[normhead]

The Pentax K-1's full autofocus shutter lag when shooting the same target multiple times was very fast for a pro-level DSLR. The K-1 required only 0.090 second for full AF using the Pentax 55mm f/1.4 SDM DA* lens. Manual focus shutter lag was just a touch faster at 0.087 second. When prefocused, shutter lag dropped only slightly to 0.086 second, which is a little slower than average for a pro DSLR.

Pentax K-1 Review - Performance

Shot-to-shot cycle time in single-shot mode was so fast (under 0.3 second) that it was difficult to measure accurately. (Fast single-shot cycle times depend a lot on the tester's agility and rhythm, so your results may vary.) We no longer test just RAW files in single-shot mode, as it's usually somewhere in between JPEG and RAW+JPEG cycle time.

There's a lot of people on this forum who need to dial it back with the criticism of Pentax AF.

Find more facts. repeat less, nonsense.

Of course all those "responsible people" still complaining about slow Pentax are going to go back and alter their posts now to reflect the measured truth? Not likely is it? A fact is only a "fact" when it's a fact that supports the internet wisdom passed down by the anti-Pentax crowd. Just today i read a post about how Pentax needs to improve their AF. Are we going to see a retraction?

Man up dudes.

Sorry about the enthusiasm with which I post, but, the anti-Pentax crows hs always used slow AF reason for not buying Pentax. A few years ago, Pentax said AF was a priority. The naysayers kept predicting they'd never catch up. Well the day of reconning has come , nay sayers. Time to show your true colours, time too eat some crow.

Now all the Canon Nikon types who claimed they had to switch to Canon or Nikon for faster AF are going to switch back right? because all that matters in a camera is how fast you get your image after you press the shutter release. At least I think that's how it was explained to me.

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Last edited by normhead; 11-03-2016 at 12:23 PM.

[Pixelhdr]

I don't think the measurements reported refer to AF speed. They are shutter lag and cycle time.

[stevebrot]

There's a lot of people on this forum who need to dial it back with the criticism of Pentax AF.

Yep...though many of the complaints are not about AF speed per se,* but about the ability of the system to acquire and maintain focus on approaching subjects. This is often perceived or communicated as "slow AF" with the blame usually being levied on the body.


Steve

* In all fairness, the quoted sections from the IR performance review dealt with shutter response (time to capture) and shot-to-shot cycle time where AF may be a component, but not the core metric being measured.

[normhead]

You read wrong. It was the time from when you push the button to when the camera performs the AF then releases the shutter? What else is important in AF? No one cares how fast the AF is if it does lead to a shutter release.

I agree the tracking is the issue some of the time, but the problem with that is, fast AF somewhat and a fast time from acquiring focus to shutter release also mean tracking becomes less necessary. If people mean tracking they better start saying it, and stop the endless tirade against Pentax AF.

[Kerrowdown]

Slow Pentax AF.... ha, eat my shorts

Now that's what I call a delightful turn of phrase... I've not come across it before, but I knew immediately what it meant. Thanks Norm for making me smile with this one.

[Davidparis]

Wish we could "thumbs down" a post...

[BrianR]

From the article:

"To minimize the effect of different lens' focusing speed, we test AF-active shutter lag with the lens already set to the correct focal distance."

Sounds like it was already focused on the target. So we can conclude the "AF to shot sequence" is fast if the target is already standing in the plane of focus.

Maybe I'm mistaken... do they have a video of their testing procedure anywhere?

[biz-engineer]

There's a lot of people on this forum who need to dial it back with the criticism of Pentax AF.

Very few people use the latest Pentax that are designed to work together. They mount a poor lens on a K1, select the wrong AF setting, or poor contrast or poor lighting and conclude with the broad statement that Pentax AF is not good.
Meanwhile, some action shots show that in some conditions, Pentax AF can be very responsive. In the shot below, I heard the noise of goose wing flap taking off, I pulled out the K1 and DFA150450 with TC (f8 wide open...) which was set to AFC 9 points medium burst (that's my defaut User3 setting when I switch on the camera), I took the camera aligned the ducks in the view finder and pressed the shutter fully like if I'd pull out a rifle and shoot, a single shot. When I chimped this photo after the shot, I could not believe it was in focus because the action was so fast that I did not have time to see the focus happening through the viewfinder.

[stevebrot]

Now that's what I call a delightful turn of phrase... I've not come across it before

Made famous by Bart Simplson...




Steve

[normhead]

The Pentax K-1's full autofocus shutter lag when shooting the same target multiple times was very fast for a pro-level DSLR. The K-1 required only 0.090 second for full AF using the Pentax 55mm f/1.4 SDM DA* lens. Manual focus shutter lag was just a touch faster at 0.087 second. When prefocused, shutter lag dropped only slightly to 0.086 second, which is a little slower than average for a pro DSLR.

I guess the phrase Full AF is a little too technical for some.
When prefocussed, the K-1 is slower than average.

The K-1 is faster acquiring focus and releasing the shutter.
Its slower for pre-fcussed, but, for 99% of my use acquiring focus and releasing the shutter is what I refer to as AF speed. Releasing the shutter mechanism without FA, ei pre-focussing is measuring shutter lag. It is interesting that with full AF, the K-1 is only .03 slower than prefocussed. There's definitely some kind of tech at play here. I wonder if they had focus priority turned on.

[surfar]

Duck 1:that guy shot us with a K1
Duck2:i didn't feel a thing
Duck3:wait for me
Duck4: missed me!

[Kerrowdown]

Made famous by Bart Simplson...

Not being a Simpson person, may explain my naivety.

[biz-engineer]

... For anyone interested, I can confirm that Pentax K1 AF uses the 86K AE sensor to track focus together with PDAF sensor but only in some conditions: when there is sufficient subject to background separation, the AE system guides the focus. How do I know this? If I select only one center point AFC and I take a bird in flight in the sky , the K1 AF focuses on the bird even if the bird is completely outside of the center AF focus zone... which proves that Ricoh have implemented something similar to what Nikon are doing... and this could explain why Ricoh did not implement more than 33 AF points on the K1. Although I have to admit that my K1 power-off is set to 30 minutes and the AE metering time set to "always on".

---------- Post added 03-11-16 at 21:12 ----------

Duck4: missed me!

Yes! That's true, there was a fourth goose and I missed it.

[wibbly]

there is no way that it only takes .090 seconds to rack the lens from completely off focus to in focus and release the shutter. considering pre focused lag was .086 that means that the focusing time is .004 seconds. not a chance


these numbers are referencing lag. not focusing speed.

[stevebrot]

I guess the phrase Full AF is a little too technical for some.
When prefocussed, the K-1 is slower than average.

I have to confess to being a little confused by the review, despite being somewhat technical. A short summary:

• No full description of methodology is provided
• Three shutter response tests were done:
  • Full Autofocus Single Area AF (Center AF point)
  • Manual focus
  • Prefocused
• Beneath the shutter response test results was the following qualifier:

  "To minimize the effect of different lens' focusing speed, we test AF-active shutter lag with the lens already set to the correct focal distance."

I am not sure what "Full" means in this context (never heard of "half" AF), but I read this to mean that they prefocus the lens for both "Full" and "Prefocused" with the difference being the time to initialize the AF system, acquire focus, and signal focus acquired. Given that I only have 35 years working in technical realms, it is possible that I completely misread. In that case, it appears that with the 55/1.4 SDM mounted to the K-1 focused in an astounding 0.004s!!!

Woo! Hoo! Go Pentax!!!


...or perhaps not...

Edit: The field test in the same review comments that the field AF performance matched the strong lab test results:

Autofocus performance was swift, comparing well with the Pentax K-3 II in my informal, real-world testing. (And our lab testing likewise found autofocus performance to be a strength of the Pentax K-1.)

After all this, I am not quite sure what they tested. If they did test the AF as part of the shutter response test, it would be helpful to know the target distance and whether the lens was defocussed to infinity or MFD.



Steve