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06-15-2015, 06:32 PM - 1 Like   #16
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Just got my K-3 II. I did a quick test of the AF (AF.C 9-point expanded area) with cars moving towards me at around 25 mph on my DA* 60-250mm and it performs pretty well. Some shots were slightly out of focus but none were particularly soft, and the camera was able to maintain a consistent frame rate of about 4-5 fps. This was under suboptimal lighting conditions as it was around 7:00 PM when I took the shots. Given my experience with the K-5, it's likely that the older camera would have had trouble getting this frame rate with a good number of usable shots in the same situation.

Edit: Hold AF Status was set to Medium. This may have degraded the tracking performance in this situation. I'll see if I can do a similar test with Hold AF Status off. I have yet to fully understand the new AF system's settings, so I may not have fully utilized it.

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06-15-2015, 07:17 PM   #17
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Have the K3/II improved vs. K5 in terms of tracking with a subject moving toward the camera?

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06-16-2015, 01:40 AM   #18
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QuoteOriginally posted by jpzk Quote
Have the K3/II improved vs. K5 in terms of tracking with a subject moving toward the camera?

JP
I'll add away from the camera as well, as both of these are really the most difficult scenarios for AF systems to deal with.

Simon
06-16-2015, 06:11 AM   #19
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QuoteOriginally posted by Srhphoto Quote
I'll add away from the camera as well, as both of these are really the most difficult scenarios for AF systems to deal with.

Simon
Yes that would be a good counterpart situation.

I think that even most "high end" cameras would have some degree of dificulty tracking/focusing on moving subjects in that manner.
What I am wondering is: is the "tracking" AF of the K3/II better now vs. the previous models ?
Let's forget comparing with Canikon's for now.

JP

06-16-2015, 08:50 AM   #20
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QuoteOriginally posted by starbase218 Quote
Funny that you should say that. DPReview found the 18-135 to be the best performing lens when they tested the K-3's AF tracking:
I'm pretty much solely on Sigma lenses when using continuous focusing - not so much because of performance, but more so because they are the most quiet lenses I have, which is a really good thing while shooting weddings. Anyhow, I'm not too sure about how my other Pentax lenses are as I don't use continuous focusing enough with them (the 50mm f1.8 is an exception though).

I just did some comparison shots with the 18-135 and my older Sigma 70-200, and while the Sigma appeared to hunt more, it still felt snappier and nailed almost all shots, while the 18-135 missed a lot.

---------- Post added 16-06-15 at 17:54 ----------

QuoteOriginally posted by jpzk Quote
What I am wondering is: is the "tracking" AF of the K3/II better now vs. the previous models ?
Let's forget comparing with Canikon's for now.
In my opinion it is - I've also tested with people approaching me and though it's clear the camera has harder time to keep up, I still feel it's better - buuut, I need to shoot more.
06-16-2015, 01:34 PM   #21
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QuoteOriginally posted by jpzk Quote
Yes that would be a good counterpart situation.

I think that even most "high end" cameras would have some degree of dificulty tracking/focusing on moving subjects in that manner.
What I am wondering is: is the "tracking" AF of the K3/II better now vs. the previous models ?
Let's forget comparing with Canikon's for now.

JP
It is infinitely better, because the K-3 is the first Pentax DSLR to have tracking AF in the first place.

Sure, the K-5 can do AF-C. But that just means that it continuously detects if focus has been lost. If so, it will reaquire it. When you combine it with automatic focus point selection, you may be able to get good results on occasion.

What the K-5 can't do, and what the K-3 does, is to use the 86000 pixel RGB metering sensor to track what it thinks is the subject. When that subject moves inside your frame, out of reach of the active AF point, it will tell the AF to activate an adjacent point instead, so that it can keep focus on the subject.

That is tracking.

What I find problematic about the implementation, though, is the fact that you only know which AF point is active when the AF actually switches to another point, or when it needs to adjust focus. Only then does it light up in the viewfinder. I would like continuous feedback on the active AF point so that I can check if the camera is still tracking my subject (even though it thinks it is). So that means the active AF point should always be lit in the viewfinder, maybe with a different color from when it's actually focusing.
06-16-2015, 05:12 PM - 1 Like   #22
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Upon further testing, I've discovered that my Sigma 70-200 behaves different and the K-3 II might not be all it's supposed to be:

Lens used: Sigma 70-200mm f2.8 Macro HSM

Settings on camera:
1st. AF.C shot: focus priority
Action AF.C continuous shooting: FPS priority
AF hold: off

Results: Horrible - as in utter crap. The first series of photos (link to album down below) sums up the kind of photos I'd typically get.

I replicated this at a later time, with different light and different targets (cars).


Settings on camera:
1st. AF.C shot: focus priority
Action AF.C continuous shooting: focus priority
AF hold: off

Results: Much better results and appear to be better than K-30 - Framerate was obviously affected, which dropped down to (I'm guessing here) something like 4 fps. The second series in the album is an example with these settings.

Click to enter the album:



Upon even further testing here at home, I've currently concluded, that bad focus is caused by bright areas such as reflections and harsh light - but don't think I'm talking about trying to focus on a reflection of the sun on a clear sky or stuff like that - here at home, a tiny reflection on a bottle standing 3 meters away from the lightsource is enough for the focus to blast to another galaxy - and I think the lit hair and shiny stuff on other test shots, forinstance a badge or zippers on bags, on the bicyclists or even approaching cars were the "culprit". It appears that way now that I look at the photos again.

However - the K-30 is not at all like this! and with K-30 I've often locked focus on lit candle lights when the environments has been so dark to be able to use anything else.

More stuff I noticed:
- Camera will fire no matter what shutter release setting I'm using - in both AF.S and AF.C and in single shot as well as burst mode - however, it can refuse if I've been tracking something (been holding AF button down) for a while and then want to take a photo before focus has been confirmed.

- If I track different targets then all of the sudden the focus can get stuck and I'll have to refocus - not a big issue, but really? In continuous focusing mode?

- Expanded AF seems to be as useless as always, though I haven't played with it much. What I've seen so far is the AF point just jumping randomly around, close to original point.

- Nitpicking here: the LCD display would be complete if it was able to see exactly which AF point has been selected and also whether AF point selection mode is on or off.


On the good side:
- I can be on AF.C and whatever shooting mode, hold the AF button, track and do a single shot - and often nail the focus, also while changing targets and taking a pic fast. It was a bit tricky with K-30.

- Low light performance is awesome - this was of most concern to me and the K-3 II delivers. I just tried with my K-30 and the 70-200 at 200mm. The K-30 couldn't lock and gave up on tons of targets. On others, also many, the lens hesitates before it has even started to focus - and then focus all the way out and in again.. and give up. All in all it's very sluggish and frustrating. It will miss targets or refuse to lock focus on stuff you'd think are bright and contrasty enough.

In fact, when I'm at weddings, the 70-200mm is the first lens to get swapped out once the light level starts to gets low.

With the K-3 II however, it's still snappy and I had to deliberately find tricky targets that would challenge the AF, such as my black LowePro bag. I was able to lock focus (properly) sometimes immidiatly and sometimes after few attempts - while focusing on the cloth, not some shiny metal stuff (that's cheating)

I think the fluke with AF is disappointing, but despite this and the camera not respecting shutter release settings, I'm all in all and at present time, still very satisfied - but only because of Focus Priority gives me the shots. If the problem persisted here too, I'd be angry and return the camera. But that's not the case and I'll repeat: I'm satisfied.
06-16-2015, 06:52 PM   #23
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QuoteOriginally posted by Zafar Iqbal Quote
Settings on camera:
1st. AF.C shot: focus priority
Action AF.C continuous shooting: focus priority
AF hold: off
- Expanded AF seems to be as useless as always, though I haven't played with it much.
My experience over the past two and a half years, shooting mostly BIF but also sports, is that your settings are robbing the K-3 of its ability to track. I agree with focus priority and continuous shooting. Try AF Hold HIGH and Expanded AF, and see the difference. Just make sure focus is locked on the target before you release the shutter, or you will have a string of misses.

Also, the 18-135mm almost never misses focus. Have you checked the calibration (AF Adjust)?

06-16-2015, 11:30 PM   #24
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QuoteOriginally posted by Zafar Iqbal Quote
Upon further testing, I've discovered that my Sigma 70-200 behaves different and the K-3 II might not be all it's supposed to be:

Lens used: Sigma 70-200mm f2.8 Macro HSM

Settings on camera:
1st. AF.C shot: focus priority
Action AF.C continuous shooting: FPS priority
AF hold: off

Results: Horrible - as in utter crap. The first series of photos (link to album down below) sums up the kind of photos I'd typically get.

I replicated this at a later time, with different light and different targets (cars).


Settings on camera:
1st. AF.C shot: focus priority
Action AF.C continuous shooting: focus priority
AF hold: off

Results: Much better results and appear to be better than K-30 - Framerate was obviously affected, which dropped down to (I'm guessing here) something like 4 fps. The second series in the album is an example with these settings.

Click to enter the album:



Upon even further testing here at home, I've currently concluded, that bad focus is caused by bright areas such as reflections and harsh light - but don't think I'm talking about trying to focus on a reflection of the sun on a clear sky or stuff like that - here at home, a tiny reflection on a bottle standing 3 meters away from the lightsource is enough for the focus to blast to another galaxy - and I think the lit hair and shiny stuff on other test shots, forinstance a badge or zippers on bags, on the bicyclists or even approaching cars were the "culprit". It appears that way now that I look at the photos again.

However - the K-30 is not at all like this! and with K-30 I've often locked focus on lit candle lights when the environments has been so dark to be able to use anything else.

More stuff I noticed:
- Camera will fire no matter what shutter release setting I'm using - in both AF.S and AF.C and in single shot as well as burst mode - however, it can refuse if I've been tracking something (been holding AF button down) for a while and then want to take a photo before focus has been confirmed.

- If I track different targets then all of the sudden the focus can get stuck and I'll have to refocus - not a big issue, but really? In continuous focusing mode?

- Expanded AF seems to be as useless as always, though I haven't played with it much. What I've seen so far is the AF point just jumping randomly around, close to original point.

- Nitpicking here: the LCD display would be complete if it was able to see exactly which AF point has been selected and also whether AF point selection mode is on or off.


On the good side:
- I can be on AF.C and whatever shooting mode, hold the AF button, track and do a single shot - and often nail the focus, also while changing targets and taking a pic fast. It was a bit tricky with K-30.

- Low light performance is awesome - this was of most concern to me and the K-3 II delivers. I just tried with my K-30 and the 70-200 at 200mm. The K-30 couldn't lock and gave up on tons of targets. On others, also many, the lens hesitates before it has even started to focus - and then focus all the way out and in again.. and give up. All in all it's very sluggish and frustrating. It will miss targets or refuse to lock focus on stuff you'd think are bright and contrasty enough.

In fact, when I'm at weddings, the 70-200mm is the first lens to get swapped out once the light level starts to gets low.

With the K-3 II however, it's still snappy and I had to deliberately find tricky targets that would challenge the AF, such as my black LowePro bag. I was able to lock focus (properly) sometimes immidiatly and sometimes after few attempts - while focusing on the cloth, not some shiny metal stuff (that's cheating)

I think the fluke with AF is disappointing, but despite this and the camera not respecting shutter release settings, I'm all in all and at present time, still very satisfied - but only because of Focus Priority gives me the shots. If the problem persisted here too, I'd be angry and return the camera. But that's not the case and I'll repeat: I'm satisfied.
On the cyclist example posted, I'm not surprised the AF struggled as there's really no areas of contrast for the AF system to work with. A black leather jacket and dark coloured trousers / skirt, coupled with what appears to be shooting into the light are really just setting the camera up to fail in my experience and opinion. The car example has more contrast, but you've again ahot into what looks to be a low angled sun which again robs the shot of contrast.

From these two examples, I'd be wary of drawing too many conclusions about the system being 'utter crap'. If you get similar results in decent light with a contrasty target, then I'd agree with you!

Simon.
06-17-2015, 12:12 AM - 1 Like   #25
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The K-3/K-3 II AF-C is complex and has a million options. It takes some practice to get results.

As audiobomber suggests, each type of subject - eg motor vehicle rally vs football game vs birding vs wedding reception - may require a different set of settings - for AF hold, for AF area etc.

This shouldn't be a surprise. You see this in the settings for other cameras - eg the Canon 7D2 has six different presets (or 'usage cases') in the menu for continuous AF that vary the settings for AF area and AF hold:

QuoteQuote:
Case6: For subjects that change speed and move erratically
Case5: For erratic subjects, moving in any direction
Case4: For subjects that accelerate or decelerate quickly
Case3: Instantly focus on subjects suddenly entering AF points
Case2: Continue to track subjects, ignoring possible obstacles
Case1: Versatile multi purpose setting
One could achieve something similar with the K-3/II by setting up a few UI/U2/U3 'User modes' for different action shooting scenarios.
06-17-2015, 05:11 AM   #26
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QuoteOriginally posted by rawr Quote
This shouldn't be a surprise. You see this in the settings for other cameras - eg the Canon 7D2 has six different presets (or 'usage cases') in the menu for continuous AF that vary the settings for AF area and AF hold.
Pentax should provide more detailed instructions on using the AF-C settings. We're all just working with trial and error.

Common sense would say no AF Hold for a BIF, where there is nothing in the foreground, but I tried it and had a dismal hit rate. The camera kept wandering off to the clouds or background scenery. Shooting a hockey game, it was incredible how AF Hold HIGH locked on a jersey, ignoring other players and the frames around the Plexiglas between the spectators and the ice.

I am 100% certain that single point AF will not track. Tracking means following your subject. If you are on Center Point AF and your aim wanders fractionally, the camera has lost the target. Relatively tiny AF points on the K-3 mean the target is tiny, and identified by colour and shape. Good luck keeping that little spot over anything that moves. Auto AF point modes will ensure something is in focus, but not necessarily your subject. The only viable tracking setting is Expandable Area, which allows the camera to lock on whatever target was in focus when the shutter was released. The only choice to make is Small, Medium or Large Area, depending on how hard it is to keep the subject in the active points area.
06-17-2015, 05:28 AM - 1 Like   #27
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QuoteOriginally posted by audiobomber Quote
Pentax should provide more detailed instructions on using the AF-C settings. We're all just working with trial and error.

Common sense would say no AF Hold for a BIF, where there is nothing in the foreground, but I tried it and had a dismal hit rate. The camera kept wandering off to the clouds or background scenery. Shooting a hockey game, it was incredible how AF Hold HIGH locked on a jersey, ignoring other players and the frames around the Plexiglas between the spectators and the ice.

I am 100% certain that single point AF will not track. Tracking means following your subject. If you are on Center Point AF and your aim wanders fractionally, the camera has lost the target. Relatively tiny AF points on the K-3 mean the target is tiny, and identified by colour and shape. Good luck keeping that little spot over anything that moves. Auto AF point modes will ensure something is in focus, but not necessarily your subject. The only viable tracking setting is Expandable Area, which allows the camera to lock on whatever target was in focus when the shutter was released. The only choice to make is Small, Medium or Large Area, depending on how hard it is to keep the subject in the active points area.
Predictive tracking for all cameras is defendant on data received on subject movement

Anyone using single point AF is not using any tracking capabilities of the camera they are purely dependent on AF speed of lens, AF systems and ability to hold target (1 slip and the camera will AF rack). As such if the camera is in FPS priority and the subject is moving faster than the linear speed (frame to frame 8Fps) then every shot will be OOF this is expected for all makes.

If you then switch to focus priority the frame rate will drop to the point the AF motor can keep up and the results will be bearable.

Switch to expanded and suddenly the camera will 'predict' subject movement this is when 'hold af' etc becomes important so the 'prediction' is accurate and won't overrun.

In summary
Never use FPS prioity and single point
Never confuse tracking and single point AF

Camera tracking performance is dependent on
1 accurate rate data form sensors in use (hold AF etc)
2 Processing power (for fast subjects limit 'expanded area')
3 decent phas variance of subject to background.

Without any further data the results posted above are indicative of the settings not the cameras performance.! He mentions when he tried expanded the AF points flickered about .... This indicates either target was not offering decent phase variance or the panning was not accurate both will give poor single point AF and not the greatest predictive AF. (the camera didn't have a clue what it was supposed to lock onto never mind track )

This is opposite to getting the best out of the K5 series where the 'predictive AF' is so primitive it's gain is lower than the performance boost from the cpu using single AF points fro most types of target.

The K3's predictions start to stutter the closer you get to head on so a expect there is some new logic in the k3ii to adapt to a growing/shrinking target in the Z axis rather than linear movement in the X-Y

Last edited by awaldram; 06-17-2015 at 06:02 AM.
06-17-2015, 05:37 AM   #28
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QuoteOriginally posted by audiobomber Quote
Pentax should provide more detailed instructions on using the AF-C settings.
I agree. The engineers must have a purpose for each K-3 / K-3 II AF option, and some lab and test experience that verified their end design too ('Yeah, that works!' ... )

Why not sit the engineers down with a technical documentation team to write up a 'Pentax K-3 AF guide-book' showing what each AF feature was designed to do, how to use all of the shooting options to best effect, and illustrate with some 'usage cases' from sports, wildlife etc.

Something like this Canon 7D2 AF Guidebook, except for Pentax, would be most useful. It would certainly help stumbling amateurs like me. Maybe even a few pros would find a 'Pentax AF guidebook' handy.
06-17-2015, 05:58 AM   #29
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QuoteOriginally posted by rawr Quote
I agree. The engineers must have a purpose for each K-3 / K-3 II AF option, and some lab and test experience that verified their end design too ('Yeah, that works!' ... )

Why not sit the engineers down with a technical documentation team to write up a 'Pentax K-3 AF guide-book' showing what each AF feature was designed to do, how to use all of the shooting options to best effect, and illustrate with some 'usage cases' from sports, wildlife etc.

Something like this Canon 7D2 AF Guidebook, except for Pentax, would be most useful. It would certainly help stumbling amateurs like me. Maybe even a few pros would find a 'Pentax AF guidebook' handy.
What you describe is exactly what used to happen in some parts of the computer industry

I'd travel to see the developers and discuss what and why each setting was in a BIOS I;d then converter them into 'layman' speak for the technical authors to use in the 'manual'

The reason we did three way split as the developers native language was not English and they were software geeks not 'engineers' so I as the 'engineer' had to bridge language gaps and hardware applicability.

Ricoh should do the same as both Nikon and Canon have lots of white papers and webinars explaining technical settings.

But in fairness their forums are just as full of miss set cameras being 'rubbish' so maybe wasted expense.
06-17-2015, 08:51 AM   #30
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QuoteOriginally posted by awaldram Quote
so maybe wasted expense
Probably as they attempt to move into 'pro' territory with the FF, new 'pro' DFA lenses etc, it would reward them to do more documentation, white papers, YouTube videos etc.

But they haven't done so even for the 645Z, so maybe not.

However Ricoh seem to do an OK job explaining the features of their photocopiers and how to use them , so it can be done for cameras too:

Feature guide videos
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