Recently getting blur/softness with Z9 while using strobes

[SCoombs]

I have been shooting with my Z8 and Z9 and Godox AD600 ProIIs for a year or longer and had no problems. I have NOT updated firmware to anything anytime recently. With the start of this school year, I have suddenly started getting issues with a blur/softness when shooting on my Z8/9 when using the strobes only. In the past, I would shoot with the 85/1.8, the 24-120/4, or the 70-200/2.8, depending on the situation. This summer I acquired the 24-70/2.8 and have primarily been using that as this year starts up. My first thought was that perhaps it was just a problem with that lens, so I did some testing and found that it is not.

Here are a few photos from last year. If you open them full size and look at the eyes you'll see they're pretty darn sharp. You'll notice that these are not even really full size photos but both represent a crop, especially the basketball one, and they still look quite good.






This one is unfinished, but I am giving you the less processed version so you can better see what the camera produced.

I even shot some with this combo just about halfway through the summer on some hot, haze-prone days and it was perfect:









Here are a few photos from the last few weeks, again mostly untouched-up so that there's no question how the retouching may haver affected things. If you open them up full size and look closely as with the others, you'll see that these have a sort of vague blurriness or pronounced softness to them.











Wondering if maybe it was just the lens, I went out and messed around with the lens with natural light only and lo and behold it's amazingly sharp. Again, view full size look at the eyes/face:







Now fortunately, the negative effect is usually minor enough that it is only going to affect pixel peeping and not the photos viewed at a normal size. Sometimes it is borderline, though. That volleyball photo of the kid in the white jersey is a pretty pronounced blur.

So: same equipment, no firmware upgrades. Same photographer and workflow and technique. Same range of settings. Different lens, but tested that lens and without the strobe it is great. Yet when I use the strobe, the one that worked fine before without any problems, I'm getting this blur or softness.

Things I have tried:

* VR On vs. Off vs. Sport

* AF-S vs. AF-C. I have previously been advised by Thom Hogan in a discussion here of some issues with the Z system using flash in AF-C and did find that keeping in AF-S avoided any issues, so I checked this again.

* Replacing the batteries in the transmitter, as I do get funny results with syncing when the transmitter battery is low.

* Making extra sure I am staying still and the subject is staying still - ie, that I haven't suddenly become very shaky.

 

[shuncheung]

I think this image could be slightly front focused. Since there is a volleyball in front of the girl by a foot or so, it is a bit more obvious, as the ball is very much in focus while her face and jersey are a bit off.

If you switch back to the other lens you previously used, I wonder whether this issue will go away.

Of course what you need is version 2 of the 24-70mm/f2.8 S. :-D

 

[TomS53]

The shot you thought was good was at f5.6, all the others are at f2.8. I suspect some of the issue is just that, the depth of field. Could very well be something else also. Good Luck. Stay Safe!

 

[SCoombs]

The shot you thought was good was at f5.6, all the others are at f2.8. I suspect some of the issue is just that, the depth of field. Could very well be something else also. Good Luck. Stay Safe!

I have considered this, but of course any of the lenses in question here ought to be sharp enough at 2.8, and in fact you can see plenty of examples of excellent shots at 2.8 with other lenses as well as with the 24-70 without the strobes. It's only been when I use the strobes with the 24-70 that I get this, and at all different apertures.

 

[jlafferty]

It looks like a combination of outright missing focus, as well as possible motion blur from using your 600 at too high a power output, under standard sync speeds. So the strobe duration is too long, and you're getting a second exposure mixing flash and ambient and it's showing your hand shake.

Switch to HSS and put your camera settings wherever you need to to get a good exposure at 1/1000 or faster, and this will go away.

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

 

[Bob A L]

It is one thing to say sharp enough at f2.8, which is very possible, but very possible that there is a noticeable difference between f2.8 and 5.6. Many if not most lenses are better closed down a stop or two, and the added depth of field can be significant. It's like comparing apples and onions.

 

[SCoombs]

It looks like a combination of outright missing focus, as well as possible motion blur from using your 600 at too high a power output, under standard sync speeds. So the strobe duration is too long, and you're getting a second exposure mixing flash and ambient and it's showing your hand shake.

Switch to HSS and put your camera settings wherever you need to to get a good exposure at 1/1000 or faster, and this will go away.

All of this seems to be contradicted by the fact that my physical technique and approach to setting the camera and flash has remained unchanged from previous shoots where I did not experience these problems.

Beyond that, it is worth adding that my flash units are, when shooting at standard sync speed, usually NOT at very high power and in fact quite the contrary.

It is further worth noting that I have experienced this issue with HSS using high shutter speeds - high enough to easily avoid camera shake even exposing with natural light only.

For example, this one is not as bad as some others but there is definitely a pronounced softness compared to the shots I showed above taken without the use of flash.



I've got it significantly more noticeable on some Tennis photos also shooting in HSS with some quite low flash power, but I do not yet have any of those which I have authorization to display.

 

[SCoombs]

It is one thing to say sharp enough at f2.8, which is very possible, but very possible that there is a noticeable difference between f2.8 and 5.6. Many if not most lenses are better closed down a stop or two, and the added depth of field can be significant. It's like comparing apples and onions.

That's true, but I would say that apart from the 180-600 none of my Z lenses and certainly none of my S lines have really seen a substantial gain by stopping down, and this can be seen with the quite sharp shots taken at 2.8 or otherwise with wide open apertures posted above, as well as - and this is the more important thing - the natural light shots taken with the 24-70.

When I said "sharp enough" my point was only that I can acknowledge that without pixel peeping these results will have been good enough for what they needed to be, as it is not unusual for people posting about sharpness to get a lot of responses that essentially brush off the question as being pixel peeping when the photo viewed at a normal size would be okay.

To reiterate, all of the lenses I am talking about here really are quite sharp even wide open at 2.8 when shooting in natural light. The issue at hand is really about the fact that when the flash is in use there has lately been a significant dropoff in performance where there was not in the past.

 

[SCoombs]

Here are some more of the 24-70 with flash, this time a speedlight bounced off the ceiling. You can certainly see some places where the falloff of the depth of field is noticeable, but leaving that aside there isn't really anything more to be desired with the sharpness.

 

[jlafferty]

All of this seems to be contradicted by the fact that my physical technique and approach to setting the camera and flash has remained unchanged from previous shoots where I did not experience these problems.

This is likely not the case. You’re just missing what you’ve changed (or what your gear has changed for you).

The fact that it’s happening with two separate camera bodies points to the lens as an issue. Here’s a random thought: do you have any of the lens’s custom controls enabled? Have you tried disabling all of them? When you attach the lens to each camera body, does it register with the body differently than your other lenses (new icons showing up on the screen?)

Beyond that, it is worth adding that my flash units are, when shooting at standard sync speed, usually NOT at very high power and in fact quite the contrary.

OK

It is further worth noting that I have experienced this issue with HSS using high shutter speeds - high enough to easily avoid camera shake even exposing with natural light only.

Strange. If you’re shooting faster than 1/1000 and this issue persists I don’t know what to say.

For example, this one is not as bad as some others but there is definitely a pronounced softness compared to the shots I showed above taken without the use of flash.



I've got it significantly more noticeable on some Tennis photos also shooting in HSS with some quite low flash power, but I do not yet have any of those which I have authorization to display.

Edit: I see you’ve tested ambient only images and they seem perfectly fine. As you’ve said, it’s clear you’ve got a strobe induced issue and you need to take your workflow apart, piece by piece, and rebuild it one step at a time, and note where the issue shows up. Some interaction with your new lens, AF mode, strobe settings are the problem, especially since the problem gets ported across bodies.

Come to think of it I’d say this is more accurately described as a lens induced issue that is made apparent by the use of strobes.

The only time I’ve observed a “drift” in my strobe workflow would be with batteries approaching being dead in my trigger. Or strobe bulbs approaching their end of life. But none of this should impact focus.

My bet is that you’ve changed something you assume is unrelated, so you’ve omitted it from your recall of what you have/haven’t done. Or the new lens has some defaults that have changed your workflow without you knowing (my 24-120 defaults to changing aperture with the ring and without knowing that, the lens sabotaged an otherwise predictable workflow).

The bottom line is the lens is the variable and the source of issues. It’s clear that it’s not obvious yet how it’s interacting with your workflow, but it is.

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

 

[Leonard Shepherd]

I think this image could be slightly front focused. Since there is a volleyball in front of the girl by a foot or so, it is a bit more obvious, as the ball is very much in focus while her face and jersey are a bit off.

If auto focus continues to work in monochrome and not colour (nobody seems to have claimed otherwise) then the ball has monochrome detail similar to the shape of an eye.

It is possible if relying on eye AF that the auto focus picked a monochrome eye outline larger than either eye on the subjects face.

--
Leonard Shepherd
In lots of ways good photography is similar to learning to play a piano - it takes practice to develop skill in either activity.

 

[shuncheung]

Off topic: I find this a strange composition: it looks like the girl is missing her right arm and hand. If she can hold the ball from the top without it slipping away, it could be better to show her arm and hand. Otherwise, her hand supporting the ball from the bottom is fine also.

 

[Krummj]

What is your focus setting? Do you use 3D tracking and eye detection? Or focus and recompose?

 

[Bill Ferris]

I think this image could be slightly front focused. Since there is a volleyball in front of the girl by a foot or so, it is a bit more obvious, as the ball is very much in focus while her face and jersey are a bit off.

If auto focus continues to work in monochrome and not colour (nobody seems to have claimed otherwise) then the ball has monochrome detail similar to the shape of an eye.

It is possible if relying on eye AF that the auto focus picked a monochrome eye outline larger than either eye on the subjects face.

That's an interesting thought. If the camera is focusing on Spalding - er, Molten in this case - instead of the athlete, that should be visible in the EVF with the small eye tracking square covering the ball.

--
Bill Ferris Photography

https://billferrisphotography.pixieset.com/arizonaslittleserengeti/

 

[j_photo]

I'm no expert, but maybe something here will be helpful:

If the problem is only happening with this one lens and only with strobes, perhaps there is some communication error between the two. It would interesting to rent another copy of the same lens and see if you experience the same problem.

I didn't see if you are shooting TTL or manual flash exposure. If TTL, I would try manual.

When you shoot with the strobes, is it possible that the camera is struggling with focus at the lower ambient light level? That's a problem I've had when shooting with my (admittedly less state of the art) Z bodies and godox strobes. There are some camera settings that can help mitigate this problem when it occurs.

Regarding your sample images, the softness to me looks like a focus problem (except in the final HSS sample).

For the first two soft shots, the basketballs in the foreground are sharp. It looks as if focus settled on the ball rather than the players' faces.

The third blurry shot also looks to me like missed focus. I don't see motion blur.

In the final shot with HSS, when I pixel peep the netting in the background, I see what looks to me like vertical motion blur.

Good luck.

 

[Bill Ferris]

I'm no expert, but maybe something here will be helpful:

If the problem is only happening with this one lens and only with strobes, perhaps there is some communication error between the two. It would interesting to rent another copy of the same lens and see if you experience the same problem.

I didn't see if you are shooting TTL or manual flash exposure. If TTL, I would try manual.

When you shoot with the strobes, is it possible that the camera is struggling with focus at the lower ambient light level? That's a problem I've had when shooting with my (admittedly less state of the art) Z bodies and godox strobes. There are some camera settings that can help mitigate this problem when it occurs.

This holds some promise. There's no indication of motion blur in any of the photos. The ambient light photos represent the 24-70 as being able to focus and make sharp photos. The exception is when using the 24-70 in combination with the strobes.

If we make the reasonable assumption that the camera, lens, and strobes are all in good working order, let's examine the camera settings and lighting conditions as factors.

The ambient light level the camera uses to acquire focus prior to the firing of the strobes is a bit low. It's not super low as evidenced by the ISOs you're using and the camera's ability to capture the background at a pleasing lower lightness.

An earlier post suggested the possibility the camera is focusing on the volleyball and, as a result, the subject's eye's are a bit defocused. That idea has some merit. If Auto Area or 3D AF were in use, I'd explore the viability of using other area modes. The OP could explore that by deactivating subject detect and using a small dynamic focus area positioned over the face to make some test images with the strobes. Make a series of exposures using AF-S and AF-C with that setup. If the results are better but still not reliably consistent, try single-point AF painting an eye.

Based on the information we have and the sample photos, that's where I'd start.

Regarding your sample images, the softness to me looks like a focus problem (except in the final HSS sample).

For the first two soft shots, the basketballs in the foreground are sharp. It looks as if focus settled on the ball rather than the players' faces.

The third blurry shot also looks to me like missed focus. I don't see motion blur.

In the final shot with HSS, when I pixel peep the netting in the background, I see what looks to me like vertical motion blur.

Good luck.

 

[SCoombs]

Off topic: I find this a strange composition: it looks like the girl is missing her right arm and hand. If she can hold the ball from the top without it slipping away, it could be better to show her arm and hand. Otherwise, her hand supporting the ball from the bottom is fine also.

This is not a pose I really like very much but it is one that many of the kids I work with think is the best default pose. I'm not sure if it comes from being used to it from working with the previous photographer over the years or if they got it from something else. Usually what I do for the team photos is give them two poses to do that I have chosen and then the option to do one that they personally want. I've been trying to introduce them to other ones over the last couple of seasons and most of the kids who I see for multiple sports have stopped doing it. Some of those who only play one sport still do it for their personal choice.

 

[SCoombs]

What is your focus setting? Do you use 3D tracking and eye detection? Or focus and recompose?

Generally I would use one of the side area boxes and eye detection or even the auto area AF and eye detection which all had been working fine. When I started to notice this I shifted back to single point focus and recompose to try to see if that would eliminate the problem.

 

[SCoombs]

I think this image could be slightly front focused. Since there is a volleyball in front of the girl by a foot or so, it is a bit more obvious, as the ball is very much in focus while her face and jersey are a bit off.

If auto focus continues to work in monochrome and not colour (nobody seems to have claimed otherwise) then the ball has monochrome detail similar to the shape of an eye.

It is possible if relying on eye AF that the auto focus picked a monochrome eye outline larger than either eye on the subjects face.

That's an interesting thought. If the camera is focusing on Spalding - er, Molten in this case - instead of the athlete, that should be visible in the EVF with the small eye tracking square covering the ball.

I could see that happening, but in practice I pay extremely close attention to what the AF box does when composing and shooting and it was definitely not on the ball in this case.

 

[SCoombs]

I'm no expert, but maybe something here will be helpful:

If the problem is only happening with this one lens and only with strobes, perhaps there is some communication error between the two. It would interesting to rent another copy of the same lens and see if you experience the same problem.

I didn't see if you are shooting TTL or manual flash exposure. If TTL, I would try manual.

When you shoot with the strobes, is it possible that the camera is struggling with focus at the lower ambient light level? That's a problem I've had when shooting with my (admittedly less state of the art) Z bodies and godox strobes. There are some camera settings that can help mitigate this problem when it occurs.

This holds some promise. There's no indication of motion blur in any of the photos. The ambient light photos represent the 24-70 as being able to focus and make sharp photos. The exception is when using the 24-70 in combination with the strobes.

If we make the reasonable assumption that the camera, lens, and strobes are all in good working order, let's examine the camera settings and lighting conditions as factors.

The ambient light level the camera uses to acquire focus prior to the firing of the strobes is a bit low. It's not super low as evidenced by the ISOs you're using and the camera's ability to capture the background at a pleasing lower lightness.

I typically turn the trigger off and then take a shot of the background and try to expose for around 1 stop under a correct exposure. I really don't think it's all that low in any of the cases I have shot so far. For instance, the soccer stuff was outdoors with very bright sunlight so that I was at 1/2000 just to get the background from being too bright. Now obviously I have the subjects standing where they are darker than the background, but it isn't that dark and would be perfectly adequate for a natural light shot, for instance. In the gym where those other photos were taken the lighting is pretty okay. It isn't as bright as it could be of course, but it's one of the brighter HS gyms you'll find. It's definitely not one of those very dark, pretty rough ones to shoot in. I also do live sports in that gym shooting with shutter speeds at 1/2000 and have never had a major issue with focus.

There are a gyms I go to which are on the darker side, but even in those I have have never previously had any major problems missing focus even shooting with the slower 24-120 f4.

An earlier post suggested the possibility the camera is focusing on the volleyball and, as a result, the subject's eye's are a bit defocused. That idea has some merit. If Auto Area or 3D AF were in use, I'd explore the viability of using other area modes. The OP could explore that by deactivating subject detect and using a small dynamic focus area positioned over the face to make some test images with the strobes. Make a series of exposures using AF-S and AF-C with that setup. If the results are better but still not reliably consistent, try single-point AF painting an eye.

I mentioned above just a moment ago but I'll add it here also that after the volleyball shoot back in late August I swapped to using single point AF in AF-S to try to avoid these problems. This was partly just "common sense" but partly motivated by some discussions I've had with Thom Hogan here about the Z system and flash usage where the conclusion was that trying to use eye detect in AF-C with the flash can sometimes cause missed focus and so I had gotten in the habit of doing that anyways in particularly low light scenarios. I had never had a real need to do it for portrait shoots before, but it was something I did move to pretty quickly to try to deal with the issue.

Based on the information we have and the sample photos, that's where I'd start.

Regarding your sample images, the softness to me looks like a focus problem (except in the final HSS sample).

For the first two soft shots, the basketballs in the foreground are sharp. It looks as if focus settled on the ball rather than the players' faces.

The third blurry shot also looks to me like missed focus. I don't see motion blur.

In the final shot with HSS, when I pixel peep the netting in the background, I see what looks to me like vertical motion blur.

Good luck.