[BrianR]

I know they are testing af-s, but I played with K1 and 5D Mark IV and when I changed the focus point from a subject standing at 1m from me to a subject standing at 2m from me, 5D Mark IV locked focus faster. Shooting in the field it's a completly different story than putting cameras on tripod in some controled enviroment and test their capabilities.

To repeat - the Imaging Resource numbers are not a test of how fast the camera can adjust the focus ring and lock on to a target, they are beginning with the target already in focus.

Read the text below the "Shutter Response (Lag Time)" charts for the K-1:

Pentax K-1 Review - Performance

"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."

And a wordier version on the d7100 review:

Nikon D7100 Review - Performance

This is not at all the same as your field test of making the camera focus on targets of different distances, so yes, it is a completely different story but not because of field vs controlled conditions.

[starbase218]

I just did a quick comparison of autofocus on the Pentax 35/2.4 and the Nikon 35/1.8. In good light, the Pentax is faster most of the time because the lens itself just moves faster (when racking the lenses from infinity to MFD the difference is quite obvious). As for accuracy, I focused on my speaker (the one you see in the video), with the ( ) symbol in the Pentax's viewfinder inside the woofer's circumference and using the center focusing point. Still I got some misses where it actually focused on the wallpaper behind the speaker. The AF points in the Pentax are larger than in the Nikon, yet the AF viewfinder indicators are smaller. Depending on the circumstances you might have to work around that more than you have to do with the Nikon. I'm probably not saying anything you don't know though. Also this may not be what you interpret as accuracy. But it is something I feel is relevant to that topic.

I am saying this partially in response to the request for more rigorous testing and testing under different circumstances (that would favour Pentax more). Maybe I'll even make a video about it. On the other hand, the more I do things like that, the more I feel like a camera operator instead of a photographer. There is truth to that, no doubt. And for me personally, that is much more interesting to make a video about or talk about. What I actually wanted with my photography was also a way of letting go of my inner nerd a bit. There are times when I succeed at that, and other times when I still fail.

[FantasticMrFox]

I just did a quick comparison of autofocus on the Pentax 35/2.4 and the Nikon 35/1.8.

I've never really had an issue with the focussing speed of Pentax lenses and cameras in AF.S, I think it's perfectly usable. My issue has always been with AF.C.

However, the lenses you compared are cheap entry-level models. With higher end stuff, there are plenty of examples of Nikon and Canon lenses being much faster than Pentax:

The Nikon 70-200 focuses about twice as fast as the Pentax:

You Tube

You Tube

The Nikon 24-70 f/2.8 is also much faster than the Pentax:

You Tube

You Tube

You Tube

You Tube

[starbase218]

I've never really had an issue with the focussing speed of Pentax lenses and cameras in AF.S, I think it's perfectly usable. My issue has always been with AF.C.

However, the lenses you compared are cheap entry-level models. With higher end stuff, there are plenty of examples of Nikon and Canon lenses being much faster than Pentax:

The Nikon 70-200 focuses about twice as fast as the Pentax:

Pentax vs Nikon 70-200mm AF Motor Speed - YouTube

The Nikon 24-70 f/2.8 is also much faster than the Pentax:

[Mobile01] Pentax K-1 Focus Speed (24-70mm f/2.8ED) - YouTube

[Mobile01] Nikon 24-70mm f/2.8G Focusing Speed - YouTube

I choose these lenses because the Pentax is known for its speedy autofocus. Infinity to MFD is faster than the Nikon (maybe twice as fast), and so is focusing in good light. When the light levels drop, however, things are different. I also noticed this before when I tried to find out if and why my 60-250 focused slower than my 55-300. I tested them side by side at home. The way I tested them was by recording focusing noises using Audacity. Racking through the range was actually slightly faster on the 60-250. But what really surprised me was that both lenses focused significantly slower in low light, with the delay mainly being before the lens actually moved. So before the main run, which gets the focus into the ballpark, and before subsequent micro-adjustments. Seeing as I can reproduce those results with the 16-50 and the 35/2.4, I think there's a pattern here. And since it happens before the motor is activated and seems consistent with whatever kind of motor is used, I think it's the body and not the lenses.

I do think there is a quick fix however: activate the AF assist light sooner.

This is also why I made the video specifically about AF in low light. Although the fact that the 16-50 sometimes failed to lock focus might have had to do with the SDM motor not having enough torque, causing it to jump around the focus point until giving up.

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Last edited by starbase218; 04-09-2017 at 04:27 AM.

[MD Optofonik]

Fast and accurate focus isn't just about sports. On the contrary, I believe it is part and parcel of the 35mm SLR legacy. HCB certainly didn't have the advantage of auto focus so he had to work within the constraints of his era's technology and the techniques of the day. Our era of technology and techniques of the today include fast, accurate, auto focus. Unless you're a Pentax owner and that makes no sense to me.

I'm certainly no HCB but "The Decisive Moment" was one of the reasons I took up photography in my teens, well before auto focus, digital or otherwise. Whether it's the light, someone's reaction to "the moment" , or the that first crack as the bat contacts the ball and breaks, a camera needs to be ready and I don't feel that Pentax's auto focus capabilities are ready for "the moment". They may never be. Hopefully when the time comes that I can afford and upgrade it will be within the Pentax brand but after years of waiting for the auto focus to meet modern standards

My kit certainly works for me a good bit of the time but it limits what I can do, many moments have fleeted with the only evidence being a shot of "the moment missed".

[Kunzite]

I guess a "modern HCB", educated in the spirit of Internet fora, would need a camera with:
- an extraordinary fast start-up time, as you never know when a decisive moment opportunity arises
- an extraordinary fast IS/SR initialization, so it won't impede immediate shooting of the decisive moment.
- an extraordinary fast autofocus, with face recognition, subject tracking and so on. The decisive moment doesn't wait!
- extremely fast FPS and a huge buffer; you must make sure to capture the right decisive moment!
- extremely fast to use camera interface, so you'd set it just in time to capture the decisive moment.

Of course, our "modern HCB" would never be able to take (make) images like the "original", no matter how fast the camera, because he wouldn't be ready

[reh321]

I'm not sure about HCB in particular, but most "street photographers" used a small aperture, "Weegee" being famous for using f/8 for example, because having a deep DOF meant they didn't have to focus at the moment ... everything was already within the DOF of their pre-focused lens.

[kkoether]

I've started using the back AF button on my K-3. It's made for a HUGE increase in keepers for my Boat Racing pics. I press and hold the back AF button then fire the shutter at will. The focus seems to track better doing this. These were all shot with my K-3 and DA* 60-250mm lens. They are ALL crops.

[biz-engineer]

I've started using the back AF button on my K-3. It's made for a HUGE increase in keepers for my Boat Racing pics. I press and hold the back AF button then fire the shutter at will. The focus seems to track better doing this. These were all shot with my K-3 and DA* 60-2550mm lens. They are ALL crops.

Those are actual photographs. Please keep in mind that most of the people judging AF speed are doing is by comparing with other cameras. Some people are commenting on camera products and have not taken a single photographs in the last 6 months and some people are still commenting on Pentax forums while having no camera and not taking any photograph. They are commenting on camera performance like seating on a bench drinking beer at a horse race and betting on what horse will win the race.

However, the lenses you compared are cheap entry-level models. With higher end stuff, there are plenty of examples of Nikon and Canon lenses being much faster than Pentax:

I did not know that photography is about betting on which horse is the fastest. I mean, commenting on horse is free of charge and does not engage anyone, owning a horse requires a much higher commitment.

[BigMackCam]

I'm not sure about HCB in particular, but most "street photographers" used a small aperture, "Weegee" being famous for using f/8 for example, because having a deep DOF meant they didn't have to focus at the moment ... everything was already within the DOF of their pre-focused lens.

Same with the wonderful Bill Cunningham...

[FantasticMrFox]

I did not know that photography is about betting on which horse is the fastest. I mean, commenting on horse is free of charge and does not engage anyone, owning a horse requires a much higher commitment.

And I fail to understand how that analogy is supposed to make any sense.

[biz-engineer]

And I fail to understand how that analogy is supposed to make any sense.

You show how the Nikon lens is faster to focus than Pentax, and you say that Nikon is twice as fast. Actually, if you did not buy the Nikon gear, that must be because you did not want to spend the money for it. So I guess you are expecting Pentax to deliver the same performance to you free of charge? unless you remain a spectator comparing camera performance but neither buying it nor using it.

[Nicolas06]

And I fail to understand how that analogy is supposed to make any sense.

It doesn't have any link indeed. In particular owning a horse equiv in camera gear would mean having some shares in Nikon or Pentax. Not using the gear. This is the horse rider role.

Even less we would not bet on it either as owner or rider this is of course forbidden, because of obvious conflincting interrest. And it is the same if your are a stackholder of Pentax or Nikon. You should not use your insider knowledge to buy or sell at the right time.

Then by that analogy, dpreview is perfect: they supposedly neutral. They tried lot of camera, they are pro photographer and take photo all the time. Unfortunately they have quite low opinion of Pentax. So biz-engineer shall we all sell, following your horse analogy?

[FantasticMrFox]

Actually, if you did not buy the Nikon gear, that must be because you did not want to spend the money for it.

Nope, that's a logical fallacy. You are saying 'A must be because of B', even though it could just as well be because of C, D, E, F or anything else. You are just drawing up a random reason why I may have decided not to buy Nikon and then asserted that that 'must' be the case

I started out with Pentax for various reasons (ergonomics, build quality etc.), and I still enjoy these features, these advantages that Pentax offers over Nikon, enough not to switch. That does not mean that I cannot acknowledge that Nikon has superior autofocus.

Just as people can acknowledge that some random person is more beautiful than their spouse, but they still stick with their spouse because he or she may be funnier, more intelligent, more caring etc., or, more likely, because they truly love their spouse, not that random other person

[biz-engineer]

Then by that analogy, dpreview is perfect: they supposedly neutral. They tried lot of camera, they are pro photographer and take photo all the time.

They are as neutral as anonymous PF members commenting about why EVF and fast AF are needed to take photos. Regarding DPR, Rishi went on a business trip to Sony HQ and on Day1 the A9 was announced , there were already hundred of video on youtube and a dozen of articles on DPR and Imaging-Resource and DXO. I want to believe that those guys are super fast and work the whole night to be the first to comment on the A9, while the more realistic version is that Sony marketing planned the go to market at least several month in advance, signed non disclosure agreements and paid content marketing contract with all the reviewers who prepared some content and presented it to Sony for agreement before publishing. DPR is a web marketing agency, they aren't photographers more than you, and most likely less qualified than you, but their jobs is to get paid for advertising new products.

Apparently, here https://www.lensculture.com/ we have to look very hard for find any photo that requires a fast AF. I don't think they care much about the camera used. Some of them still use film view cameras.