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09-09-2017, 11:09 AM - 3 Likes   #16
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QuoteOriginally posted by Gutta Perka Quote
....and camera brand used!

(But there are are other things to enjoy - K1 is cheap.....)

---------- Post added 09-09-17 at 06:02 PM ----------

About heard of hunting...


You are happy - here we have those often interesting scenes.
I don't think You bought the K1 for just high contrast scenes .... or?

(However: "Blessed are the meek ones.")
Is this a troll thread?

09-09-2017, 11:15 AM   #17
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1) AF is module that is not connected to the SR system. Literally light from the lens is diverted into the AF module and up into the viewfinder. The sensor (which is held by the SR system) is hidden behind the mirror during this process
2) SR system takes a bit to become active (little icon in viewfinder lights up when its active) but if you full-press the shutter, it will take a photo regardless of SR being active or not.
3) You can select Focus priority or Shutter priority in camera. Focus priority won't let you snap until focus is locked. I prefer shutter priority, as I generally see when AF is good enough, and I enjoy using QS and MF

QuoteOriginally posted by Gutta Perka Quote
Heard of "hunting" ?
But this does not mean "slow AF" and i don't see how SR could affect this. Hunting is AF being indecisive and not locking on. And yes, if AF doesn't lock on and it keeps going through the focus range back and forth, that is a waste of time. But its not the same as "slow AF" (which would imply slow AF motors)

And, as above, I never found that to be a problem. Even on my old K-r. AF is a tool that you have to learn to use, and using it in combination with Live view (with focus peaking), Catch in focus, Manual focus and quick shift can give you even faster results. Basically, the idea that you just half press the shutter for 0,3 of a second before you full-press the shutter and the photo should be perfectly in focus and sharp, is kind of wrong.
I would agree that Pentax tracking AF.C is not the best, especially with subjects coming toward the camera. But this has more to do with AF algorithms than motor speed or even SR. If you need 500 AF points, if you need top-notch tracking, then please, go ahead and get Nikon or Sony or whatever brand you think has that covered. I think for most of us here, the Pentax AF is good enough, especially once you develop some skills
09-09-2017, 11:48 AM   #18
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QuoteOriginally posted by Digitalis Quote
The IBIS system needs to spool up whether you are using it to stabilize a shot or not, this process introduces lag,
Than why does imaging resource measure a faster AF response from the K-1 0.090 seconds than from the D5 0.132? Seems to me that spooling up can happen as soon as af is activated which is before the shutter is released. Because it happens simultaneously it causes no delay.
09-09-2017, 12:45 PM   #19
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QuoteOriginally posted by Gutta Perka Quote
You are happy - here we have those often interesting scenes.
I don't think You bought the K1 for just high contrast scenes .... or?
I bought the K1 for many different types of scenes i photograph.

But I am clever enough to realise how AF works and when it cannot focus on a scene due to lack of contrast. So if my AF point/s are pointing at a totally white or black surface, I wont be listening to the lens whir back and forth and thinking about posting a thread on how bad Pentax AF is. I will be doing what countless photographers have done for decades and focus manually.

09-09-2017, 12:51 PM   #20
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QuoteOriginally posted by Digitalis Quote
The AF sensor does not move, this is an empirical fact. But the Sensor does, quite a bit actually. The IBIS system needs to spool up whether you are using it to stabilize a shot or not, this process introduces lag, which is compounded by AF lag*. And all this has to happen before the mirror has even flipped up and the first curtain gets moving.
How long is the IBIS spooling-up time? Does this happen every time you half-press the shutter button, or when the camera comes on/wakes up?
09-09-2017, 01:00 PM - 3 Likes   #21
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QuoteOriginally posted by leekil Quote
How long is the IBIS spooling-up time? Does this happen every time you half-press the shutter button, or when the camera comes on/wakes up?
Usually 3 weeks, but the Pentax men in white coats are hoping to get this down to a day.

For pity's sake folks go out and take pictures. If you want a camera system that will take pictures before you even see the idea go and buy a Canikon.


edit. Apologies to leekil. My frustration should not be aimed at you.

Last edited by pschlute; 09-09-2017 at 01:10 PM.
09-09-2017, 01:47 PM - 2 Likes   #22
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QuoteOriginally posted by Gutta Perka Quote
Heard of "hunting" ?
"Hunting" has nothing to do with IBIS.

There's nothing in the IBIS system that affects the PDAF system and nothing in the PDAF system that affects IBIS. They live in entirely separate physical parts of the camera. Only in live view does IBIS affect AF and then it serves to help stabilize the image so the CDAF system doesn't misinterpret motion blur as out-of-focus blur.

Given that IBIS also gives you pixel shift, controllable anti-aliasing, astrotracer, horizon leveling, and composition adjustment, I'd say IBIS is very much the superior feature.

The only reason Canikon doesn't copy IBIS is so they are sell all their over-priced stabilized lenses.
09-09-2017, 01:59 PM   #23
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QuoteOriginally posted by photoptimist Quote
Given that IBIS also gives you pixel shift, controllable anti-aliasing, astrotracer, horizon leveling, and composition adjustment, I'd say IBIS is very much the superior feature
In addition to that list, SR/IBIS means you can have a stabilised camera/lens setup using lenses that were manufactured before autofocus was even invented.

09-09-2017, 09:26 PM   #24
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QuoteOriginally posted by Jens Lyn IV Quote
The original question was whether IBIS slows AF
It doesn't have any direct effect on AF. However he mechanisms wind up time introduces lag.

QuoteOriginally posted by D1N0 Quote
Than why does imaging resource measure a faster AF response from the K-1 0.090 seconds than from the D5 0.132?
Let us scrutinize this further shall we?

I lifted these tables from Imaging resources performance report on the Pentax K-1 and Nikon D5.

Left: Pentax K-1 with the Pentax SMC-55mm f/1.4 SDM Right: Nikon D5 with the Micro NIKKOR AF-S 60mm f/2.8G ED


If it was up to me, doing this test I would have used the Nikkor 50mm f/1.4G* so than it would be on equal footing with other camera systems. The use of the Nikkor 60mm f/2.8G Macro which is not known for being a AF speed demon**, rather than using a fast 50 is somewhat perplexing. There is no mention to which degree the lens is mis-focused in order to obtain an accurate reflection of the AF systems speed and responsiveness***. The Manual focus and pre-focused timings are more important IMO, as it shows how fast and efficient the AF algorithms are at confirming the phase differential has been resolved. Those timings on the Nikon D5 are noticeably faster than what the K-1 can accomplish.

*which was released in 2008, long before the D5 even existed.
** including a number of complaints and demonstrations that it is even slower focusing than the Micro-Nikkor AF-S 105mm f/2.8G ED VR.
***or whether this is an aggregate of timings derived from multiple runs. As usual, there are more questions than actual data.

Last edited by Digitalis; 09-09-2017 at 09:38 PM.
09-10-2017, 12:48 AM   #25
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QuoteOriginally posted by Wheatfield Quote
Is this a troll thread?
Most likely it is
09-10-2017, 01:11 AM   #26
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Some lenses I have will sometimes "hunt" while others rarely do this. With them, AF is faster and more sure. Some of these are the old screw-driven type, while others are the quiet DC motor-driven type. As to the camera, AF speed and accuracy is better on some of the more recent models, in my experience.
09-10-2017, 01:25 AM   #27
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QuoteOriginally posted by Digitalis Quote
The Manual focus and pre-focused timings are more important IMO, as it shows how fast and efficient the AF algorithms are at confirming the phase differential has been resolved.
The timings on the K-1 are barely faster than when using AF. That would make the lag due to AF very small. The D5 shows more significant improvement when not using AF, showing it's lag due to AF is a bit more. AF speed is not the problem here. Any troubles with Pentax AF derive from unsophisticated tracking algorithms and slow lenses.

Last edited by D1N0; 09-10-2017 at 01:30 AM.
09-10-2017, 01:28 AM   #28
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Please will people stop mentioning 'IBIS' ! All that'll happen is that security forces will confiscate all Pentaxes.
09-10-2017, 02:19 AM - 1 Like   #29
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QuoteOriginally posted by Wheatfield Quote
Is this a troll thread?
Isn't it obvious?
09-10-2017, 03:44 AM - 1 Like   #30
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QuoteOriginally posted by 35mmfilmfan Quote
Please will people stop mentioning 'IBIS' ! All that'll happen is that security forces will confiscate all Pentaxes.
Why would the security services be interested in a hotel chain or a wading bird ?

Last edited by pschlute; 09-10-2017 at 05:37 AM.
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