Overexposed at 150 mph!

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!

 

 

 

 

2 comments on “Overexposed at 150 mph!

  1. Phil on said:

    To my eye, the “corrected” photo looks a little dark or under exposed and the “lost data” you speak of shows up, once again, to my eye, seems to be the side of the train.
    True, the original the ballast is a little bright, but I’ve seen ballast that light after being sun bleached but would I be observing corrected that the side of the cars shows the “lost data”.
    If you hadn’t called attention I likely would’ve thought there’s something amiss but my only clue would be the sides of the cars look a little blurry.
    But that’s why your the pro and representing it correctly it the bottomline. Good job!

  2. Phil on said:

    To my eye, the “corrected” photo looks a little dark or under exposed and the “lost data” you speak of shows up, once again, to my eye, seems to be the side of the train.
    True, the original is a little bright, but I’ve seen ballast that light but would I be observing corrected that the side of the cars shows the “lost data”.
    If you hadn’t called attention I likely would’ve thought there’s something amiss.
    But that’s why your the pro. Good job!

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