FX Z8/9 Sensor in DX Mode......... 'Advantages'?

[mike_halliwell]

I know I'm not getting any conventional increase in lens 'reach', but fewer pixels makes for smaller sized files.

Is there any benefit regarding tracking and AF..... ie. does the smaller number of pixels reduce the workload for the Expeed regarding things such as subject detection and changes in AF? To use a human analogy, it doesn't have to concentrate on the whole screen just a smaller area of it.

Does Spot/Point AF cover the same number of actual pixels?

I noticed recently that using the Z8 with the 24-120mm f4 that despite using Custom 2 (set to square about the size of the centre circle) in Animal Detect, it found and locked focus on a clear human face OUTSIDE the AF area. The bird in question had turned it's back on me and got lost in the background, but the AF was clearly 'looking' outside the AF Box. Seeing the small yellow 'AF locked' icon outside the box on a face is very frustrating as it's hard to get it to unlock sometimes.

I'm guessing DX mode prevents any out-of-frame peeking?

Anyone experience something similar? Am I missing a setting somewhere?

 

 

[ShunCheung]

Apparently the Z8 and Z9 use the feed into the EVF/LCD monitor to evaluate AF. Therefore, some people feel that they get (slightly) improved AF results in the DX crop mode. I haven't explored the DX mode for still photography because for action, I would rather capture more and then crop later on, as frequently it is difficult to keep the subject in the center of the frame. Occasionally I use DX crop for 4K video.

[ilkka_nissila]

I don't think the camera will focus on an area that is too far outside of the box (in the wide-area AF modes); it may identify the subject and focus slightly outisde of the box though, but as long as one is aware of this it shouldn't be too much an issue. One may sometimes need to select single-point or 9-point dynamic area to handle such situations though.

 

I haven't used DX crop mode on these cameras. I prefer having the extra room around the subject and when possible, use as much of the sensor area as I can for the subject.

[mike_halliwell]

16 minutes ago, ilkka_nissila said:

it may identify the subject and focus slightly outside of the box

..and who (what) allowed that?

[ilkka_nissila]

1 hour ago, mike_halliwell said:

..and who (what) allowed that?

Every Nikon interchangeable lens autofocus camera that I remember was the same way: the box in the viewfinder is a bit smaller than the actual sensitivity field of the autofocus system. My guess for the reason is that the phase-detection sensor doesn't have a sharp boundary in its sensitivity.

[mike_halliwell]

True,

However, i thought the advent of mirrorless was a WYSIWYG system?

15 hours ago, ilkka_nissila said:

it may identify the subject and focus slightly outisde of the box though, but as long as one is aware of this it shouldn't be too much an issue

Agreed. It's the persistence thing that's annoying. I can shift the box further away, and it still sticks on the face.

I'll have a go with the Z9 and see if the same happens in Bird Mode.

[ilkka_nissila]

3 hours ago, mike_halliwell said:

True,

However, i thought the advent of mirrorless was a WYSIWYG system?

Agreed. It's the persistence thing that's annoying. I can shift the box further away, and it still sticks on the face.

I'll have a go with the Z9 and see if the same happens in Bird Mode.

Right, it should make a big difference if you specify what type of animal to detect. Humans are mammals and will probably resemble some other mammals sufficiently to be detected at times. There are so many different shapes, sizes, head positions and orientations of birds and other animals that it's a wonder that it works at all. Quite frankly I am disappointed by the bird detection in the current Z8 animal mode and how often it'll not focus on the head of the bird when in various small bird in forest scenarios. But I'm hopeful the future firmware update with its bird mode will improve things. For humans I find the Z8 (and Zf) to be very good in detecting subjects and eyes.

Edited January 10 by ilkka_nissila

[mike_halliwell]

1 minute ago, ilkka_nissila said:

Quite frankly I am disappointed by the bird detection in the current Z8 animal mode and how often it'll not focus on the head of the bird when in various small bird in forest scenarios

Absolutely! It can't 'see' ducks on water either  🙁

I prefer the ergonomics of the Z8, but the AF of the Z9. 

Awaiting the Bird firmware too 🙂 I remember Nikon removing Bird Mode from all its Z8 promo stuff, I guess to help Z9 sales 🤔

[ilkka_nissila]

13 minutes ago, mike_halliwell said:

Absolutely! It can't 'see' ducks on water either  🙁

I prefer the ergonomics of the Z8, but the AF of the Z9. 

Awaiting the Bird firmware too 🙂 I remember Nikon removing Bird Mode from all its Z8 promo stuff, I guess to help Z9 sales 🤔

Nikon said that bird mode will come in a firmware update to the Z8 in the first half of 2024, along with other improvements. They also said in a video that auto capture will soon come to the Z8 in a FW update, which didn't happen so far, and Nikon removed that part of the promotional video. So I'm not quite sure what will come to the Z8, but it seems clear that Nikon wants to (artificially) keep the Z9 sales going even though the Z8 has almost the same hardware so its potential is underused. It seems silly to play these games. If I had known that Nikon will keep giving to the Z9 and not the Z8, I would have bought the Z9 instead of the Z8, but at the time of its launch the Z8 had more AF subject recognition modes than the Z9. So how is one to know which camera to get? To add, the Zf has more options in custom AF box sizes and shapes than the Z8, and a subject-recognition mode for manual focus  (where there will be confirmation of the eye in focus on CPU-equipped lenses but not CPU-less ones, but even those can benefit from the punch-in-zoom to the eye feature). So in a way the Zf is ahead of the Z8 and Z9 in some ways. VR too, and low-light AF.

Edited January 10 by ilkka_nissila

[Dieter Schaefer]

On 1/9/2024 at 6:59 AM, mike_halliwell said:

Seeing the small yellow 'AF locked' icon outside the box on a face is very frustrating as it's hard to get it to unlock sometimes.

Could it be that it was initially inside the box and the subject moved outside - then the yellow box would do what it is supposed to, isn't it?

 

On 1/10/2024 at 10:39 AM, ilkka_nissila said:

If I had known that Nikon will keep giving to the Z9 and not the Z8, I would have bought the Z9 instead of the Z8, but at the time of its launch the Z8 had more AF subject recognition modes than the Z9.

I had toyed with the idea of getting a Z8 to use with the small and light 500PF expecting better handling and balance. Glad I did not go that route. Almost certain now that eventually I will let go of every Nikon camera that uses the EN-EL15 battery in any of its many incarnations.

[bgelfand]

7 hours ago, Dieter Schaefer said:

 

Please delete. Entered in error.

Edited January 20 by bgelfand
Error

[ilkka_nissila]

On 1/19/2024 at 8:41 PM, Dieter Schaefer said:

I had toyed with the idea of getting a Z8 to use with the small and light 500PF expecting better handling and balance. Glad I did not go that route. Almost certain now that eventually I will let go of every Nikon camera that uses the EN-EL15 battery in any of its many incarnations.

Well, the Z8 is to get some of the features the Z9 got earlier, in a firmware update due in the first half of 2024, including the bird AF subject detection mode and usability improvements. For me the EN-EL15c battery is fine and the vertical grip works generally well too, although there have been some random contact problems with the A slot. Being able to use the same batteries with many other cameras is a positive.

 

Sluggish release of seemingly trivial firmware updates (i.e. significantly delayed Z8 firmware compared to the Z9 which has many of the same components) is not a Nikon novelty. 😉 Sony just released they will add shutter angle in a firmware update to the FX3 and FX30, compact cinema cameras that have been several years on the market. (Adding shutter angle option is about as trivial-to-implement a fw change as can be.)