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11-03-2017, 11:57 AM   #16
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Predictive AF will increase the probability of getting focused shots if not all in focus.

11-03-2017, 11:57 AM   #17
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Thanks, everyone, for your your replies! Lots of good info and ideas here.

I never thought about turning off SR to improve shutter lag performance. It makes sense though, doesn't it? The SR mechanism is controlled by the camera's processor and the processor's computational power is finite. Why waste MHz clock cycles on SR that is usually negated anyways by the high shutter speed of 1/1000? I might as well put those clock cycles to use with the AF algorithm.

I may have been confused about Nikon's AF configuration re: closer vs. further subject focusing. It was probably something closer to the 3D tracking or predictive algorithms. Pentax needs something like that. Now I truly understand how "primitive" the C-AF system here is. Maybe this will be addressed in the next FF body?

Next year I will shoot at f/8 and hope the extra DoF will help counter the laggy shutter firing times.
11-03-2017, 03:30 PM   #18
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Take one of your User Configuration slots and setup the following settings:

Menu 1
--Phase Detection AF
----AF Mode: AF.C
----AF Active Area: SEL
----AF.S Setting: Focus Priority
----1st Frame Action in AF.C: Focus-priority
----Action in AF.C Cont.: Focus-priority
----Hold AF Status: Off
Menu 2
--Crop: FF
--Image Capture Settings
----File Format: RAW
----JPEG Recorded Pixels: XS
----JPEG Quality: 1-star
----RAW File Format: PEF
----Color Space: AdobeRGB
--Dynamic Range Settings: All Off
--Noise Recution: All Off

This will remove almost all of the lag issues you are facing. It won't remove the miss firing of the focus though.
11-03-2017, 05:46 PM   #19
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Why PEF format?

11-03-2017, 06:02 PM   #20
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QuoteOriginally posted by UncleVanya Quote
Why PEF format?
And why bother with JPEG settings when you are shooting RAW?
The only JPEG that gets created is a small preview within the RAW. I doubt that would be impacted by any camera JPEG settings.

And if one simply wants the quickest AF performance, make all your AF.C or AF.S settings Auto, or the defaults. And make sure your metering is set to Multi-segment.

Quickest speed step is to just set the camera mode dial to 'Auto'. It turns on some extra camera intelligence, and works really well for AF, if you don't need to take control over certain AF and exposure behaviours..

Last edited by rawr; 11-03-2017 at 06:16 PM.
11-03-2017, 07:11 PM   #21
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QuoteOriginally posted by UncleVanya Quote
Why PEF format?
I was struggling with a lag that was very significant. I chronicled it in this post: Forum Post
I started turning of the SR, NR and other settings and still no affect of the significant delay. I even tried Shutter priority. You can read more here.
Like I said there is a lot of woo-woo. You can see other settings here.

QuoteOriginally posted by rawr Quote
And why bother with JPEG settings when you are shooting RAW?
The only JPEG that gets created is a small preview within the RAW. I doubt that would be impacted by any camera JPEG settings.
I then went back to factory settings and after reading beholder3's writeup, I noticed the small section on JPEG settings.

So I went back to factory settings and tuned the JPEG settings down and wrote about my success here. I had suddenly removed the lag between autofocus and shutter release.

It turns out that the JPEG that is embedded into the RAW isn't some small JPEG, but instead the JPEG settings is used to generate this image.

My next focus was to test AdobeRGB to see if that would be be ok. And I had success and wrote about it here.

For each test I took no less than 50 to 80 shots. I would change one setting and then take another 50 to 80 shots. I ended up with over 2000 shots when I ended with those final settings.
At that point I was satisfied with the results and I was tired testing. I had reached a satisfying result and stopped. The rest of the autofocus problems were related to the predictive algorithm of the K-1. Which is not great. Switch on Shutter Priority and you take several sequence shots and you will get to know the algorithm's results.

I can tell you that Shake Reduction adds almost no noticeable delay. Then again why have it on for action shots, which will have shutter speeds above 1/500?

QuoteOriginally posted by rawr Quote
And if one simply wants the quickest AF performance, make all your AF.C or AF.S settings Auto, or the defaults. And make sure your metering is set to Multi-segment.

Quickest speed step is to just set the camera mode dial to 'Auto'. It turns on some extra camera intelligence, and works really well for AF, if you don't need to take control over certain AF behaviours..
I don't think Auto settings gives you the most control. At least with the settings above, you could develop a technique of achieving shots like these:
(I didn't process these because I wanted to display them as close to how the camera captured them)

Or this shot:


Getting the focus on the eyes with a small DOF, on a Z-Axis moving target, is not that easy. After 2000 shots of practice, I have about a 10% (max) success rate at achieving these shots. I don't know how Auto settings would be able to do this, unless it is luck.

I hope the information is helpful.
11-03-2017, 11:04 PM   #22
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QuoteOriginally posted by Jeffvan Quote
After 2000 shots of practice, I have about a 10% (max) success rate
Surprising. Not my experience.

If you are interested in scrutinising focus, a tool that is worth exploring is the geeky but useful Fastrawviewer by Iliah Borg. Amongst other features, it has several Focus Peaking displays:

About | FastRawViewer

A tool that we are all missing, however, is a RAW or JPEG viewer that shows us the active focus points in an image. They exist for Nikon and other cameras, but I haven't seen one that works with Pentax cameras after the K-5/K-x.
11-04-2017, 12:12 AM - 1 Like   #23
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QuoteOriginally posted by rawr Quote
Surprising. Not my experience.

If you are interested in scrutinising focus, a tool that is worth exploring is the geeky but useful Fastrawviewer by Iliah Borg. Amongst other features, it has several Focus Peaking displays:

About | FastRawViewer

A tool that we are all missing, however, is a RAW or JPEG viewer that shows us the active focus points in an image. They exist for Nikon and other cameras, but I haven't seen one that works with Pentax cameras after the K-5/K-x.
To clarify going forward, when I refer to action shots, I mean subjects moving toward or away from the camera (Z-Axis).

I actually created an action in Photoshop that overlays the measured area of the center focus spot. Then I examined if that area was in focus. I will attempt to elaborate: My 10% (max) accuracy is getting the focus to land on the eyes, which involves getting your aim dead on with a very small DOF, and this is on a good day (good contrasting lines). Measuring the actual accuracy in the center spot, well that can go higher. My response, that included the 10%, was directly to the concept of using the Auto settings, which in many cases would not place the focus on the eyes, or where you would like it, with the small DOF. My point was that if you wanted to hit a specific focus with a very small DOF, on an action target, you could expect about 10% accuracy; with practice using spot focus with the settings I listed above. Sure, if you want the whole subject in focus, increase your DOF and your accuracy could easily jump to 40%. I have seen many people post their fantastic shots (low res), which shows how they did achieve such a shot. But: What we need is a sequence of shots, to actually measure the accuracy rate.

Once I became critical of what was actually in focus, using the action to outline the center spot area, I noticed that the accuracy on the K-1 is not as great as you might think. On a high contrasting subject moving towards you, I could reach a 40% accuracy. But even on a bright day, with a different sun angle, it could quickly drop to 20%.

I have hoped others would duplicate similar tests, just to get some more data. A useful data would require having a subject move towards you, while you have an extremely small DOF and taking a sequence of shots with a center spot focus. Then measure the area of the center spot and actually see how many of the shots have that area in focus. If a piece of software could do this, then great! But that is what I did with 2000 shots. And when you become critical of the results, the accuracy can vary from 10% on bad contrast subjects to 40% on ideal setups. So the task of doing these tests are very time consuming and tiresome.

Now my critique of my own method: If you know your subject and you can setup your shot, of course you can go far beyond 40% accuracy. Increasing your DOF, would immediately result in better accuracy.
But keep in mind my aim was to find the best settings for the K-1 (I did stop early, since I didn't test DNG files, but I was exhausted of doing these tests). Now for the horrible part: Taking out our Nikon D3000 resulted in a 40% accuracy using the same methods, the very first time. You can do action shots with the K-1, but it will require mastering the K-1 auto focus system. Which, on the plus side, could make anyone a better photographer. If action shots are a large part of your focus, then consider your cell phone camera as an alternative. If you want that very shallow depth of field, then maybe a dedicated action camera is a better solution.

The reality is, that I really don't take a lot of action shots. So for all the shots I do take, the K-1 is a beast and always performs!
I hope this doesn't seem negative. I am trying to provide honest information.

11-05-2017, 03:44 PM   #24
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The lens seems to make a big difference to AF performance too. DFA 28-105 and *70-200 are far more reliable than the DFA24-70 and the L31, for example.
11-05-2017, 07:46 PM   #25
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QuoteOriginally posted by Dericali Quote
The lens seems to make a big difference to AF performance too.
Very true. Certainly for AF speed, and perhaps accuracy.
11-06-2017, 06:34 AM   #26
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I have observed that my 24-70 has a problem with being able to read depth properly. E.g. it doesn't refocus between objects that are say 20cm apart on the z-axis, whereas the DC motored 28-105 seems to be snappier and more accurate. I have had my lens calibrated on the camera so the settings are okay.

In general, my problem with Pentax AF is not on hitting fast-moving objects in bright sunlight, but more just not accurately focusing on portraits, especially in soft light.
11-06-2017, 07:43 AM   #27
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QuoteOriginally posted by Dericali Quote
The lens seems to make a big difference to AF performance too.
It makes a lot of a difference even when comes to colors and sharpness also, not only when comes to af performance. See the 3 images from below. The first one was taken with a Sigma lens on 5D Mark IV. The other 2 images were taken with Canon L lenses on the same body. The image taken with the Sigma lens has the focus on the eye which is what I wanted, but I'm not very enthusiastic with the details and the colors, at least not when I look at the second image, taken with a Canon L lens.

The third image make look easy to take, but it was not. I was depending on the:
1. right settings of the af
- I was using Expand Af area with one main af point and other 4 surroundings activated; I tend not to use the Expand Af area with one main af point and other 8 surroundings activated because it cover a much wider area than I want
- focus priority for the 1st image
- Case 3 (from the 6 cases available) - Instantly focus on subjects suddenly entering AF points; I customise the case 3 even further in order to match my shooting style

2. the option to change:
- one point Af to expand Af area; I was shooting in portrait mode with single point Af activated but I've customise the camera so that when I turn it from portrait mode to landscape mode, the af changes also from single point Af to Expand Af area with one main Af point and other 4 surroundings activated
- the Af from Af-S to Af-C (Ai servo) on the fly; I've customise the DOF button to change the Af at a single press of a button.

I was shooting the bird which initially was sitting on the ground in Af-S with a sigle Af activated but it suddenly took off in a fraction of a second; I only had time to make 3 moves:
- turn the camera from portrait mode to landscape mode
- while turning the camera I was changing the Af from Af-S to Af-C with a press of a button
- press the shutter and take one picture; I couldn't take another one because the bird came to close for the lens to focus

3. af speed of the Canon lens; with a Sigma 150-600mm I don't think I would have had a chance to take the image

4. the shooting technique - it may sound silly, but from my balcony I see a lot of pigeons flying around and I'm improving my technique by shooting pigeons with tele lenses at widest aperture; I often use the panning mode of the stabilisation with subjects that doesn't move quickly in any direction

Once you find the best settings for af-c from your camera, then all depend on:
- the technique used, which fortunately can be improved with a lot of practice
- lenses used; good lenses offer great results even with the aperture wide open
- how you customise the camera to be able to react in a fraction of a second to subjects that change speed and move erratically

Someone mentioned above that the keeper rate with his Pentax gear was close to 10% when shooting action. It seems way too low, even if I know that Pentax lack behind competition in terms of af-c. I don't have experience with K1 when comes to tracking, but with K-3 II that I had I was getting 45-55% of images in focus in action shots and I'm sure that with the new lenses the keeper rate would have increased with 10-15%.

I hope that the image can be seen properly once you zoom on it. If not, try to download it.


Last edited by Dan Rentea; 11-06-2017 at 07:55 AM.
11-06-2017, 08:14 AM   #28
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QuoteOriginally posted by Dan Rentea Quote
4. the shooting technique - it may sound silly, but from my balcony I see a lot of pigeons flying around and I'm improving my technique by shooting pigeons with tele lenses at widest aperture; I often use the panning mode of the stabilisation with subjects that doesn't move quickly in any direction
That might be one of the best tips I've read on the forum. The idea that practice is just as important as gear. Way too many think the camera should be able to do all the work for them. Your technique has to be good enough to give the camera a chance, no matter what you shoot. If you can find a place to practice where the images are not critical and you aren't sweating bullets, you are way ahead of the game.

It's telling that hunters spend time shooting targets because they know they have to, but so many amateurs think they should be able to get results without practice.

Anyone can buy the same camera you do. If you want to stand out, you have to work harder than the next guy.
11-06-2017, 05:03 PM   #29
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I finally got out and took some train pictures today. It was bright and sunny. The trains weren't moving fast, but I was only able to get off a couple of shots because the focus wouldn't lock in. I have changed my settings to the one recommended by Jeffvan and will give it another try tomorrow. The pictures that I was able to take were absolutely sharp and clear. They are far cleaner than pictures I have taken with other cameras. The dynamic range is far grater than expected. The biggest challenge is for me to get the camera to focus on the locomotives as well as the Nikon's. I have seen excellent train pictures taken by K-1 cameras, so I am hoping I can get the auto focus to do what I need it to do.
11-07-2017, 03:14 AM - 1 Like   #30
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QuoteOriginally posted by normhead Quote
That might be one of the best tips I've read on the forum. The idea that practice is just as important as gear. Way too many think the camera should be able to do all the work for them. Your technique has to be good enough to give the camera a chance, no matter what you shoot. If you can find a place to practice where the images are not critical and you aren't sweating bullets, you are way ahead of the game.

It's telling that hunters spend time shooting targets because they know they have to, but so many amateurs think they should be able to get results without practice.

Anyone can buy the same camera you do. If you want to stand out, you have to work harder than the next guy.
Without practice no theory will help us in the field. I heard a lot of excuses such as:
- I don't have time to go out and shoot
- I don't want to waste shutter counts on my camera by shooting everything that moves
- I don't own expensive lenses and I don't own tele lenses
- etc.

Well, I don't have time either to go out and shoot birds as much as I want, I don't buy either a 300mm f2.8L lens because I don't justify spending 6.000$ on a lens that I use 15-20 times a year. I preffer to rent expensive lenses when I want to have fun and costs me 50$ for 2 days. But, I'm not going out either and blame each time the camera or the lens for my lack of practice. As far as I'm concerned, you don't even need a camera to practice. I often use a simple metal tube (it is 40cm long, it has a diameter of 12cm and it weights around 2,5kg) and I look through the hole of the tube at the pigeons, sparrows, starling and other common small birds that live anyware and I try to keep them in the frame as long as posible when they fly. Doing that once a week helps me to be prepared when I go out and shoot birds.

So yes, practice helps me to understand a lot of things regarding my camera, helps me improve my reaction speed and so on. To me, if the percentage of missed focus images is under 45-50% with a K3/K1, I tend to believe that:

- the camera/lens is not the primary responsible for that low percentage
or
- the shooting conditions are to bad for the camera/lens to handle (a slow lens in some bad conditions can lead to low percentage of images in focus)

Last edited by Dan Rentea; 11-07-2017 at 03:21 AM.
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