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05-07-2016, 12:48 AM   #61
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QuoteOriginally posted by tomO2013 Quote
.

Tonight I've done a side by side with a buddy with a D750 (set to release priority as well as well as focus priority) in single shot AFS.
In the ISO6400 and low light (possibly -2EV) the K1 was both noticeably faster and more accurate when both had their focus point set to center af point. Pentax with the DFA* 70-200 and Nikkor 70-200 F2.8 on the D750. Both wide open at F2.8.
Very interesting, Tom.





05-07-2016, 01:22 AM   #62
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A question to K-1 owners about AF when using AUTO exposure mode:

I notice that in the K-1 Pentax continues to highlight the contribution it's 'scene analysis system' makes to AF performance, especially tracking:
QuoteQuote:
Auto tracking with PENTAX Real-time Scene Analysis System
Supported by the PENTAX Real-time Scene Analysis System, the K-1’s Auto Tracking function accurately detects the subject’s motion based on various factors including color, then keeps pinpoint focus on the subject throughout the imaging process by automatically shifting the in-focus point.
The same system was basically there in the K-3/K-3II.

However what is new to the K-1 is this:
QuoteQuote:
Scene Analyze AUTO Much-improved accuracy, through the adoption of artificial intelligence technology
Supported by the PENTAX Real-time Scene Analysis System, the K-1’s Scene Analyze AUTO mode automatically optimizes exposure settings, and selects the most appropriate finishing touch for your subject. When using the optical viewfinder, it is also assisted by an algorithm that adopts the deep learning artificial intelligence technology, and makes an extensive analysis of a given scene based on the enormous volume of data accumulated from previous scenes.
Features5 | PENTAX K-1 | RICOH IMAGING


This 'Deep Learning' only seems to come into play if you shoot with the camera's exposure mode set to 'AUTO', and it seems to be mainly about exposure.

However it got me wondering: does this new set of camera 'smarts' make any contribution to AF performance? If you shoot the camera in AUTO mode, in conjunction with AF.C, does the K-1 AF.C tracking (for instance) work any smarter/better than if you just shot with, for example, Shutter Priority + AF.C? And how smart/accurate is AUTO mode in guessing shutter speed when shooting action?

Perhaps unrelated, I see from the K-1 manual that unlike previous Pentax DSLRs (save the 645Z), the K-1 dispenses with the AF.A (AF Auto) setting, which lets the camera choose which AF mode to use, according to the detected subject. This is probably because Pentax decided AF.A was 'non-pro' (similarly in Nikon, the D610 offers AF.A, but the D810 or D500 don't).

Last edited by rawr; 05-07-2016 at 01:29 AM.
06-15-2016, 07:42 AM   #63
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QuoteOriginally posted by tomO2013 Quote
Ok further update....

I think I've narrowed this weird low light behaviour down to PDAF focus settings in AFS. I'm convinced a firmware update will quietly update this. And I have confirmed behaviour on two shop bodies.
If you enable AF-S but have focus priority (even with center point) enabled the camera will focus to the point, hesitate frustratingly, then light up the focus point LED and release the shutter. This hesitation is crazy because of the aforementioned post with CDAF being faster in live view than OVF and PDAF.

Switching the PDAF and AFS to release priority and it's an entirely different ball game and makes a huge difference to focus performance and camera operation for event work. A half depress has the camera racing to focus and a full press has it light the focus LED and grab the shot. Even test shots going from infinity to close with a full depress of the shutter in this mode have yielded in focus and accurate shots. It's blazing quick with 24-70, 15-30, the 3 amigos and even 70-200.

Tonight I've done a side by side with a buddy with a D750 (set to release priority as well as well as focus priority) in single shot AFS.
In the ISO6400 and low light (possibly -2EV) the K1 was both noticeably faster and more accurate when both had their focus point set to center af point. Pentax with the DFA* 70-200 and Nikkor 70-200 F2.8 on the D750. Both wide open at F2.8.

For now I've my camera set to release priority and I'm suddenly really enjoy this camera a lot - it's focusing is pro-grade DSLR quick
Hi everyone !

I can't tell you how useful are these informations. Thank you so much @tomO2013, and all of you for this precious knowledge.

First it's important to say that I'm a very inexperienced photographer (I prefer to call myself a "picture taker") who had the opportunity to shoot (very) intensively. I did architecture during 2 months using a Fuji XM1, tried a Nikon D3100 for one month (portraits) and bought a K1 45 days ago in order to use my dad's old SMC Pentax M optics (SMC-K 50mm F1.4, SMC-K 35mm F3.5, SMC-K 75-150mm F4, SMC-K 35-70mm F2.8-3.5, Hisawa 200mm F4). I choosed a DFA 24-70mm F2.8 and a FA 50mm F1.4.

I started to shoot improvisation and dance shows for a month now (about 7 representations lasting 2 to 4 hours each) in low light environnement. I noticed that about 85% of my pictures were out of focus, at that point, I've already spent hours reading about focusing techniques, manual focus, focus traps, focus modes and focusing scenarios. I came to the conclusion that I had a bad focusing technique, and read more and more. I tried to fire faster, stop breathing, crouch, prone, use tripod and every focusing modes / selections possible on the K-1 even if I knew there weren't appropriate to the situation, always the same result: 85% percent of not-so-sharp pictures **BUT**, I' never tried to switch release / focus priority... As I can often verify it, gear won't replace a solid experience.

Yesterday I saw this post, set the shutter to release priority before the night show, equiped my big Īss 24-70, and.... SHARPNESS, sharpness everywhere. I took 500 photos as always during 2 hours telling myself that I'll be compelled with throwing 85% as usual but 85% of my pictures where focused, I could achieve quick focus locks with so little light, that I could finally stop worrying about focus and start composition work, so good, soo so good.

**Warning, what follows needs further testing and knowledge to be confirmed, these informations come from my experience which is way to small to be an assertion.** Then I used the FA 50mm and I struggled as usual (in low light only) to get an accurate focus. I checked every single photo I took with this lens yesterday and I only used cross type sensors to focus, in AFS SEL with one movable dot on static actors, **BUT** I never tried to use only the center sensor which I realise would have been a good check. In a few days, I'll have to shoot an event in a probably low and / or crappy light, I'll try to use different sensors while shooting fast and still on non moving actors, and see if I can point a systematic behaviour of the body coupled with the FA 50mm. It was a calibration problem

It may be important to add that I was never allowed to use AF light assist during shows for obvious reasons.

Last edited by Guillaume; 06-18-2016 at 12:53 PM.
06-15-2016, 08:39 AM   #64
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QuoteOriginally posted by tomO2013 Quote
I think I've narrowed this weird low light behaviour down to PDAF focus settings in AFS. I'm convinced a firmware update will quietly update this. And I have confirmed behaviour on two shop bodies.
If you enable AF-S but have focus priority (even with center point) enabled the camera will focus to the point, hesitate frustratingly, then light up the focus point LED and release the shutter. This hesitation is crazy because of the aforementioned post with CDAF being faster in live view than OVF and PDAF.

Switching the PDAF and AFS to release priority and it's an entirely different ball game and makes a huge difference to focus performance and camera operation for event work. A half depress has the camera racing to focus and a full press has it light the focus LED and grab the shot. Even test shots going from infinity to close with a full depress of the shutter in this mode have yielded in focus and accurate shots. It's blazing quick with 24-70, 15-30, the 3 amigos and even 70-200.

Tonight I've done a side by side with a buddy with a D750 (set to release priority as well as well as focus priority) in single shot AFS.
In the ISO6400 and low light (possibly -2EV) the K1 was both noticeably faster and more accurate when both had their focus point set to center af point. Pentax with the DFA* 70-200 and Nikkor 70-200 F2.8 on the D750. Both wide open at F2.8.

For now I've my camera set to release priority and I'm suddenly really enjoy this camera a lot - it's focusing is pro-grade DSLR quick
For "objects" I tend to use AF.C. But for people, where any such delay really matters, I tend to use AF.S. This is relevant to me.

QuoteOriginally posted by Guillaume Quote
Yesterday I saw this post, set the shutter to release priority before the night show, equiped my big Īss 24-70, and.... SHARPNESS, sharpness everywhere. I took 500 photos as always during 2 hours telling myself that I'll be compelled with throwing 85% as usual but 85% of my pictures where focused, I could achieve quick focus locks with so little light, that I could finally stop worrying about focus and start composition work, so good, soo so good.
Very interesting!

Now - what about AF.C? I currently run AF.C with both first and subsequent frames set to "Focus Priority".

Interestingly, by pressing the button down fast, (rather than pausing part-way down so that it can lock on before firing the shutter), I can cause it to fail to focus properly on the first frame about 2/3rds of the time. It tends to recover by the 2nd frame, and if not by the 3rd frame.So it isn't obvious to me what "Focus Priority" means with AF.C.

I must admit that I'm getting confused by this thread and my own experience. It is almost as though the settings mean the opposite of what they say!

06-15-2016, 05:59 PM   #65
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release priority? maybe that gets rid of that small lag you can get between the time it locks focus and fires?

Thanks

Randy
06-16-2016, 01:59 AM   #66
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As it was explained before by @tomO2013, the lag is created when a focus priority is set on and used with PDAF which, I suppose, can occur in both AFC ans AFS modes.

There is no reason to think that AF.C isn't affected by the bug as long as it uses phase detection (in the optical viewfinder) and you set it to focus priority. What you are describing @Barry Pearson is very similar to my problem: a misfocused pic that was taken with an option that only allows focused pics.

By checking again and again old shots, I noticed that bursts taken with live view (=contrast detection AF) were more focused than OVF ones. (at that time focus option in AFC were set to "'auto", as I haven't read this thread).

K-1 firmware seems to have a problem, turning the focus priority off make the body focus really faster in my case, and in low light, it seems to make it focus better but that may be just a feeling. I'm hoping for a very quick update from Ricoh.


edit: i just called Pentax support to warn them of this issue, they'll answer me quickly, I'll post here the results.

Last edited by Guillaume; 06-16-2016 at 02:18 AM.
06-23-2016, 11:38 PM   #67
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Any reply from Pentax yet?

Did you hear anything from Pentax yet Guillaume?

Brgds,
Ro
06-24-2016, 11:15 AM   #68
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QuoteOriginally posted by roksonne Quote
Did you hear anything from Pentax yet Guillaume?

Brgds,
Ro
Hello, not at the moment, my support ticket have been closed saying the'll get in touch quicly and my local Pentax seller didn't get any news from his tech support.

edit: 16 days ago I opened a support ticket, it has been closed without technical infomations, I asked for news and they said that communications with Japan (I'm in france) can be slowed down by the distance. Still waiting.

edit 2: one month and still no technical information provided


Last edited by Guillaume; 07-16-2016 at 01:07 AM. Reason: updates
09-22-2016, 09:53 AM   #69
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QuoteOriginally posted by biz-engineer Quote
A few more AFC tracking shots: a burst of 17 images with AFC tracking, 100% keeper (with trees and branches in the way of the target).
Best regards.
Hi
Congrats on a excellent hit rate. Would you care to advise on your settings and which lens used?
I have tried with the k3ii and 150-450mm combo. Settings AFC - focus priority. Shutter - focus priority and Focus hold off and tried low/medium. Tracking Red kites feeding. Not as successful as you though I might add.
09-22-2016, 01:10 PM - 1 Like   #70
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QuoteOriginally posted by rob2402 Quote
I have tried with the k3ii and 150-450mm combo. Settings AFC - focus priority. Shutter - focus priority and Focus hold off and tried low/medium. Tracking Red kites feeding. Not as successful as you though I might add.
I preset focus just beyond the actual focus distance range, the 150-450 has that feature. For example, if you shoot birds , you know the approximate size of your subjects and so you know the range of shooting distance to achieve reasonable image quality. When the bird takes off, I track without shooting, and as soon as the camera give AF confirm I star the burst. Until the AF isn't locked, don't trigger the shutter because it sucks processing power. When doing so, you don't waste camera processing power into blurred shots. Anyone can train to do this by just concentrating of AF confirm and repeating the same routine: 1) after each shooting sequence, always refocus the lens beyond subject distance 2) Activate AF tracking and concentrate on receiving AF confirm form the camera 3) burst shooting. I never use AF auto. I use AF point selection 9 points or more, with center point as primary focus point (that mean the camera use the center point to acquire focus and then track with adjacent points if the subject moves away from the center point).
09-26-2016, 04:31 PM   #71
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I just got mine last week, and my first impressions. I've been out early morning. I have shot with the K3 since it was introduced. I shoot long almost all the time, but use shorter lenses as well. The most experience is with the Sigma 500mm f4.5

It is better than the K3 all around. I found that the K3 would not fix or find proper focus and had to retry, but missed many many shots because of this. Slightly off focus. But would then focus perfectly if the light was a bit better or there was more contrast. The K1 hasn't done that to me. Static subject a good improvement.

I'm still working with the modes to find what works best, but first impression is that a spot is so tiny in the frame it is both very difficult all the while very useful for precise focus. I find that focusing on a specific detail seems to work better than the K3. Even 9 spot is tiny and hard to track a moving subject. The 33 point works well, but the latency of the mechanism causes things moving from and away at speed to be out of focus, but again, better than the K3.

Low light is better than the K3 in practice.

It is an improvement from my standpoint, but I can't compare to other brands. I'm getting shots that I missed with the K3 already. It could be better in tracking, and it is a challenge to follow something moving about quickly. It doesn't.
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