[repaap]

I do not hav a K-3iii...yet. But nowhere in this discussion that I have seen is anyone saying whether they use back button focus. A focus jump just before shutter activation is what bbf prevents.

Thanks for this note. I have just tried bbf briefly and was going to try from now on if I can make difference, and what kind of difference it does make. I'm still experimenting with different AF modes also...Will report back.

---------- Post added 06-03-21 at 09:44 ----------

Thanks! That's my logic as well - if the camera has good shadow detail, it's better to underexpose slightly to avoid losing highlight detail.



That makes sense. I noticed last weekend that repeatedly half-pressing the shutter resulted in a series of different focal points being selected without changing the framing. So you may be right in that the camera is searching for a subject - even though in the specific situation I was photographing a garden. I haven't experimented much with AFC yet.

Yes, I'll be trying these differences too. I wish that I had PLM lens to see how differently it does focus, compared to DC and SDM motors. Some how screwdrive is actually very reliable, yes noisy, but fast and reliable. No jumping.

All in all. it is very nice AF. I know that they will make it even better.

[dicki]

That is correct. Subject Recognition works in Full Auto and Zone AF only.
AF Sel when coupled to the AE meter will recognize color and shape for where the focus is. What I've found is that when using large AF Sel, such as M or L the focus point can jump off so quick you don't even notice it when you take the picture but you'll see it in the image review by using "info" to bring up the full shoot info. When you zoom in to 100% it will zoom to where the focus point was, press the joystick in and it will go to the center of the image. That's how I've been testing the eye AF. There's times when I thought "Far out! Awesome!" just to realize after that it did not actually put the AF point over the eye. Instead it's side of the nose, the ear, eye brow, cheek bone, or it shows zero AF points being used (still a slight mystery as to why this happens).

This is the point ! And when I switch Eye-Focus off, it will be the same!
An "AP-Point" that is an area of 5 points is no AF-Point! An following AF-C that jumps ist no following AF-C.

[reh321]

This is the point ! And when I switch Eye-Focus off, it will be the same!
An "AP-Point" that is an area of 5 points is no AF-Point! An following AF-C that jumps ist no following AF-C.

Small birds move very fast.
An AF-point that is a second behind the bird is better than I could ever do.
I would have trouble keeping the swallows in my OVF, let alone keeping them in focus, let alone keeping their tiny eyes in focus.
You will feel however you do; I am very impressed with the photos posted so far!

added: If I had a spare $2000 lying around, I would happily spend it on a K-3iii {based on the swallow photos I have seen here}.

btw - I have not yet seen you formulate a question for @Adam; to ask of a Pentax representative about expected behavior ..... of the people who would know what to expect

[repaap]

There is one setting, which is about that tracking. Atleast in my camera(Finnish language). When you go to settings, you choose AF settings with OVF. When you subject tracking on, it will use AE RGB sensor to find the spot for AF. This might sound crazy, but could it be possible for this system to use ’just’ AE sensor, if it is in between the box, what it think that ’eye’ is.

That would leave AF box unused?

Could it also be that with PLM lens it could use AE more effectively, since that tech will also open AF-C in video mode also? That will use sensor AF, but they could have mix those 2 with OVF and this new AE sensor?

I’m not engineer, or anything like that, but I’m just trying to connect some dots at here.

[cfraz]

There is one setting, which is about that tracking. Atleast in my camera(Finnish language). When you go to settings, you choose AF settings with OVF. When you subject tracking on, it will use AE RGB sensor to find the spot for AF. This might sound crazy, but could it be possible for this system to use ’just’ AE sensor, if it is in between the box, what it think that ’eye’ is.

That would leave AF box unused?

The AE RGB sensor cannot perform AF on it's own. It can, under the right conditions, identify where in the frame an eye is located. But it can't even say whether that eye is 2 meters or 2 kilometers away. It only knows the X-Y coordinate position of the eye within the frame. The PDAF system then uses the focus point* nearest the eye X-Y coordinate to determine distance and move the lens accordingly.

* I suppose it's possible for the PDAF module to find distance for multiple focus points near the eye, and then use some sort of average to set focus distance.

[repaap]

The AE RGB sensor cannot perform AF on it's own. It can, under the right conditions, identify where in the frame an eye is located. But it can't even say whether that eye is 2 meters or 2 kilometers away. It only knows the X-Y coordinate position of the eye within the frame. The PDAF system then uses the focus point* nearest the eye X-Y coordinate to determine distance and move the lens accordingly.

* I suppose it's possible for the PDAF module to find distance for multiple focus points near the eye, and then use some sort of average to set focus distance.

Yeah, that sounds like there should be PDAF module too, for calculate the distance.

I was just wondering of what caused that...but it could be as simple as camera loosing focus just before the shutter go off and this caused no focus points to be used. I have setting which will stop focus if camera loses AF, which would cause othervise hunting effect in my other cameras.

Why focus would jump from focused point, I suppose that something must have moved and box which was in focus was no longer there. I would think that PLM will improve this.

[reh321]

The AE RGB sensor cannot perform AF on it's own. It can, under the right conditions, identify where in the frame an eye is located. But it can't even say whether that eye is 2 meters or 2 kilometers away. It only knows the X-Y coordinate position of the eye within the frame. The PDAF system then uses the focus point* nearest the eye X-Y coordinate to determine distance and move the lens accordingly.

The AE RGB sensor serves the same function as the joy-stick or BBFing does - selecting the point to be used to determine distance,
After that, it is up to the PDAF system as usual to determine focusing.

[Yoda boy]

I use spot focus metering for static objects and decide where I wish the most in-focus location, hold down the trigger half way, compose the photo and then take the shot. I have found this technique eliminates most focusing surprises, especially when combined with the appropriate depth of field setting.

[repaap]

I’m still experimenting with bbaf and half press. What it good about half press is that you don’t have to think, and it works. Bad thing is that sometimes it is too fast. You really feel like being in controlling camera more with bbaf. I think that there might be times when you might want more of other than other. BBAF is more flexible than AF-S, since it does bring instantly that AF-C when needed. Bad thing about bbaf is that when you want to use joystick it is a bit more fiddle if you want to be fast.

I’m going to keep both alternatives in different User slots. So I can change between those 2 quick. As bad you can’t change quick other way. (Finally I’m learning why one would like to have these user presets...)

[reh321]

Last Winter I was watching a cardinal picking sunflower seeds from our squirrel-feeder. Just as I pressed the shutter button, he took off. I don't seem to be able to find that photo amongst my old ones from back then - perhaps I deleted that one as unusable {something I don't do very often because I sometimes change my mind} because he was in the lower right corner of the photo I did take. I could have zoomed out a tad, but I was totally unaware he would move so far so quickly {and in zooming out, I would have put even fewer pixels on him}. However, the K-3iii's AF-C would have been very useful it that case - he would have been in the best focus possible in that case despite the inability of my reflexes to adjust framing or focus as he took off.

[Larrymc]

I use spot focus metering for static objects and decide where I wish the most in-focus location, hold down the trigger half way, compose the photo and then take the shot. I have found this technique eliminates most focusing surprises, especially when combined with the appropriate depth of field setting.

Your technique is no different than pushing the AF button (BBF) and holding it down. Different strokes for different folks.

[reh321]

Your technique is no different than pushing the AF button (BBF) and holding it down. Different strokes for different folks.

His method is also basically what we used in the days when everything was Manual Focus.
His method seems to work best for those of us with limited coordination.

[dicki]

Small birds move very fast.
An AF-point that is a second behind the bird is better than I could ever do.
I would have trouble keeping the swallows in my OVF, let alone keeping them in focus, let alone keeping their tiny eyes in focus.
You will feel however you do; I am very impressed with the photos posted so far!

added: If I had a spare $2000 lying around, I would happily spend it on a K-3iii {based on the swallow photos I have seen here}.

btw - I have not yet seen you formulate a question for @Adam; to ask of a Pentax representative about expected behavior ..... of the people who would know what to expect

At Sunday I can take a look to the K1-2. So I realised thatr the K3 have an other AF-C than the K1.
The AF from the K3-3 is very good. And so fast.
Last 8 Years I use the K3 AF-C with AF-Area. This was so gread and I need no Eye-AF and no automatic traking of AF-C. The traking with the point can do all this together. Is was a great idea. In combination with the fast AF from the K3-3 it will be the best AF-C ever!

[repaap]

Yeah, I’v been experimenting with eye AF, and while it might not be on par with milc cameras, I do confirm that it is working. Now I did use a-21 to get the right eye, and I can really see that the box does find the eye. It has to be visible, so you have to be close enough for the box to Fiat the eye area and enough light, or then it will find more ’easy’ target, like a nose.but when it does find it, it will hold it unless face turn away, and then it will catch ear or so. You’ll have to wait untill face is back and refocus(which happens fast). This is my finding so far. Compared to LV and face detect for example, the difference is big between the face and the eye AF when you try to catch the eyes, or even face in focus. It did/does even find the eye when one is in profile, which is to me amazing.

[5shot]

I’m still experimenting with bbaf and half press. What it good about half press is that you don’t have to think, and it works. Bad thing is that sometimes it is too fast. You really feel like being in controlling camera more with bbaf. I think that there might be times when you might want more of other than other. BBAF is more flexible than AF-S, since it does bring instantly that AF-C when needed. Bad thing about bbaf is that when you want to use joystick it is a bit more fiddle if you want to be fast.

I’m going to keep both alternatives in different User slots. So I can change between those 2 quick. As bad you can’t change quick other way. (Finally I’m learning why one would like to have these user presets...)

Once you switch to BBAF you will never go back. I can't imagine using the shutter button again. It does take a bit of time to break yourself of the habit, but once you do, the BBAF is second nature.