In this tutorial we show you step-by-step how to use your Depth of Field Preview button to check your test shots and ensure everything is as sharp as you want.
How to use your Depth of Field Preview button
01 Don’t trust the viewfinder
The viewfinder on a digital SLR is designed to be as bright as possible, and should give you an idea of what the shot would look like if you used the widest lens aperture available.
SEE MORE: What is depth of field in photography?
02 Use the Preview button
Most digital SLRs come with a Depth of Field Preview button. When pressed, this helpful button closes the lens diaphragm to the aperture currently set, so you can check the amount of depth of field.
03 Instant darkness
The problem with the Depth of Field Preview, however, is that it makes the viewfinder image go much darker – making it harder to see the effect that this feature is actually trying to show!
04 Zoom in
A better solution than using the Depth of Field Preview button is to take a test picture, and then review it on the LCD screen. Use the zoom function key (signified by a magnifying glass and a plus sign).
05 Look at the detail
The zoomed-in preview of your test shot on the LCD will typically give you 10x magnification, enabling you to check exactly which parts of the picture are sharp – or how much they are blurred.
06 Check in every corner
Use the cursor keys to move around the magnified image, so that you can see the full extent of the depth of field, and whether you need to adjust the aperture to get a better result.
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