bjornthun wrote:
I suppose you don't get a little green square placed on the eye that the camera is tracking, using an OVF. How do you then know which eye or what the camera is tracking before you take the picture?
It moves the AF point in the OVF around and onto the eye, eventually. The AF spot is erratic and inaccurate but the actual focusing is very accurate and reliable (moreso than Sony's Eye AF, in my limited anecdotal tests).
In addition to defaulting to the next focus mode if it can't find an eye (compared to the Sony mode just sitting idly when it can't find an eye) another nice advantage is that it does a much better job of finding eyes that aren't just straight on. In fact it would even lock on to my son's eye when he was looking down and all I could see was the top of his eyelid, whereas Sony's Eye AF seems to need to be able to see at least the white of the eye if not the pupil too.
Vcize wrote:
It moves the AF point in the OVF around and onto the eye, eventually. The AF spot is erratic and inaccurate but the actual focusing is very accurate and reliable (moreso than Sony's Eye AF, in my limited anecdotal tests).
In addition to defaulting to the next focus mode if it can't find an eye (compared to the Sony mode just sitting idly when it can't find an eye) another nice advantage is that it does a much better job of finding eyes that aren't just straight on. In fact it would even lock on to my son's eye when he was looking down and all I could see was the top of his eyelid, whereas Sony's Eye AF seems to need to be able to see at least the white of the eye if not the pupil too....Show more →
Using the OVF all the AF-C Auto has to do is to find the face on some part, and the face/eye is recognized very quickly and it just works. It is very fast and surprisingly accurate. It is not well documented which is frustrating. When reviewing the shots it will identify the faces it has recognized with a small green square similar to in live view mode.
charles.K wrote:
Using the OVF all the AF-C Auto has to do is to find the face on some part, and the face/eye is recognized very quickly and it just works. It is very fast and surprisingly accurate. It is not well documented which is frustrating. When reviewing the shots it will identify the faces it has recognized with a small green square similar to in live view mode.
Is it as accurate as Sony's implementation? I confess I'm spoiled by it.
Fred Miranda wrote:
Is it as accurate as Sony's implementation? I confess I'm spoiled by it.
I have used both extensively and definitely the Nikon is much better in terms of speed, dynamic response and accuracy. There are some combination of lenses that are extremely fast and accurate. This is an area where the DSLR's are better for now. There are many options in adjusting the Nikon AF both for S and C modes and it is an ongoing learning process. In terms of accuracy the A7rII is superb with the PDAF but no where near as fast or responsive, nor is the Fuji XT2 surprisingly. The only issue with DSLR's is a quick check to make sure the fine AF is correctly adjusted.
I am certain the AF with the A9/A7rIII will equal if not surpass the higher end DSLR's which will be great for everyone
wow!! this lens hadn't really been on my radar, but these shots are gorgeous! not to hijack, but what does disabling the first curtain e-shutter do with regards to image quality?
3catsinky wrote:
wow!! this lens hadn't really been on my radar, but these shots are gorgeous! not to hijack, but what does disabling the first curtain e-shutter do with regards to image quality?
Actually you enable electronic first curtain, to have fewer vibrations when you shoot. The explanation: the first curtain opens the shutter, exposing the sensor to light. The second curtain closes it. With a mechanical first curtain, the opening of the shutter creates a small "bump" causing vibrations. An electronic first curtain removes this little "bump" and the associated vibrations. The second shutter curtain makes its "bump" only when the exposure is ended, so that doesn't matter. Electronic first curtain (EFCS) during hand held shooting is only available on mirrorless. DSLRs (only a few) let you use in in mirror-up or liveview mode, on a tripod.
The advantage of no shutter "bump" and no mirror slap translates into fewer vibrations than with a DSLR, and thus better sharpness due to no double lines and the possibility of using a little longer shutter speeds and thus lower ISO.
Sony IBIS works with the Sigma 135/1.8 Art, and is a feature offered by no Canon/Nikon DSLR.
3catsinky wrote:
not to hijack, but what does disabling the first curtain e-shutter do with regards to image quality?
bjornthun wrote:
Actually you enable electronic first curtain, to have fewer vibrations when you shoot.
There are several conditions under which EFCS causes the images to look worse (either all the time or as a function of shutter speed)
(1) certain lenses have worse bokeh with EFCS and shutter speeds faster than 1/2000
(2) bracketed shooting can be affected, and
(3) i think i recall something about IBIS can degraded as well
There have been a few threads on this that can be searched for if interested.
p.3 #10 · Sigma 135 1.8 thoughts? AF functionality
3catsinky wrote:
wow!! this lens hadn't really been on my radar, but these shots are gorgeous! not to hijack, but what does disabling the first curtain e-shutter do with regards to image quality?
If the EFCS is used at higher shutter speeds, typically higher than 1/1000sec., the EFCS may have a negative effect on the background bokeh; it could become harsher. This effect has been documented but I am not sure as what contributes to the harsher bokeh though. Maybe some other folks can chime in here....
p.3 #12 · Sigma 135 1.8 thoughts? AF functionality
Oh man, would love to have an AF 135/2-ish capability for my A7RII.
So it's either the A-mount Sony 135/1.8 or the Sigma n135/1.8 - both adapted - correct?
What's the opinion on these two options relative to each other for wide open candid shots?
p.3 #13 · Sigma 135 1.8 thoughts? AF functionality
AGeoJO wrote:
This effect has been documented but I am not sure as what contributes to the harsher bokeh though. Maybe some other folks can chime in here....
The harsher bokeh is due to the fact that the physical shutter sits in front of the sensor, whereas the electronic shutter acts as if it is flush with the sensor.
At high shutter speeds the curtains are very close together (you get a small slit moving up the frame as the closing physical shutter chases the opening electronic shutter). But because the physical shutter is not in the same plane as the electronic shutter the opening (gap between shutters) is larger when viewed from the top than from the bottom This distorts the bokeh from being a nice circle into a teardrop shape.
At slower shutter speeds the electronic shutter is mostly/fully open before the physical shutter starts closing so you don't get this effect.
p.3 #14 · Sigma 135 1.8 thoughts? AF functionality
jhinkey wrote:
Oh man, would love to have an AF 135/2-ish capability for my A7RII.
So it's either the A-mount Sony 135/1.8 or the Sigma n135/1.8 - both adapted - correct?
Or the Canon 135L
jhinkey wrote:
What's the opinion on these two options relative to each other for wide open candid shots?
Haven't got any direct experience of either but the ZA 135/1.8 requires the LAEA-4 adapter with the semi-tranlucent mirror and screw drive. This put me off the lens.
The Canon is by far the best value but image quality with the Sigma will be better.
p.3 #15 · Sigma 135 1.8 thoughts? AF functionality
I think I'm going to check out this lens because the image examples are so beautiful (though it looks like a somewhat unwieldy, heavy monster for HH shots).
p.3 #17 · Sigma 135 1.8 thoughts? AF functionality
Matt Grum wrote:
Or the Canon 135L
Haven't got any direct experience of either but the ZA 135/1.8 requires the LAEA-4 adapter with the semi-tranlucent mirror and screw drive. This put me off the lens.
The Canon is by far the best value but image quality with the Sigma will be better.
Well the Canon is really outdated by now so it really cannot compare to the Sigma or Samyang as has been tested previously. As far as the ZA vs the Sigma, at 1.8 with a 135mm focal range, I think Eye AF becomes VERY important so that is why I chose it. And of course as you mentioned the Sigma wont be affected by the light loss of the ZA either.
Regards
p.3 #18 · Sigma 135 1.8 thoughts? AF functionality
GMPhotography wrote:
I'm ordering it today as soon as someone buys my Rokinon. Already ordered the adapter. I'm selling it dirt cheap just to get this.
I'm hanging on to my Rokinon, until I know if the Sigma is a keeper. The Rokinon is a laser, and I've got a good copy.
Might be worth hanging onto, even if the Sigma stays.
p.3 #20 · Sigma 135 1.8 thoughts? AF functionality
charles.K wrote:
Yes the Nikon eye AF does work very well. It is not well documented and I recently started a thread. I have the D750 and D850 and it works extremely well in a dynamic AF situations. It is not obvious as all you have to do is change the metering (b) matrix metering to face detection on. The AF-C is set Auto and it will find the face and nearest eye. The only issue with the OVF is that the AF may track onto any part of the face but the algorithm will find the nearest eye accurately. I have used this a lot with difficult lenses like the 58/1.4G, 85/1.4G and 105/1.4G
