Tag Archives: #150mph

photography

Overexposed at 150 mph!

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My goal was to stop Amtrak’s Acela Expressat speed.

I wanted to use the fastest shutter speed, so I dialed in a wide aperture on my Lumix LX-7.

However, I was using the aperture priority ‘A’ setting, and when I ‘opened up’, I inadvertently overexposed, because the maximum shutter speed possibly on this camera is 1/2000thof a second, and the correct shutter speed/f-stop combination for my wide aperture was probably closer to 1/4000thof a second.

Whoops.

The result is an overexposed digital RAW file.

That means I let in toomuch light. Not only is the tonality too bright, but I’ve suffered data loss in the highlight areas.

This is a Jpg made from the unadjusted RAW file. In other words I’ve not made an effort to correct for over exposure.

Working with the RAW file in Lightroom, I was able to adjust my exposure, and recover some of the highlight detail lost in the in-camera Jpg.

The result is pretty good.

Working in Lightroom, I’ve adjust the RAW file to compensate for over exposure, and made the image appear more-or-less as it did at the time of exposure.

So why bother getting the exposure right if you can adjust the photo after the fact?

Data.

Ideally, when a photo is exposed properly the RAW file should capture the maximum amount of information. When a photo, such as this one, is overexposed it suffers from data loss. Although the correction looks presentable, the bottom line is that the file has less data than if it had been correctly exposed.

So while you can ‘fix it’ after the fact, it pays to get right on site—when you can.

Tracking the Light Posts Every Day!