Focus tracking

Started 3 months ago | Questions
OP DavidWright2010 Senior Member • Posts: 1,808
Focus tracking summary : nothing worked

So I think the experiment is finished for now. It's supposed to rain tomorrow and then I'm leaving this target-rich environment.

After sorting through all the suggestions, I went out this afternoon and took about 100 bird pix; about 80 being BIF. I used back button focus to track a bird, then snapped an image when I liked the view. I used spot focusing, TAv mode 1/800 sec and f/8.

This first image exemplifies  what I think is a common problem for me still - I'm not getting the center point on the bird:

focus on sand and gulls, not the heron

The 'best' results were with gulls. I could track them coming, then shoot as they went by:

uncropped image. The bird's right wing is folded down, not clipped. Left wing is clipped

But the above image is not that great when you look at it closely.

I'm including a final picture which may have a hint in it. I was tracking this gull; took several shots which were not that sharp, then with this last shot, the gull had just landed. (So it was barely moving.) This image is pretty sharp. Detail is a little sparse, but it was further away than the above shot. So maybe I should set the SS to 1/1000 or faster? Those gulls aren't really moving that fast, and not beating their wings barely all, so I thought that 1/800 would be fine...

un-cropped, un-sharpened image (warts and all). The piling is pretty sharp.

Again, thanks for the suggestions.

Even though nothing worked.

David

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Sigma DP1 Merrill Sigma DP2 Merrill Sigma DP3 Merrill Sigma SD1 Merrill Pentax K-1 +1 more
kypfer Regular Member • Posts: 160
Re: Focus tracking summary : nothing worked

DavidWright2010 wrote:

So I think the experiment is finished for now. It's supposed to rain tomorrow and then I'm leaving this target-rich environment.

After sorting through all the suggestions, I went out this afternoon and took about 100 bird pix; about 80 being BIF. I used back button focus to track a bird, then snapped an image when I liked the view. I used spot focusing, TAv mode 1/800 sec and f/8.

This first image exemplifies what I think is a common problem for me still - I'm not getting the center point on the bird:

focus on sand and gulls, not the heron

The 'best' results were with gulls. I could track them coming, then shoot as they went by:

uncropped image. The bird's right wing is folded down, not clipped. Left wing is clipped

But the above image is not that great when you look at it closely.

I'm including a final picture which may have a hint in it. I was tracking this gull; took several shots which were not that sharp, then with this last shot, the gull had just landed. (So it was barely moving.) This image is pretty sharp. Detail is a little sparse, but it was further away than the above shot. So maybe I should set the SS to 1/1000 or faster? Those gulls aren't really moving that fast, and not beating their wings barely all, so I thought that 1/800 would be fine...

un-cropped, un-sharpened image (warts and all). The piling is pretty sharp.

Again, thanks for the suggestions.

Even though nothing worked.

David

I think my previous recommendations would have covered just about all bases in these examples.

In the first example, you realise the problem, non-central subject against a cluttered background - more practice required.

In the second example, multi-point AF would have tracked it easily.

For subject movement freezing - 1/1500sec is the minimum in my experience. The K-70 has really very good low-noise performance at high ISO settings, your choice is crisp detail or a bit of grain in the shadows in poor light, I know which I prefer

1/1500sec @ f/8, 1100ASA TAv mode, just a few days ago. A local wild Marsh Harrier, ringed locally on the nest as a chick last year, photographed from within a public hide.

KPM2 Contributing Member • Posts: 828
Re: Focus tracking summary : nothing worked

Hello DavidWright2010

It is not eays to take a BIF, so don't give up !

Now nailing the focus is one thing, but even when it did work, the bird can looks so...so.

Your gull picture show that: The plumage of some birds get only a good vividness, when the illumination cause light and shadows on it. On a dull day, like I think it was the case here, a plumage of a gull get a dull look anyway. So don't be too worry about the picture. It was good that you did try it out at such a dull day, you teach yourself. For me personally, I need a contrasty illumination day, the right position of the bird so that it's plumage get light and shadows on it, and ideally... good background too, but having such situation is so seldom. That mean, such dull days I use for teaching myself, but even when a bird got in focus, I do not expect a good picture.

I have only one gull picture, where all my wishes above was there :

with the illumination of the day you had, my gull plumage would looks similar to yours.

So, the moments are rare and therefore, don't be too sad about your pictures at that dull day.

Now this is a picture of a X-Y movement of the bird and the among of a Z-direction was not big. That's why I could do that picture with a ist DS and the not so fast focusing first version of the DA 55-300.  That is some important point, despite all the tips you get what AF mode, shutter speed and so on, you get, a BIF picture in X-Y movement of the bird is easier to do. For pure Z-direction pictures you need a fast focusing camera/lens combination.

DavidWright2010 wrote:

The 'best' results were with gulls. I could track them coming, then shoot as they went by:

uncropped image. The bird's right wing is folded down, not clipped. Left wing is clipped

But the above image is not that great when you look at it closely.

Again, thanks for the suggestions.

Even though nothing worked.

David

I do BIF pictures not often, but I personally use than shutter speeds beginning at 1/1000 sec. For to follow the bird I like to use a zoom lens, because I use first a wide framing, on that way I do not lost the bird in my frame, focus sometimes on the bird during I followed it's flight and when it is close enough I quickly zoom in, let the camera focus and take at once a series of 2-3 pictures.

best regards KPM2

MrB1 Regular Member • Posts: 119
Re: Focus tracking summary : nothing worked

If the gull was moving across the field of view at 20 mph, it would travel about 1 cm in 1/800 second.  Unless your panning technique is very good, that will give some subject motion blur to the image.  You might add to that the possibility of some blur from camera + long lens movement, and it can't be easy to get a perfectly sharp shot.  It would seem that a much higher shutter speed would give the best chance of a sharp bird-in-flight image.

Philip

John_A_G Veteran Member • Posts: 7,825
Re: back button focus

DavidWright2010 wrote:

John_A_G wrote:

DavidWright2010 wrote:

Yes, I've come to the same realization.

When the next bird comes by I will try AF.C mode, TAv , and back-button focusing, and see what happens.

David

David - I think people suggest back button focus without understanding what it does and doesn't do. It will have zero impact on the camera's ability to track a moving subject.

But when I hold down the BBF button and pan around, the cam re-focuses continuously. Doesn't that save some time - I then just press the shutter when the BIF looks good?

The continuous focus behavior is the same whether you use BBF and thumb or half press on the shutter.  Exactly the same.

Adam007 Regular Member • Posts: 424
Miles Green FTW

I used the Miles Green "method" posted earlier.  I also updated the firmware.  It works great.  I have tracked birds flying across the Y axis as they passed behind tree branches that might've fooled the system. I'm not saying it's perfect; I'm saying that using AF-C and all 25 points has taken my BIF photography from "non-existent" to "not bad and occasionally great".

I find that a minimum shutter speed for a BIF seems to be around 1/1250.  Smaller birds closer to 1/2500.  I keep my aperture around F8, though I could probably open that bit, given how far away they are most of the time (300m DA*, which isn't the fastest-focusing lens I can think of).

Keep plugging away at it.

 Adam007's gear list:Adam007's gear list
Sony RX10 III Pentax K-1 Pentax smc FA 31mm F1.8 AL Limited Pentax smc FA 43mm F1.9 Limited Pentax smc FA 77mm 1.8 Limited +3 more
OP DavidWright2010 Senior Member • Posts: 1,808
Focus tracking - the final final word

Based on all your helpful suggestions, and my experience so far, I tried again this morning. (Even though the forecast was 'cloudy', it is sunny right now.)

I think the issue for me is mostly shutter speed. I shot at 1/1600 this morning - 70 shots of BIF and 6 with acceptable sharpness (as opposed to 0 previously). Here's the best, shown uncropped:

I'm going back out to see if 1/2000 gives me a higher keeper rate.

I'll probably mark one of the replies as the 'answer', but in truth you were all helpful.

Thanks again.

David

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Sigma DP1 Merrill Sigma DP2 Merrill Sigma DP3 Merrill Sigma SD1 Merrill Pentax K-1 +1 more
OP DavidWright2010 Senior Member • Posts: 1,808
Re: Miles Green FTW

Adam007 wrote:

I used the Miles Green "method" posted earlier. I also updated the firmware. It works great. I have tracked birds flying across the Y axis as they passed behind tree branches that might've fooled the system. I'm not saying it's perfect; I'm saying that using AF-C and all 25 points has taken my BIF photography from "non-existent" to "not bad and occasionally great".

I find that a minimum shutter speed for a BIF seems to be around 1/1250. Smaller birds closer to 1/2500. I keep my aperture around F8, though I could probably open that bit, given how far away they are most of the time (300m DA*, which isn't the fastest-focusing lens I can think of).

Keep plugging away at it.

I will try his method also.

But right now, spot focus, BBF until the bird comes close, then 1/1600 and f/7.1 gives some keepers, see below.

David

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Sigma DP1 Merrill Sigma DP2 Merrill Sigma DP3 Merrill Sigma SD1 Merrill Pentax K-1 +1 more
KentG Veteran Member • Posts: 4,584
Re: Focus tracking

A lot depends on how smart and fast the processor is in the camera. This falls under both predictive-AF and the panning skills of the shooter. The more focus points you enable, the more the processor has to watch, and the slower it will respond to change. Pretty much each camera, regardless of brand, has a limit. The old PZ-1p with its 1 AF point was actually not bad at shooting with panning. Not as good as the Minolta Maxxum 9 I used for motorsports at the time which had 3 AF points and the smarts to successfully follow cars moving and changing aspect ratios close to 200MPH (It actually did 168 MPH once when I happened to have a crew member from Roush with a radar gun standing right next to me). I have found that most digital cameras have a hard times going as fast as the last few series of professional film cameras. The point is the fewer AF points you allow it to use the more time it can devote to figuring things out. So the better the panning skills the fewer AF points you can get away with having to use. BIF is generally much easier for the camera than race cars.

Art Morris, one of the best bird shooters there is, used to teach that the maximum lens you could easily use for BIF with a FF (film) camera is 400mm F5.6. Because the scale of the image in the VF determines how much real-estate you have to deal with to keep the bird on the AF points. Too little magnification and you will need to blow the image up, too much magnification and its hard to keep the bird centered on the AF point (s). For APS-C the equivalent view due to the "crop factor" is, as it happens, about 300mm. Which is one reason why Pentax never offered anything above 300mm F4 in the APS-C era. I hear people all the time saying "I need to get closer" or "I need more magnification". That's fine but if you do you need to accept a lower number of keepers. Doesn't apply if they are not moving of course. I could use my K-1 and 150-450 zoom, but at my age I can't move the combo as fast as a lighter one. So when I want to get above 50% keepers I use my Canon 60D and Sigma 100-300/4 zoom with or without a 1.4x TC on it (Canon 1.4x II). Which is why I took that only to Daytona for the Rolex 24 in 2017 when I was invited down.

To get the maximum number of keepers you have to balance all the factors. And be realistic to boot.

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KPM2 Contributing Member • Posts: 828
the transom window test

Hello

I had a K5 and went to a KP and K1. The SelS, SelM SelL I didn't had on my K5, also the hold time setting was new for me. Before I made endless out of focus BIF pictures, I did try out the behaviour of this new to me AF fields and hold time. Instead of using a moving object, like a bird, I used a static object and moves myself. My object was a transom window. Before I go on, I will mention this: we give the OP our tips what will do work, but we must count in that we use sometimes other cameras like the OP. The K70 has a SelEX, where it use 11 AF points. When I for example use the 25 AF points with my KP, I use than a similar AF-frame area size as a K 70, but my 9 AF point frame area size is much smaller than the 11 AF point frame area size of the K 70.

I write now about the test.

Camera (is a KP) in AF-C, hold time is off, I used the 9 AF point area (SelS)

I have to use the pointed out focus point (the centre AF point) for to focus on my sash bar

now I still let the camera continuously focusing, meanwhile a swing to the left and right.

The KP switch during that always to a AF point, which cover the sash bar. But the 9 AF point frame area size is not big, so that I can quickly swing out of this 9 AF point frame area. Try out what happens than. My KP focus at once to the background object and even when I have my 9 AF point frame area back on my sash bar, KP use now the 9 AF point for to stay on the new focus plane object, the tree:

Only a restart (=stop pressing the shutter release button and hold it down again) of the AF can bring me back to the sash bar. And that's what I do when I use such multi AF point's for BIF pictures. When I notice that my camera switched away from my bird, I quickly restart the focus. I do not wait if eventually my camera do catch the bird again, because the chance of staying on the new focus plan (something in the background) is big, like the example test above show.

When I use the SelM, it's clear that, because the 25 AF point frame area size is bigger, I lost my focus on the sash bar not so quickly when I swing to the left and right, but when I lost it, the advantage of using the 25 AF points invert there using like the 9 AF points, too, because the camera use than 25 AF points for to be able to stay on the tree.

When I use only one AF point, it's clear that when I swing to the left and right, that my KP do focus at once always to the object, my AF cover, so it focus to the sash bar or the tree or back to the sash bar. And this can be a goody of using only one AF point, when I can bring back my AF point to the object, my camera do focus again on it. A restart is not needed.

What do the hold time setting ?

Try it out with our own camera. I tried it out with my KP in AF-C, single AF point and when I swing to the left and right, my KP hold the focus on the sash bar, depending on my time setting, short, middle or long, before it focus to the region, where my AF point was. Now on that way I lost my sash bar not so quickly when I swing to the left or right, but when it did happens that my KP focus to the tree, it's clear that it also did wait as long for to focus back on my sash bar. So when I use a hold setting and a single AF point, I must be aware that when I lose the focus on my object, and the camera focus to an other one, I can held back my focus point to my object, but the hold time prevented that my camera focus at once to it. So, when you use a long or middle hole time, it's better to restart the focus than.

can the hold time cause other not wonted behaviours too ?

Yes it can. For that I move now back and forth. Camera in AF-C, single AF point.

hold time is off:

My KP focus continually on the sash bar during my movement:

but now I use hold long and with the same movement my KP did used the hold time, so that it show me that for a while until it start to focus again:

That the camera interpret a moving to a hold time needed moment, depends to my mind on how contrasty my object is. The sash bar has a bad contrast, but when I use a object with a good contrast, my KP do not interpret my moving to a hold time needed moment, it do continually focus on my object than.

So, when I use the hold time, I try to be sure that my object has a good contrast, else, I use no hold time.

BTW: I take during this tests no pictures, I only watch what my camera do. The pictures I made only for to show what I see than.

best regards KPM2

flektogon
flektogon Veteran Member • Posts: 3,742
Re: the transom window test

KPM2 wrote:

Hello

I had a K5 and went to a KP and K1. The SelS, SelM SelL I didn't had on my K5, also the hold time setting was new for me.

Well, I can't find any reference to SelS, SelM SelL  in the KP operational manual.

Before I made endless out of focus BIF pictures, I did try out the behaviour of this new to me AF fields and hold time. Instead of using a moving object, like a bird, I used a static object and moves myself. My object was a transom window. Before I go on, I will mention this: we give the OP our tips what will do work, but we must count in that we use sometimes other cameras like the OP. The K70 has a SelEX, where it use 11 AF points. When I for example use the 25 AF points with my KP, I use than a similar AF-frame area size as a K 70, but my 9 AF point frame area size is much smaller than the 11 AF point frame area size of the K 70.

Basically what you want to say is to use as large frame area (which contains the AF points) as possible.

Only a restart (=stop pressing the shutter release button and hold it down again) of the AF can bring me back to the sash bar.

But only if you pre-set (manually) your lens to focus on that closer area. If the camera's AF system is happy with the sharpness of the immediately projected image, it won't bother to look for another (even if it was a closer) area.

When I use the SelM, it's clear that, because the 25 AF point frame area size is bigger, I lost my focus on the sash bar not so quickly when I swing to the left and right, but when I lost it, the advantage of using the 25 AF points invert there using like the 9 AF points, too, because the camera use than 25 AF points for to be able to stay on the tree.

SelM ?

When I use only one AF point, it's clear that when I swing to the left and right, that my KP do focus at once always to the object, my AF cover, so it focus to the sash bar or the tree or back to the sash bar. And this can be a goody of using only one AF point, when I can bring back my AF point to the object, my camera do focus again on it. A restart is not needed.

What do the hold time setting ?

Try it out with our own camera. I tried it out with my KP in AF-C, single AF point and when I swing to the left and right, my KP hold the focus on the sash bar, depending on my time setting, short, middle or long, before it focus to the region, where my AF point was. Now on that way I lost my sash bar not so quickly when I swing to the left or right, but when it did happens that my KP focus to the tree, it's clear that it also did wait as long for to focus back on my sash bar. So when I use a hold setting and a single AF point, I must be aware that when I lose the focus on my object, and the camera focus to an other one, I can held back my focus point to my object, but the hold time prevented that my camera focus at once to it. So, when you use a long or middle hole time, it's better to restart the focus than.

can the hold time cause other not wonted behaviours too ?

Yes it can. For that I move now back and forth. Camera in AF-C, single AF point.

hold time is off:

My KP focus continually on the sash bar during my movement:

but now I use hold long and with the same movement my KP did used the hold time, so that it show me that for a while until it start to focus again:

That the camera interpret a moving to a hold time needed moment, depends to my mind on how contrasty my object is. The sash bar has a bad contrast, but when I use a object with a good contrast, my KP do not interpret my moving to a hold time needed moment, it do continually focus on my object than.

So, when I use the hold time, I try to be sure that my object has a good contrast, else, I use no hold time.

BTW: I take during this tests no pictures, I only watch what my camera do. The pictures I made only for to show what I see than.

best regards KPM2

Yes, I agree with all what you wrote and demonstrated, just those SelX  terms are mystery for me.

-- hide signature --

Regards,
Peter

OP DavidWright2010 Senior Member • Posts: 1,808
Re: the transom window test

flektogon wrote:

KPM2 wrote:

Hello

I had a K5 and went to a KP and K1. The SelS, SelM SelL I didn't had on my K5, also the hold time setting was new for me.

Well, I can't find any reference to SelS, SelM SelL in the KP operational manual.

I have the same problem. What are these?

Before I made endless out of focus BIF pictures, I did try out the behaviour of this new to me AF fields and hold time. Instead of using a moving object, like a bird, I used a static object and moves myself. My object was a transom window. Before I go on, I will mention this: we give the OP our tips what will do work, but we must count in that we use sometimes other cameras like the OP. The K70 has a SelEX, where it use 11 AF points. When I for example use the 25 AF points with my KP, I use than a similar AF-frame area size as a K 70, but my 9 AF point frame area size is much smaller than the 11 AF point frame area size of the K 70.

Basically what you want to say is to use as large frame area (which contains the AF points) as possible.

Only a restart (=stop pressing the shutter release button and hold it down again) of the AF can bring me back to the sash bar.

But only if you pre-set (manually) your lens to focus on that closer area. If the camera's AF system is happy with the sharpness of the immediately projected image, it won't bother to look for another (even if it was a closer) area.

When I use the SelM, it's clear that, because the 25 AF point frame area size is bigger, I lost my focus on the sash bar not so quickly when I swing to the left and right, but when I lost it, the advantage of using the 25 AF points invert there using like the 9 AF points, too, because the camera use than 25 AF points for to be able to stay on the tree.

SelM ?

When I use only one AF point, it's clear that when I swing to the left and right, that my KP do focus at once always to the object, my AF cover, so it focus to the sash bar or the tree or back to the sash bar. And this can be a goody of using only one AF point, when I can bring back my AF point to the object, my camera do focus again on it. A restart is not needed.

What do the hold time setting ?

Try it out with our own camera. I tried it out with my KP in AF-C, single AF point and when I swing to the left and right, my KP hold the focus on the sash bar, depending on my time setting, short, middle or long, before it focus to the region, where my AF point was. Now on that way I lost my sash bar not so quickly when I swing to the left or right, but when it did happens that my KP focus to the tree, it's clear that it also did wait as long for to focus back on my sash bar. So when I use a hold setting and a single AF point, I must be aware that when I lose the focus on my object, and the camera focus to an other one, I can held back my focus point to my object, but the hold time prevented that my camera focus at once to it. So, when you use a long or middle hole time, it's better to restart the focus than.

can the hold time cause other not wonted behaviours too ?

Yes it can. For that I move now back and forth. Camera in AF-C, single AF point.

hold time is off:

My KP focus continually on the sash bar during my movement:

but now I use hold long and with the same movement my KP did used the hold time, so that it show me that for a while until it start to focus again:

That the camera interpret a moving to a hold time needed moment, depends to my mind on how contrasty my object is. The sash bar has a bad contrast, but when I use a object with a good contrast, my KP do not interpret my moving to a hold time needed moment, it do continually focus on my object than.

So, when I use the hold time, I try to be sure that my object has a good contrast, else, I use no hold time.

BTW: I take during this tests no pictures, I only watch what my camera do. The pictures I made only for to show what I see than.

best regards KPM2

Yes, I agree with all what you wrote and demonstrated, just those SelX terms are mystery for me.

So, ignoring the fact I don't know what SelM is, thank you for this extensive discussion, but it seems to me that you are using what you see in the viewfinder as what you use to determine focus. That is not nearly good enough to judge best focus, for me at least. And if you are talking live view, my lens is very marginal about AF in live view, often failing.

David

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Sigma DP1 Merrill Sigma DP2 Merrill Sigma DP3 Merrill Sigma SD1 Merrill Pentax K-1 +1 more
KPM2 Contributing Member • Posts: 828
Re: the transom window test

Hello DavidWright2010 and flektogon

DavidWright2010 wrote:

flektogon wrote:

KPM2 wrote:

Hello

I had a K5 and went to a KP and K1. The SelS, SelM SelL I didn't had on my K5, also the hold time setting was new for me.

Well, I can't find any reference to SelS, SelM SelL in the KP operational manual.

I have the same problem. What are these?

Maybe pictures are better: When my camera is in AF-C, I have this menu :

now SEL S is this:

SEL M is this:

and SEL L is this:

When I write about the pointed out AF point in this AF array, I mean the pure red one and via the arrow buttons I can select an other one: This is the AF point the camera use for it's first focusing !

So when I send this pure red AF point to the right like you see above and focus to my sash bar, this red AF must cover my sash bar, else the camera focus at once to the tree.

I hope you don't mind that I wrote SelS and so on, instead SEL S

The K 70 do not have this SEL S or SEL M or SEL L it has to my mind only a SEL EX, but I don't have a K 70, I have only there manual.

Before I made endless out of focus BIF pictures, I did try out the behaviour of this new to me AF fields and hold time. Instead of using a moving object, like a bird, I used a static object and moves myself. My object was a transom window. Before I go on, I will mention this: we give the OP our tips what will do work, but we must count in that we use sometimes other cameras like the OP. The K70 has a SelEX, where it use 11 AF points. When I for example use the 25 AF points with my KP, I use than a similar AF-frame area size as a K 70, but my 9 AF point frame area size is much smaller than the 11 AF point frame area size of the K 70.

Basically what you want to say is to use as large frame area (which contains the AF points) as possible.

Only a restart (=stop pressing the shutter release button and hold it down again) of the AF can bring me back to the sash bar.

But only if you pre-set (manually) your lens to focus on that closer area. If the camera's AF system is happy with the sharpness of the immediately projected image, it won't bother to look for another (even if it was a closer) area.

When I use the SelM, it's clear that, because the 25 AF point frame area size is bigger, I lost my focus on the sash bar not so quickly when I swing to the left and right, but when I lost it, the advantage of using the 25 AF points invert there using like the 9 AF points, too, because the camera use than 25 AF points for to be able to stay on the tree.

SelM ?

When I use only one AF point, it's clear that when I swing to the left and right, that my KP do focus at once always to the object, my AF cover, so it focus to the sash bar or the tree or back to the sash bar. And this can be a goody of using only one AF point, when I can bring back my AF point to the object, my camera do focus again on it. A restart is not needed.

What do the hold time setting ?

Try it out with our own camera. I tried it out with my KP in AF-C, single AF point and when I swing to the left and right, my KP hold the focus on the sash bar, depending on my time setting, short, middle or long, before it focus to the region, where my AF point was. Now on that way I lost my sash bar not so quickly when I swing to the left or right, but when it did happens that my KP focus to the tree, it's clear that it also did wait as long for to focus back on my sash bar. So when I use a hold setting and a single AF point, I must be aware that when I lose the focus on my object, and the camera focus to an other one, I can held back my focus point to my object, but the hold time prevented that my camera focus at once to it. So, when you use a long or middle hole time, it's better to restart the focus than.

can the hold time cause other not wonted behaviours too ?

Yes it can. For that I move now back and forth. Camera in AF-C, single AF point.

hold time is off:

My KP focus continually on the sash bar during my movement:

but now I use hold long and with the same movement my KP did used the hold time, so that it show me that for a while until it start to focus again:

That the camera interpret a moving to a hold time needed moment, depends to my mind on how contrasty my object is. The sash bar has a bad contrast, but when I use a object with a good contrast, my KP do not interpret my moving to a hold time needed moment, it do continually focus on my object than.

So, when I use the hold time, I try to be sure that my object has a good contrast, else, I use no hold time.

BTW: I take during this tests no pictures, I only watch what my camera do. The pictures I made only for to show what I see than.

best regards KPM2

Yes, I agree with all what you wrote and demonstrated, just those SelX terms are mystery for me.

So, ignoring the fact I don't know what SelM is, thank you for this extensive discussion, but it seems to me that you are using what you see in the viewfinder as what you use to determine focus. That is not nearly good enough to judge best focus, for me at least. And if you are talking live view, my lens is very marginal about AF in live view, often failing.

David

try out this very simple test for yourself, than maybe, it is much better understandable what I did try to explain.

best regards KPM2

flektogon
flektogon Veteran Member • Posts: 3,742
Re: the transom window test

David,

I suppose you meant to thank to KPM2 (not to me ) for his extensive explanation. But I agree with his findings, just have some reservations. At least, that's what I am experiencing:

If your picture has, let's say two "well defined" subjects (i.e. exhibiting adequate contrast), the camera after half depressing the shutter button will focus on the first subject, which the lens will find. Well, I assume the lens is preset to focus on infinity. If the closer subject exhibits a higher contrast, then the camera will select this one. But unfortunately not always. Right now I tested my KP, and I could say that the consistency on what the camera considers to be the most important subject is around 70%.

I am not using the LV mode at all, as it's auto-focusing performance is much slower, though it might be more consistent (due to using the CDAF method).

Btw. I found the SELexpression. On the KP it is one of the AF area selection mode. It is the single AF point, which you can move to any position away from the centre. Well, that's the only AF mode I have never ever tried .

-- hide signature --

Regards,
Peter

KPM2 Contributing Member • Posts: 828
Re: the transom window test

Hello flektogon

flektogon wrote:

David,

I suppose you meant to thank to KPM2 (not to me ) for his extensive explanation. But I agree with his findings, just have some reservations. At least, that's what I am experiencing:

If your picture has, let's say two "well defined" subjects (i.e. exhibiting adequate contrast), the camera after half depressing the shutter button will focus on the first subject, which the lens will find. Well, I assume the lens is preset to focus on infinity. If the closer subject exhibits a higher contrast, then the camera will select this one. But unfortunately not always.

That is right, but the camera search at a closer object only in the AUTO AF arrays, but not when you use the SEL AF arrays, like I did used in this test. In the SEL AF arrays, like the SEL S SEL M or SEL L the KP use the pure red AF for it's first focusing. I think that on a K70 this is the SEL EX mode and when you use the AUTO AF array mode, it's like you describbed, it seach to a closer object in this AF array. The Auto AF arrays are equal here in there behavior, on a K 70 and KP and other cameras too. With a SEL AF array you have the advantage, that you can put the AF exactly to the point, your pure red AF point is, when you focus the first time. With a AUTO AF array it is sometimes a little luck, where the camera put it's focus on....it must not always be the bird, that depends so much on the contrast of the objects also.

Right now I tested my KP, and I could say that the consistency on what the camera considers to be the most important subject is around 70%.

I am not using the LV mode at all, as it's auto-focusing performance is much slower, though it might be more consistent (due to using the CDAF method).

Btw. I found the SELexpression. On the KP it is one of the AF area selection mode. It is the single AF point, which you can move to any position away from the centre. Well, that's the only AF mode I have never ever tried .

Best regards. KPM2

flektogon
flektogon Veteran Member • Posts: 3,742
Re: the transom window test

Thanks KMP2,

Well yes, I should play more with my camera (like with those SEL modes), but ...

-- hide signature --

Regards,
Peter

dick eduard
dick eduard Senior Member • Posts: 1,437
Re: the transom window test

flektogon schreef:

Bedankt KMP2,

Nou ja, ik zou meer met mijn camera moeten spelen (zoals met die SEL-modi), maar ...

-
Groetjes,
Peter

Ron Brandxs, knew very much about this. For BIF he claimed the max focus points. I'm not to good in this but a few weeks ago I tried that in combination with CIF and it worked well.

Cheers

Dick

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