Using Focus Check LV
Given the limitations of focusing modes, this ‘real’ LV has a similar overall functionality to current Canon and Nikon LV rather than Olympus, Panasonic or Pentax. Pentax is the odd one out, because the K-5 enables CDAF with all lenses and does so using a double cycle of ‘wide sweep’ and ‘refinement’ focus actions which take a couple of seconds and make a lot of noise, but actually work well enough. The 4/3rds and Micro4/3rds systems do offer true CDAF, like the NEX.
The depth of field button is pure magic – it works in Focus Check LV mode, and not only that, you can enlarge to 7.5X or 15X, press or release the button, and the lens will change aperture and show you the actual pixel sharpness wide open versus stopped down
To focus for still shots when using FCLV and either Phase Detection as a menu choice, or a screw drive lens fitted which automatically reverts to this mode, you press the shutter lightly and get a very brief blanking of the screen during which you should keep first pressure until focus confirm beeps and the viewing image returns. During this short interval the lens is focused. It is fast compared to the Nikon or Canon ‘flip the mirror and focus’ methods, and also loud – it sounds like taking a picture, and you might be fooled into thinking you have done so, when all you have done is focused. If you press the shutter fully in a single action, you may get an unfocused shot and the same applies if you just jab the first pressure. The PDAF system will not have time to operate.
Although the sensor is uncovered by the shutter (open) in FCLV mode, when a picture is taken even using manual focus the mirror has to flip down to allow the shutter to close, then lift again for the exposure, then flip down at the end of the exposure before rising again to restore LV. It would be better if the shutter alone could do the close/open/close/open action, with no mirror action. But the system is a single mechanism driven by a motor which can’t be decoupled from part of the cycle.
Revision: thanks to Dan Vincent for pointing out the 2 sec mirror pre-lift mode in Comments very shortly after I posted this review! When you use FCLV plus the 2 sec timer, the delay is inserted AFTER the mirror has flipped and closed the shutter – so you get 2 seconds and then a single (almost vibration free) exposure sweep of the shutter blades. During this 2 seconds both the rear screen and the optical finder are blacked out. This can not be made to work with a wireless release, but it will work with a cable remoted release and may also work with some third-party IR or radio remote triggers and timers. I think this 2 second delay is enough to ensure vibrations have died down on most microscope, telescope, astro, and macro setups.
After taking each shot in FCLV mode, the camera returns to the live view. This is an advance over the A500/550 manual focus check LV, which is cancelled when an exposure is made. You must press the Focus Check LV button again to return to using it. With the 580/560, you can keep shooting and using LV. The button is used to cancel the mode and return to either OVF or Quick LV. FCLV will turn itself off after the preset sleep/energy saving time.
Using SAM/SSM lenses the overall LV/movie functionality of the A580/560 is similar to other conventional DSLRs, even if Nikon shows signs that CDAF during filming is closer to a practical technology. I use an Alpha 55, so my view if different. The A580 does not begin to compete with the experience of filming with the A55, which can focus accurately all the time and offers the single biggest benefit of the SLT design, eye-level viewing. In cold weather, I found that the arm’s length grip needed to compose and shoot movies on the rear screen was very unstable (not shivering, but not that steady). The A55 pressed to the eye was far more stable – even if your hands are shaking, your head tends to be shake-free!