How UV-Filters may Damage Your Photographs

Often UV-Filters and similar (Sky, 1A, KR1, etc) are used for pure protection purposes only. Whether a filter is capable of protecting a lens at all is questionable and heavily discussed in the web. This article, however, focusses on the cost of this questionable protection - the damage that filters can do to your actual photography.

This kind of arrebation is always there when you use an UV filter for whatever purpose, although it is significant and clearly visible on night shots and other situations with very high contrasts. While collecting these example photographs I got a studio photography with two women in front of an illuminated white background. The girl's silhouette was visible in each other's faces caused by the same phenomenon that I am presenting here. Unfortunately one of these ladies did not agree to publishing the photograph in this context. That I have to respect.

For a start I show you the effects that Axel observed when he photographed some firework with a filter as protection.

Feuerwerk mit Spiegelungen der Feuerwerkskörper am Himmel

How to get proper images of a firework

Cheat-Sheet:

  • Use a good tripod
  • Use a remote control (a simple cable trigger is best)
  • 100 ISO and apetrure 11 or 200 ISO and f/16 respectively (starting point)
  • M + bulb or B
  • Focus manually to infinite
  • Release the shutter before the firework display (individual figure) begins, close it when it is finished.

Don't do new year/hogmanay

About 99.9% of all well done firework snaps are from professional altitude fireworks. Private fireworks play in a different league. You hardly know where exactly is is fired, how high it gets and the air is full of smoke. (And you are probably not sober yourself and will make mistakes :-) )

How the Sun may damage your Camera

Luckily this never happened to myself.

During the past years I saw worried questions about this risk in various forums and discussion groups. Amongst them I found view reports about actual damage. Some of these amateur photographers I asked for sample pictures and the permission to share it in this article. So don't thank me for this article but thank them for sharing their experience. However, I do not name any publicly because I don't want to expose them to any kind of embarrassment.

When the sunlight falls through the lens into the body then it will meet the inside of the body more or less focus. Basically that is what the lens is about, to focus the motive on the pane of the sensor or film. Let us look at this more closely in two scenarios.

While sharping a photograph, it really does not become any sharper because no algorithm in the world can create image data that has not been there before.

The algorithm detects edges, that is where areas of different color or brightness actually touch. In the areas surrounding these edges the contrast is enhanced.
Doing so, it well creates an impression of sharpness.

 

(Unsharp mask with various values for radius. The original is top left.)

 

Have a close look at the first two photographs. Those are four strip light portraits composed into one family portrait 

 

 

 

Although this is quite some popular editing style, here is a common mistake. All individual photographs are taken with the same distance to the models. When composing the models appear to stand next to each other but partly behind each other so that the distance to the camera appears different in the composing. By doing so the propotional size of he models does not seem to match reality.

This effect is not related to displaying he smallest head to the left or in front of the others respectively. To demonstrat that I composed the faces from the smallest to the largest and vice versa.

Why is that?