Catch-In Focus discovery

**JensE** · 04-10-2019, 12:59 AM

Originally posted by biz-engineer

I don't know. I tried with my K1 and DFA2470, with focus priority , and CIF worked! I could never have CIF working with an AF lens that doesn't have a AF/MF switch. Now I can.

Could you please explain, what exactly you tried? I couldn't get CIF to work with my D-FA 100 WR Macro based on the above discussion.

biz-engineer · 04-10-2019, 01:22 AM - **1 Like**

Originally posted by JensE

Could you please explain, what exactly you tried? I couldn't get CIF to work with my D-FA 100 WR Macro based on the above discussion.

- Button customization set to AF2 (back button AF), and CIF enabled, center point AFS focus priority.
- Press back button AF the camera focuses on whatever is , turn the lens focus ring to defocus the lens (for the experiment)
- Keep back button AF pressed and press the shutter button, the camera won't take a picture
- Keep pressing both back button AF and shutter button, turn the lens focus ring to get the center point in focus, as soon as the center point is in focus the camera will take the shot.

So, in real photography scenario, let's say photographing a mountain bike race at a corner of the race path:
- I could press the back button AF to focus at the distance I predict the subject to be when I want to have it snapped
- keep the back AF button pressed while recomposing (center point gets OOF)
- press the shutter button, and wait.

When the bike appears in the frame within the plane of focus, the camera will trigger.

photolady95 · 04-10-2019, 03:47 AM

Turning the focus ring of an AF lens, won't that damage an AF lens?

**JensE** · 04-10-2019, 03:48 AM

Originally posted by photolady95

Turning the focus ring of an AF lens, won't that damage an AF lens?

This requires a lens with quick-shift.

photolady95 · 04-10-2019, 03:51 AM

Originally posted by JensE

This requires a lens with quick-shift.

Thanks. I won't be trying that with any of my AF lens then.

biz-engineer · 04-10-2019, 04:50 AM

Originally posted by photolady95

Turning the focus ring of an AF lens, won't that damage an AF lens?

I did that for the purpose of testing with my dfa2470. In real case shooting you wouldn't defocus the lens manually, you'd press AF to focus the lens for the distance you want it to be focused and then recompose. For example, if there is a tree beside a bike track, you pre-focus on the tree trunk by pressing the back AF button, then recompose and press the shutter button, the camera won't take the shot until a bike arrives at the level of the tree. At no point in time the AF ring of the lens was touched.

photolady95 · 04-10-2019, 05:02 AM

Ah Okay. That makes more sense now. Thanks.

Tom G · 04-10-2019, 05:52 PM

I've always had problems with CIF - I tried for a while to set a user mode to use it, but between the back button focus which I always use and who knows what else it never was satisfactory for me, although sometimes I could get it to sort of work.

In this case I set things...

- Button customization set to AF2 (back button AF), and CIF enabled, center point AFS focus priority.
- Press back button AF the camera focuses on whatever is , turn the lens focus ring to defocus the lens (for the experiment) - or move the camera so it isn't pointing at something in focus as I would like to do...
- Keep back button AF pressed and press the shutter button, the camera takes a picture - a very blurry picture.

The way I think CIF should work doesn't seem to be how Pentax makes it work - or else I am missing something in the settings. What I'd like to have work is I press the back button to focus, then take my thumb off the focus button, then point the camera somewhere that the focus point isn't in focus and press the shutter button. Nothing should happen until there is something in focus at the focus point, then it should take a photo. I could live with having to hold the back button down, but I'd really rather not.

On messing around more it seems the whole focus priority doesn't seem to be a big concern to the camera - it will take a photo if things are in focus or not as soon as I press the shutter button (which is normally how I want it to behave and half the reason to use the back button). Maybe I'll go back to the manual and see if I can make sense of that - although the K-1 manual seems to only tell you how to get into a mode, and not what it actually does or how to make use of it.

**Oakland Rob** · 04-10-2019, 05:54 PM

I couldn't seem to get this to work on my K-1ii with the 28-105mm.

The camera will shoot the picture even if the shot is completely defocused.

**brightseal** · 04-10-2019, 06:34 PM

Are we are talking K1ii only and specifically?

Tom G · 04-10-2019, 06:34 PM

I messed around with this a bit more and was able to get it to sort of work with a manual focus lens if I held the back focus button down and then moved towards the subject until it was in focus at which point it would take a photo - sometimes. Sometimes it would just take a photo when I pressed the shutter button. In the earlier experiments I tried with the 100mm macro and the 24-70 - both autofocus lenses - it would just take photos as soon as I pressed the shutter button focus or not. The K-1 manual implies it only works with manual focus lenses and doesn't say anything about rear button focus.

photolady95 · 04-11-2019, 01:49 AM

I've only ever used it with manual focus lenses and it was the same, move in til it found focus then the shutter would fire. I've never tried it with using the back button focus or a K-1 cause I don't own one.

I would like if it would work with AF lenses but I see no real point in that, as far as I can see AF works okay for me in what I shoot at any rate. I don't do much sports photography, or birds in flight either, except gulls and pelicans. And they're easy to track.

**JensE** · 04-11-2019, 03:59 AM

Originally posted by Oakland Rob

I couldn't seem to get this to work on my K-1ii with the 28-105mm.

The camera will shoot the picture even if the shot is completely defocused.

Same here, I replicated the setting in biz-engineer's post, but the camera in most cases just fires immediately when using an AF lens. With a manual lens (SCM-A 200mm F/4), it works as described using the AF-button.

**Oakland Rob** · 04-12-2019, 07:58 AM

I wonder why they limited it to manual focus lenses. I'm no engineer, but it just seems like instead of doing a beep to confirm focus it tripped a relay to fire the shutter it would work.

pschlute · 04-12-2019, 01:20 PM - **1 Like**

Originally posted by Oakland Rob

I wonder why they limited it to manual focus lenses

They didn't simply limit it to manual focus lenses, but it is engineered to work with any manual focus lens or any AF lens that has a MF/AF switch on the lens itself.

The point being the camera needs to be set to AF mode, and the lens needs to be set to MF (or is a manual lens) for it to work as documented in the manuals.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Catch in focus, live view doesn't catch	Oktyabr	Troubleshooting and Beginner Help	4	02-24-2019 12:44 AM
Mark's K-1 II discovery thread	MarkJerling	Pentax K-1 & K-1 II	49	11-29-2018 01:58 AM
Nature Grizzly - Wolf Discovery Center outside Yellowstone	dwalt	Post Your Photos!	3	08-13-2018 12:39 PM
How to use Trap-focus or Catch-in focus	eurostar	Pentax DSLR and Camera Articles	34	07-22-2017 08:29 PM
Focus Trapping (aka Catch-In Focus)	regor	Pentax K-01	7	01-05-2013 11:32 PM

04-10-2019, 12:59 AM	#16
JensE Site Supporter Join Date: Dec 2015 Location: Leipzig Photos: Gallery \| Albums Posts: 1,969	Originally posted by biz-engineer I don't know. I tried with my K1 and DFA2470, with focus priority , and CIF worked! I could never have CIF working with an AF lens that doesn't have a AF/MF switch. Now I can. Could you please explain, what exactly you tried? I couldn't get CIF to work with my D-FA 100 WR Macro based on the above discussion.

04-10-2019, 01:22 AM - 1 Like	#17
biz-engineer Pentaxian Join Date: Feb 2015 Photos: Gallery Posts: 12,231	Originally posted by JensE Could you please explain, what exactly you tried? I couldn't get CIF to work with my D-FA 100 WR Macro based on the above discussion. - Button customization set to AF2 (back button AF), and CIF enabled, center point AFS focus priority. - Press back button AF the camera focuses on whatever is , turn the lens focus ring to defocus the lens (for the experiment) - Keep back button AF pressed and press the shutter button, the camera won't take a picture - Keep pressing both back button AF and shutter button, turn the lens focus ring to get the center point in focus, as soon as the center point is in focus the camera will take the shot. So, in real photography scenario, let's say photographing a mountain bike race at a corner of the race path: - I could press the back button AF to focus at the distance I predict the subject to be when I want to have it snapped - keep the back AF button pressed while recomposing (center point gets OOF) - press the shutter button, and wait. When the bike appears in the frame within the plane of focus, the camera will trigger.

04-10-2019, 03:47 AM	#18
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	Turning the focus ring of an AF lens, won't that damage an AF lens?

04-10-2019, 03:48 AM	#19
JensE Site Supporter Join Date: Dec 2015 Location: Leipzig Photos: Gallery \| Albums Posts: 1,969	Originally posted by photolady95 Turning the focus ring of an AF lens, won't that damage an AF lens? This requires a lens with quick-shift.

04-10-2019, 03:51 AM	#20
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	Originally posted by JensE This requires a lens with quick-shift. Thanks. I won't be trying that with any of my AF lens then.

04-10-2019, 04:50 AM	#21
biz-engineer Pentaxian Join Date: Feb 2015 Photos: Gallery Posts: 12,231	Originally posted by photolady95 Turning the focus ring of an AF lens, won't that damage an AF lens? I did that for the purpose of testing with my dfa2470. In real case shooting you wouldn't defocus the lens manually, you'd press AF to focus the lens for the distance you want it to be focused and then recompose. For example, if there is a tree beside a bike track, you pre-focus on the tree trunk by pressing the back AF button, then recompose and press the shutter button, the camera won't take the shot until a bike arrives at the level of the tree. At no point in time the AF ring of the lens was touched.

04-10-2019, 05:02 AM	#22
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	Ah Okay. That makes more sense now. Thanks.

04-10-2019, 05:52 PM	#23
Tom G New Member Join Date: Jan 2012 Posts: 13	I've always had problems with CIF - I tried for a while to set a user mode to use it, but between the back button focus which I always use and who knows what else it never was satisfactory for me, although sometimes I could get it to sort of work. In this case I set things... - Button customization set to AF2 (back button AF), and CIF enabled, center point AFS focus priority. - Press back button AF the camera focuses on whatever is , turn the lens focus ring to defocus the lens (for the experiment) - or move the camera so it isn't pointing at something in focus as I would like to do... - Keep back button AF pressed and press the shutter button, the camera takes a picture - a very blurry picture. The way I think CIF should work doesn't seem to be how Pentax makes it work - or else I am missing something in the settings. What I'd like to have work is I press the back button to focus, then take my thumb off the focus button, then point the camera somewhere that the focus point isn't in focus and press the shutter button. Nothing should happen until there is something in focus at the focus point, then it should take a photo. I could live with having to hold the back button down, but I'd really rather not. On messing around more it seems the whole focus priority doesn't seem to be a big concern to the camera - it will take a photo if things are in focus or not as soon as I press the shutter button (which is normally how I want it to behave and half the reason to use the back button). Maybe I'll go back to the manual and see if I can make sense of that - although the K-1 manual seems to only tell you how to get into a mode, and not what it actually does or how to make use of it.

04-10-2019, 05:54 PM	#24
Oakland Rob Loyal Site Supporter Join Date: Apr 2015 Location: Bay Area California Photos: Gallery \| Albums Posts: 798	I couldn't seem to get this to work on my K-1ii with the 28-105mm. The camera will shoot the picture even if the shot is completely defocused.

04-10-2019, 06:34 PM	#25
brightseal Site Supporter Join Date: Dec 2015 Photos: Albums Posts: 629	Are we are talking K1ii only and specifically?

04-10-2019, 06:34 PM	#26
Tom G New Member Join Date: Jan 2012 Posts: 13	I messed around with this a bit more and was able to get it to sort of work with a manual focus lens if I held the back focus button down and then moved towards the subject until it was in focus at which point it would take a photo - sometimes. Sometimes it would just take a photo when I pressed the shutter button. In the earlier experiments I tried with the 100mm macro and the 24-70 - both autofocus lenses - it would just take photos as soon as I pressed the shutter button focus or not. The K-1 manual implies it only works with manual focus lenses and doesn't say anything about rear button focus.

04-11-2019, 01:49 AM	#27
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	I've only ever used it with manual focus lenses and it was the same, move in til it found focus then the shutter would fire. I've never tried it with using the back button focus or a K-1 cause I don't own one. I would like if it would work with AF lenses but I see no real point in that, as far as I can see AF works okay for me in what I shoot at any rate. I don't do much sports photography, or birds in flight either, except gulls and pelicans. And they're easy to track.

04-11-2019, 03:59 AM	#28
JensE Site Supporter Join Date: Dec 2015 Location: Leipzig Photos: Gallery \| Albums Posts: 1,969	Originally posted by Oakland Rob I couldn't seem to get this to work on my K-1ii with the 28-105mm. The camera will shoot the picture even if the shot is completely defocused. Same here, I replicated the setting in biz-engineer's post, but the camera in most cases just fires immediately when using an AF lens. With a manual lens (SCM-A 200mm F/4), it works as described using the AF-button.

04-12-2019, 07:58 AM	#29
Oakland Rob Loyal Site Supporter Join Date: Apr 2015 Location: Bay Area California Photos: Gallery \| Albums Posts: 798	I wonder why they limited it to manual focus lenses. I'm no engineer, but it just seems like instead of doing a beep to confirm focus it tripped a relay to fire the shutter it would work.

04-12-2019, 01:20 PM - 1 Like	#30
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,198	Originally posted by Oakland Rob I wonder why they limited it to manual focus lenses They didn't simply limit it to manual focus lenses, but it is engineered to work with any manual focus lens or any AF lens that has a MF/AF switch on the lens itself. The point being the camera needs to be set to AF mode, and the lens needs to be set to MF (or is a manual lens) for it to work as documented in the manuals.