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04-10-2019, 08:44 AM   #151
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QuoteOriginally posted by stevebrot Quote
The answer is that Sony does not do it with the AF system. They do it by real-time frame analysis after initial focus has been attained.

Steve
So, they do it after AF, but before shutter is activated, requiring MILC technology?

04-10-2019, 09:43 AM   #152
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QuoteOriginally posted by reh321 Quote
So, they do it after AF, but before shutter is activated, requiring MILC technology?
All recent DSLRs come with a built-in MILC. Live view on a DSLR such as the K-1 can do face detection and AF-S on faces. Doing tracking AF on faces requires a sensor with PDAF pixels (the 36 Mpix sensor in the K-1, D810, and a7R lack this).
04-10-2019, 09:46 AM - 1 Like   #153
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QuoteOriginally posted by BigMackCam Quote
hat's one of the very problems I used to have, Bill... rolling the camera to the right.
...and a likely cause of user questions regarding "tilted" sensor.

I tend to drop my right shoulder during shutter press due to an old shoulder injury and nothing working correctly with that arm anymore. The shoulder is made of metal and plastic now and with time, perhaps the muscles will fall in line with the fix.


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04-10-2019, 09:50 AM - 1 Like   #154
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QuoteOriginally posted by BigMackCam Quote
That's one of the very problems I used to have, Bill... rolling the camera to the right. It's visible in a number of my earlier shots I still have to check myself occasionally on my right hand grip, as every now and then I drift back to my old ways, but it's happening less and less often
I have a sort of mental checklist that I go through. Itís pretty automatic, but itís something to do while waiting for the shot to enter the viewfinder. If you have a part of your technique that is causing problems, add it to your checklist.
For the right hand death grip, something I have cured myself of, I made a point of relaxing my right hand to the point of the camera being lose in my hand once I had it cradled in my left hand and then grabbing it again. Eventually I got past it. This was when I was shooting with my F2s, which was a pretty sizeable rig.
My solution now more and more involves a tripod. With the D FA* 50/1.4 Iíve become something of a sharpness freak again, and Iím handholding quite a bit less now.

04-10-2019, 10:50 AM - 2 Likes   #155
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QuoteOriginally posted by BigMackCam Quote
It actually took me quite a few years of shooting before I even realised I was doing this. It's only in the last four years or so that my lens hand takes most of the weight, while my camera hand has a relatively gentle hold on the grip, with shutter activation an equally gentle squeeze. It makes a huge difference in steadiness, makes tracking easier, and is far less tiring.
As Dan stated, everyone has their own unique approach. If the three of us shot the same exact scene under the same conditions and virtually at the same time, there would be three different renditions. That's why when I read an article about how a photographer was tired of shooting the same old as he quipped "tourist traps", I disagreed. My take on let's say the Eiffel Tower may be different than someone else's. Photography is as infinite as the people taking the pictures. I am often reminded of my old Evidence Professor in law School. He was talking about types and credibility of evidence and in cross-examination tactics and he stated (I'm paraphrasing now) that when you have multiple witnesses to an event, each one will be coming from a different perspective. It doesn't mean they are lying necessarily particularly if they were an eyewitness, it means that you must scratch the surface of their testimony.
In my example, when you 'scratch' the surface of each photographer's EXIF data, it will reveal their perspective. That's why I continue to shoot city skylines and coastlines. Done before? Certainly....Done like me? Not a chance...That's the real joy of photography for me: the rugged (well I'm stretching it a bit there) individualism.
04-10-2019, 11:32 AM   #156
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QuoteOriginally posted by photoptimist Quote
Doing tracking AF on faces requires a sensor with PDAF pixels (the 36 Mpix sensor in the K-1, D810, and a7R lack this).
My K-3 also lacks this, but is able to track a face quite nicely in live view. What it is not able to do is continuous AF while tracking in live view. Some have claimed that Pentax cameras having the 86K RGB exposure meter should be able to do face priority PDAF (ala higher-end Nikon products) with a simple firmware update.* Whether that is possible and how well it might work with Pentax's limited number of AF points is difficult to say.


Steve

* The usual evidence given is that the FaceDetect tag (ExifTool label) in the makernotes metadata has a value of 1 0 (taken to mean Face Detect = ON with zero faces detected) for non-live view photos while live view not using face detect shows 0 0 (Face Detect = OFF with zero detected). The same is true even with AF turned off.
04-10-2019, 11:50 AM - 1 Like   #157
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QuoteOriginally posted by Merv-O Quote
My take on let's say the Eiffel Tower may be different than someone else's. Photography is as infinite as the people taking the pictures.
So very true. I live in a part of the world that is rich with cliche' calendar pictures.* One can literally walk up, stand on the dot, and get exactly what was on the cover of the July issue of Sunset magazine. It truly takes some effort to avoid duplicating the standard shot, but there is a sense of achievement in doing so in a pleasing way.


Steve

* Within a days drive: Mt Shuksan from Picture Lake, Liberty Bell Mtn., Mt. Rainier from Reflection Lakes, Snoqualmie Falls ala Twin Peaks, Mt. St. Helens from Johnson Ridge, Multnomah Falls, Cannon Beach, Smith Rocks, Painted Hills (Oregon), multiple spots on the Oregon Coast, and Crater Lake, to name a few icons easily accessible from paved highways.
04-10-2019, 08:23 PM   #158
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I use a K-3 for wildlife. The main problem I had with autofocus is using the white squares found in autofocus modes. I shoot using the red squares only. These are the squares representing autofocus points. Hope this helps someone.

04-10-2019, 09:05 PM - 1 Like   #159
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QuoteOriginally posted by traderdrew Quote
I use a K-3 for wildlife. The main problem I had with autofocus is using the white squares found in autofocus modes. I shoot using the red squares only. These are the squares representing autofocus points. Hope this helps someone.
What do you mean "white squares" and "red squares"? The autofocus points available show as little squares which light up red when that autofocus point attains focus. That would mean that any "white square" will become a "red square" when the camera has achieved focus at that point. Or am I misunderstanding what you're saying?
04-11-2019, 05:15 AM - 1 Like   #160
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QuoteOriginally posted by MarkJerling Quote
What do you mean "white squares" and "red squares"? The autofocus points available show as little squares which light up red when that autofocus point attains focus. That would mean that any "white square" will become a "red square" when the camera has achieved focus at that point. Or am I misunderstanding what you're saying?
Just what I was thinking. My mind is programmed, when the white square turns red, depress the shutter release button. It's automatic.
04-11-2019, 05:16 AM   #161
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QuoteOriginally posted by MarkJerling Quote
What do you mean "white squares" and "red squares"? The autofocus points available show as little squares which light up red when that autofocus point attains focus. That would mean that any "white square" will become a "red square" when the camera has achieved focus at that point. Or am I misunderstanding what you're saying?
Itís not what you see when looking through the viewfinder. What Iím referring to is on the big view screen on the camera. On the side of the K-3 there is a button called AF MODE. Press that button when a lens is attached to the camera and use a dial to select the amount of AF points. With the red squares you can select 1,9,25, or 27 of them. I found out through testing that the autofocus mode with white squares donít work well with my 500mm F/4.5 lens. I suspect it eliminates part of the functionality of the system. I couldnít find an explanation for it in the user manual.
04-11-2019, 05:20 AM   #162
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QuoteOriginally posted by traderdrew Quote
Itís not what you see when looking through the viewfinder. What Iím referring to is on the big view screen on the camera. On the side of the K-3 there is a button called AF MODE. Press that button when a lens is attached to the camera and use a dial to select the amount of AF points. With the red squares you can select 1,9,25, or 27 of them. I found out through testing that the autofocus mode with white squares donít work well with my 500mm F/4.5 lens. I suspect it eliminates part of the functionality of the system. I couldnít find an explanation for it in the user manual.
With every system, Canon, Sony, Nikon, pick your poison, selecting more squares impedes subject acquisition, possible tot he point with wildlife that you never achieve a focus lock. Some top cameras are as much as 3x slower with their famous 39 or 56 squares selected at focus acquisition than a Pentax is with single point acquisition. There is a price to be paid for enabling AF tracking, and it's missed images in some circumstance, those where single point would have nailed an image that tracking would have missed.
04-11-2019, 05:29 AM   #163
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QuoteOriginally posted by traderdrew Quote
Itís not what you see when looking through the viewfinder. What Iím referring to is on the big view screen on the camera. On the side of the K-3 there is a button called AF MODE. Press that button when a lens is attached to the camera and use a dial to select the amount of AF points. With the red squares you can select 1,9,25, or 27 of them. I found out through testing that the autofocus mode with white squares donít work well with my 500mm F/4.5 lens. I suspect it eliminates part of the functionality of the system. I couldnít find an explanation for it in the user manual.
If I understand you correctly, what you're describing is the functionality where you can select the number of focus points you'd like the camera to use.
Per this page of the manual: (From the K-3II manual, but the K-3 manual is the same)

I'm not sure I understand what you mean. This functionality is where you tell the camera which focus points to use.
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04-11-2019, 05:29 AM   #164
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QuoteOriginally posted by normhead Quote
With every system, Canon, Sony, Nikon, pick your poison, selecting more squares impedes subject acquisition, possible tot he point with wildlife that you never achieve a focus lock. Some top cameras are as much as 3x slower with their famous 39 or 56 squares selected at focus acquisition than a Pentax is with single point acquisition. There is a price to be paid for enabling AF tracking, and it's missed images in some circumstance, those where single point would have nailed an image that tracking would have missed.
Iíve experimented with different combinations of autofocus points. I donít think anyone who has seen my work would say that have a tough time with focusing.
04-11-2019, 05:30 AM   #165
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QuoteOriginally posted by normhead Quote
With every system, Canon, Sony, Nikon, pick your poison, selecting more squares impedes subject acquisition, possible tot he point with wildlife that you never achieve a focus lock. Some top cameras are as much as 3x slower with their famous 39 or 56 squares selected at focus acquisition than a Pentax is with single point acquisition. There is a price to be paid for enabling AF tracking, and it's missed images in some circumstance, those where single point would have nailed an image that tracking would have missed.
Ah, yes. Agreed!
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