In partial defense of protective filters: I am not a dedicated protective filter user. My lenses do not have filters on them for protection most of the time. I depend on a lens hood...

DirtFarmer Loc: Escaped from the NYC area, back to MA

I am not a dedicated protective filter user. My lenses do not have filters on them for protection most of the time. I depend on a lens hood for protection from ordinary hazards such as having the camera bump into things. However there are situations where I use protective filters. Usually those situations involve environmental hazards such as salt spray, blowing sand, flying mud, or small hazardous things flying around (e.g. welding).

There are many instances in which someone claims that his lens was saved by something hitting the front of his lens and breaking the filter but not the lens. I believe that something hit their filter and broke it but I do not believe that their lens would have necessarily been broken in the same situation without the filter. After all, the front element of a lens is probably several millimeters thick while a filter is generally going to be a millimeter or less in thickness. This opinion is based on Steve Perry's post in which he performs extreme tests of things hitting lenses with and without filters. (I emphasize here that this is my opinion. YMMV).

On the other side of the coin there are a lot of people who claim that the excessive use of filters can affect image quality. While it is true that adding surfaces to an optical path increases the chance of reflections causing flare and such things, well made filters will have antireflective coatings which will reduce (not eliminate) this possibility.

So, being an experimentalist, I decided to do the experiment.

I did a study of edges to look at image sharpness. It was a limited study, using only one lens, but results to date show no significant effect of filters on the sharpness of an image. I also used a piece of regular window glass as one of the test filters. No significant effect was seen there. I concluded from this study that using a filter will not significantly affect the sharpness of objects in the image. The study did NOT include the possibility of flare or other effects. A PDF of the study is attached below.

Study of edge sharpness and filters (PDF)
Attached file:
(Download)

Quixdraw Loc: x

Dead horse. Have used them for decades with success and satisfaction. Others have never, will never use them with equal commitment. Never the twain shall meet!

Longshadow Loc: Audubon, PA, United States

quixdraw wrote:

Dead horse. Have used them for decades with success and satisfaction. Others have never, will never use them with equal commitment. Never the twain shall meet!

Another individual volition.

Soul Dr. Loc: Beautiful Shenandoah Valley

I say, whatever floats your boat. The only time I will use a protective filter, is when I am shooting in a hostile environment. When dirt, sand, water or whatever else might be blowing around.
I have been using a CPL filter on my Fuji lenses when I am shooting outside on sunny days. And sometimes on cloudy days too.

will

TriX Loc: Raleigh, NC

DirtFarmer wrote:

I am not a dedicated protective filter user. My lenses do not have filters on them for protection most of the time. I depend on a lens hood for protection from ordinary hazards such as having the camera bump into things. However there are situations where I use protective filters. Usually those situations involve environmental hazards such as salt spray, blowing sand, flying mud, or small hazardous things flying around (e.g. welding).

There are many instances in which someone claims that his lens was saved by something hitting the front of his lens and breaking the filter but not the lens. I believe that something hit their filter and broke it but I do not believe that their lens would have necessarily been broken in the same situation without the filter. After all, the front element of a lens is probably several millimeters thick while a filter is generally going to be a millimeter or less in thickness. This opinion is based on Steve Perry's post in which he performs extreme tests of things hitting lenses with and without filters. (I emphasize here that this is my opinion. YMMV).

On the other side of the coin there are a lot of people who claim that the excessive use of filters can affect image quality. While it is true that adding surfaces to an optical path increases the chance of reflections causing flare and such things, well made filters will have antireflective coatings which will reduce (not eliminate) this possibility.

So, being an experimentalist, I decided to do the experiment.

I did a study of edges to look at image sharpness. It was a limited study, using only one lens, but results to date show no significant effect of filters on the sharpness of an image. I also used a piece of regular window glass as one of the test filters. No significant effect was seen there. I concluded from this study that using a filter will not significantly affect the sharpness of objects in the image. The study did NOT include the possibility of flare or other effects. A PDF of the study is attached below.

I am not a dedicated protective filter user. My le... (show quote)

Now that is what I would term a professional, well controlled and comprehensive experiment! Thank you for performing this and sharing - scientific rigor at its best.

lamiaceae Loc: San Luis Obispo County, CA

DirtFarmer wrote:

I am not a dedicated protective filter user. My lenses do not have filters on them for protection most of the time. I depend on a lens hood for protection from ordinary hazards such as having the camera bump into things. However there are situations where I use protective filters. Usually those situations involve environmental hazards such as salt spray, blowing sand, flying mud, or small hazardous things flying around (e.g. welding).

There are many instances in which someone claims that his lens was saved by something hitting the front of his lens and breaking the filter but not the lens. I believe that something hit their filter and broke it but I do not believe that their lens would have necessarily been broken in the same situation without the filter. After all, the front element of a lens is probably several millimeters thick while a filter is generally going to be a millimeter or less in thickness. This opinion is based on Steve Perry's post in which he performs extreme tests of things hitting lenses with and without filters. (I emphasize here that this is my opinion. YMMV).

On the other side of the coin there are a lot of people who claim that the excessive use of filters can affect image quality. While it is true that adding surfaces to an optical path increases the chance of reflections causing flare and such things, well made filters will have antireflective coatings which will reduce (not eliminate) this possibility.

So, being an experimentalist, I decided to do the experiment.

I did a study of edges to look at image sharpness. It was a limited study, using only one lens, but results to date show no significant effect of filters on the sharpness of an image. I also used a piece of regular window glass as one of the test filters. No significant effect was seen there. I concluded from this study that using a filter will not significantly affect the sharpness of objects in the image. The study did NOT include the possibility of flare or other effects. A PDF of the study is attached below.

I am not a dedicated protective filter user. My le... (show quote)

I use both lens hoods and protective filters. Protective filters are less needed for my longer lenses. But I still do not want finger smudges on my long lenses when the hood is in storage position or off altogether. More importantly, I have many shorter lenses, normal and wide angle that use very shallow lens hoods, these hoods to not protect the lens from dirty fingers, sticks, rocks, etc. I try to avoid ever having to clean the elements of my lenses beyond dusting off with a brush. I try to avoid using solvents and lens cloths. So I keep high quality B&W or similar protective filters on all my lenses. Shallow hoods protect only for their intended use, possibly stray light and flare.

Sidwalkastronomy Loc: New Jersey Shore

I live 3 miles from Atlantic Ocean and take sunset photos from Manasquan inlet and other beach related things. My filters never come off

Longshadow Loc: Audubon, PA, United States

DirtFarmer wrote:

I am not a dedicated protective filter user. My lenses do not have filters on them for protection most of the time. I depend on a lens hood for protection from ordinary hazards such as having the camera bump into things. However there are situations where I use protective filters. Usually those situations involve environmental hazards such as salt spray, blowing sand, flying mud, or small hazardous things flying around (e.g. welding).

There are many instances in which someone claims that his lens was saved by something hitting the front of his lens and breaking the filter but not the lens. I believe that something hit their filter and broke it but I do not believe that their lens would have necessarily been broken in the same situation without the filter. After all, the front element of a lens is probably several millimeters thick while a filter is generally going to be a millimeter or less in thickness. This opinion is based on Steve Perry's post in which he performs extreme tests of things hitting lenses with and without filters. (I emphasize here that this is my opinion. YMMV).

On the other side of the coin there are a lot of people who claim that the excessive use of filters can affect image quality. While it is true that adding surfaces to an optical path increases the chance of reflections causing flare and such things, well made filters will have antireflective coatings which will reduce (not eliminate) this possibility.

So, being an experimentalist, I decided to do the experiment.

I did a study of edges to look at image sharpness. It was a limited study, using only one lens, but results to date show no significant effect of filters on the sharpness of an image. I also used a piece of regular window glass as one of the test filters. No significant effect was seen there. I concluded from this study that using a filter will not significantly affect the sharpness of objects in the image. The study did NOT include the possibility of flare or other effects. A PDF of the study is attached below.

I am not a dedicated protective filter user. My le... (show quote)

rmalarz Loc: Tempe, Arizona

There really isn't such a thing as a "protective" filter. Protection provided by a filter, as it is, is minimal. The reason for filters is optical in that they control the visual, and invisible, various wavelengths of light used in making an exposure. Once a filter is attached to a lens it becomes part of the optical system of that lens. Thus, using the best optical grade filters is a must.

As I stated, in an earlier attempt to beat a dead horse on this issue, I regularly use UV, CPL, K2, 25A, X1, 85B filters. They are all from quality manufacturers, much like my lenses. Additionally, I find them a necessity for most photos. Yes, they provide protection but that is incidental and secondary.

I applaud your work with the experiment and results you posted.
--Bob

DirtFarmer wrote:

I am not a dedicated protective filter user. My lenses do not have filters on them for protection most of the time. I depend on a lens hood for protection from ordinary hazards such as having the camera bump into things. However there are situations where I use protective filters. Usually those situations involve environmental hazards such as salt spray, blowing sand, flying mud, or small hazardous things flying around (e.g. welding).

There are many instances in which someone claims that his lens was saved by something hitting the front of his lens and breaking the filter but not the lens. I believe that something hit their filter and broke it but I do not believe that their lens would have necessarily been broken in the same situation without the filter. After all, the front element of a lens is probably several millimeters thick while a filter is generally going to be a millimeter or less in thickness. This opinion is based on Steve Perry's post in which he performs extreme tests of things hitting lenses with and without filters. (I emphasize here that this is my opinion. YMMV).

On the other side of the coin there are a lot of people who claim that the excessive use of filters can affect image quality. While it is true that adding surfaces to an optical path increases the chance of reflections causing flare and such things, well made filters will have antireflective coatings which will reduce (not eliminate) this possibility.

So, being an experimentalist, I decided to do the experiment.

I did a study of edges to look at image sharpness. It was a limited study, using only one lens, but results to date show no significant effect of filters on the sharpness of an image. I also used a piece of regular window glass as one of the test filters. No significant effect was seen there. I concluded from this study that using a filter will not significantly affect the sharpness of objects in the image. The study did NOT include the possibility of flare or other effects. A PDF of the study is attached below.

I am not a dedicated protective filter user. My le... (show quote)

luvmypets Loc: Born & raised Texan living in Fayetteville NC

Thank you, Dirtfarmer, for all that wonderful information. This may help those that are on the fence about protective filters. I have them on my lenses but not extremely tightened so if I feel the need to take it off for a shot I simply leave the lens cap on and unscrew them as a unit. When finished I screw them back on being careful not to over tighten. As a precaution, I purchased a filter removal tool and have only used it once.

I will disagree with Quixdraw that this is a "dead horse"; new information is necessary for growth and advancement.

Thank you for sharing!!!

Dodie

CHG_CANON Loc: the Windy City

It's not easy to filter out the bad ideas in photography, especially to those who suspect the equipment is the cause.

Quixdraw Loc: x

luvmypets wrote:

Thank you, Dirtfarmer, for all that wonderful info... (show quote)

Ain't going to be changing many / any minds. Folks are going to do as they will, and fortunately can!

Sidwalkastronomy Loc: New Jersey Shore

I would say operator error is the reason for bad results much more than the equipment failure

rook2c4 Loc: Philadelphia, PA USA

DirtFarmer wrote:

However there are situations where I use protective filters. Usually those situations involve environmental hazards such as salt spray, blowing sand, flying mud, or small hazardous things flying around (e.g. welding).

For such situations, I certainly wouldn't want to have an expensive filter on my lens. It would be a shame to have to throw away a $50 (or more) filter after a single use because it got all scratched up or chipped. Personally, I avoid shooting under those conditions. As a hobbyist, I don't really need to use my camera equipment when I feel there is possible risk of damage.

luvmypets Loc: Born & raised Texan living in Fayetteville NC

rook2c4 wrote:

For such situations, I certainly wouldn't want to have an expensive filter on my lens. It would be a shame to have to throw away a $50 (or more) filter after a single use because it got all scratched up or chipped. Personally, I avoid shooting under those conditions. As a hobbyist, I don't really need to use my camera equipment when I feel there is possible risk of damage.

I rarely remove the protective filter for a shot and since I am going to leave it on I would rather have a quality piece of glass that won't lessen the quality of my shot. (not that a low cost one would interfere with image quality but just in case) I have never had to replace a protective filter but in the event I do, I will have had years of protection from it so it will have paid for itself especially if the front element is undamaged.

Dodie