a protective filter. Now the price has changed so that change should be factored into the equation. (BTW – the costs I’m giving as examples below are our costs. Your prices may be different. But we’re a really large repair customer based in the U. S. so by ‘different’ I mean ‘yours will probably be a bit more expensive.’)

Most people aren’t surprised that a Canon 70-200 f/2.8 IS lens ($1,800 or so) has a $270 front element, or that the Canon 24-70 f/2.8 Mk II ($1,700) runs just over $200 for a new front element. You might not even be surprised that a 150-600mm telephoto lens that costs $900 or so runs over $200 to $250 to get the front element replaced (either brand) since that is a big piece of glass.

But you might get a little queasy when you find out a Nikon 24-120mm lens that costs from $900 to $1100 new (they go on sale a lot) costs $320 to replace the front element. If you own a Zeiss Otus lens, you probably have reasonable funds in your bank account, but you may still have sticker shock if you need a front element replaced; it will cost $900 to $1,500. Some Sony FE lenses require replacement of the entire optical group ($800 to $1,500) to replace a front element scratch because the front element isn’t available as a part; the entire optical assembly is the only part. (Sony is working on separating the front element part to reduce this cost. They’ve already done so on the FE 24-70mm f/4; now a front element replacement is only $270. They say they are doing so with most of their other lenses, too, but right now an FE 16-35 f/4 front glass replacement is $785, for example. We have bins full of Sony lenses that just aren’t worth the cost of front element replacements, hoping that some day the price will become reasonable.)

More important, perhaps, is that the cost of a front element replacement can be very high even for a not-so-expensive lens. A decade ago you could assume a relatively inexpensive lens (under $1,000) had a relatively inexpensive front element. A Canon 70-200 f/4 IS lens, for example, cost around $950 and a front element replacement was under $100. Most newly released under-$1,000 lenses will run $200-$300 for a front element replacement.

My point here is not to provide a list of what every manufacturer charges for every front element. You can call or email them if you want to know. It’s not that one manufacturer has really high prices and another doesn’t. They all have some high and low-cost lenses. For example, manufacturer X has front element replacement costs that range from 9% of the lens price to 33%. If there’s a general rule it’s that lenses released 5 or more years ago are reasonable cost for front element replacement, newly released lenses are expensive. There are exceptions, of course. And so I’m clear, it’s not that the cost goes down over time. Unlike sale prices, repair prices don’t go down after the lens has been out a while.

So, front element replacement costs, particularly on new lenses, are higher than they used to be and some lenses are breathtakingly higher. There are some real reasons this is so. These new, sharper lenses often have front elements that are unique glass types, nano-coated, highly aspherical and a lot of other things. Manufacturers are pulling ever trick out of their bag to make lenses sharper and better. One of those tricks is that front elements, which often used to be simple, protective elements, got fancy. ‘Fancy’ is the optical word for damned expensive.

Some of the increased expense is just poor planning. Let’s pretend, for example; the manufacturer thought, “Well, this front group is so difficult to adjust optically that the service center can’t do it. So instead of making the front element a part, let’s just make the entire front group of lens elements a part so that we can adjust it in the factory, and the service center can just replace the whole group.” I have talked to manufacturer’s lens designers who had absolutely no idea the front element was more likely to need replacing than other parts (we replace more front elements than all other parts combined). That’s not what they do; they design lenses.

Does This Really Matter?

Small front element scratches, the kind that filters will protect against, rarely affect image quality at all. Once in a while, shooting into bright lights, you may (or may not) get some flare from the scratch. So if your lens gets some little front element scratches, as most eventually do, it matters very little.

But if you plan on selling your lens at some point, it does affect resale value significantly. We make this decision every day: The lens has a small scratch on the front group, is it worth the price of replacing it? A few years ago we’d spend $100 on a new front element and get $150 more in asking price for the used lens. These days the math is different. It’s not worth spending $250 on a new front group to get a $150 higher selling price.

Of course, there’s a positive for people who buy used lenses. A small front element scratch means a bargain lens for sale that will function just fine.

So does this mean you should put a UV filter on all of your lenses? No. I still recommend looking at the cost-to-benefit ratio for the specific lens, and considering what you’re going do with it. If it’s a lens for studio portraiture only, why bother? If you shooting surf at the beach, then you better wear protection.

In most cases, a lens hood (actually mounted on the lens, not left in your bag) provides plenty of front element protection. Wide-angle lenses are a unique case, though, since those hoods don’t provide much protection. But if you are outdoors and your lens is exposed to dust, sand, water, or other things lenses don’t like, then a hood doesn’t provide protection and UV filter is probably worthwhile.

How Much Does A Filter Impact Image

Well, if you buy a $30 filter, then it can impact the image a lot. Waviness in the thickness of glass, poor coatings, poor quality glass, even shiny metal in the mounting ring can cause problems. If you choose to buy a cheap filter, you’ll probably see effects if you look critically; although it won’t be in every shot. You may see some effect on absolute sharpness, but you’re far more likely to see effects from light flare, ugly bokeh, ghosting, and reflections.

A high-quality filter is made from good optical glass, flat to within 1/4 wavelength, and multicoated on BOTH SIDES. It’s expensive, but it doesn’t have much effect on image quality at all. (When you do your filter shopping, make sure the filter is coated on both sides; some cheap filter makers multicoat one side only, then advertise it as multicoated). A good filter should avoid most (not all, but almost all) effects regarding ghosting, flare, and reflection. It shouldn’t affect sharpness even at the highest level of measurement.

Here’s an example of a Canon 50mm f/1.2 lens tested on our optical bench to demonstrate there’s no sharpness penalty with an excellent filter. First the lens with no filter at all.

Olaf Optical Testing, 2016

Olaf Optical Testing, 2016

 

And then tested with a high-quality UV filter in place.

Olaf Optical Testing, 2016

Olaf Optical Testing, 2016

There are no effects on MTF from the filter, either on or off axis. This doesn’t mean there might not be a bit of ghosting if you’re shooting street lights at night or star trails, etc. But it won’t be often, and you can always remove the filter if you notice that happening in a particular shot.

So Do I Recommend Filters Now?

Not necessarily, no. I support common sense and looking at the cost-to-benefit ratio. But if you have one of the newer lenses, especially if you know the front element has Nano-coating, is aspherical, or is just expensive to replace, then I’d certainly at least have a filter available. I’d especially recommend it if you expect you might sell that lens someday; even a minor scratch is probably a 10% price reduction on the retail market. If you say they’ll pry that lens out of your cold, dead fingers, then I wouldn’t worry so much.

I also really recommend you look carefully at the filter threads and front element BEFORE you mount a filter on the lens, especially if it’s an ‘ultra-thin’ filter. Several lenses we know of have slightly projecting front elements, and some ultra-thin filters can actually touch the center of the front element causing a scratch if the filter is tightened all the way down.

While I’m on the subject of touching the front element, though, those nice new thick lens caps a lot of manufacturers use these days, the ones with the big spring-loaded squeeze release handles, are a problem for some lenses, especially when they are 82mm wide. There’s a lot of plastic underneath that cap, right over the center of the lens. If the lens cap gets pushed down in the middle, it can scrape the front element. I know: glass is harder than plastic. But coatings aren’t. And a coating scratch is just as visible as a glass scratch.

 

Roger Cicala

Lensrentals.com

December, 2016

Author: Roger Cicala

I’m Roger and I am the founder of Lensrentals.com. Hailed as one of the optic nerds here, I enjoy shooting collimated light through 30X microscope objectives in my spare time. When I do take real pictures I like using something different: a Medium format, or Pentax K1, or a Sony RX1R.

Posted in Equipment
  • Steve Millqvist

    They make pretty good loupes.

  • Impulse_Vigil

    It’s kinda curious filter prices have remained so steady… I put a filter on any of my lenses which are weather sealed (so I’m way more likely to take risks with them) or over $700… That’s actually a minority of them within my cheap/small system, but it gives me enough peace of mind and convenience.

    Been using B+W clears as well… And I don’t sell any very often, so it works out. Smaller filters are even cheaper to boot. The Xume (now Manfrotto?) magnetic filter mount system looks interesting for those that really think they would use their filter situationally… Never been available <49mm so I didn't pay much attention to it but I might now that I have some larger lenses.

  • Impulse_Vigil

    Recognizing what kind of protection you need for any given situation is often forgotten in these discussions… Beach spray vs general clumsiness vs sticking a macro/ultra-wide in something vs a tree branch spank are all avoided best by different deterrents. Straps, bags, and carry gear all play a role there too…

  • Impulse_Vigil

    There’s already (varying degrees of) UV filtering stacks on digital sensors, AFAIK that’s why extra UV filtering is pointless… I never found a good reason to opt for a UV these days either so I’ve bought clears, when I bought one at all.

    OTOH I did buy a couple more intense (2A) UV filters for certain fringe scenarios where it does make a difference (Google about Oly vs Panasonic’s UV filtering differences within the same system and how lenses handle it).

  • Marc P.

    I’ve never seen image degradation with HQ B&W UV Filters (XS-Pro Nano, or the cheaper F-Pro 010 MRC UV), or Carl Zeiss T* UV Filters, or Hoya HD Series – and these are the 3 Brands i do use mostly, 95% – but i can recommand Tianya XS-Pro1 UV Filters, if you are onto a budget, and even for more expensive lenses. Most of my MF lenses do have Tianya, because of the cost factor. I’ve put a Zeiss T* UV onto my few Zeiss T* lenses.

    The reason whileas i am using (UV) Filters is only – to protect the Front Element, from smear, dust, sand, pollen, etc…and it’s way easier, cheaper even to replace a Filter then the Front Lens Element – also, the resale value doesn’t degrade, because the Lenses are handled like raw eggs always, carefully, and doing so (with a protective Filter) the Lens looks like mint, new.

  • Glen

    I use filters to keep gunk off the front element (or prevents scratches). After thirty years of shooting, I’ve ended up using UV or protection filters on zoom lenses and no filters on primes (except for NDs if required.) I guess I’m not using my primes very much, and I am careful when using them. I don’t have any nano coated or otherwise exotic primes – my primes are generally very old manual focus. I do try to buy better filters (mostly Hoyas).

    I would be astonished to have a lens with filter threads where the filter actually touches the front element. Seems like a bit of a design flaw unless there are actually filters that have the glass protruding past the threads. Is there some sort of industry standard offset from the end of the threads to the glass?

    I notice that adding a UV filter to a lens rental is free. Are these just always supplied? Or do we have to add these to the cart? (Yes, I’ve never rented a lens, but I have bought one – the front element was perfect!)

  • Bartek

    did a test of various filters for myself once to see how (if) they affect the results I get from different lenses.
    test was on a Canon 450D (12Mpix crop sensor, which was back then high-resolution) with 24-105/4 L (mkI) and 300/4 L (the nonIS oldie).evaluation based on “what my eyes see” for the lack of proper measurement instruments (and severe lack of interest in such 😉 )

    it turned out to coincide with common knowledge that the longer the focal length the more impact is be visible.

    @50mm only the Vari-ND filter or combination of two resin grads had clear impact on sharpness. UV’s, polarizers passed this one with flying colours

    @105mm impact of single resin filters was clear. no problems whatsoever with decent UV, polarizers. slight impact for cheapo Polaroid filters (sold for 30 EUR in set of 4 filters for 67mm diameter 🙂 ) with exception of their polarizer which was significantly worse. Vari-ND useless

    @300mm basically only UV filters survive intact. here no distinction between B+W’s, Hoya’s or Marumi’s. there was some impact of polarizers (any polarizer, including multicoated B+W’s and Hoya’s and Marumi’s). visible loss for cheapo Polaroids. big impact for a single resin filters, with two resins basically lost AF ability (Live View preview shows ghost image). Vari-ND (LCW Fader mkII) useful only as a soft filter for those art photographers 😉

    plan to retry this shot some day with 24Mpix, will probably see more difference 😉 will post update if this ever happens

  • Brian Luscher

    Appropriate filters for UV (e.g., UV2) can significantly reduce
    chromatic aberration as well. I have found that although you can do
    fair automatic chromatic aberration correction in Lightroom, it isn’t
    perfect and in many outdoor lighting situations it is better to avoid
    the disease than try to do a later cure.

  • Bob B.

    Aren’t clear filters more appropriate for digital cameras? UV light affects film, no?
    What Roger has to say is balanced and sensible, though. As always!
    For me, I put B+W Clear MRC Nano filters on all of my lenses at purchase.
    I currently own 27 lenses across two format systems.
    It gives me ultimate peace-of-mind in all situations (put a price on that, please! :-)), and when I sell a lens, I get top dollar for the lens AND for the filter sold separately.
    The cost has dropped on filters and the cost of the best lenses has skyrocketed.
    It’s a no-brainer and my images look great…all the time.

  • Marc P.

    Dear Roger,

    i do use UV Filters always for about ~25 years now, but just for one reason: front element protection.

    1) It’s quite easier (and cheaper) to screw-on a new UV Filter, as having the whole lens being serviced because of that damaged front element.

    2) It protects the front element lens from all the elements, dust, light rain, snow, smudges, tree pollen, sand, moisture, etc.
    3) One doesn’t touch it accidently with the fingers, and the lens basically always looks like new.
    4)Nowadays, I do use only B&W F-Pro MRC 010 UV, XS Nano Pro Variants, a few Carl Zeiss T*, and Hoya HD UV Series,
    and haven’t seen any kind of image degration because of using a UV Filter as lens front element protection.

    Thanks for your interesting article (as always the LensRentals Blog)
    kind regards, Marc

  • Sean T

    I have no truly expensive glass (my most expensive lens is my Tamron 150-600) and I have a toddler who really likes daddy’s camera stuff. I have UV filters on everything and they don’t come off. And the lens I didn’t put a filter on now has a small mark in the coating to remind me why I put UV filters on everything (SEL35OSS). Oops.

  • I was thinking it was getting time for me to enroll in a surfing course or two and move to the islands. Fear of boredom, though, keeps me from taking the plunge.

  • Volker Bartheld

    Hi Roger!

    I find it confusing (and a bit misleading) that people often use the term “UV-Filter” synonymous to “Protection Filter”.

    While some types of glass indeed absorb UV radiation (regular plain window glass for example), others such as quartz glass (as used in – surprise! – UV radiation lamps) do not. And protection from UV radiation is not what you would be really caring about, especially if you shoot standard lenses on digital cameras: The small amount that is emitted by the sun merely makes it through the lens stack and is then absorbed to a high percentage in the AA filter (lithium niobate), so won’t degrade image quality much.

    You would rather want protection from scratches, impact, acids (Ever shot in Yellowstone? My polarizer can tell a sad story…) and other environmental influences. This is where specialist filters enter the game. You probably already read about a product from Hoya the call “HD Filter PROTECTOR” (http://www.hoyafilter.com/hoya/products/hdfilters/hdfilterprotector) and it is supposed to have “Chemically Enhanced Optical Glass [which] is 4x Stronger [than standard glass]” plus some special “HD coating” that repels oil/water and resists scratches better.

    I typically use those, but didn’t put them to the test yet. On the other hand alternative protection filters such as the Kenko Protector Pro1D (http://www.kenkoglobal.com/photo/filters/protector/PRO1D_Protector.html) which is in my bag as well for sure has seen better times already (shooting motocross on the 70-200 F/2.8 Nikkor) while the Hoya still looks pretty decent.

    There are also some videos circulating the net (check out https://www.youtube.com/watch?v=NgMsmSdwGQI vs. https://www.youtube.com/watch?v=_4hMYDDGzzw for starters) which are quite impressive. Sure, those clips might be fake, biased, sponsored by the manufacturer or just plain snake oil. But why not subject one of your throw-away front elements to this ANSI standardized drop/impact test (ANSI Z80.3 : 2001) and see, if the Hoya does a better job?

    While you probably don’t have a dedicated slow motion cam for rent, even a mediocre GoPro, flimsy tripod plus coffee mug would do. This guy here: https://www.amazon.co.uk/inch-Chrome-Steel-Ball-Bearings/dp/B002SRTXOW just has 1/2 inch diameter but you can always compensate with more height (E=1/2m*v^2)… 😉

    Greets,
    Volker

  • Omesh Singh

    LOL, I meant to write “aisle”

  • Ian Goss

    “Isle?” The United Kingdom? 😉

  • Gearsau

    My Nikon 300mm f2.8 AF-S, Nikon 500mm f4 AF-I, and Nikon 800mm f5.6 Manual Focus, all have a clear glass plate at the front. Factory fitted. Not an ” Optional extra “…. Standard.
    My lenses without a front protective filter / glass plate, are my Nikon 8mm f2.8 , Nikon 16mm f2.8 and Nikon 14-24mm f2.8.

  • Kbrasier

    this is an example of someone getting lucky with having a filter on. It doesn’t mean much more than a single instance.

    http://petapixel.com/2016/10/31/drastic-diy-get-broken-filter-off-lens-mythbuster-style/

  • Turniphead

    Excellent information as ever! Please could you do a test with a cheap and nasty filter on?

    Actually that’s another potential series; MTF filter tests. Not that you’re looking for extra work, but it would be useful to know which filters are genuinely worth the extra money, and which are just brand gouging… Might be useful for you to know for your (possible) upcoming plan to rent filters on the lenses with expensive to replace front elements too!

    Happy New Year!

  • Great article, thank you. What about the large lenses that do not have any filter thread (200/2, 300/2.8, 600/4, etc…)? Those are most expensive, and a front element alone would cost probably like a regular lens.

  • Randy Stuehm

    What is the quality of your images and work worth?

  • denneboom

    Roger, can you do a quick UV filter test to see if there is a bigger image quality loss on a telephoto than on a wide angle lens. The longer the better, as long as it has a sensible front filter size

    I tried once to take pictures behind a thick window in a train, and the decrease in sharpness was much worse on the telephoto than on the wide angle.

    I think it makes sense. with a telephoto the light comes in pretty perpendicular, so any distortion by a extra glass element has more impact versus a wide angle lens that accept light from a wider range, and doesn’t magnify as much.

  • SpecialMan

    UV filters are a relic of the film days when they helped cut through aerial haze and make photos look a little bit crisper. For reasons I do not recall—or may have never known in the first place—digital cameras don’t have the same sensitivity to UV light and so clear glass is now the preferred lens protector.

    The other olden-days solution was a Skylight 1A which was slightly pink to eliminate the blue cast in pictures shot outdoors. We don’t have to worry about that with digital cameras either, though the pink can give skin a healthier look in some cases.

    I myself find most lenses too sharp for people photography so I sometimes protect my lenses with a quarter-strength Tiffen Digital Diffusion filter.

  • Andrew

    I’m wondering why UV filters are used? I spent hours and hours reading as much as I could on the topic of front end protection about ten years ago when I began to invest in expensive lenses and I have a Nikon Clear NC Glass filter on just about all my lenses (none are Nikons) but I also have a bonnet on most of the lenses as well. I’d rather clean the salt spray, spider webs and other ‘gunk’ off the filter than touch the lens. But again, why UV as opposed to a high quality clear glass filter?

  • Joshua White

    Great article!

    I am an artist and photography professor, and experiment with lenses and having students build things with optics. Would happily pay shipping for a big box of them!!

  • Doctor Nick

    You guys are just the cleanest photographers ever or something. I use a UV filter because I end up with random gunk on my lens, double gunk if in a sandy or dirty environment. I much prefer cleaning the filter to working on the lens front element. Especially in the field.

  • l_d_allan

    wow … 20,000 lenses run by a family business. Well done, and have a great 2017.

  • SpecialMan

    Dear Roger,
    We are going to be very sorry to lose you, but it is time for you to enroll in the Japanese language program at the University of Memphis for a couple of semesters and then get yourself a professorship at the Institute of Industrial Science, University of Tokyo, where you will be enlightening the next generation of optical engineers. Summers, of course, will be spent conducting seminars at the Institut für Optik in Berlin.
    Thank you for your service and Godspeed!

  • Carleton Foxx

    Ebay!!!

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