To use a filter or not to use a filter on a lens?

[Steve Waldman]

Do you always put a filter on your lenses to protect them or do you never put a filter on your lenses because it makes the photo less sharp?

[Pieter]

I'm using filters on my lenses for the following reasons:

 - If you buy good quality filters, the impact on the optical quality of the lens in my opinion is negligible (like 0.3% light loss and almost zero additional ghosting/flare).

 - I clean my lenses quite often. Even when first blowing/brushing off dust before a wet wipe, you'll inadvertedly cause abrasion on the front element. In time, the degradation of the coating on this element will have adverse effects on image quality as well. Replacing a front filter is cheap, replacing a front lens element not so much.

 - Don't expect the filter glass to protect your front element from a direct impact with a solid object, but having some metal ring protruding beyond the front element certainly helps in keeping it from harm. A lot of impact energy can be dissipated by the deformation of the filter ring before wrecking the front of your lens. Always keeping the lens hood on also helps here.

- Resale value: a minor scratch on the front element (e.g. by accidentally rubbing a grain of sand over the lens while cleaning it) won't affect image quality much, but it severely affects resale value.

Have a read here, you might find it interesting:

https://www.lensrentals.com/blog/2017/06/the-comprehensive-ranking-of-the-major-uv-filters-on-the-market/

[scrane]

If you use a high quality MC filter the whole protective filter "controversy" is a non issue.

Edited December 1, 2020 by scrane
additional content.

[DaviVascaino]

Can people post examples of good quality filters that don't affect image quality?

[Pieter]

Have a read at that link I posted, some good ones there. Filters always affect image quality, but good quality filters have such incredibly small influence that - in my opinion - the influence is negligible.

Some people however just don't accept anything that might affect image quality. Filters are not for them.

Edited December 13, 2020 by Pieter

[petrochemist]

I only use a filter when it produces an effect I want or to experiment on what results a new filter type gives.

There is no evidence that significant protection is gained from normal UV type filters so I rarely use them on digital (film is highly UV sensitive so I do  use them for film). Many experiments show that impact damage can be increased by such a filter, but with salt spray etc their protection is meaningful.

I regularly use infra red filters, polarisers, & (at least fairly often) one of a host of more exotic filters. I typically get huge differences from using filters :)

With most lenses I find the IQ effect from using cheap old filters to be perfectly acceptable, but on my 150-500 and other very long focal length lenses regular filters can give visual problems.

[XKAES]

On 11/26/2020 at 11:56 AM, Pieter said:

I'm using filters on my lenses for the following reasons:

 - If you buy good quality filters, the impact on the optical quality of the lens in my opinion is negligible (like 0.3% light loss and almost zero additional ghosting/flare).

 - I clean my lenses quite often. Even when first blowing/brushing off dust before a wet wipe, you'll inadvertedly cause abrasion on the front element. In time, the degradation of the coating on this element will have adverse effects on image quality as well. Replacing a front filter is cheap, replacing a front lens element not so much.

 - Don't expect the filter glass to protect your front element from a direct impact with a solid object, but having some metal ring protruding beyond the front element certainly helps in keeping it from harm. A lot of impact energy can be dissipated by the deformation of the filter ring before wrecking the front of your lens. Always keeping the lens hood on also helps here.

- Resale value: a minor scratch on the front element (e.g. by accidentally rubbing a grain of sand over the lens while cleaning it) won't affect image quality much, but it severely affects resale value.

Have a read here, you might find it interesting:

https://www.lensrentals.com/blog/2017/06/the-comprehensive-ranking-of-the-major-uv-filters-on-the-market/

All excellent points.  I've had a very expensive lens saved because I had a filter on the front -- it broke the fall.  I've also had a very expensive lens saved because I had a METAL lens hood on the front -- it broke the fall.  No, I'm not clumsy, and it was a LOT cheaper to replace the filter and the lens shade.  Just make sure your lens shades are metal.

And I agree that a good quality filter will not degrade the image enough to make a difference, BUT a correct lens shade WILL make it better in lots of cases.

[slackercruster]

I generally use filters. Although I do use lenses with no filter in terrible conditions that require cleaning multiple times a day and had no issues except 1 time on a boat. The coating got marred some. Otherwise, no issues. And the 1 time was an old legacy lens. The reason I didn't use a filter those times were the lenses were fisheyes.

[thebeardedgroundsman]

I have uv filters on all my lenses except my Tamron 15-30mm and my Minolta 500mm reflex (they don't have filter threads) for protection.

I then have a Firecrest filter holder that I use with Formatt Hitech,  Polariing, ND and ND grad/reverse grad filters.

The Minolta reflex lens has rear mounted ND filters that slot into the lens mounting.

[XKAES]

1 hour ago, slackercruster said:

I generally use filters. Although I do use lenses with no filter in terrible conditions that require cleaning multiple times a day and had no issues except 1 time on a boat. The coating got marred some. Otherwise, no issues. And the 1 time was an old legacy lens. The reason I didn't use a filter those times were the lenses were fisheyes.

Just curious.  Why would use NOT use filters "in terrible conditions"?  It seems to me that those would be the BEST times to use filters.

[XKAES]

17 minutes ago, thebeardedgroundsman said:

I have uv filters on all my lenses except my Tamron 15-30mm and my Minolta 500mm reflex (they don't have filter threads) for protection.

I then have a Firecrest filter holder that I use with Formatt Hitech,  Polariing, ND and ND grad/reverse grad filters.

The Minolta reflex lens has rear mounted ND filters that slot into the lens mounting.

FYI, Minolta's 500mm reflex lenses have filter threads -- TWO, in fact.

They have a 39mm rear filter thread, and they have a 77mm front filter thread:

http://www.subclub.org/minman/500.htm

These also have an INTEGRAL rear 39mm UV filter that is part of the optical system -- and is often mistakenly removed.

Their 100-500mm zooms have 72mm front threads:

http://www.subclub.org/minman/1005008.htm

FYI, any 500mm reflex lens CLAIMING to be f8 with a filter thread LESS than 77mm can not possibly be f8.  There are MANY out there.  These are f8.5 at best and suffer from severe light fall off.

Edited March 6, 2021 by XKAES

[thebeardedgroundsman]

Thanks for that info Xkaes, my 500 reflex didn't come with a handbook, so I assumed the lens hood was integral,. As it turned out, it was just screwed in really tightly. 

The filter diameter is 82mm and the rear one is a drop in filter rather than a screw thread.

I guess I'm about to purchase a new UV filter and steppe ring!

PS, Skip the step up ring - the Firecrest filter holder is based on an 82mm ring - Result!

Cheers

Edited March 7, 2021 by thebeardedgroundsman
Found that filter holder has 82mm ring

[felipe]

Hola,yo siemore tengo puesto un uv de calidad fijo de rosca,no lo quito nunca ?

Salu2 de Felipe ☺️

[XKAES]

8 hours ago, thebeardedgroundsman said:

Thanks for that info Xkaes, my 500 reflex didn't come with a handbook, so I assumed the lens hood was integral,. As it turned out, it was just screwed in really tightly. 

The filter diameter is 82mm and the rear one is a drop in filter rather than a screw thread.

I guess I'm about to purchase a new UV filter and steppe ring!

PS, Skip the step up ring - the Firecrest filter holder is based on an 82mm ring - Result!

Cheers

You must be using an AF Minolta 500mm -- MAXXUM or Sony lens.  That has an 82mm front thread.  Minolta's earlier manual focus models had a 77mm front thread.  The optical design is basically the same for both, but they added an extra element in the MAXXUM AF model to allow for auto-focusing.  My understanding is that it is the only auto-focusing CAT ever made.  Sony just re-badged it as "SA50080" -- or something like that.

Edited March 7, 2021 by XKAES

[alasdairmac]

I never use filters except for a specific purpose, like a CP or an ND. Using a UV filter, no matter how good it is supposed to be, will always have a detrimental effect on your images. If you want to protect the front element of your lens the solution will have come with it free of charge: your lens hood.

The sad fact is that some camera vendors will still try and persuade you to buy a UV filter for your new lens and the reason they do it is simple: they make extra profit from it

[XKAES]

Alas, it's easy to spout off claims without any evidence.  Unfortunately, I guess some of us still haven't had enough of that!

Photography is not alone in being an arena full of beliefs -- much of which is just opinion sold as fact.  Decades ago, I learned from Dr. Richard Henry's book, "Controls in Black and White Photography" (1983, 1986), to always run your own tests -- don't simply believe what some photographer or author or guru says.  So I do.

I use UV filters on all of my lenses.  The only time I take them off is when I want to avoid vignetting when using additional filters.  My main reason for using them is to protect the front glass of my lenses, but they are also important in keeping my lenses clean.  Dust is everywhere, and I never mind cleaning an easily replaced UV filter, instead of wearing out/scratching the coating on my lenses.

It's so easy to trash this "filters are bad" opinion.  Just take a test shot with and without any filter.  YOU BE THE JUDGE.

[Aldowski]

Have to say that it may be matter of individual approach.

I had to try more possibilities when clouds were lost at sky at photos being made at very bright days. Using RAW and making number of exposures at postprocessing may help to some limit. Using DRO higher levels may help as well. Also, Auto HDR when makes 3 different exposures is helpful. Bracketing is very usable, results are really good, when there are no moving objects and camera is stabilized (otherwise - ghosts, may be fixed to some extent in postprocessing).

So, I bought more CPL and ND (also GND) filters and adapters for different filter threads. CPL, of course used for expanding the blue sky color (only "issue" related to it, there are specific angles when filter is achieving better results, as polarizing itself, is working that way).

Using GND filters, sometimes GND2 or GND4, most of the time GND8, as it's really helpful for balancing the light between sky and clouds and the "land" part of the landscape.

Having both circular ones and quadratic mounting ones (which are more robust, but not as practical), it is good to have those, when carefully cleaned, there should be minimal or no impact to image quality, and there are significant benefits, as in this case, postprocessing steps are partially being performed during photos capturing.

I know for sure that number of photography enthusiasts are at the other side of the opinion "border"; some of those openly, strongly disagree about filters being used; anyway, results are there.

Everybody can make own, individual decision.

[JCC]

I shoot from the mosh pits, beer, glitter, etc.  

I almost always have a UV filter on to help protect the lens.

I use Heliopan, B&W, and Hoya

JCC

[XKAES]

It seems foolhardy to spend hundred of dollars -- sometimes thousands -- on a lens and not protect the front glass.

[Aldowski]

Have to agree. Most of the time have filter at the lens, not using just it with some old manual ones.

[MikeInMI]

Pretty interesting.  There was a Sony group on Facebook and someone asked about putting a filter on the Sony 200-600 lens.  There were many responses and not a one used or recommended a filter, which is very different from this group.

I used to use a UV filter to protect the lens, and then so someone give a presentation on the physics of filters and the impact on optical quality.  Today, I don't use filters because I've been shooting for 50 years and never had a scratched front lens element, so I figure the risk is very small (but yes, the lens hood has definitely been helpful on many occasions).

Also, one time I saw a post from a photographer who had a rock hit and damage his front lens element.  He sent the lens in for repair and the repair cost wasn't that horrible, so I figured I could handle it If I had one of those once in 50 year events.

As always, your personal shooting style and circumstances might be different than mine, so there is that to consider.

[Gerald S. Williams]

On 12/13/2020 at 2:49 PM, DaviVascaino said:

Can people post examples of good quality filters that don't affect image quality?

Just use top optical quality filters like from B+W (made be famed Schneider Optical of Germany) and then no worries. As an award-winning pro of over 47 years in the business, I always have protective filters over my good glass. The filters have sacrificed themselves many times over the years, saving the front element of my expensive lenses from impact damage. And having a pristine front element with no scratches or dings means more value if and when you sell that lens. I have never lost a client, lost a job, lost a publication or lost a contest by having top optical filters over my lenses. Worth their reasonable cost. 

Edited October 8, 2021 by Gerald S. Williams

[XKAES]

I've with you 100%.  I can't remember how many times UV filters (Hoya HMC is my standard) have saved my lenses in all my wilderness backpacking adventures.  I'm talking about expensive 35mm and large format optics that are no longer made and cannot be repaired.

Without a UV filter, you will eventually end up with a damaged front element -- even if just from cleaning.

Interested in quality?  It only takes a few minutes to actually test the supposed damage done by a UV filter.  I did.  If you just believe what someone says or posts, I've got a wonderful bridge I can sell you in Brooklyn.

Edited October 8, 2021 by XKAES

[Aldowski]

As already mentioned, I am using filters almost all the time, found GND, ND and CPL very usable, providing good result photos. Most of the time, I am trying to clean lens side and filter both sides, especially the side at filter closer to lens with very soft microfiber. Filter, of course, must not have any damage on itself.

If there are any dark dots at photos, skies, clouds, for example, some basic test with white paper may be performed to check what causes the issue. There are very good utilities capable to fix those issues (postprocessing) easily (some of those specially created just for that). But, of course, better is to clean all glass surfaces, when preparing equipment.

At the other side, I am having small packages of silica gel at all boxes with lenses, cameras, filters as well, to protect parts from fungus. 

 

[Pieter]

4 hours ago, Aldowski said:

If there are any dark dots at photos, skies, clouds, for example, some basic test with white paper may be performed to check what causes the issue.

Dark dots in the sky are usually caused by dust on the sensor, not by dust on the lens. Dust on the lens causes dark dots in bokeh balls when using a large aperture but is otherwise pretty much invisible on photos.