Live Preview - Digital SLRs

Digital SLRs

Live preview in DSLRs does not typically serve as their principal means of framing and previewing before taking a photograph, with this function still being mainly performed with optical viewfinder. The first DSLR to feature live preview was the 2004 Fujifilm FinePix S3 Pro.

While initially largely a novelty feature, live-preview functionality has become more common on DSLR cameras, and almost all new DSLRs have had the feature since mid-2008. This is particularly the case since the advent of movie mode features on these cameras.

The following is a partial list of DSLRs with live preview:

• Canon: 20Da, 40D, 50D, 450D, 500D, 550D, 600D, 650D, 1000D, 1100D, 1D Mark III, 1Ds Mark III, 5D Mark II, 7D, 60D, 1D Mark IV
• Fujifilm: FinePix S3 Pro, FinePix S5 Pro, FinePix IS Pro
• Leica: Digilux 3
• Nikon: D90, D300, D300s, D700, D5000, D5100, D3100, D3, D3x, D7000, D3s, D4, D800
• Olympus: E-10, E-20, E-330, E-410, E-420, E-450, E-510, E-520, E-620, E-30, E-3, E-5
• Panasonic: DMC-L1, DMC-L10
• Sony: A300, A330, A350, A380, A500, A55, and A77
• Pentax: K20D, K-7, K-x, K-r, K-5
• Samsung: GX-20

The principal function of live preview on Canon DSLRs from the 20Da onwards has been allow, via LCD viewing, rapid acquisition of consistent and predictable exposure selection before taking a photograph via its 'exposure simulation' (ExpSim) enabled mode, or exposure priority display. This mode replaces the shortcomings of traditional estimation involved in the through-the-lens (TTL) metering techniques of the older framing type live view DSLRs with autogain/framing only, DSLRs without live view, as well as the shortcomings of optical viewfinders when ambient lighting becomes too low.

Real time exposure simulation live preview (or exposure priority display) had been available in many prosumer cameras, such as the Canon PowerShot G series, before being available to in live view DSLRs. Some manufacturers of compact cameras, including prosumer models, still lack this exposure simulation live view feature, instead relying on the more rudimentary autogain/framing only live view, where slow focus and slow exposure estimation via TTL metering techniques are relied upon. Real time exposure simulation capable live preview digital cameras make achieving the desired exposures, especially in manual modes, more quickly available for both still and video photography.

Among the DSLRs that do manage to focus using the standard phase-detection sensors used by DSLRs, unlike some compact digital cameras none has managed to show 100% frame coverage. This removes one of the key advantages of live preview over optical viewfinders, especially on more budget cameras. Additionally, 100% coverage optical viewfinders have recently become more common and affordable with the appearance of the Canon EOS 7D, Nikon D300, Olympus E-3 and the Pentax K-7. Still more recently, the (upper) mid-range Nikon D7000 has brought the feature to a somewhat lower price point.

Some real time exposure simulated capable live preview digital cameras also offer live histogram graphs for tonal balance or color, where the graph changes instantaneously as exposure adjustments are made. Other features include live depth of field (DOF) preview, and live indication of overexposed areas of the image

Almost all modern bridge and compact cameras have a movie mode, while this feature only became available on DSLRs during 2008. The Nikon D90 with 720p video was announced in August 2008, and the Canon EOS 5D Mark II with 1080p video was announced in September 2008. The Canon EOS 5D Mark II was the first DSLR to offer full control over its real time exposure simulation live preview for video, rather than just autogain/framing only live preview.