What Are Advantages To Electronic First Curtain Shutter

Started Mar 16, 2012 | Discussions thread
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PeterZheng Regular Member • Posts: 315
Re: What Are Advantages To Electronic First Curtain Shutter

DavieK wrote:

DPr claiming that there's no noticeable difference in lag between A700 and A77 must be measuring the NOISE of the shutter release not the actual timing. This is not so. The A77 on electronic first curtain takes the picture before you hear any noise from the shutter, mechanically. It is very slightly slower than the NEX-7 (etc) when a fixed aperture lens is used (manual) because the A77 aperture actuator can not be disabled, and takes a fixed time to 'stop down' a fitted lens even if that lens has no aperture mechanism or is used wide open. The NEX-7 in contrast will fire instantly if the lens is set to f/3.5 or a wider aperture in good light.

In practice, the advantages of the electronic first curtain are exceptionally fast response (usually less than 1/50th second on mirrorless and less than 1/30th on DSLT) between shutter finger action and exposure happening; and lack of any vibration caused by a physical first curtain being braked/stopped. The two together can make a significant difference.

The disadvantages of electronic first curtain are that the transit speed of the electronic curtain is very precise compared to the mechanical 'end of exposure' transit of the second curtain. When the exposure time is very short (1/4000-1/8000th) this can lead to banding. Also, the speed of response of the exposure may not be matched by the aperture actuation of older Minolta or third party lenses, so it's possible the exposure may start before the working aperture is stable (the iris is still closing when the exposure occurs). When these two factors combine, you get the uneven illumination which can happen with older lenses at high shutter speeds.


Hello David,

1. if someone who was so claiming that would be surprising. In a DSLR camera the mirror flipping upward is the shutter lag 50ms - 150ms various cameras, here must require a time lag makes the mirror's slap vibration to be gradually dropped down. But the SLT camera is no mirror flipping, the shutter lag is likely 20 - 50 ms, the new NEX-6 is 20ms, since the processor is new and with faster speed.

The a77 (Pre-focused) shutter lag is 54ms.
The a700 is the (Pre-focused) shutter lag in 75ms.
People who if claimed the shutter time lag but cannot be including the AF or MF time-consuming.

2. The electronic 1st shutter curtain mode can be turned on or off. It is better for natural lighting shooting. For the important worth is the low exposure speeds, like 1/4s - 1/200s. In 1/1000s or faster speed that the shutter bounce vibration is already less effect.

3. When the flash lighting is the main light source, the electronic 1st shutter curtain mode is not needed, can be turned off, in Canon camera will automatically switch to the mechanical 1st shutter curtain. When other artificial light is being a strong spot with backlighting, maybe it needed to switch to the mechanical 1st shutter curtain, actually like this light source makes you are impossible to get a good shooting, even though the mechanical 1st shutter curtain used.



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