Opinions on this AF strategy?

Spock · 06-30-2021, 03:04 AM

Hi everyone, I'd really appreciate some feedback/advice on my AF setup strategy:

In the past, with the original K3 and earlier Pentax DSLRs, I've generally used the rear AF button and a (single) centre AF point in AFS and had good results with stationary subjects. I found that AFC wasn't particularly useful as the camera just didn't focus fast enough to keep up with moving objects.

Now, with the K3-3, I am trialing using AFC - again exclusively using the rear button for AF. This way I can simply release the AF button when my subject is in focus or alternatively (if say, my cat starts walking towards me), I just hold down the AF button and snap away with the camera tracking the moving subject.

This method seems to work really well in the test shots I just did. It circuvents the need to switch from AFS to AFC on the fly and risk missing the shot due to the delay in changing AF settings.

What do you action photographers think of this strategy? Is there a better way?

aaacb · 06-30-2021, 03:47 AM - **1 Like**

I use this rather often, af-c with back button focus. No drawbacks that I can see for stationary subjects, if there's a difference in accuracy I'm not able to tell.

**Mooncatt** · 06-30-2021, 04:30 AM - **1 Like**

The only drawbacks I've heard for this is it's an extra step in the act of taking a photo, but that's subjective based on how one likes to set up a shot. I used it all the time on my last camera with good results. The half press of the shutter was not very stiff, leading to unwanted shutter clicks, and back button focus is quicker to effectively switch to manual focus than to hunt for a dedicated switch. I don't use it now on my K3 II because the shutter button is more solid, but just personal preference. I've debated setting it up for BBF.

**Larrymc** · 06-30-2021, 06:00 AM - **2 Likes**

Originally posted by Spock

Hi everyone, I'd really appreciate some feedback/advice on my AF setup strategy:

In the past, with the original K3 and earlier Pentax DSLRs, I've generally used the rear AF button and a (single) centre AF point in AFS and had good results with stationary subjects. I found that AFC wasn't particularly useful as the camera just didn't focus fast enough to keep up with moving objects.

Now, with the K3-3, I am trialing using AFC - again exclusively using the rear button for AF. This way I can simply release the AF button when my subject is in focus or alternatively (if say, my cat starts walking towards me), I just hold down the AF button and snap away with the camera tracking the moving subject.

This method seems to work really well in the test shots I just did. It circuvents the need to switch from AFS to AFC on the fly and risk missing the shot due to the delay in changing AF settings.

What do you action photographers think of this strategy? Is there a better way?

Yes by all means use the back button, I used BBAF for almost 5 years with my K-3 and it works even better with the Mk III. BTW, the autofocus with the K-3 was pretty good, it just didn't track well. I also use TAV a bunch more with AFC, however I also use spot focus when not in AFC since it is the most accurate focus with the Mk III. Also you can use a good bit higher shutter speed and that really helps especially with BIF and other fast moving subjects with very little noticeable noise.

kypfer · 06-30-2021, 06:38 AM - **1 Like**

I've tried "back button focussing" and simply don't get on with it, though I can see the attraction in some circumstances. When I did manage to get used to using it, the weather turned colder and I found I couldn't operate the af button reliably with gloves on. I seem to manage quite well with a half-press on the shutter button followed by a full press as required.
I've got AFS/spot, AFC/spot and AFC/zone set up as the options for my Smart Function wheel. My thumb operates this wheel on a regular basis whilst I keep the camera to my eye and my finger on the shutter button … became second nature very quickly! I'm sure I'll find other things to do with the SFn wheel as time goes by, and I'll store that with any other appropriate settings in an appropriately named User Mode, but I'm a bit "old school" and can take time to deviate from well established work routines

noelpolar · 06-30-2021, 06:58 AM - **1 Like**

mmm.... how can you be sure when you release the back focus button that it was in focus at the time? or in between focus attempts?... assuming.... say ... hold is set to off.

Spock · 06-30-2021, 07:28 AM

Originally posted by noelpolar

mmm.... how can you be sure when you release the back focus button that it was in focus at the time? or in between focus attempts?... assuming.... say ... hold is set to off.

Green hexagon?

dlhawes · 06-30-2021, 07:54 AM

"trialing"?

Spock · 06-30-2021, 08:27 AM - **2 Likes**

Originally posted by dlhawes

"trialing"?

I'm Australian.

But I spelled it wrong:

trialling | Australian English

the process of formally testing a product to discover how effective or suitable it is: In just two weeks of trialling the company has already signed up tens of thousands of customers.

**Larrymc** · 06-30-2021, 04:07 PM - **1 Like**

Originally posted by noelpolar

mmm.... how can you be sure when you release the back focus button that it was in focus at the time? or in between focus attempts?... assuming.... say ... hold is set to off.

When back button focusing you don't release the button until after you trigger the shutter release or you can continue to hold the back button down and grab some more images. BBF works much better with continuous auto focus. Say for instance you were doing continuous autofocus with the shutter release and having to hold the shutter release half way down to track a subject. This could pose a problem simply by depressing the shutter button slightly past its detent and releasing the shutter inadvertently then having go through the target acquisition process all over again when you can hold the back button down against the positive stop and hold the target in focus then at the moment of your choosing release the shutter. But some folks just don't care to get used to BBF.

**Mooncatt** · 06-30-2021, 05:44 PM - **1 Like**

I somewhat alluded to this in my last comment, but I guess the easiest way to grasp the benefit of BBF is it essentially gives you all three focus modes instantly and at the time of your choosing without changing any menu settings or switches.

When you set up as AF-C you can:

-press and hold for AF-C focusing.

-press, then release once you get a positive lock for AF-S. Good for static subjects or to focus and recompose.

-Do nothing and have manual focus.

kypfer · 07-01-2021, 12:16 AM - **1 Like**

Originally posted by Mooncatt

I somewhat eluded to this in my last comment, but I guess the easiest way to grasp the benefit of BBF is it essentially gives you all three focus modes instantly and at the time of your choosing without changing any menu settings or switches.

When you set up as AF-C you can:

-press and hold for AF-C focusing.

-press, then release once you get a positive lock for AF-S. Good for static subjects or to focus and recompose.

-Do nothing and have manual focus.

Excellent summary!
Certainly food for thought and a concept for further consideration!
Thank you

PS :- to "elude" is to avoid … I suspect you meant "allude" … auto-spell-check getting in the way?

Unregistered User · 07-01-2021, 12:57 AM - **1 Like**

I use Back button to focus all the time. I have set the new function dial to change between AFS with select one spot, AFC with Select small and AFC with AF21. So if a bird is flying I use AFC with AF21, if it sits down and are still I switch to AFS since I do not trust AFC to do the job, but this is coming from K-1. I am more and more trusting the AFC with very good results.

Hold I have tested and it works well but I keep it off most of the time.

pjsaure · 07-01-2021, 01:11 AM - **1 Like**

I used to use only BBF.
Now with the K-3 iii, I have an "action" user mode with half press = AF, and AF button = AF stop. Tracking is generally good enough so I don’t fear losing focus. So why would I want to not AF when half-pressing?
For me now it only makes sense when I want to frequently fine tune the focus manually, so I don’t want the AF to be triggered when I press the shutter button. Think macro on a tripod, this kind of things.

Spock · 07-01-2021, 02:30 AM

Originally posted by pjsaure

I used to use only BBF.
Now with the K-3 iii, I have an "action" user mode with half press = AF, and AF button = AF stop. Tracking is generally good enough so I don’t fear losing focus. So why would I want to not AF when half-pressing?
For me now it only makes sense when I want to frequently fine tune the focus manually, so I don’t want the AF to be triggered when I press the shutter button. Think macro on a tripod, this kind of things.

This seems like a good idea.
Just one question: After you press the rear AF button to stop AF, how do you restart AF - ie. so a half press of the shutter button works again?

06-30-2021, 03:04 AM	#1
Spock Pentaxian Join Date: Aug 2009 Location: Perth, Western Australia Photos: Albums Posts: 674	Opinions on this AF strategy? Hi everyone, I'd really appreciate some feedback/advice on my AF setup strategy: In the past, with the original K3 and earlier Pentax DSLRs, I've generally used the rear AF button and a (single) centre AF point in AFS and had good results with stationary subjects. I found that AFC wasn't particularly useful as the camera just didn't focus fast enough to keep up with moving objects. Now, with the K3-3, I am trialing using AFC - again exclusively using the rear button for AF. This way I can simply release the AF button when my subject is in focus or alternatively (if say, my cat starts walking towards me), I just hold down the AF button and snap away with the camera tracking the moving subject. This method seems to work really well in the test shots I just did. It circuvents the need to switch from AFS to AFC on the fly and risk missing the shot due to the delay in changing AF settings. What do you action photographers think of this strategy? Is there a better way?

06-30-2021, 06:38 AM - 1 Like	#5
kypfer Pentaxian Join Date: Jan 2018 Location: Jersey C.I. Posts: 3,593	I've tried "back button focussing" and simply don't get on with it, though I can see the attraction in some circumstances. When I did manage to get used to using it, the weather turned colder and I found I couldn't operate the af button reliably with gloves on. I seem to manage quite well with a half-press on the shutter button followed by a full press as required. I've got AFS/spot, AFC/spot and AFC/zone set up as the options for my Smart Function wheel. My thumb operates this wheel on a regular basis whilst I keep the camera to my eye and my finger on the shutter button … became second nature very quickly! I'm sure I'll find other things to do with the SFn wheel as time goes by, and I'll store that with any other appropriate settings in an appropriately named User Mode, but I'm a bit "old school" and can take time to deviate from well established work routines Last edited by kypfer; 06-30-2021 at 08:43 AM.

06-30-2021, 05:44 PM - 1 Like	#11
Mooncatt Loyal Site Supporter Join Date: May 2020 Location: Wisconsin Photos: Gallery Posts: 1,372	I somewhat alluded to this in my last comment, but I guess the easiest way to grasp the benefit of BBF is it essentially gives you all three focus modes instantly and at the time of your choosing without changing any menu settings or switches. When you set up as AF-C you can: -press and hold for AF-C focusing. -press, then release once you get a positive lock for AF-S. Good for static subjects or to focus and recompose. -Do nothing and have manual focus. Last edited by Mooncatt; 07-01-2021 at 03:19 AM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
AF Assist/Modelling Light Strategy	BruceBanner	Flashes, Lighting, and Studio	42	02-12-2020 02:17 AM
Lens prices and our channel strategy in the U.S. - Ned Responses	LFLee	Pentax News and Rumors	716	06-18-2012 08:38 AM
Job Creation Strategy?	newarts	General Talk	15	02-16-2011 09:10 AM
Obama calls nuclear strategy 'significant step'	Artesian	General Talk	94	04-12-2010 08:21 AM
Another lens buying strategy thread.	Sprags	Pentax SLR Lens Discussion	2	02-06-2008 07:48 PM

06-30-2021, 03:47 AM - 1 Like	#2
aaacb Pentaxian Join Date: May 2016 Photos: Gallery Posts: 3,724	I use this rather often, af-c with back button focus. No drawbacks that I can see for stationary subjects, if there's a difference in accuracy I'm not able to tell.

06-30-2021, 04:30 AM - 1 Like	#3
Mooncatt Loyal Site Supporter Join Date: May 2020 Location: Wisconsin Photos: Gallery Posts: 1,372	The only drawbacks I've heard for this is it's an extra step in the act of taking a photo, but that's subjective based on how one likes to set up a shot. I used it all the time on my last camera with good results. The half press of the shutter was not very stiff, leading to unwanted shutter clicks, and back button focus is quicker to effectively switch to manual focus than to hunt for a dedicated switch. I don't use it now on my K3 II because the shutter button is more solid, but just personal preference. I've debated setting it up for BBF.

06-30-2021, 06:00 AM - 2 Likes	#4
Larrymc Site Supporter Join Date: Jun 2014 Location: Mississippi, USA Posts: 5,251	Originally posted by Spock Hi everyone, I'd really appreciate some feedback/advice on my AF setup strategy: In the past, with the original K3 and earlier Pentax DSLRs, I've generally used the rear AF button and a (single) centre AF point in AFS and had good results with stationary subjects. I found that AFC wasn't particularly useful as the camera just didn't focus fast enough to keep up with moving objects. Now, with the K3-3, I am trialing using AFC - again exclusively using the rear button for AF. This way I can simply release the AF button when my subject is in focus or alternatively (if say, my cat starts walking towards me), I just hold down the AF button and snap away with the camera tracking the moving subject. This method seems to work really well in the test shots I just did. It circuvents the need to switch from AFS to AFC on the fly and risk missing the shot due to the delay in changing AF settings. What do you action photographers think of this strategy? Is there a better way? Yes by all means use the back button, I used BBAF for almost 5 years with my K-3 and it works even better with the Mk III. BTW, the autofocus with the K-3 was pretty good, it just didn't track well. I also use TAV a bunch more with AFC, however I also use spot focus when not in AFC since it is the most accurate focus with the Mk III. Also you can use a good bit higher shutter speed and that really helps especially with BIF and other fast moving subjects with very little noticeable noise.

06-30-2021, 06:58 AM - 1 Like	#6
noelpolar Veteran Member Join Date: Oct 2013 Location: Goolwa, SA Photos: Gallery Posts: 4,310	mmm.... how can you be sure when you release the back focus button that it was in focus at the time? or in between focus attempts?... assuming.... say ... hold is set to off.

06-30-2021, 07:28 AM	#7
Spock Pentaxian Join Date: Aug 2009 Location: Perth, Western Australia Photos: Albums Posts: 674 Original Poster	Originally posted by noelpolar mmm.... how can you be sure when you release the back focus button that it was in focus at the time? or in between focus attempts?... assuming.... say ... hold is set to off. Green hexagon?

06-30-2021, 08:27 AM - 2 Likes	#9
Spock Pentaxian Join Date: Aug 2009 Location: Perth, Western Australia Photos: Albums Posts: 674 Original Poster	Originally posted by dlhawes "trialing"? I'm Australian. But I spelled it wrong: trialling \| Australian English the process of formally testing a product to discover how effective or suitable it is: In just two weeks of trialling the company has already signed up tens of thousands of customers.

06-30-2021, 04:07 PM - 1 Like	#10
Larrymc Site Supporter Join Date: Jun 2014 Location: Mississippi, USA Posts: 5,251	Originally posted by noelpolar mmm.... how can you be sure when you release the back focus button that it was in focus at the time? or in between focus attempts?... assuming.... say ... hold is set to off. When back button focusing you don't release the button until after you trigger the shutter release or you can continue to hold the back button down and grab some more images. BBF works much better with continuous auto focus. Say for instance you were doing continuous autofocus with the shutter release and having to hold the shutter release half way down to track a subject. This could pose a problem simply by depressing the shutter button slightly past its detent and releasing the shutter inadvertently then having go through the target acquisition process all over again when you can hold the back button down against the positive stop and hold the target in focus then at the moment of your choosing release the shutter. But some folks just don't care to get used to BBF.

07-01-2021, 12:16 AM - 1 Like	#12
kypfer Pentaxian Join Date: Jan 2018 Location: Jersey C.I. Posts: 3,593	Originally posted by Mooncatt I somewhat eluded to this in my last comment, but I guess the easiest way to grasp the benefit of BBF is it essentially gives you all three focus modes instantly and at the time of your choosing without changing any menu settings or switches. When you set up as AF-C you can: -press and hold for AF-C focusing. -press, then release once you get a positive lock for AF-S. Good for static subjects or to focus and recompose. -Do nothing and have manual focus. Excellent summary! Certainly food for thought and a concept for further consideration! Thank you PS :- to "elude" is to avoid … I suspect you meant "allude" … auto-spell-check getting in the way?

07-01-2021, 12:57 AM - 1 Like	#13
Unregistered User Guest	I use Back button to focus all the time. I have set the new function dial to change between AFS with select one spot, AFC with Select small and AFC with AF21. So if a bird is flying I use AFC with AF21, if it sits down and are still I switch to AFS since I do not trust AFC to do the job, but this is coming from K-1. I am more and more trusting the AFC with very good results. Hold I have tested and it works well but I keep it off most of the time.

07-01-2021, 01:11 AM - 1 Like	#14
pjsaure Forum Member Join Date: Jan 2017 Location: Toulouse Posts: 82	I used to use only BBF. Now with the K-3 iii, I have an "action" user mode with half press = AF, and AF button = AF stop. Tracking is generally good enough so I don’t fear losing focus. So why would I want to not AF when half-pressing? For me now it only makes sense when I want to frequently fine tune the focus manually, so I don’t want the AF to be triggered when I press the shutter button. Think macro on a tripod, this kind of things.

07-01-2021, 02:30 AM	#15
Spock Pentaxian Join Date: Aug 2009 Location: Perth, Western Australia Photos: Albums Posts: 674 Original Poster	Originally posted by pjsaure I used to use only BBF. Now with the K-3 iii, I have an "action" user mode with half press = AF, and AF button = AF stop. Tracking is generally good enough so I don’t fear losing focus. So why would I want to not AF when half-pressing? For me now it only makes sense when I want to frequently fine tune the focus manually, so I don’t want the AF to be triggered when I press the shutter button. Think macro on a tripod, this kind of things. This seems like a good idea. Just one question: After you press the rear AF button to stop AF, how do you restart AF - ie. so a half press of the shutter button works again?