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05-13-2021, 05:32 PM - 6 Likes   #31
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QuoteOriginally posted by gatorguy Quote
Excellent! Focus on contrasting lines is good advice Clackers.
Yes, I know it's very sad to encounter photographers who after decades, don't know how to take a photo, Gatorguy, but there are plenty!

There is no such thing as when we read a post about someone complaining 'I focused on my child, but ...'. To a PDAF focus system, there are no children, there are no dogs, no cups of coffee, just distinct lines.

Below is how to do it ...

Coffee cups don't move, so for action photographers, the game is to keep the chosen (usually central) point on a line on the subject as they go about their business. Expanded Area AF helps flagship Pentax owners by moving that point for them - tracking - between the Rule of Thirds markers, approximately, so there is margin for our errors.

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Last edited by clackers; 05-13-2021 at 08:55 PM.
05-13-2021, 06:48 PM - 1 Like   #32
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QuoteOriginally posted by clackers Quote
Yes, I know it's very sad to encounter photographers who after decades, don't know how to take a photo, Gatorguy, but there are plenty!

There is no such thing as 'I focused on my child'. To a PDAF focus system, there are no children, there are no dogs, no cups of coffee, just distinct lines.

Below is how to do it ...
...and that's a perfect example. Worth way more than a thousand words.
05-14-2021, 06:03 AM   #33
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QuoteOriginally posted by clackers Quote
There is no such thing as when we read a post about someone complaining 'I focused on my child, but ...'. To a PDAF focus system, there are no children, there are no dogs, no cups of coffee, just distinct lines.
But now we have autofocus that uses the AE sensor to track subjects, so there are children and dogs and birds and cars that the camera recognizes.
05-14-2021, 06:21 AM   #34
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QuoteOriginally posted by ThorSanchez Quote
But now we have autofocus that uses the AE sensor to track subjects, so there are children and dogs and birds and cars that the camera recognizes.
That's also a very good point. Clackers advice is still sound, but yes your K3 III camera may decide on its own where to properly focus based on subject recognition, depending on the settings.

05-14-2021, 08:20 AM - 2 Likes   #35
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QuoteOriginally posted by clackers Quote
That's user error, Thor - you've let the focus point fall over a tree, which of course is a distinct line!

If you say you only briefly passed the focus point over the fence or parent or whatever, that is what the Hold function is for on Pentax, Canon, Nikon, etc. If you are panning and there will be a considerable gap in the play, that's what Back Button Focus is for, you can resume pressing with your thumb once the players in the foreground cover the light pole at the back.

Sports photography requires technique, there's no escaping it. Shooting flowers or cups of coffee is nothing.

You can see in my picture below there were plenty of tempting lines and edges other than my subject, the skill is to lay the focus point on our target and just our target. And not the dark part of the rider's outfit, either, that's useless, there is no distinct line there. The target would've been the border of the white patch below it, my lens is a not fast Tamron 70-200 screwdrive but it kept up enough at f3.5 here.
Some sage advice here for a newbie like me! In using this technique is it OK to use centre focus to grab the point you want using AF Button and continue holding (lock) and then frame and pan?? (Sorry if this is an obvious question)

---------- Post added 05-14-21 at 08:45 AM ----------

QuoteOriginally posted by MrNPhoto Quote
From my post K-3 iii track meet success:

I had wonderful success at a high school track meet using these settings:
  • AF-C with Expanded Area AF (S)
  • Focus Hold OFF
  • Shake Reduction OFF
  • AF-C release 1st frame: focus priority
  • AF-C release action: focus priority
  • High, Medium and Low continuous drive mode
  • TAv mode, with aperture set from 3.5 to 5.6 and shutter speed 1/800 to 1/2000

These settings on the K-3 iii produced better results than I've ever achieved with the K-3.
What Exposure Mode do you use?
05-14-2021, 11:00 AM   #36
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QuoteOriginally posted by snappyhoffy Quote
What Exposure Mode do you use?
I was using center-weighted metering with TAv. My shutter speed was set to 1/800 up to 1/2000, and my aperture was set from 3.5 to 5.6. I changed settings as lighting conditions changed (clouds passing overhead) and where the athletes were in the stadium (the orange track reflected more light than the turf or grass).
05-15-2021, 02:32 PM   #37
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QuoteOriginally posted by ThorSanchez Quote
But now we have autofocus that uses the AE sensor to track subjects, so there are children and dogs and birds and cars that the camera recognizes.
According to the manual, that's the feature *only* in Auto or one of 21 AF points in the new Zone mode.

Not any of the other modes, or your favourite single point centre, right, Thor?

You have the camera now, you should know!

05-15-2021, 02:38 PM   #38
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QuoteOriginally posted by gatorguy Quote
That's also a very good point. Clackers advice is still sound, but yes your K3 III camera may decide on its own where to properly focus based on subject recognition, depending on the settings.
If you don't like fighting the camera - you have one idea and it has another, and the action right now is very important - p62 of the manual indicates you can turn that off.

For instance, who wants eye detection to go the wrong person in the frame?
05-15-2021, 02:45 PM   #39
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QuoteOriginally posted by snappyhoffy Quote
Some sage advice here for a newbie like me! In using this technique is it OK to use centre focus to grab the point you want using AF Button and continue holding (lock) and then frame and pan?? (Sorry if this is an obvious question)
Glad to be of help, Snappyhoffy!

That is a fundamental technique which will work for any camera with AF-C, including models like the K-70 and K-30, etc that don't have an AE sensor that can track for the AF system.

I use it all the time, and with a camera that does have tracking like the K-1, I'm really doing the same thing. Expanded focus from the centre point (which is the best point, a cross point capable of using horizontal or vertical lines, and rated to f2.8) with back button like you.

I think back button liberates your mind - you know that you can never make the mistake in the heat of the moment and release the shutter button too far and lose that halfway position lock on focus and have to reacquire partly through a sequence. All movements you make are deliberate and decisive.
09-08-2021, 04:29 AM - 2 Likes   #40
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QuoteOriginally posted by clackers Quote
According to the manual, that's the feature *only* in Auto or one of 21 AF points in the new Zone mode.

Not any of the other modes, or your favourite single point centre, right, Thor?

You have the camera now, you should know!
I never use single center point with the Mark III because Expanded Area works, unlike with previous cameras.
09-08-2021, 10:20 PM   #41
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QuoteOriginally posted by ThorSanchez Quote
I never use single center point with the Mark III because Expanded Area works, unlike with previous cameras.
Then you are not using subject recognition, Thor.

There is no bird tracking, or eye tracking, or whatever, in Expanded mode.
09-19-2021, 12:20 PM   #42
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QuoteOriginally posted by ThorSanchez Quote
I never use single center point with the Mark III because Expanded Area works, unlike with previous cameras.
QuoteOriginally posted by clackers Quote
Then you are not using subject recognition, Thor.

There is no bird tracking, or eye tracking, or whatever, in Expanded mode.
This is a statement (that with expanded area subject recognition doesn't work), that I can not really follow, since its 1st appearance in the K-3: Feature 1?K-3 | RICOH IMAGING. The manual is very weak in that respect. p62 speaks about "Subject recognition" on/off.

You can also turn it on/off in expanded area mode, not just in zone select. It is not greyed out, as usual when a feature is not present. In the K-3 there was an explicit mention of limit. For the K-3 iii this asterixes have disappeared: Image Tracking | PENTAX K-3 Mark III | RICOH IMAGING Imaging Power | PENTAX K-3 Mark III | RICOH IMAGING

If you take a pupet with zone select or extended area N and focus on the nosee, the K-3 iii does exactly the same thing, which you can see from which AF sensor is highlighted, when the camera is slowly moved. Also the zone is rather small, if the face is big in the image, it would struggle. With expanded area, you can increase. Also when using expanded area, if it detects a face, it writes it into the exifs. I know, this is a different topic of discussion.

Looking at Nikon's documentation for the D500, which is much better. D500 TIPS | Technical Solutions | Nikon Professional Services and https://crossgate.nikonimglib.com/dsd_redirect/redirect.do?P=myGyO65&R=Z3GOe...LG03&O=7Btqc00

These analysis systems all work more or less the same for Pentax, Nikon, Canon since there 1st appearnce in the D3. Just the labels are different.

Pentax Scene Analysis System = Nikon 3D-Tracking

p104 "Auto-area AF: The camera automatically detects the subject and selects the focus point; if a face is detected, the camera will give priority to the portrait subject. The active focus points are highlighted briefly after the camera focuses [...]."

I wonder whether the zone select vs expanded area code is not just the difference of initialisation. In one case the user selects the starting point of tracking, in the zone select one, the camera selects the starting point. For both cases, the tracking is very similar. A question that I would pose to Pentax for clarification.

Also Clackers regarding the selection of contrast lines for AF starting. In Triathlon sports and similar individual sports, this may work. In many other sports situations this may not work, e.g. swimming with water bubbles etc. There are other good ways for initialization of the AF. Color for examples works almost as good as contrast lines. Sometimes contrast lines even need to be avoided. Example in soccer with a goalie standing in front of the goal net. I find that Nikon guides also provide very good suggestions here of how to properly set the camera AF.

Last edited by UlrichSchiegg; 09-19-2021 at 01:03 PM. Reason: Spelling
09-19-2021, 08:18 PM   #43
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QuoteOriginally posted by UlrichSchiegg Quote
This is a statement (that with expanded area subject recognition doesn't work), that I can not really follow, since its 1st appearance in the K-3: Feature 1?K-3 | RICOH IMAGING.
I think you are getting confused, Ulrich!

The subject recognition I am talking about and the Zone modes it needs do not exist in the older K-3.

The resolution is too low.

The new K-3 III triples the number of pixels, so it can do eye and bird focus in the OVF, for example.

You cannot do that with the K-3.

That is why the manuals are now different, and have additional options.

QuoteOriginally posted by UlrichSchiegg Quote
You can also turn it on/off in expanded area mode, not just in zone select.
Page 62 explicitly says: "Subject Recognition: You can make settings so that the recognized subject is
prioritized while autofocusing when [AF Active Area] is set to [Auto Area] or [Zone Select]."

Not Expanded.

QuoteOriginally posted by UlrichSchiegg Quote
Also Clackers regarding the selection of contrast lines for AF starting. In Triathlon sports and similar individual sports, this may work. In many other sports situations this may not work, e.g. swimming with water bubbles etc.
Then you will have problems.

*All* PDAF sensors from every camera brand need a line to split like the old rangefinders. Mirrorless cameras are more limited because they cannot use both horizontal and vertical lines, Pentaxes have cross points to do that.

CDAF is even worse in swimming with water bubbles, because there may be nothing of high contrast on the subject. Same problem in any backlit scene!

I like shooting football, because the coloured uniforms usually have stripes or clearly defined bands of colour where I can focus on their boundary.

09-20-2021, 06:21 AM   #44
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QuoteOriginally posted by UlrichSchiegg Quote
This is a statement (that with expanded area subject recognition doesn't work), that I can not really follow, since its 1st appearance in the K-3: Feature 1?K-3 | RICOH IMAGING. The manual is very weak in that respect. p62 speaks about "Subject recognition" on/off. You can also turn it on/off in expanded area mode, not just in zone select. It is not greyed out, as usual when a feature is not present. [...]

QuoteOriginally posted by clackers Quote
I think you are getting confused, Ulrich!

The subject recognition I am talking about and the Zone modes it needs do not exist in the older K-3.

The resolution is too low.

The new K-3 III triples the number of pixels, so it can do eye and bird focus in the OVF, for example.

You cannot do that with the K-3.

That is why the manuals are now different, and have additional options.

Page 62 explicitly says: "Subject Recognition: You can make settings so that the recognized subject is
prioritized while autofocusing when [AF Active Area] is set to [Auto Area] or [Zone Select]."

Not Expanded. [...]
Also K-3, K-3 II, KP and also the FF K-1 and K-1 II have it in the documentation. Not in the manual, but if you check it in the feature product pages (Image: Pentax Real Time Analysis System) it is there. The K-3 ref I had given above. For the other:

Feature 1?K-3 | RICOH IMAGING
Feature 5? PENTAX K-3 II | RICOH IMAGING
Features4 | PENTAX KP | RICOH IMAGING
Other features 1 | PENTAX K-1 Mark II | RICOH IMAGING
Features5 | PENTAX K-1 | RICOH IMAGING

Sometimes call subject recognition (e.g. K-3 II), often subject detection. It is the same thing. Your statement, that the 86k Sensor resolution is too low does origin from where? Nikon quotes that it works with the D90 and a much smaller AE sensor.

As I wrote, I know what is in the handbook on 62. But I also know what is in the K-3 III Menue in front of me. The option is not greyed out for Expanded Area, as it should be.

Personally I experience a lot of improvements with the K-3 III in both zone and expanded area methods. I attribute this mainly to resolution and speed improvements (buffer, processor, AE sensor, Mirror down time, ...). I don't think that the system works differently now, than it used to. It is still the same DSLR OVF system that all Pentax, Canon and Nikon have for more than 10 years now. What is new is, that there are now options in the Menue to turn it on or off.

The origin of the problem is to me the poor documentation since its first appearance. And no, I have no problem using the AF. With help of Canon and Nikon documentation and check versus practical Pentax use, I am fine. Don't know why you refer to mirrorless. The discussion was about OVF AF methods.

PS AF Tracking to me is rarely about individual images, but rather hit rate. Question is, with which method the best hit rate can be achieved. Whatever method is used, misses will happen.
PPS Using the Canon one, beside the nikon one: https://www.canon-europe.com/pro/infobank/autofocus/ gives some more insight. As I read the various sources, the difference in method between zone select and expanded area select is rather the AF tracking initialization than the AF tracking itself.

"Some cameras also feature a couple of AF Point Expansion settings for more control over tracking moving subjects. In AF Point Expansion mode, a single AF point is selected manually and the camera then uses that point plus four or eight surrounding points to help track the subject. These are very useful for sports photography when you're able to keep the active area over the subject. It's easier to keep a group of AF points over a moving subject than a single AF point.

Several EOS cameras also have a Zone AF method and in some cases more than one with additional options such as Large Zone AF: Vertical and Large Zone AF: Horizontal. These options allow you to target specific areas or zones of the image frame for focusing. The photographer selects the zone while the camera selects the particular AF points to use within that zone.

The Zone AF options are useful when you know approximately where the subject will be in the frame and it would be hard to keep a smaller active area over the subject."

Last edited by UlrichSchiegg; 09-20-2021 at 06:52 AM. Reason: Link corrected
09-20-2021, 09:12 AM   #45
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I am genuinely enjoying both major contributors in this conversation thus far:
- Ulrich for your sharing of excellent information and details regarding your progressive perspective and the basis behind it.
- Clackers likewise for sharing excellent simple clarity in explanation and examples regarding conventional wisdom in the application of AF principles.

For those interested the specific menu based Nikon D500 'Tips - Settings by Events':
- Specific settings recommendations (little discussion) for specific events within; soccer, track and field, gymnastics, water sports etc.
- This information can be found as a subset of the information Ulrich linked to.
- The direct sub-link is here: D500 TIPS - Details: Settings by Event | Technical Solutions | Nikon Professional Services
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