If one argument gets photographers riled, it’s whether one should protect the front element of a lens with a UV filter. Should we instead use a lens hood? Let’s settle the argument with this definitive answer by testing an Urth Plus+ pro filter.
Last week, I bought an Urth Plus+ UV filter. I use their ND filters and am impressed with their optical qualities. Historically, I had used their UV filters too. My reason for stopping was partly because a one-time camera company representative told me that the front elements of their lenses were much more robust and, consequently, had greater resistance to damage. However, I see OM Digital Systems – the camera brand I use – and Nikon, Canon, and Sony are all manufacturing their protective filters. If the lens manufacturers sell their own protectors, there must be a reason. Should I start protecting my lenses with filters again?
The History of the UV Filter
Back in the days when film cameras ruled, we used to fit skylight filters to our lenses. The filters had a very slight magenta hue and would counter the blue cast that would show up on film when shot in daylight. There were two common types: 1A and the slightly darker 1B filters. One would choose a stronger UV filter if shooting in conditions with intense UV light, such as at high altitudes.
These filters had a secondary function: they protected the lens’s front element from damage.
With the arrival of digital cameras, arguments started to break out. Firstly, digital sensors were not prone to the ghosting haze caused by UV light on film. Secondly, the auto white balance in cameras is outstanding, so the blue cast from the sunlight is automatically corrected. Then thirdly, and this is where the controversy stems from, it was argued that the increasingly improved resolution of both sensors and lenses meant that lower-quality glass placed in front of the lens would degrade the image quality. I wanted to prove or disprove this theory, so I put a UV filter to the test.
The Arguments for Using a UV Filter
I have real-life examples of why using a filter is a good idea:
- I do a lot of shooting on the beach. One night, I was shooting a fireworks display by the sea and noticed the lens had spray droplets on it. I carefully dabbed them off to continue shooting but still scratched the front element; sand must have been present too.
- A couple of years ago, I bought a legacy Zeiss lens attached to a camera for very little money from a market stall holder. The person at the stall told me the lens was broken. I like experimenting with old film equipment, so I bought the camera without looking too closely at it. It cost the equivalent of around $7. When I got the camera home, I discovered it was just a smashed UV filter. That sacrificial piece of glass had done its job and saved the lens.
- I was shooting an evening event, and a child was interested in my photography. Always keen to encourage youngsters, I let him look through the viewfinder, and he immediately pressed his greasy fingers to the glass. It was my fault; I should have instructed where to hold it. But cleaning a filter would have been much quicker than carefully de-greasing the lens, which was out of action for the rest of the shoot.
- A relative of mine is a wedding photographer. He bought a new pro lens for his camera, and on the first shoot he used it on, a bridesmaid sprayed it with hair lacquer.
- Additionally, a UV filter can help to cut through the haze on a summer's day.
Those are the reasons I started using high-quality UV filters to protect the lenses. At the time, I didn’t carry out any measured image-quality comparisons, but there seemed to be no difference between the images I shot with the filter and those without.
Filters Can be Faulty
I once did buy a filter that produced strange artifacts in the photos. This was particularly noticeable with any out-of-focus balls of light. They had pronounced lines running across them.
I contacted the manufacturer and sent them photos demonstrating the issue. They said it was a manufacturing fault and sent me a replacement. That solved the problem. The replacement was better. But, looking at my back catalog, my newer equipment and the Urth Plus+ filters give better results.
Recently, I visited a Facebook photography group I sometimes drop into. Someone was complaining about the image quality of their new lens compared with the one they had borrowed. Looking at the sample shots, I could see ugly artifacts like those I had observed. I asked the photographer if they had fitted a UV filter. They said they had. It was a Tiffin, so it should have been good quality. Removing the filter solved the problem. She bought another, and that showed no issues at all. Clearly, UV filters can suffer from manufacturing faults like any product.
Do Lens Hoods Offer Better Protection?
Many photographers swear by using lens hoods instead of UV filters. Hoods are designed to stop sunlight from falling on the glass from an oblique angle, which can fog your images and cause unwanted flaring. They can protect the lens’s front element against impact, falling rain, and accidentally rubbing against clothes. Furthermore, they are not adding a layer of glass in front of the lens, which might affect image quality.
However, like UV filters, they are not designed for those additional protective purposes.
Many quality lenses are made so that the part that holds the front element in place will sacrificially shear off in an impact, thus protecting the rest of the lens. It acts like a crumple zone in a car. A lens hood increases the leverage making this more likely. I have had it happen. Moreover, hoods don’t offer perfect protection for the front element. Someone I know dropped a camera onto a rock. Despite having a hood fitted, the glass still cracked.
For me, it has not been an either/or debate. I’ve used both. Previously, I have replaced scratched filters that have protected my lens from damage, and I invariably have a lens hood attached to the lens, which has offered some protection too.
The Filter Tests
I chose the best-quality Urth Plus+ filters for this experiment. I like Urth. They are an environmentally positive company, which is essential for me. They plant trees in rainforests with every purchase; over a million have been planted so far.
For comparison, I also acquired some cheaper filters. Some I was given, and I bought a couple too.
To start the tests, I mounted my OM System OM-1 fitted with the 12-40mm f/2.8 PRO lens on my tripod overlooking the water with the sun reflected on it. I shot in aperture priority at f/5.6, so I would get a constant behavior of the lens. I dropped the lens out of focus, underexposed, and photographed the sunlight sparkling on the water, as this would highlight any optical defects.
I started with the cheaper K&F Concept, Hoya, and Kood filters. In the resulting images, concentric rings appeared within and around the balls of light. Then, a slight softness was apparent when I focussed the lens on subjects. The drop in image quality is sufficient for me to conclude that I would never use them.So how about the more expensive filter?
Using the Urth Plus + (professional standard) UV filter, I could see no difference in image quality between having the filter fitted and not.
The out-of-focus balls of light were broken, which was to be expected because the water moved organically, and the reflected light was uneven. However, there was no repeating pattern or banding visible. In later tests, I pointed the lens at an out-of-focus LED, and the result was clean. Not so with the cheap filters.
In later tests, I pointed the lens at an out-of-focus LED, and the result was clean. Below, the first image was with no filter, and the second, on the right, with the Urth. I shot this handheld, hence the slight difference in size. The LED in the photo is rectangular, which accounts for the horizontal lines just visible.
On my first day of testing, the sun was constantly disappearing behind clouds, so the light levels frequently changed. Consequently, other comparative tests were difficult to make. However, images shot with and without the Urth filter were as sharp as each other.
The above two seascapes were shot a few seconds apart. The one on the right was with the filter fitted. the slight changes in the lighting were due to the fast-moving clouds. Later tests showed no color changes when I added and removed the filter.
In the above slider, the left-hand image has the filter fitted.
The flowing morning, the weather was calmer, and I managed to shoot some images with the filter on and off the lens. There was no change in the white balance. There was no additional lens flare when pointing the camera almost directly at the sun.
Back home, I tested the exposure against a plain white wall because the daylight was rapidly getting brighter when I shot the sunrise. The exposure was identical both with and without the filter.
What I Like and What Could Be Improved
The tests finally assured me that it is worth having a good quality filter attached to the camera, and the Urth Plus + filters are that. I could see no difference between using the filter and not.
They come nicely packaged in a metal tin and plastic-free, recyclable cardboard. There is a lens cloth included with the filter. Remember to look inside that box for the code to enter on a website, so Urth will plant an additional five trees on top of the five they grow when you buy the filter.
The filter itself comprises a solid yet slender metal mount. The German-made B270 Schott optical glass has a 30-layer coating.
I cannot think of anything other than positive things to say about the filter. If you shoot with professional standard glass and want to protect it, I recommend using this filter.
I could not say the same for any of the cheaper filters I tried. I must add that I didn’t test the more affordable filters on entry-level lenses. For those shooting on a budget or even using vintage glass, then would they be okay? This experiment didn’t prove that one way or another. Perhaps I will acquire an entry-level camera with a budget lens for testing that.
I would like to hear about your experiences and see your tests with and without the filters you use.
I'm firmly in the lens hood camp but there is one use case where a UV-type filter is necessary. Some lenses have their strongest water resistance ONLY when there is a filter mounted on the front. If I recall correctly, the Canon 16-35 lens is a case in point. You'll have to RTFM for your lens to find out which ones need this.
I wasn't aware that some brands require a filter for weather sealing. That's both very interesting, thanks, and a bit shocking, especially for those who don't want to use a filter. My lenses are IP53 sealed, so it isn't necessary for that, but I do use one along with a hood. Thanks for taking the time to comment.
I prefer a protection filter over a hood, not because of catastrophic protection, but because of the day-to-day accumulation of water spots, dust, and atmospheric grime. A hood won't protect against those!
A blower, a soft brush ( lens pen) and a soft cloth helps against grime. Clean your lens after use, don’t let grime accumulate. A filter doesn’t protect against dirt, you end up shooting through a dirty filter.
Unless you clean the filter, Ruud. That is much easier to do than cleaning a lens, and less costly if the cleaning goes wrong.
Like you I shoot a lot on the coast, and I’ve never scratched one of the front elements on my lenses. In very advert conditions, wet sand flying around, I use a filter because you have to clean intermittently and can’t wait to get home. Otherwise the lens would be alright without a filter if you clean the lens with a little care.
I periodically throw all my filters in the dishwasher — sans dirty dishes, of course.
I'm not willing to do that with even an IP53-rated lens!
Lol. Would come out nice and shiny. But again a blower, a brush and some lenscloth (with optional lens cleaner) will do nicely for the lens
Woa, scored two thumbs-down! No love for dishwashers in this group, I see!
Urth “UV” filter made with Schott BG270?
UV begins with wavelengths shorter than 400nm (nanometers). The transmission curve of Schott BG270 glass is flat from about 360nm through all visible light (90% transmission for 2mm thick glass), and shows a 50% transmission point at 315 nm like ordinary glass, and falls to 0% at 270nm (that’s why it’s called “BG270”). The interference filter in front of the sensor usually cut all UV wavelengths shorter than 400 nm and infrared wavelengths longer than 700nm. So the BG270 glass cuts absolutely nothing that the sensor filter and the lens itself don’t already cut, except that it add 10% visible light loss, not including the coating losses. In fact it is impossible to do UV photography with a digital camera not modified for this purpose, and if you want to record UV wavelengths shorter than 300nm then you need a special lens made with quartz crystal (such as the Hasselblad 205mm UV that costed more than $20,000 40 years ago). So your Urth “UV” filter on a digital camera only serves as a glass protector with a very light ND filter. Maybe that’s the reason it’s test is good…
You are right about the glass. However, the filters are tested to cut out 99.6% of ultraviolet light. The glass specifies a very high transmission of light including UV. However, the schott website says "The homogenous transmittance achieved by B 270® makes it an ideal substrate for a variety of filter coatings, closely controlling the light for the best possible performance." It's the coatings that cut out the UV light.
Thanks for the comment.
That’s what I thought. Schott also makes UV cutting long pass glass filter, such as the GG395. Now I am interested to see the transmission curve of the Urth filter to see how it compares with Schott glass filters. Schott glass are excellent, I once ordered a custom made RG-9 filter for IR photography as Kodak Wratten 88 (not 88A) is impossible to find. The advantage of RG-9 and 88A is that they just begin to transmit IR where at the wavelength that it is still slightly visible, so the beautiful infrared effect can be seen directly through the filter.
Thank you for your reply.
^^ This is why I love comment sections.
--- "To start the tests, I mounted my OM System OM-1 fitted with the 12-40mm f/2.8 PRO lens on my tripod overlooking the water with the sun reflected on it. I shot in aperture priority at f/5.6, so I would get a constant behavior of the lens."
I don't know about that. These were clearly, clearly shot at different settings and/or distance.
As you said, you don't know! They were all shot on a tripod with the same settings as shown in the post. The difference was with the K&F concept and Kood filters I didn't have to crop the image very tightly to show the optical faults. The Hoya, performed slightly better so I cropped the image in more closely. Despite a much tighter crop with no filter and the Urth Filter shots, which enlarged the balls of light in the resulting JPEGS, the images were still free of the artifacts that were visible. I didn't bother writing that in the article because I thought it would be obvious, plus it is irrelevent as the sole purpose was to show the lack of artifacts with the filter I was reviewing.
Thanks you for taking the time to comment.
--- "As you said, you don't know!"
Let's not be coy. The saying "I don't know about that" is just a polite way of saying "I think you are lying".
-- "They were all shot on a tripod with the same settings as shown in the post."
That's total bs. On the side-by-side screenshots I provided, take the first and third image. Are you seriously going to say these were shot at the same settings and distance? Oh, I don't know about that.
And, wouldn't you know it, you did treat the samples different. Cropping in more than others. So, who knows what other fanaggling was done.
For once in your articles, treat your examples equally and let us judge for ourselves.
Your hostility undermines any point you were trying to make. If you're convinced Ivor is just outright lying, you should probably avoid clicking on his posts in the future.
You must have pretty thin skin if you think I'm being hostile. Sometimes, there just needs to be debate when the examples presented are clearly suspect.
--- "If you're convinced Ivor is just outright lying, you should probably avoid clicking on his posts in the future."
Wrong. Quite the opposite. We don't want to embolden writers with fakenews style of writing.
I think accusing someone of lying is quite hostile if you're simply speculating. And your overall tone strikes me as hostile. But don't take my observation personally. I just upvoted a comment you made on a different post. Cheers. :-)
Lol, those images are beyond speculation. One would have to turn a blind eye to not see the stark differences. And, this isn't the the first time he's done this.
As I have told you before, Eddie. You really ought to be very careful about making unsubstantiated false allegations. You will find yourself in very deep water.
And, as before, you admitted there were inconsistencies with your post. And, stop it with the posturing already.
There's nothing false of what I'm bringing up here. I'm telling you what I'm seeing. You act as though experienced photographers can't tell the difference of scenes shot with different focal lengths, apertures, and/or distance.
I agree with you that image comparisons are useless and illustrate nothing at all unless they are shot under identical controlled conditions where every single variable is identical.
I value a lot of what Ivor writes here, but using lens "comparisons" where some variables were not identical is not really helping him make any points and I think the article would be stronger without the so-called comparisons. But maybe be nice to him because he really is a decent guy in a lot of ways.
All my initial comments in his posts are typically benign and merely questioning what I see vs what's he has posted. But, then he responds with some snide and condescending retort. From there, you how it goes, snarky comments begets snarky comments.
Ivor does always, always, always defend everything he has said in any article. He will never admit that what he wrote was wrong, or that he should have written something different. That's been his modus operandi for as long as I have been engaging with him in comments. I would love to see that one thing about him change, but good luck with that. But overall he is a good guy. Many of us have such flaws. I, too, get an ego over certain things too even though I know it's wrong. I gotta give him some slack because I have some of the same personality and character deficiencies.
Actually, I always, always reply to readers comments.
If someone publically flasely accused you of being a liar, would you not react to that. And if he does that repeatedly numerous times, would you not want to point out that he is basing accusations on unfounded and incorrect beliefs.
It is Eddie that is mistaken. I was standing with the camera on a tripod, with another photographer, and I have the raw images that show they were taken around the same time and at just about the same focal lenght, although I clearly nudges the zoom ring by 7 mm between the first and last shot. The differences are in the crop. The images without the filter and with the Urth filter I cropped much further to show that there really were no concentric circles as could be clearly seen.
If you want a closer crop of the other filters that shows up their failings even more, here you are.
The differences he is pointing out are irrelevent. The images show that the artifacts are visible in the cheap filters and not with the Urth filter. The first is Hoya, the second Kood.
You're not a liar, Ivor. I have never thought of you as being dishonest in any way.
As for the comparison photos you posted, to really be viable for comparison, they would need to be of subject matter that did not change at all. Something completely static, so that the subject could be eliminated as a variable.
"Real world, real life conditions" are not much good when it comes to needing to isolate every variable in order to make a viable comparison.
--- "The differences are in the crop."
No. These clearly are more than just crop. See the two below. And, read the captions you have on each. How are you going to compare the quality of bokeh when one is more telephoto for smoother bokeh, and the other wide for harsher bokeh?
You really need to keep your comparisons equal. What you do to one side, you must do to the other.
So, between these two, what where their focal lengths and aperture? Can you post the original unaltered camera settings? The camera settings have been stripped from the jpgs' exif data, though all other info are present, so I can't see myself.
Off course there’s a reason camera manufacturers make UV filters, making money. And yes in advert conditions like in a storm on a sandy beach I use a protect filter , a B&W one, because you don’t want to rub wet sand across your lens. But in other conditions I never use an UV filter, because time and again it is proven that it doesn’t do anything to protect your lens in a fall.
Ha ha, that's a reason why anyone produces anything, isn't it. There must be a demand for them or they wouldn't supply them.
As I said in the article, there are plenty of circumstances where the filter could have and has protected the lens from damage, including impact damage. Thanks for the comment.
I don’t believe a filter will protect you lens against impact damage. The argument people give, the filter broke instead of the lens so it saved the lens isn’t valid because I think without the filter the outcome would be the same and the lens would have been fine. There’s also a lot of stories around where after impact people couldn’t get the broken filter off the lens and had to send it in for removal.
In the end it’s all personal choice and believe and the argument will live on. You won’t be the last to write about it.
<blockquote>I never use an UV filter, because time and again it is proven that it doesn’t do anything to protect your lens in a fall.</blockquote>
I agree that neither a filter nor a hood is likely to protect against a catastrophic event.
I use them to protect against the day-to-day accumulation of dust, water droplets, and grime. I can clearly see a difference between a pristine, protected front element and ones with a bulbous front element without filter threads.
I've seen many more lenses with "cleaning marks" than I have with signs of blunt-force trauma!
And if I'm shooting something really critical, I simply remove the filter for a little while.
No 'protective' filter for me. The two accidents I had were knocks coming from the side against the lens rim. The lens hood caught the energy well, no issues with the lenses. Any filter would have been destroyed and still transfer the impact to the lens filter thread. Lens hood all the time.
That's fair enough if you are happy that any potential damage will only come from a sideways impact. It's why I keep a lens hood on as well as a filter.
Did I miss something here? Did you specify which model or designation of the "cheap" filters you tested? K & F and Hoya make a number of models. So it would be helpful to know which ones were tested. And would the same results be found for shooting film?
The Hoya filter is purely marked Hoya 62mm UV. The box says Hoya PRO1 Digital Filter UV. The K&F Concept filter came is labelled Digital HD Slim UV. I hope that helps. I mention the effect of a UV filter on film in the article, but this review of the Urth filter did not incude using it on my film camera. I'll save that for another article.
That's very interesting. I was expecting you to say they were standard range Hoya and K&F filters but those are far from standard.
I didn't look into the those filters' standards as it wasn't what I was reviewing. You are right, they are not their cheapest models.
Interesting. Thanks for sharing your tests. In all the examples above, I prefer the no filter ones.
Thank you. I could't actually see any difference in the no-filter images and the ones with the Urth filter, apart from the changing lighting conditions.
I dropped my camera lens from about 5 feet high. The lens shattered. But it was the UV filter that broke. Not the camera lens. But I need to bring it to a repair shop to get the dented UV filter metal ring removed from the camera lens so that I can replace it with a new one. I would put both a filter & lens hood to protect the lens.
Being both an engineer and a photographer, I am in the belt-and-suspenders camp. I always have a protector filter on my lenses along with a hood. I look at them as cheap insurance. That said, no filter or hood would have helped when I inadvertently knocked over my tripod one day. The lens mounting ring shattered and tore up some of the circuitry. The body was fine, but that was a $500 lesson.
Every time I drop a lens or a body hard on the rocks it seems like it ends up being somewhere between $300 and $700. But there's not much you can really do to prevent dropping camera gear on rocks if you regularly use your gear on steep rocky hillsides with precarious footing. Such damage is just part of the price of admission, so to speak.
Many of the lenses I use aren't even capable of accepting a traditional screw-in filter. I mean the larger lenses like the 400 f2.8, 600mm f4, 300-800mm f5.6, etc. I haven't checked yet to see if my new-to-me 60-600mm f6.3 has filter threads or not.
I think filters are only a thing for little lenses like 100-400mm and smaller. The little lenses I have are all equipped with female threads for a filter. But I don't use filters because I don't really care if the front elements of my lenses get tiny scratches on them or if coatings get a bit degenerated because of a bit of salt water or whatever. Small damage to a front element doesn't affect image quality at all, not even when pixel peeping and scrutinizing at 300 or 400 percent.
But protecting a lens is important to some people, especially if they care about resale value. For those folks if a filter makes them feel better then they should use one. But front elements are much cheaper to replace than many folks may realize. I mean, buying a $150 filter to protect a $150 front element is kinda a wash.
Roger Cicala, founder of LensRentals as well as a lens designer himself, used to make the argument that you make in your comment. In fact, maybe that is where you picked it up. But Roger has completely changed his position on this because of the skyrocketing cost of front elements.
Roger also runs a rental house that sends lenses to be used by people who are willing to take risks with his lenses that they would not be willing to take with their own.
Once I was hiking and when scrambling up some boulders my camera swung on the shoulder strap and smacked into a pointed rock face. The filter was smashed but the lens was unhurt. As it was a fairly wide lens with a fairly shallow hood I don't think it would have been protected without the filter in place.
Oh, and it was a Canon 17-40L and the manual states that it requires a filter to be water resistant. My old Olympus WR lenses did not require filters for that purpose.