kymarto Loc: Portland OR and Milan Italy

One trick I learned many years ago, when lenses need to be cleaned, it to exhale on the lens surface. It is nearly pure water, and it is just enough moisture to exponentially increase the cleaning power of lens tissue. It leaves no trace and dries immediately, unlike lens cleaning compounds, which streak if you do not wipe the surface dry, which means considerably more contact with the paper on the lens surface. The best tissue I have found - for me beats Zeiss by a country mile, is made by Kenko. It is soft, almost like microfiber cloth, so it is very effective. Unfortunately only available in Japan.

Longshadow Loc: Audubon, PA, United States

I use currently Zeiss Wipes, and oddly, I kept real lens tissues from decades ago when I had a microscope.

Yup, haaah, haaah works also.

selmslie Loc: Fernandina Beach, FL, USA

The job of the UV filter is to remove the UV light that the eye cannot see. Otherwise the blue part of the image would be brighter than it looks to us.

I have a camera with no UV filter over the sensor. It has no IR filter or Bayer array either so the images can be only B&W. To show what happens to the image when the filters are added back on the lens I took three shots and analyzed them using RawDigger:


With no filter over the lens visible light, UV and IR can reach the sensor.


With a UV filter alone visible light and IR can reach the sensor.


A cut filter blocks both the UV and IR and allows only visible light to reach the sensor.

Note that the image gets progressively darker depending on the colors being recorded.



Overall the UV filter alone drops the recorded brightness for this scene by about 0.051 stops. The cut filter reduces the overall brightness more dramatically, especially for the pine needles, grass and red brick.

Longshadow Loc: Audubon, PA, United States

In the third, the grass blends into the lake.

selmslie Loc: Fernandina Beach, FL, USA

Keep in mind that that was only one UV filter. It's just over the lens instead of over the sensor. A second filter would be somewhat redundant.

A color image with a UV filter over the sensor and a second one over the lens does not double the effect of the first UV filter. It's difficult to measure with this scene since there is a lot of variation in the water surface.

An educated guess from the combined results indicates that the second UV filter has only about 1/3 as much additional effect on the image as the first one.

Nevertheless, the second UV filter can still add a little clarity to an image where UV light is being scattered by atmospheric conditions.

No UV filter

(Download)

With UV filter

(Download)

rgrenaderphoto Loc: Hollywood, CA

Huh? I mean, seriously dedicated work to prove a point.

eadler

I’m all in on the filter but the reality is that the strap did not go from perfect condition to breaking. It no doubt had a period of fraying or wearing thin. Before you leave the house the strap’s condition is part of your equipment check just as you would check the charge level on your battery.

starlifter Loc: Towson, MD

To protect my lens' I have a rider on my homeowners.

starlifter Loc: Towson, MD

To protect my lens' I have a rider on my homeowners.

petrochemist Loc: UK

Lesson not learned, the minor impact the smashed that filter would probably have had no affect at all on the lenses front element.
The ease with which filters crack gives a quite incorrect idea of what will affect a lens.

I don't normally use UV filters on my lenses, and despite a few knocks have never had to replace a front element. I sadly have bust a few filters dropping them from heights a lens tends to survive from (even though it gets dented).

topcat Loc: Alameda, CA

I don't think that the degradation would be noticeable, and I don't think that the protection would be much. The only real protection that I see would be that any dirt would be on the filter, not the lens.
I have a filter on most of my lenses. Too lazy to take them off.