Calibrating the Camera Screen

"Assessing exposure correctly using the LCD screen."

You need to start with a calibrated camera screen In order to correctly assess exposure when shooting on location. This is a simple process but can often be overlooked. Here is a quick guide.

1. Start by setting your camera picture style to STANDARD (sometimes called NATURAL). If you are shooting RAW this has no effect on your final image as picture styles are overruled by Lightroom or Photoshop anyway. Set the white balance to AUTO white - again, this has no effect on the final selections made when converting your RAW files.

2. Select ‘JPG Large’ setting on the camera - don’t use RAW. Fit a standard lens, step outside and take a picture of an average scene. This could be your garden, car park, whatever.

3. Download the picture to your desktop on your computer and insert the memory card back into the camera. Open the jpg in Photoshop and view it on a colour hardware calibrated monitor. Press play on the camera and compare the two images. Zoom into 100% on camera and scoot around the picture taking note of highlight and shadow areas. If the picture on the camera seems lighter or darker than the one on your computer screen, enter the menu system select LCD brightness and adjust to taste.

Confirm your selection is correct by comparing the two images again and you should now be able to accurately assess exposure using your camera screen. Switch your camera back to RAW if that’s your normal shooting system and you’re good to go.

The reason you can’t use RAW to do the same process is that Lightroom or Photoshop builds its own interpretation of the RAW data and to some extent plays a part in the exposure process. In practice, the differences should be negligible, but the image you see on the back of the camera is a camera processed jpg so it makes sense to compare this image with a hi-res version of the same in-camera processed jpg on your computer screen.

It’s the little tweaks like these that make the whole shooting process easier and give you confidence in your exposure decisions.

If your picture looks good on the camera screen, it is good.

"Original article by Damien Lovegrove at www.prophotonut.com revised and updated by John Curgenven. All permissions granted."

When shooting in RAW, the histogram shown on the camera’s LCD is based on the camera processed jpg. The raw file isn’t actually a picture with distinct image pixel values so it can’t be represented in a histogram. Each picture pixel has a value of red, green and blue, whilst each camera pixel has a luminance value only. So the histogram is created in camera at the same time as the jpeg preview based on the values in the jpeg. You can confirm this by selecting different white balance settings and shooting the same frame several times. The histogram values for each of the colours will change even though the raw files will be identical. The histogram is not a very useful tool to asses exposure but it is brilliant at the post production stage.

Thanks for your help.