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09-17-2017, 06:44 AM   #76
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I will give those options a try. My only concern with the 33 AF points, is that the focus won't be on the dog but somewhere else.

I will do another test this week with some different settings.

09-17-2017, 06:59 AM   #77
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QuoteOriginally posted by angerdan Quote
Menu �� Tab 1 Group Phase Detection AF
AF Mode: AF.C
AF Active Area: Expanded Area AF (L) or as alternative AUTO (33 AF Points) 1st Frame Action In AF.C: Focus Priority Action In AF.C Cont.: Auto Hold AF Status: Medium
Have you actually tried those settings? AF hold set to medium would actually make the AF worse under these conditions.
The wide area 33 AF point setting is slower than the single point or the 9 point. Ricoh is either using very slow hardware or very poor algorithm..... or both.

QuoteOriginally posted by Jeffvan Quote
It made me think that the auto focus is slow
Yes. There is noticeable latency in the system. It is possible to shoot moving action like a race where you have predictable movement, but for dogs running dead at you, the AF is going to struggle compared to that of Canon, Nikon, Sony, Fuji, Olympus, or Panasonic. It is better than Phase One or Hassy though. Part of the problem is the D-FA* 70-200mm is not a really fast focusing lens. My Sigma 85mm F/1.4 is my fastest focusing lens and is noticeably faster than my D-FA* 70-200mm. I believe the 28-105mm is also pretty quick, but I have only used it once.
09-17-2017, 10:10 AM   #78
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QuoteOriginally posted by Jeffvan Quote
My only concern with the 33 AF points, is that the focus won't be on the dog but somewhere else.
I will do another test this week with some different settings.
There are still some sunrays left this week
Good thing to know about AF is that it will focus on the closest object regarding to dog racing.
So if you activate all AF points, the nearest dog will be in focus with its closest to camera body part. Since you're shooting with f6.3 aperture, dof will include sharpness of the eyes.
09-18-2017, 09:49 AM   #79
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Another 390 shots down, with some new information.

33 AF is a no go. The closest object isn't always the target that is selected. And now that I go through a small thought experiment, that wouldn't make sense either. The grass in the fore ground, would be the closest and would be the object focused on the most, if that method was true. What I did find with the 33 AF point focus, is that the focus was all over the place, until the dogs were real close and took up most of the area. But the system was still plagued by an issue that I will discuss in a bit.

The settings I found to work the best so far:
Menu 1:
--Phase Detection AF:
----AF Mode: AF.C
----AF Active Area: Spot or SEL (BUT NOT SEL S, SEL M, or SEL L)
----AF.S Setting : Focus-priority
----1st Frame Action in AF.C: Focus-priority
----Action in AF.C Cont.: Focus-priority
----Hold AF Status: Off
--Contrast Detection AF
----Contrast AF: Spot (Bottom one)
----Focus Peaking: Peak On (doesn't matter for this)
----Contrast AF Options: Focus-priority

I read in some of the discussions that AE Metering might help in focus detection. In my tests so far it plays no role of any kind. In the 390 shots, I tried different values of the AE meter, and found no difference, in fact the AE spot meter might be better (not based on tests), since less area is evaluated in making the calculations for exposure. My next test session will be completely manual instead of TAv, which might have a role to play in what I discuss below.

The other item mentioned, was that the 70-200 lens might be too slow to keep up with the dogs. This might be true, but I am very doubtful of this, since the lens can go from infinity focus to 2 meters in under a second. The Hyper focal distance being 347 meters in my setup, would mean the lens can go from 347 meters out to 2 meters in under a second, which is faster than the dogs.

With the setup above I was starting to get some better shots, but there was a more consistent issue that plagued the setup the whole time. Here is what I was able to surmise as the problem:
The autofocus is actually spot on most of the time, but there is a significant delay between the autofocus acquiring a target and the timing of the shutter. This was made evident with sequences such as below. Watch the focus travel from the tail of the dog to the face of the dog as the dog transitions from jogging to laying down.









Some additional considerations to take into account: The dog was not running fast at all. This would be the pace of a slow jogger at the time that the sequence started.

I need to take another sequence of shots where I go completely Manual to determine where the issue is. But I can already state that someone walking towards you with the aperture wide open (small DOF) will result in very poor results.

So to summarize what I am experiencing:
The autofocus is dead on target most of the time (95%), but the delay between focus acquisition and shutter firing is too slow to keep up with an object moving towards you, unless you go to a big DOF. There were a few focus jumping events but it was much better than before.

All shots were on a tripod and I did try shots with Shake Reduction off and on. So far I like the Shake Reduction on with tracking some of the targets. It helped remove motion blur with tracking targets at 1/1600. BUT I want to do a more definitive test with just this feature.

I also want to do tests with all the NR features off as well as the Highlight and Shadow corrections off. They should only be in effect after the image is in the buffer, but I will try testing this.

For all those that find the Autofocus fast, you might be correct, but the issue might be the time delay of the shutter firing. I would love to see if anyone else can replicate what I have found, since it could just be my setup.

I welcome any input on what I might want to consider, the next time I head out.

09-18-2017, 12:15 PM   #80
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I would not be uding a tripod for this situation. I would be in AFC using back button mashed down and my shutter finger shooting at will.
09-18-2017, 12:27 PM   #81
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QuoteOriginally posted by jbinpg Quote
I would not be uding a tripod for this situation. I would be in AFC using back button mashed down and my shutter finger shooting at will.
I am using AFC with back button AF down and keeping the spot on the head. I will do short bursts of shutter on continuous shooting while holding down the back AF button.

The tripod is to reduce any shake on my side while I am tracking. A lot of people in wild life photography will recommend a tripod for these kinds of setups. Could you enlighten me as to why you think a tripod should not be used?

Have you attempted anything similar to what I have done (target moving towards you or away), with better results? I would love to know, it could be a problem with my setup. What are your AF settings?

Thank you!

Jeff
09-18-2017, 02:02 PM   #82
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If you do a search through the many AF threads here, you will see that technique seems to have a great deal to do with AFC on the K-1. I shoot the same way as you have been doing in your testing: handheld, AFC, center spot, all in-camera corrections turned off, keeping center spot on intended point of focus as best I can. One thing I try to do is to keep SR off if I have a high enough shutter speed. Just one less thing the onboard CPU has to do. My go-to lens is a DA*300/4 with or w/o the 1.4 RC. I find that if you manage to keep the center spot on your point of focus then results improve greatly.

Jack
09-18-2017, 05:05 PM   #83
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QuoteOriginally posted by jbinpg Quote
If you do a search through the many AF threads here, you will see that technique seems to have a great deal to do with AFC on the K-1. I shoot the same way as you have been doing in your testing: handheld, AFC, center spot, all in-camera corrections turned off, keeping center spot on intended point of focus as best I can. One thing I try to do is to keep SR off if I have a high enough shutter speed. Just one less thing the onboard CPU has to do. My go-to lens is a DA*300/4 with or w/o the 1.4 RC. I find that if you manage to keep the center spot on your point of focus then results improve greatly.

Jack
Thank you for replying.

The only two things I noticed, that is different between my approach and your setup, is the tripod and the lens. Everything else I do, is the same as yours or I have at least tried extensively. I did several shots without the SR while on the tripod and I notice the difference in the effect, but there is no difference in the Autofocus results, but I would like to dedicate a whole session towards this, since I can increase shutter speed and see if I get better results. So the SR item will go back on the todo list.

I still don't understand what the tripod would change. I am really trying to isolate the variables here, so excuse my ignorance. I have read the other AF posts and a lot of the information is great, but some of it is interwoven with some serious woohoo. If we can identify the variables then we can isolate for them and try to figure out what is a good setup.

I would love to see how your 300/4 lens does with someone running towards you at f/4.5. I haven't been able to isolate the lens as a culprit in this situation and I would greatly appreciate any tests you can do with your setup. Pictures would be great!

So far I surmise that the problem is a delay after autofocus acquisition and before shutter firing. I am thinking of maybe building a testing rig that would allow me to measure the delay in a much more controlled manner. Then I could quantify the different features more accurately and see what works best. But that will take time to build.

I have to admit, my heart sank when I noticed $400 to $800 cameras (from 2008) out performing, in the autofocus scenario, compared to my K-1 setup.

Thank you!

09-18-2017, 07:11 PM   #84
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QuoteOriginally posted by Jeffvan Quote
So far I surmise that the problem is a delay after autofocus acquisition and before shutter firing. I am thinking of maybe building a testing rig that would allow me to measure the delay in a much more controlled manner. Then I could quantify the different features more accurately and see what works best. But that will take time to build.
You will find there is latency in they system. How much? I don't know, but your results are consistent with what has been posted before. By the time the AF locks and sends the signal to release the shutter the subject has moved out of focus. Even with a toddler walking towards you, you will get similar results. I keep hoping Ricoh will improve this with better firmware, but so far nothing.
09-18-2017, 07:35 PM   #85
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@Winder Thank you.
09-18-2017, 08:00 PM   #86
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Nothing new here. We all know Z-axis AF.C is the weak spot. Everything else can be learned. Pentax AF (using FA*300 & D FA 28~105) is quite good in my uses, including small children.
09-19-2017, 10:32 AM   #87
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I'll mirror most everyone's response here and say the K-1 is pretty good for static subjects. In fact i think it's typically more accurate once it locks as compared to my previous setup (Nikon DF).

For action photography it's a crapshoot. It seems to do ok with left to right motion, but anything coming towards you or moving away causes it to struggle. Still though i've been able to get in focus shots maybe 1/6 or so with those sorts of circumstances.

I think it's honestly a perfect camera unless your main style of photography involves lots of motion.
09-19-2017, 08:41 PM   #88
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I'm a bit bemused ... I'm an amateur casually pointing my handheld K-1 with a Tamron 70-200 (not some expensive sports lens) at a runner.

This the entire sequence, the ninth was cropped and processed for my social media. She is not on wheels, she is bobbing up and down too. If I can do it, anyone can.

On this forum we have plenty of Pentax shots of runners, cars, aircraft, motorbikes and galloping horses.









































09-19-2017, 11:03 PM   #89
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QuoteOriginally posted by clackers Quote
I'm a bit bemused ... I'm an amateur casually pointing my handheld K-1 with a Tamron 70-200 (not some expensive sports lens) at a runner.

This the entire sequence, the ninth was cropped and processed for my social media. She is not on wheels, she is bobbing up and down too. If I can do it, anyone can.

On this forum we have plenty of Pentax shots of runners, cars, aircraft, motorbikes and galloping horses.
Thank you, clackers.

I am excited to see these pictures. I noticed that you had a massive DOF.
Just a guess, but I would say the F-stop is between 7.1 to 9.

I have researched some pictures of birds in flight, last night, and focused quite a bit on those flying towards the camera, or away from the camera. One thing I noticed is that the pentax cameras consistently had to have a significantly higher F-Stop values.

I also located this research by DPReview: Special K? Pentax K-1 Review: Digital Photography Review

I have been able to locate more information on what the problem is. The issue is the lag time between autofocus acquisition and shutter release. This link has actual measurements of the problem: Pentax K-1 Review - Performance

Here are some sample pictures of 2008 cameras shooting at low F-Stops, being able to achieve this:
flight | The Cattle Egret for me are te fastest flyers.They ? | Flickr
Owl in flight | While visiting a bird show, this owl came fl? | Flickr

And here are some pentax equivalent pictures:
Flight | Phil Morgan | Flickr
_IMG7380. 300 mm. 1-1000 sec at f - 8,0. ISO 100. 0 EV | Flickr

One great shot I found of a K-1 was this one: The bird was about to land, so very little forward speed. By my calculations the bird was between 20 and 25 meters away and the DOF was about 1.1 meters. I wonder if there was a nest below the bird and he just setup the focus before hand (which is one of my ideas as a work around).
Undercarriage Down! | Peter Wood | Flickr

I agree, you can get magnificent shots with a large DOF. And it is an effective way to overcome this flaw. I was hoping to get some nice action shots with some great separation between the subject and background.
For those hoping to take shots of someone walking towards them, with low F-Stop values, they will be quite frustrated. I am sure it is a rare scenario and you can always just start pushing the F-stop value higher until you get what you want. But it is helpful to know why you need to do so.
I am still happy with my K-1, but I wish it didn't have this limitation.
For bird pictures, on a bright day, there really is no difference, since the distance between the background and the subject would yield similar results with the higher F-stop values. But it does eat away from the available shutter speed and ISO combinations, you could have had.

Thank you everyone, for your input. I didn't know what the problem was at first, since it manifested it self in some very strange ways. I can now live with it, now that I know what the issue is. I think I have a few workarounds for different situations.
09-20-2017, 03:42 AM   #90
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QuoteOriginally posted by Jeffvan Quote
Thank you, clackers.

I am excited to see these pictures. I noticed that you had a massive DOF.
Just a guess, but I would say the F-stop is between 7.1 to 9..

That sequence is in fact at f4.5, Jeff, so if I can do it, you can do it.

The focal length is 140mm at the furthest, 78mm as she runs past me.

And if you're shooting as close as I was with as long as that lens, yes, on full frame you're really dicing with Depth of Field.

With a small dog, I think you're going to struggle to keep the AF point over the eyes... it will be very easy for the tail or the collar to be the strongest line under the point at a given time.

Below you can see that f5.6 with the same K-1 and Tammy 70-200 f2.8 isn't deep enough to get all three riders on full frame at 130mm or so - it would need to be more f8, even f11.

The cyclists are approaching my camera at around fifty kilometres per hour (30 mph or so).


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