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sirhawkeye64
Forum Pro
IDK that the green assist lamp on the cameras themselves really help all that much... I mean for me, I have my AF Assistant lamp turned off, and the focusing ability (at least on the Z8) is pretty much the same, whether it's on or off.
I seem to remember reading that the in Z8 and Z9, the data from the sensor is spit into two data streams -- one for the viewfinder and one for processing the image. The AF algorithms work on the viewfinder data stream, so if the viewfinder looks dark, the AF will have trouble. If you set D8 as Thom describes and brighten the view in the viewfinder, the AF system actually get better data to work with.
It should be easily testable. Try focusing in dim light with different D8 settings. If I get a chance, I'll give it a try.
sirhawkeye64
Forum Pro
I'll have to try it, but this almost sounds backwards. If there are two streams, one for EVF and one for the processing, then the one for the EVF shouldn't impact the EVF at all, thus my comment about how the option may not have any impact as it may just impact the EVF stream only. I think on older Z models, processing and AF AND the EVF were read off the same stream since they only used one stream instead of 2 like on the Z8/Z9 and that's why the other Z cameras struggle a bit more (although likely mostly because of the slower sensor read-out speed on the other Z cameras that are non-stacked sensors).
For the OP: I should note that I don't shoot on-camera flash so maybe that's why I haven't really run into the AF issue; as I Mostly shoot almost exclusively off-camera flash
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NOTE: If I don't reply to a direct comment in the forums, it's likely I unsubscribed from the thread/article..
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Yes that is the solution to more responsive AF in low light; wide open/higher ISO. But it is not a solution when there is a preference for shooting at a lower ISO (400-1600) in a dark room at 5.6 with a flash. Some subjects look better with more depth of field, less noise, suppressing ambient light and really relying on the Flash
It's been discussed here before. Nikon Z6II with SB-900 - AF-assist (i-TTL) question
And elsewhere here, with idea being dismissed (dissed) by one of Nikon defenders.
camerosity
Veteran Member
I remember in the old days shooting wedding receptions in a dimly lit room we'd just set the 35mm lens to f5.6.5 and preset focus and shoot away. Never missed a shot!
I can remember in the old days of setting camera's aperture to guide-number vs. range in distance. A few moons later, using the ultra advanced auto-flashes such as Vivtar 283 with it's adjustable return flash power sensor. :-D
just Tony
Veteran Member
It is visible red light, not IR which will not get through the IR-blocking filter in front of the sensor.
I don’t know whether to “thank” Nikon (the specifier of the sensor toppings) or Sony (the sensor fabricator) for the lack of red pixel membership in the sets of AF-masked pixels. It’s easy to imagine that the folks who work on flashes and the folks who work on sensors have never met in person or sent each other an email. If there’s a technical reason for the glaring functional disconnect it would be good to hear it explained.
Actually not as it turns out. The AF modules are internally masked down to f/5.6 so there is zero advantage to faster lenses. DSLRs and MLs are on level ground so far…
I’m making a reasonable sounding guess here: DSLRs have an advantage of larger sensing elements in the AF modules vs pixels within imaging sensors, therefore they have a better signal level to work with. Likewise the Z6 AF sensing pixels are larger than those in the 45 MP Z bodies so they have a slight low light focusing advantage over their brothers.
That is a hot ticket. The AF algorithms are fed the same video stream that goes to the monitor and viewfinder. The signal level needs to get well above the noise level.
LTheWafflePWN
Senior Member
Well, no, because if you did both there wouldn't be much point to the flash. You still need to set your exposure for the room, and count on your flash to properly illuminate your subjects. If you were wanting illuminated subjects while making the room turn to darkness, opening your aperture up would make you lower your ISO.
I agree with most of this (less noise, suppressing ambient lighting, and actually using/relying on flash for exposure), but I've never been of the opinion that f/5.6+ is required for impromptu group shots. At 35mm, f/2.8, 10 feet away, I have over 4 feet of focus which should be plenty. The room around them is going to be dark anyway, so I've never thought that it needed to be in focus.
I suppose this could be considered a matter of personal preference though. If shooting stopped down to f/5.6+ is required, then I'd still suggest finding a high-contrast part of a subject to focus on, switch to Dynamic if Single Point isn't working, and go from there. I just wanted to clarify, I am not raising my ISO to achieve autofocus.
why is f/5.6 used for AF on Z bodies?
Is that to ensure the corners of the sensor are sharp enough for AF to work, or something?
I wonder if Nikon could make a low-light AF mode where the lens focuses wide-open, but only uses a handful of central AF sensors.
Is that to ensure the corners of the sensor are sharp enough for AF to work, or something?
I wonder if Nikon could make a low-light AF mode where the lens focuses wide-open, but only uses a handful of central AF sensors.
Please list your source for internally stopped down to f5.6.
per Thom Hogan Z8 and z6 ii guide, it works as I listed.
Nikon’s own AF spec listing measuring range is with a f1.2 lens, so fast lens must have better detection range.
Z8
-7 to +19 EV (-9 to +19 EV with starlight view Detection range (ISO 100, f/1.2 lens, 20 °C/68 °F using single servo AF (AF-S)
z6 ii
-4.5 to +19 EV (-6 to +19 EV with low-light AF)
Detection range (ISO 100, f/2.0 lens, 20 °C/68 °F)
Z6 ii range appear much worse, but was with a F2 lens. Z8 with fastest glass appears much better, but likely due to quoted with f1.2 lens
Gary Barnett
Senior Member
I have to agree on that. I noticed that too, with my Z5 when it comes to shooting moving kids in the poor light indoor when I was testing the Z5.
I found the Dynamic AF to be really good and nailed the shot in the poor light every time where the subject detection (face/eye detection) struggled (and missed).
It is almost as if the subjection detection and Dynamic AF (both in AF-C) work in a very separate ways. Had the subjection detection worked like the Dynamic AF, it would have been brilliant in the poor light!
Ernie Misner
Forum Pro
Yes. Is your VF quite dark when using flash? Mirrorless AF is dependent on having a bright VF. So if having that setting on is giving you a dark VF along with your flash settings, then that is one culprit.
Ernie Misner
Forum Pro
That's for seeing in the dark to make compositions when shooting starry skies, etc. It's extremely noisy, like night vision goggles. I don't think you can really focus much with it on.
Sounds like another reason that DSLR's are unlikely to completely go away at least for the immediate future. It's hard to believe Nikon missed this one. Did other manufacturers do the same? Will no one's new mirrorless focus in really dark situations, or just Nikon?
batleys
Leading Member
Confused my Z9 hasfocussed suitably well in very dark conditions - even if reliant on the AF assist lamp on the camera. Yes sometimes the AF gets slower and there can be some hunting but it focusses as long as there is something discernible for the DSP to suitably handle. With most of my lenses I can focus on the brighter planets.
Also with flash you can set the EVF to reflect the settings chosen - but also to disable that automatically when using flash - ie the EVF will show the image for easiest visibility when using flash. Either way I don't the image in the EVF at all noisy.
Now yes if I use a manual off board flash strobe I have to manually adjust the EVF visibility setting as the Z9 has no way of knowing its using flash.
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Simon
https://www.flickr.com/people/suffolkimages/
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I have tried to ascertain this, by asking around in forums when I come across photographers who have used other systems but have not gotten a conclusive answer , although the trend from what I consider reliable posters point towards other systems having similar issues.
There is so much input from shooters who never use flash for events and from shooters who have never used DSLRs and shooters who are just devoted brand fans. This makes it hard to get a reliable answer.
One thing is sure: While the Z cameras are optimized to focus around F5.6, IN GOOD LIGHT. The best low light AF performance is with a fast lens used wide open and "Apply Settings to Live View" ON
I have been mentioning for years on these forums that we desperately need a menu setting "Focus at maximum aperture". The way a DSLR focuses. It is possible Sony or Canon have this option. This way fast lenses would be an added benefit to AF performance but I don't think it could ever match the performance of Infrared AF assist light with DSLRs
When a flash is turned on a Z body, "apply settings to live view" automatically switches off, and the camera defaults to focusing around F5.6 no matter what aperture is set and the EVF ISO is boosted resulting in the grainy, laggy EVF struggling to focus.
It would be nice if these annoying youtubers would actually do the relevant test with typical event dance floor lighting: a dark room with just about no overhead lighting and with lights on the walls. And compare the performance of cameras to capture dancers at ISO1600 F5.6 1/30th shutter. See how the cameras compare!
batleys
Leading Member
Where did you get this from and what do you mean 'optimised'. I have found my Z 800pf f/6.3 lens works rather well with birds in flight in lowish light with ISO pushing sometimes 10,000 or higher - but yes I am talking my Z9 here. My z7ii was not successful in this regard at all - whether it was the camera or operator I don't know.
Your statement would suggest the Z 800 f/6.3 VR S could never ever focus optimally with any Z camera - which is clearly not the case.
Simon
https://www.flickr.com/people/suffolkimages/
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Thom Hogan
Forum Pro
Focusing on the Z's is always done from the EVF stream. Thus, if the EVF stream is brightened, the camera will focus better ;~).
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