[Reinier]

Hello Photozoners,



Many people use UV-filters as an extra protection for their lenses. Personally I don't, because I am careful and use a sun hood, which works fine. I also wonder what is more expensive a good UV-filter or a repair of the front element of a lens? Of course an UV-filter is easier to replace.



But do UV-filters add anything to the image under normal circumstances? I have read they can be useful high in the mountains or the mediterranean sea for example with harsh light and a blue sky. But I live in the Netherlands and don't notice much difference with or without a UV-filter.





Best wishes,



Reinier

[wim]

Hi Reinier,



From a UV POV, with digital a UV-filter doesn't really add anything, as the AA-filter assembly already takes care of UV light. With digital, UV-filters are generally used as protection filters, for the simple reason that it is reltively hard to get protection filters as such, and UV filters actually work as well as protection filters for exactly that: protection.



With film it is a different story. Even on a sunny day it is useful, even in the Low Lands, to use a UV filter.



As to the use of a good filter vs a not so good one for protection: a sensor effectively is a half-mirror, it reflects about 40 % to 60 % of the light it receives. With less good filters, i.e., non-MC ones, you will find that under certain conditions you may get a lot of flare and reflection induced image degradation in your photographs, often due to reflections off the filter, and especially from the back of the filter.



Whether it is worth your while to get a good filter for a specific lens, is up to you. I've been using UV-filters for protection for over 35 years now, and I am glad for it considering some of the mishaps that occurred to my lenses. I did unwiitingly use not so great filters when I started with digital, but after some serious flare and halo problems, which effectively ruined my images, I went for good quality ones, and have never looked back. The problem really is that under circumstances which allow for intriguing images, these same circumstances may also generate lots of potentially unwanted effects, caused by, e.g., a low sun etc. With good filters I haven't encountered any problems yet in this regard, with not so good ones I did.



HTH, kind regards, Wim

[Reinier]

Hello Wim,



Thanks for your reply.



I didn't use UV-filters as protection, but after reading your reply, I think it's better to start using them after all. Even if the repair of a front element is as expensive as a good UV-filter getting a lens repaired can take several weeks. Whilst if you break only a UV-filter, you can still use the lens.



Don't we need UV-filters anymore in, lets say, mountains with digital camera's for too much UV or is it all neutralised by the sensor(surface)?





Best wishes,



Reinier











[quote name='wim' timestamp='1339089827' post='18747']

Hi Reinier,



From a UV POV, with digital a UV-filter doesn't really add anything, as the AA-filter assembly already takes care of UV light. With digital, UV-filters are generally used as protection filters, for the simple reason that it is reltively hard to get protection filters as such, and UV filters actually work as well as protection filters for exactly that: protection.



With film it is a different story. Even on a sunny day it is useful, even in the Low Lands, to use a UV filter.



As to the use of a good filter vs a not so good one for protection: a sensor effectively is a half-mirror, it reflects about 40 % to 60 % of the light it receives. With less good filters, i.e., non-MC ones, you will find that under certain conditions you may get a lot of flare and reflection induced image degradation in your photographs, often due to reflections off the filter, and especially from the back of the filter.



Whether it is worth your while to get a good filter for a specific lens, is up to you. I've been using UV-filters for protection for over 35 years now, and I am glad for it considering some of the mishaps that occurred to my lenses. I did unwiitingly use not so great filters when I started with digital, but after some serious flare and halo problems, which effectively ruined my images, I went for good quality ones, and have never looked back. The problem really is that under circumstances which allow for intriguing images, these same circumstances may also generate lots of potentially unwanted effects, caused by, e.g., a low sun etc. With good filters I haven't encountered any problems yet in this regard, with not so good ones I did.



HTH, kind regards, Wim

[/quote]

[Brightcolours]

Filters are not great for protection. They do work fine in especially dusty and sandy places like windy beaches to keep the lens "clean", but the damage control of them on impact situations is low. In fact, front elements are very hard to break, but filters very easy. Which makes filters a hazard for scratching front elements. They are known to get jammed badly into the lens filter threads too.



Your usage of hoods is a very good practice. Hoods do have a habit of absorbing bumps. Of course, lens caps are great protecting when the lens is not in use.



And no, UV filters add nothing to digital in regards to filtering UV, as the sensor/glass already does that. With film UV could give a haze, with digital without UV filtering we would get false colour. That is why digital cameras filter UV standard.

[Guest]

I have seen counter examples to this explicitly showing how UV filter helps; so I think perhaps you meant on SOME cameras UV filters add nothing in regards to filtering UV.



[quote name='Brightcolours' timestamp='1339100880' post='18751']



And no, UV filters add nothing to digital in regards to filtering UV, as the sensor/glass already does that. With film UV could give a haze, with digital without UV filtering we would get false colour. That is why digital cameras filter UV standard.

[/quote]

[Brightcolours]

[quote name='you2' timestamp='1339109071' post='18753']

I have seen counter examples to this explicitly showing how UV filter helps; so I think perhaps you meant on SOME cameras UV filters add nothing in regards to filtering UV.

[/quote]

No, I do not mean that. Maybe you mean that on SOME cameras UV filters do help. Only one I can think of is the Leica M8.

[bryan conner]

My reasoning for not using a UV filter is that the only difference that I could see in my images was a bit lower contrast. Granted, I did not do a scientific test, I just took some images with and without the filter and compared in Photoshop. AND...this was back in my digital/film transition days and maybe 2012 camera's sensors would reveal a difference that a Canon D30 could not back in the early 2000's. I always use lens hoods, so protection was not an advantage to me. In the end, instead of buying a €100-200 filter that produces slightly lower contrast images, why not just buy a €100-200 lens that produces slightly lower contrast images?



In the end, I understand that it is a peace of mind issue with some people. If a person feels safer and more secure with a UV filter, then so be it. To each his own.

[wim]

[quote name='Bryan Conner' timestamp='1339129253' post='18756']

My reasoning for not using a UV filter is that the only difference that I could see in my images was a bit lower contrast. Granted, I did not do a scientific test, I just took some images with and without the filter and compared in Photoshop. AND...this was back in my digital/film transition days and maybe 2012 camera's sensors would reveal a difference that a Canon D30 could not back in the early 2000's. I always use lens hoods, so protection was not an advantage to me. In the end, instead of buying a €100-200 filter that produces slightly lower contrast images, why not just buy a €100-200 lens that produces slightly lower contrast images?



In the end, I understand that it is a peace of mind issue with some people. If a person feels safer and more secure with a UV filter, then so be it. To each his own.

[/quote]

Actually, I doubt very much one can see a difference with a good quality multi-coated filter (Hoya and B&W multicoated filters), and whether it is even measurable within measuring accuracy parameters.



I can't see the difference.



Kind regards, Wim

[popo]

The simplest way to see the impact, if any, a UV filter has is to try it. On degradations, I have in the past done a pixel peeping test with what I think was a mid range Hoya HMC. Basically I couldn't see any difference at picture level. At pixel peeping level, there *might* have been a slightly better sharpness to the unfiltered one, but we're talking borderline perceptions here and even a slight difference in focus might account for it. In practice, no real world negative impact. In night shooting, I have seen the classic inverted ghost caused by front filters, cheap or expensive. In those conditions, no filter is the way to go.



I haven't tested filters for possible improvement due to UV rejection, but I will say recently I got a narrowband 393nm-ish filter, which is located kinda borderline between visible and UV. I can tell you the camera sensitivity at that wavelength, with all filters over the sensor removed, was very low. It would likely be even lower for an unmodified camera. Compared to possible IR contamination, UV is nothing.

[wim]

[quote name='Brightcolours' timestamp='1339100880' post='18751']

Filters are not great for protection. They do work fine in especially dusty and sandy places like windy beaches to keep the lens "clean", but the damage control of them on impact situations is low. In fact, front elements are very hard to break, but filters very easy. Which makes filters a hazard for scratching front elements. They are known to get jammed badly into the lens filter threads too.[/quote]

I disagree with you here. From my personal experience they provide very good protection indeed.



A camera retailer friend of mine will supply a good filter if you care enough to want one. Based on his experience, lenses with filters mounted generally only suffer from superficial damage, and only require replacement of the filter. Those with no filter, lens hoods mounted or not, generally siffer much more, and internal damage when knocked.



He gets several damaged lenses a week in, approximately half with and half without filter. Almost all of those without filter have to be sent on to a repair shop, the ones with the filters mounted only rarely so. They generally just require the mounting of a new filter. And if a filter gets stuck in the threads: he has the tools and the tricks to remove them easily and quickly, without damage to lens or camera.



He reckons the metal filter ring is likely the reason they suffer less damage. He thinks it provides additonal protection to distortion when knocking it against something, or dropping it.



As to the idea that filter glass breaks easily: in the 35+ years I have been shooting slrs and dslrs, this has never happened to me, and I have always owned a considerable amount of lenses, all equipped with filters. And I know I have dropped quite a few of them.

Your usage of hoods is a very good practice. Hoods do have a habit of absorbing bumps. Of course, lens caps are great protecting when the lens is not in use.

Lens caps actualy easily fall off lenses, certainly in my experience. I use them, but IME one of the first things that happens when a lens is dropped, is that the lens cap detaches itself from the lens. Speaking from experience here. It seems to take only very little for this to happen, like a relatively soft fall on long grass.

And no, UV filters add nothing to digital in regards to filtering UV, as the sensor/glass already does that. With film UV could give a haze, with digital without UV filtering we would get false colour. That is why digital cameras filter UV standard.

Of course the whole filter/no filter debate is really endless, and all I can say is that based on my own experience and based on what I have seen and heard at my friend's, I reckon a good quality UV or protection filter, be it relatively expensive, is a very good investment as a lens protector.



My lenses all wear B&W MRC nano-filters these days, except a few mFT lenses with 46 mm thread, which wear normal B&W MRC filters. MRC nano filters are not available in 46 mm thread, but since MRC was the filter of choice for me prior to the advent of the nano MRCs, I don't consider that a big drawback <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.



Kind regards, Wim