Why the depth of field is different
In theory, lenses will give the same depth of field on both FX and DX cameras, so why do FX cameras seem to yield so much less?
Typically, you need to close down the aperture on an FX camera by about a stop and a third to get similar depth of field to the one you’d get from a DX-format camera.
So why is this? It’s because you wouldn’t actually use the same lens on both. On the DX camera, the smaller sensor means that you’d use a shorter focal length lens to get the same angle of view.
For example, if you use a 50mm lens on an FX camera, you’d need to use a 35mm lens on a DX camera to get the same angle of view – and the 35mm lens will yield much more depth of field because of its shorter focal length.
Our infographic below illustrates why crop-sensor cameras keep more in focus.
How to shoot with a full frame sensor
You’ll need to tighten up your shooting technique to properly exploit the advantages of a full frame sensor. Here’s how to do it.
Invest in lenses
You’ll lose any resolution advantage if you use old or cheap lenses. Nikon’s new 24-85mm VR zoom is a good choice, or the 24-70mm f/2.8.
Focus with care
Pin-point focusing is crucial to exploit the extra resolution. Manual focussing is not always precise enough, and autofocus may prove more accurate.
You’ll need an aperture one stop smaller, maybe more, to get the depth of field of a DX camera. Avoid apertures smaller than f/11 as diffraction will affect sharpness.
‘Safe’ shutter speeds
The old ‘reciprocal’ rule is only approximate. Instead of using 1/30 sec with a 30mm lens, for example, consider using 1/60 sec or even 1/125 sec.
Use a tripod
To be sure of maximum sharpness, use a tripod. Choose a good one – the best aren’t just sturdy, they also dampen vibrations from traffic or people walking past.
Improve your memory
An 8Gb memory card might be all right in your 16-megapixel DX-format camera, but in the D800 it’s enough for just 103 uncompressed RAW files.
Expose to the right: the camera technique every landscape photographer must know
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Live View: 7 Do’s and 3 absolute Dont’s every photographer should remember