The Alpha 580 – a three-way view
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!
David,
Thank you for the review and helping me understand my camera better.
I do have many questions,, but i will only ask one.
Which Auto-focus mode do you feel is most accurate when using Minolta Primes such as the 50mm f/1.7?
The reason i ask is from experience with terrible back-focusing when using a a560 with my Minolta lenses ,, which are tack sharp on my a100.
After reading your review i see it may have just been a matter of me not understanding the camera and the different focus modes.
To be honest ,, i dont really care about the Live view, i use the optical viewfinder for everything. Yeah, im that old.
Anyway, thanks again.
I always use single shot, centre AF point. The A580 has not proved immune to FF/BF issues though and I am afraid it tends to go with that type of AF sensor despite continued improvements. I have only recently started using the 50mm f/1.4 lens after getting the A77, it’s the only camera I have owned so far which focuses it accurately.
David
The Sigma is a much better lens. Since you have a choice between OS and SSS there really isn’t an issue. The Sigma is so much better at the long end of the range, optically.
David
Thanks David. Now that I’ve gotten an a55, I’ve been thinking of selling my Tamron 18-250 and getting the Sigma 18-250, for the potential of better IQ and less distortion, as well as the OS for video. Your review comments stopped me for the moment. From your reviews, it sounds like you’d recommend this kind of switch (it’s affordable), so long as the video would be in the 18-100 range or so. Am I correct in that?
BTW – do you still find that you get better IQ at 200-250mm from the Sigma compared to the Tamron? Are they pretty much equal from 18-150? Thanks again for your advice.
William
I did not use a tripod; at times, I used a binocular support (a monopod with a sort of Y-shape at the top) because I was so cold I could not hold the camera still at all. The stabilisation on the Sigma 18-250mm seems fine for movies up to a middle setting, maybe 100-150mm. At a certain point (always at 250mm) it becomes impossible to pan or move the camera without the distorted effect. I think this is due to the type of stabilisation used in that lens, and some other Sigma lenses might behave differently. What I do know for sure is that the in-body SSS does not produce the same effect.
David,
I was struck by your comment about video and the Sigma OS system: “Don’t think that in-lens OS will be your solution to longer clip lengths before overheating shuts the system down. It doesn’t agree with the movie mode, in contrast to SS which works well.”
Q: Did you use a tripod when making the video on YouTube? If so, could the “ripple” effect due to the OS stabilizer being on and the lens trying to stabilize something that is already still — the same kind of difficulty as leaving the SSS on when using a tripod?
Is there any reason to get a Sigma OS lens for a55 or a580 video — or is it always best just to go with SSS and a steady hand?
Thanks, William
In terms of camera handling I would rate Minolta 7D as best camera made by Minolta/Sony. Suppose A700 and A900 also were designed by Minolta, but ‘improved’ by Sony and both are already one step down.
The D-lens distance encoder is great for ADI calculations, and in that case focus produces a distance measurement rather than the other way around. But the D encoders are mechanical, and are too coarse to allow the camera to finely control focus motor speed for silky smooth contrast AF.
I feel sure the encoder in the E-mount lenses is a high resolution encoder (probably optical) for that reason. Since contrast AF doesn’t really care about distance, I’m pretty sure the LA-EA1 and Alpha cams don’t even use the D encoders.
With much less mechanical backlash (gear slop) than body-driven lenses, the SAM and SSM lenses contrast focus smoother and quieter (and the LA-EA1 with not drive motor can only focus with them anyway). But E-mount lenses will always contrast focus much better than any of them because there is precise feedback of focus group position and speed to the camera.
Excellent article! The best ever explanation of the three viewing systems in use on these newest Alphas.
One thing regarding the suitability of SSM and SAM lenses for contrast detection AF is the lack of a focus group position encoder in the 8-pin A-mount lens system.
The E-mount lens system is most suitable for contrast detect AF not just because the focus motor is smooth, but because the control system has knowledge of the exact position of the focus group.
I believe that is the purpose of the extra 2 pins on the E-mount lenses. It is the A and B phase of an electronic position encoder on the focus group.
Such an encoder allows the control system to move the focus group very precisely in executing the contrast AF scheme. All A-mount lenses lack this encoder (not needed for phase detect AF). A side benefit of the encoder is the camera body can enter manual focus check magnification automatically whenever the focus ring moves the group.
The D-lens specification is supposed to report a fairly accurate focused distance and the initialisation of the A-mount lens, on startup, has always included a ‘focus range check and park’ process. We need to wait and see how things develop. Pentax devised a very good way to get single shot CDAF with any lens, including screw drive – a simple process by which the camera does a ‘big’ focus range check, maps the result; homes in on the approximate position for sharpness, and does a second smaller sweep around around this; then it moves to the detected peak contrast position and if necessary does a tiny final shuffle; and locks. I don’t think the story is over yet.
There are two obvious options open to camera designers. One is very simple – detect focus from the focusing screen in an SLR design. Optical devices like the split image RF or microprism create phase contrast in a form the eye can see, and what the eye can see can also be detected by a sensor. The second option is go down the Contax N body route, and build a fine focus mechanism into the sensor carriage – have a sensor which can move forward of backward over a small but functional range such as 3mm. Used with a manually focused lens this could allow enough video focus adjustment with shorter focal length (below 100mm) lenses to enable video CDAF.
Now that you have reviewed extensively both the Alpha 55 and the Alpha 580 which would you choose if you needed only one camera for family and vacation shots, no studio?
Alpha 55. GPS, eye level video shooting, autofocus during video, quiet operation, smaller, lighter, EVF is great in low light.
The 2s timer for MLU would not work for me. So often, I raise the mirror and wait for the right moment, perhaps waiting for the wind to drop or for someone to move into/out of frame.
Thanks for a couple of really interesting reviews – this one and the A55.
With all the latest Sony models – NEX, SLT, 560, 580 – you do not see image noise in typical shooting conditions until ISO 3200, provided you process the raw file sensibly. That does not mean cranking up to maximum NR either. I am just going to add a link to a full size version of the antiquey furniture shop interior which is at 1600. I’m sorry these large file download links are restricted to subscribers, but I need to limit bandwidth and obtain subscriptions alike. Anyone with an existing YUDU or Payloadz subscription, or a magazine subscription paid up, can email me [email protected] and I will manually upgrade their Free registration on the site to Normal or Premium status as appropriate.
David:
That report was extremely interesting (and for me timely). Especially enlightening was your discussion of High ISO low light handling by Sony vis-a-vis Nikon’s strategy. This would explain some of the results I’ve seen on various sites and from photos I’ve received from people working with the A580. The statement you made about ISO 1600 being virtually noise-free caught my attention. My A850 has fairly strong noise from ISO 800 and above (raw, right out of the camera). So I was wondering can you quantify the raw file low light ISO advantage of the A580 over the A850 (or A900) in terms of stops? I promise this will be my last low light question.
Regards
John
I would figure that the 2s timer would be enough to tame most vibrations, even with FCLV’s double-dip of the mirror. Of course, once you nail the focus, you could leave FCLV, wait a few extra seconds, then trip the shutter. Yes, it’s not as good as having the a900’s multi-fire MLU mode, but I’d say it’d get the job done for 99.9% of the people who relied on 2s timer before.
Bingo! It’s only a 2 second respite, but in FCLV mode combined with the 2 second selftimer, the mirror lifts for the 2 seconds and the shutter closes – both optical and screen finders are black. Then the shutter fires and the mirror briefly flips to return to FCLV mode.
This doesn’t work with the wireless remote release, if set to remote and the 2 sec button used, you just get a rapid-bleep 2 sec delay and normal firing. It does work with the wired cable release.
My error – I was thinking about the lack of it in Focus Check LV mode when testing this. I’ve altered the paragraph involved to state this. For me, not having the mirror drop and rise in FCLV mode would be the most important (probably impossible) change. That’s because FCLV is the focus and viewing mode I would use on telescopes, microscopes, macro bellows and similar setups needing zero vibration. Of course I have also been working with the Alpha 900 for two years, and that has a true mirror lockup mode not just a pre-lift.
But you have given me an idea. I have not tried combining the FCLV mode with 2 second mirror prelift or 10s self timer. I’ll check this out right away and add something to the review.
David,
The a580/560 does have Mirror Lockup in the 2s self timer. It’s right on the Sony specs pages for the cameras.