Tag Archives: #PanAmRailways

Headlights too Bright? Now What?

I’d heard complaints about this. You’ll find my solutions are the very end of this blog text.

Pan Am Railway’s 7552, a former CSX General Electric-built DASH8-40C (sometimes simplified as ‘C40-8’), features modern white light-emitting diode (LED) headlights.

The sun went in, so I ‘opened up’ the aperture to f5.6. This exacerbated the effect of LED headlight bleed.

The problem is that these white LEDs viewed head-on are much brighter than ordinary incandescent-bulb headlights. Unnaturally bright headlights may have some advantages; they undoubtedly offer better illumination and can be spotted from greater distance.

However they tend to be mesmerizing, which may have something less than the desired effect from a safety point of view.

I first encountered these headlights about 10 years ago photographing an electric locomotive in Munich, Germany.

With the sun out slightly, I used a smaller aperture and also was nominally  off-axis, two things that help minimize the effects of light bleed.

For photography bright LED headlights pose a couple of problems. They can confuse both auto exposure and auto focusing systems, and as a result may contribute to under exposed and/or out of focus digital photos.

Also, many digital cameras only have a limited ability to handle extreme contrasts, resulting in an unappealing effect that I’ll call ‘light-bleed’, when bright light appears to spill over to adjacent areas of the image. A similar problem is a ghosting effect caused by reflections from external filters or inner elements on some lenses.

So what do you do?

I found that these LEDs are only unacceptably bright when viewed head-on, so by moving off axis, you can greatly reduce the unpleasant visual effects of these bright lights. That’s one solution, anyway.

Here I’m significantly off axis, which virtually eliminates the bleed problems.

Another way to suppress headlight bleed is to select a smaller aperture (larger f-number). I work my cameras manually, so this is easy enough to accomplish. If you are using automatic modes, you’ll need to select an aperture priority setting that allows you to control the aperture. Just mind your shutter speed or you might suffer from motion blur.

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