Recently getting blur/softness with Z9 while using strobes

[j_photo]

So that could be used to know whether the softness comes from the camera focussing on an unexpected point of not ....

I think that that is true, yes. The only reason I haven't posted any examples of this is because I know there are enough people on this forum who aren't confident in what NX Studio says and would say that it is not always accurate.

That said, here it is for the curious:



(By the way, I notice that this says auto-ISO, which is definitely a mistake on my part. I never use auto-ISO when shooting with a flash).

There have been many past instances of an image such as this, where the indicated focus point is not where focus landed. To me, these are simply cases where the focus recognition system has correctly located the intended focus point, but for whatever reason, focus itself didn't get there. Finding the subject and successfully focusing on the subject seem to be two separate steps in the process.

 

[SCoombs]

So that could be used to know whether the softness comes from the camera focussing on an unexpected point of not ....

I think that that is true, yes. The only reason I haven't posted any examples of this is because I know there are enough people on this forum who aren't confident in what NX Studio says and would say that it is not always accurate.

That said, here it is for the curious:



(By the way, I notice that this says auto-ISO, which is definitely a mistake on my part. I never use auto-ISO when shooting with a flash).

There have been many past instances of an image such as this, where the indicated focus point is not where focus landed. To me, these are simply cases where the focus recognition system has correctly located the intended focus point, but for whatever reason, focus itself didn't get there. Finding the subject and successfully focusing on the subject seem to be two separate steps in the process.

My sense from all the time I've used the system is that this is true where subject detect is concerned. I think that the subject detect basically positions the AF point and then the AF system actually does the focusing. Think of it like how a human being positions the single point AF and then after that the AF system focuses. I think it's like that with the subject detection algorithm taking the place of the human.

 

[fotowbert]

Several times in this thread you said that you switched to using AF-S from AF-C in your attempts to fix the lack of sharpness issue. What caught my attention was this post where you said "I shifted back to single point focus and recompose".

"Focus and recompose" is an old school technique known to have issues when shooting at large apertures. As you rotate the camera to recompose the plane of critical focus also moves such that it no longer passes through what you focused on. At large apertures you risk your subject's eyes, for example, no longer being within your shallow depth of field.

If this describes your AF-S mode focus technique then I suggest you consider the possibility it may have contributed to some of the softness you are continuing to see at least in the f/2.8 shots.

• John

 

[SCoombs]

Several times in this thread you said that you switched to using AF-S from AF-C in your attempts to fix the lack of sharpness issue. What caught my attention was this post where you said "I shifted back to single point focus and recompose".

"Focus and recompose" is an old school technique known to have issues when shooting at large apertures. As you rotate the camera to recompose the plane of critical focus also moves such that it no longer passes through what you focused on. At large apertures you risk your subject's eyes, for example, no longer being within your shallow depth of field.

If this describes your AF-S mode focus technique then I suggest you consider the possibility it may have contributed to some of the softness you are continuing to see at least in the f/2.8 shots.

• John

Well, by focus and recompose I mean placing the focus point close to where it will need to be in the upper third of the frame and then recomposing by a fairly small amount, not by a great deal as if I am just keeping the focus point in the center and then swinging the camera around by a half a frame or more before taking the shot.

Also, I can't show it right now (I may get authorization in a few days) but I now have a few shots taken with this lens at wide apertures with multiple people at quite different distances who are each in great to pretty good focus, so I think as I would expect at these shorter focal lengths the depth of field at the wider aperture is sufficient to cover the literally millimeters worth of difference in focus distance when recomposing even across the entire frame.

 

[jlafferty]

Why aren’t you doing 3D tracking? Place the box over the face, lock focus, recompose with AF engaged, the AF will adjust for your camera movement.

Honestly with the Z series, esp. the two camera bodies you’re using, the only modes you should be shooting in for portraits are Wide Area C1 with subject detect in a portion of the frame of your choosing (I’d do upper third); and 3D tracking, with or without subject detect.

There’s really little point in anything else - for static subjects like these *especially*.

AF-S and single point are outmoded ways of working.

 

[Leonard Shepherd]

Why aren’t you doing 3D tracking? Place the box over the face, lock focus, recompose with AF engaged, the AF will adjust for your camera movement.

+10 (or + more)

with the Z series, esp. the two camera bodies you’re using, the only modes you should be shooting in for portraits are Wide Area C1 with subject detect in a portion of the frame of your choosing (I’d do upper third); and 3D tracking, with or without subject detect.

This is good though not exclusive combination of settings.

Probably more important IMO is your comment that making the best of the limited AF ability "work arounds" from a few years ago is unlikely to as successful as results using the much improved AF capability options of many recent Z bodies.

 

[SCoombs]

Why aren’t you doing 3D tracking? Place the box over the face, lock focus, recompose with AF engaged, the AF will adjust for your camera movement.

Honestly with the Z series, esp. the two camera bodies you’re using, the only modes you should be shooting in for portraits are Wide Area C1 with subject detect in a portion of the frame of your choosing (I’d do upper third); and 3D tracking, with or without subject detect.

There’s really little point in anything else - for static subjects like these *especially*.

AF-S and single point are outmoded ways of working.

With subject detection engaged, 3D tracking is actually not any different from auto area AF, something I use all the time. (It is technically different in that with 3D tracking one can specify the target whereas with auto area the camera chooses, but given the frequency with which the system switches subjects with 3D tracking engaged it is for all intents and purposes the same as auto area.

Without subject detection engaged, 3D tracking is a little different but still has a few extra layers of algorithm working on top of the basic AF.

I use 3D tracking all the time for wildlife and frequently - though not exclusively - for live action sports.

All of that having been said, the key point here is that when the camera's subject detection is having issues for whatever reason, 3D tracking will normally have the same problems. I hope that you do not think this is an especially extraordinary claim as virtually every wildlife photographer I know, including the big names, has as part of their workflow an alternative way to focus when subject detection is not working. We also had on this board a 4 thread long discussion a couple of years back which resulted in the conclusion that in some situations where flash is needed the subject detect can do funny things sometimes (eg, consistently back-focusing or focusing on the rear eye even when the EVF indicates focus on the front eye). All of this is why I had first tried switching to single point AF. The Z system's subject detection is quite good most of the time, but it does in some situation run into issues and when this happens single point AF has proven to be a reliable alternative.

In other words, the reason I was in single point AF here at all was because I was finding the more "automatic" modes, including 3D tracking, to be having some issues - something that, again, does happen from time to time.

 

[jlafferty]

But I shoot Z6III, Z8 and Z9 and never have issues that you’re describing in the scenarios your images shared here show. You’re not shooting wildlife. Forget what those guys like Steve Perry or any “top wildlife shooter” say for your situation. You shouldn’t be doing handoffs - it’s absolutely unnecessary for static, single subject type portraits. These are photos where the mental energy required and active intervention into the AF should approach zero.

To be clear: I’m not suggesting 3D tracking with subject detect active. I’m saying you use the two separately as complimentary AF modes. Subject detect for scenarios where the face is unobstructed and fairly obvious - you should be able to kick back, relax and let the camera take over. 3D tracking for scenarios where the face either isn’t providing the camera with something easy to grab (so you grab a piece of wardrobe or the body near the same plane as the eye); or you use 3D in a scenario where you intentionally want to grab focus on a part of the body other than the face - or for example, if a player holds a ball toward the camera and you want to jump from their face to the ball for a shot. The fact that you describe these scenarios as equally problematic for the AF runs 100% opposite to my experiences. 3D tracking is an absolute champ for me, and frankly I’d never use subject detect at all it’s so good, except I periodically like being a laughably lazy b*stard with these new cameras and still nailing the shot.

I can imagine a scenario - “a couple years back” - where you were in a low lit environment and tighter aperture, the camera struggled. But that’s a thing of the past. Current Z8 firmware with the Lv open aperture focusing option mostly eliminates that as a source of problems. If you throw a cheap, lower powered LED into your workflow for AF assist, I promise you between that and the current firmware - assuming good & consistent technique - you’re going to get near zero missed focus shots. And I’m only suggesting the AF assist for poorly lit, low contrast, tighter aperture scenarios (like in a gym) - the Z8 will benefit from it, and perhaps for the Z9 there’s situations where it’s absolutely necessary (IIRC the Z9 hasn’t gotten an Lv shooting update?).

If you’re missing focus semi regularly, especially some number of shots approaching/surpassing 5%, it’s absolutely user error.

TBH across a lot of use between the Z8 and Z6III I’ve seen my camera struggle to stay on a 3D tracked target once or twice, but these are fast moving, erratic situations with several high contrast/similar saturation objects competing for the camera’s attention. And this is exactly where you’d use Wide Area C1 with a smaller box to corral the camera into a narrower FOV for the AF, using Subject detect. And none of your photos resemble that situation remotely.

It’s so strange to read your accounts of Nikon’s top two cameras as struggling with these absolutely basic situations and know that my experience with the same cameras is miles apart from that. If you’re describing your Z9 - and especially your Z8 if you’re on current firmware - as struggling, or the 3D tracking or subject detect as interchangeably erratic and ineffective, I just… can’t relate at all. You’re doing something to sabotage what is an otherwise very easy, consistent and predictable AF scenario.

I’m wondering if you have somehow set up a workflow that interrupts or drops tracking altogether, somehow has it decoupled from taking the photo… especially with all of these examples you’re sharing where the camera acquires the eye, but then mysteriously loses it, or acquires focus elsewhere when the photo is taken. I can’t engineer a scenario with my cameras where that happens, and it points to a workflow that renders 3D or Subject tracking irrelevant at the time the shutter fires. AF-S and “focus and recompose” presents some possibilities where you’re disrupting what the camera would otherwise nail.

The fact that it only happens erratically, and only with a new lens - and only paired with strobe - I can’t really explain, certainly this thread hasn’t gotten me closer. It’s “a lens issue” but your approach to nailing down the problem is so fluid it’s impossible (for me) to diagnose remotely. I just know I shoot similar subjects, the same cameras, and almost exactly the same strobes (the earlier AD600Pros) and never have this experience.

Anyway, I’m tapped out. Best of luck going forward. Get an AF assist light - a cheap and compact 60w LED works. Update all the firmwares. Factory reset your cameras after that and start over. Meet up with a Nikon pro in your area, or travel to a nearby city for a weekend workshop and get some in-person coaching. Your AHA moment is out there.

--
http://jimlafferty.com
Evocative beats academic.

 

[SCoombs]

But I shoot Z6III, Z8 and Z9 and never have issues that you’re describing in the scenarios your images shared here show. You’re not shooting wildlife. Forget what those guys like Steve Perry or any “top wildlife shooter” say for your situation. You shouldn’t be doing handoffs - it’s absolutely unnecessary for static, single subject type portraits. These are photos where the mental energy required and active intervention into the AF should approach zero.

To be clear: I’m not suggesting 3D tracking with subject detect active. I’m saying you use the two separately as complimentary AF modes. Subject detect for scenarios where the face is unobstructed and fairly obvious - you should be able to kick back, relax and let the camera take over. 3D tracking for scenarios where the face either isn’t providing the camera with something easy to grab (so you grab a piece of wardrobe or the body near the same plane as the eye); or you use 3D in a scenario where you intentionally want to grab focus on a part of the body other than the face - or for example, if a player holds a ball toward the camera and you want to jump from their face to the ball for a shot. The fact that you describe these scenarios as equally problematic for the AF runs 100% opposite to my experiences. 3D tracking is an absolute champ for me, and frankly I’d never use subject detect at all it’s so good, except I periodically like being a laughably lazy b*stard with these new cameras and still nailing the shot.

I can imagine a scenario - “a couple years back” - where you were in a low lit environment and tighter aperture, the camera struggled. But that’s a thing of the past. Current Z8 firmware with the Lv open aperture focusing option mostly eliminates that as a source of problems. If you throw a cheap, lower powered LED into your workflow for AF assist, I promise you between that and the current firmware - assuming good & consistent technique - you’re going to get near zero missed focus shots. And I’m only suggesting the AF assist for poorly lit, low contrast, tighter aperture scenarios (like in a gym) - the Z8 will benefit from it, and perhaps for the Z9 there’s situations where it’s absolutely necessary (IIRC the Z9 hasn’t gotten an Lv shooting update?).

If you’re missing focus semi regularly, especially some number of shots approaching/surpassing 5%, it’s absolutely user error.

TBH across a lot of use between the Z8 and Z6III I’ve seen my camera struggle to stay on a 3D tracked target once or twice, but these are fast moving, erratic situations with several high contrast/similar saturation objects competing for the camera’s attention. And this is exactly where you’d use Wide Area C1 with a smaller box to corral the camera into a narrower FOV for the AF, using Subject detect. And none of your photos resemble that situation remotely.

It’s so strange to read your accounts of Nikon’s top two cameras as struggling with these absolutely basic situations and know that my experience with the same cameras is miles apart from that. If you’re describing your Z9 - and especially your Z8 if you’re on current firmware - as struggling, or the 3D tracking or subject detect as interchangeably erratic and ineffective, I just… can’t relate at all. You’re doing something to sabotage what is an otherwise very easy, consistent and predictable AF scenario.

I’m wondering if you have somehow set up a workflow that interrupts or drops tracking altogether, somehow has it decoupled from taking the photo… especially with all of these examples you’re sharing where the camera acquires the eye, but then mysteriously loses it, or acquires focus elsewhere when the photo is taken. I can’t engineer a scenario with my cameras where that happens, and it points to a workflow that renders 3D or Subject tracking irrelevant at the time the shutter fires. AF-S and “focus and recompose” presents some possibilities where you’re disrupting what the camera would otherwise nail.

The fact that it only happens erratically, and only with a new lens - and only paired with strobe - I can’t really explain, certainly this thread hasn’t gotten me closer. It’s “a lens issue” but your approach to nailing down the problem is so fluid it’s impossible (for me) to diagnose remotely. I just know I shoot similar subjects, the same cameras, and almost exactly the same strobes (the earlier AD600Pros) and never have this experience.

Anyway, I’m tapped out. Best of luck going forward. Get an AF assist light - a cheap and compact 60w LED works. Update all the firmwares. Factory reset your cameras after that and start over. Meet up with a Nikon pro in your area, or travel to a nearby city for a weekend workshop and get some in-person coaching. Your AHA moment is out there.

The issue with the Subject detect misfocusing in flash lighting conditions was reproducible and tested extensively by multiple forum members, including one of this board's most respected technical guys. It was tested using wide apertures. I and others posted lengthy videos demonstrating our the behavior occurring and making our exact technique and methods available for all to scrutinize. Then, as with you, some people said that they had not experienced the problem, but regardless it was reproducible by multiple people who tried it and over on the FM forums one of that board's most rabidly pro-Nikon users, someone known for blaming almost any issue people report as user error also reported experiencing the same problem.

As with many other issues that people raise on photography boards, the exact reason that some people experience certain behavior and others do not are not always discernable, but ultimately the reality is that all of us have our unique use cases, shooting circumstances, etc. and often the exact factors that influence each of our experiences can be much more common or much more unique than we realize.