Catch-in-Focus defect on K-x

Marlboroman · 12-06-2010, 06:42 AM

Heyho,

i recently discovered that my Catch-in-Focus option stopped working on my k-x. With a MF Lens attached the camera does not bother wether CiF is activr or not.

Any suggestions what is wrong or how to fix this?

greez,
Marlboroman

Last edited by Marlboroman; 12-06-2010 at 06:50 AM.

newarts · 12-06-2010, 07:18 AM

Originally posted by Marlboroman

Heyho,

i recently discovered that my Catch-in-Focus option stopped working on my k-x. With a MF Lens attached the camera does not bother wether CiF is activr or not.

Any suggestions what is wrong or how to fix this?

greez,
Marlboroman

Check all your settings.

Make certain at least some of the camera mount pins are short-circuited.

Dave

JeffJS · 12-06-2010, 08:45 AM

Also make sure you are still set for AF-S.

reeftool · 12-06-2010, 10:30 AM

There have been some third party lenses through the years that were almost all plastic and I have seen some metal mounts that were painted. A plastic or painted surface won't short the pins to allow catch in focus to work. If the mount is metal, the paint can be sanded off (carefully!) or you could slide a strip of alumunium foil between the lens and mount to short the pins. I keep some foil in my bag to use with my Taks which won't short the pins.

blende8 · 12-13-2010, 05:23 AM

reeftool is correct on this.

But I am wondering why this must be so.
Is there any need for the camera to have the pins shortened?
It asks for the focal length so it should know that a lens is attached.
Perhaps we could persuade Pentax to change this?
I mean this aluminum foil trick isn't exactly ideal.

newarts · 12-13-2010, 06:22 AM

Originally posted by blende8

reeftool is correct on this.

But I am wondering why this must be so.
Is there any need for the camera to have the pins shortened?
It asks for the focal length so it should know that a lens is attached.
Perhaps we could persuade Pentax to change this?
I mean this aluminum foil trick isn't exactly ideal.

Aluminum duct tape is a good alternative until Pentax fixes the firmware (if ever.)

Quote:

It asks for the focal length so it should know that a lens is attached.

K-x asks for focal length even with no lens.

Dave

reeftool · 12-13-2010, 07:27 AM

The camera gets lens information through the pin connections. It will ask for lens info if it doesn't receive it regardless whether the pins are shorted or open which is the case with most Takumars. There have been discussions in the past as to whether or not catch in focus was a planned feature or an accidental benefit of the design of the auto focus system. I never remembered reading anything about it in the K10D manual and first heard about it from other users here in the forum a few years ago. Newer camera bodies document it in their manuals.

falconeye · 12-13-2010, 07:50 AM

Originally posted by reeftool

There have been discussions in the past as to whether or not catch in focus was a planned feature or an accidental benefit of the design of the auto focus system.

Interesting note.
Accidental benefit is plausible enough.

When Pentax moved the AF in LV from the AF button to the shutter button (in some K-7 firmware release), all of a sudden the mirror flipped in LV when touching the shutter button even in manual focus mode, provided LV focus was set to phase AF. So, the mirror action flag wasn't unset by AF manual mode. It is unset by LV focus set to contrast/face AF.

That's a sign that the firmware uses a bunch of flags (or logical expressions) which are rather independent and a manual focus lens probably disables one flag (lens AF motor) while not disabling another (autotrigger when in focus). The AF mode switch would set both modes, but again forgot the mirror action flag ...

So, the firmware design lacks a flag state chart or state matrix diagram.

You get the idea ...

blende8 · 12-13-2010, 11:14 AM

Originally posted by newarts

Aluminum duct tape is a good alternative until Pentax fixes the firmware (if ever.)

Is that working stable? Will it not become loose from the bajonet locking pin and the AF Pin?

It seems that one has to shorten just one pin, any pin, to get it to work.

newarts · 12-13-2010, 12:52 PM

Originally posted by blende8

Is that working stable? Will it not become loose from the bajonet locking pin and the AF Pin?

It seems that one has to shorten just one pin, any pin, to get it to work.

In my experience aluminum duct tape lasts well. I typically have used it only in the region of the pins to be shorted. At least once I covered an entire m42 base and held up well.

jolepp · 12-13-2010, 01:16 PM

CIF is not the only difference when no pins are shorted, on green button press in M-mode the k-x releases the aperture lever and flips the mirror with an M-lens (chromed base, some pin(s) shorted), but leaves both alone with no lens (no pins shorted as with a coated base M42). Again, no obvious reason for the difference in operation.

Dubious Drewski · 12-13-2010, 01:26 PM

I don't want to derail this thread, but I don't think I should start another.

What are the conditions needed to make catch-in work? This is what I'm trying:

•A K7 with an old Asahi 50mm F1.4, a Rokinon 85mm f1.4 and my 50-135 (just to see how different an autofocus lens behaves.)

•I have my camera set to center point and AFS. And I turned on the catch-in focus option in the menu.

BUT It doesn't matter if I'm 40 feet out of focus, the camera takes the picture if I press the shutter; it doesn't wait for focus.

What am I doing wrong?

EDIT: OK, thanks for the help everyone :P . I phoned Pentax support and we found out that you must have the shutter button activate focus. You can not use the thumb AF button.

0rangepeel · 12-13-2010, 06:14 PM

I think I know what's wrong, I had this problem and posted in another thread.

Like someone mentioned, it is not set in AF.S

Basically, what happens is when you put on an AF lens on, it lets you choose between AF.S/AF.C/AF.A on a K-x. But, when you take off the AF lens, and put on a manual lens, you cannot change this mode anymore. When you stick a manual focus lens on, it is stuck no whatever mode you last set it to.

So, if you want CIF to work again, you will have to mount the AF lens back on, switch the mode back to AF.S, then put your manual lens back on, and voila it will work again.

This is a lame software error, but for the higher end bodies, switching between AF.S/AF.C is done with a dedicated button, and not a menu, so it was probably thought few users with an entry level dslr would be dabbling with MF lenses and switching AF modes at the same time.

Cheers!

tdannar · 03-02-2011, 10:17 PM

I cannot get the CIF to work on my K-x. I have tried all the above and it will not automatically fire. I will focus on something, press the shutter release, move into the area that I focused and nothing happens. If I focus on my hand and hold down the shutter release, it will fire when my hand comes back into focus, but it will not fire again unless I release the shutter and press it again, hold it, and move my hand back into focus.

This sounds like a feature that I would like to use........

**crewl1** · 03-02-2011, 11:22 PM

@tdannar
It is working as designed, the problem is the K-x does not have the ability to enable constant shutter press since it does not have a wired remote facility. This is where building a mechanical device to do what you are doing with your finger is required.
You also need to set drive mode to continuous if you want it to repeatedly take pictures once something comes into focus.
See https://www.pentaxforums.com/forums/pentax-camera-field-accessories/132847-d-...lease-k-x.html

12-06-2010, 06:42 AM	#1
Marlboroman Junior Member Join Date: Aug 2010 Photos: Gallery Posts: 29	Catch-in-Focus defect on K-x Heyho, i recently discovered that my Catch-in-Focus option stopped working on my k-x. With a MF Lens attached the camera does not bother wether CiF is activr or not. Any suggestions what is wrong or how to fix this? greez, Marlboroman Last edited by Marlboroman; 12-06-2010 at 06:50 AM.

12-13-2010, 07:50 AM	#8
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	Originally posted by reeftool There have been discussions in the past as to whether or not catch in focus was a planned feature or an accidental benefit of the design of the auto focus system. Interesting note. Accidental benefit is plausible enough. When Pentax moved the AF in LV from the AF button to the shutter button (in some K-7 firmware release), all of a sudden the mirror flipped in LV when touching the shutter button even in manual focus mode, provided LV focus was set to phase AF. So, the mirror action flag wasn't unset by AF manual mode. It is unset by LV focus set to contrast/face AF. That's a sign that the firmware uses a bunch of flags (or logical expressions) which are rather independent and a manual focus lens probably disables one flag (lens AF motor) while not disabling another (autotrigger when in focus). The AF mode switch would set both modes, but again forgot the mirror action flag ... So, the firmware design lacks a flag state chart or state matrix diagram. You get the idea ... Last edited by falconeye; 12-13-2010 at 07:55 AM.

12-13-2010, 01:26 PM	#12
Dubious Drewski Forum Member Join Date: Mar 2008 Location: Calgary Posts: 67	I don't want to derail this thread, but I don't think I should start another. What are the conditions needed to make catch-in work? This is what I'm trying: •A K7 with an old Asahi 50mm F1.4, a Rokinon 85mm f1.4 and my 50-135 (just to see how different an autofocus lens behaves.) •I have my camera set to center point and AFS. And I turned on the catch-in focus option in the menu. BUT It doesn't matter if I'm 40 feet out of focus, the camera takes the picture if I press the shutter; it doesn't wait for focus. What am I doing wrong? EDIT: OK, thanks for the help everyone :P . I phoned Pentax support and we found out that you must have the shutter button activate focus. You can not use the thumb AF button. Last edited by Dubious Drewski; 12-13-2010 at 02:49 PM.

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12-06-2010, 07:18 AM	#2
newarts Inactive Account Join Date: Dec 2008 Location: Ames, Iowa, USA Photos: Albums Posts: 2,965	Originally posted by Marlboroman Heyho, i recently discovered that my Catch-in-Focus option stopped working on my k-x. With a MF Lens attached the camera does not bother wether CiF is activr or not. Any suggestions what is wrong or how to fix this? greez, Marlboroman Check all your settings. Make certain at least some of the camera mount pins are short-circuited. Dave

12-06-2010, 08:45 AM	#3
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Also make sure you are still set for AF-S.

12-06-2010, 10:30 AM	#4
reeftool Pentaxian Join Date: Dec 2007 Location: Upstate New York Photos: Gallery \| Albums Posts: 9,554	There have been some third party lenses through the years that were almost all plastic and I have seen some metal mounts that were painted. A plastic or painted surface won't short the pins to allow catch in focus to work. If the mount is metal, the paint can be sanded off (carefully!) or you could slide a strip of alumunium foil between the lens and mount to short the pins. I keep some foil in my bag to use with my Taks which won't short the pins.

12-13-2010, 05:23 AM	#5
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521	reeftool is correct on this. But I am wondering why this must be so. Is there any need for the camera to have the pins shortened? It asks for the focal length so it should know that a lens is attached. Perhaps we could persuade Pentax to change this? I mean this aluminum foil trick isn't exactly ideal.

12-13-2010, 06:22 AM	#6
newarts Inactive Account Join Date: Dec 2008 Location: Ames, Iowa, USA Photos: Albums Posts: 2,965	Originally posted by blende8 reeftool is correct on this. But I am wondering why this must be so. Is there any need for the camera to have the pins shortened? It asks for the focal length so it should know that a lens is attached. Perhaps we could persuade Pentax to change this? I mean this aluminum foil trick isn't exactly ideal. Aluminum duct tape is a good alternative until Pentax fixes the firmware (if ever.) Quote: It asks for the focal length so it should know that a lens is attached. K-x asks for focal length even with no lens. Dave

12-13-2010, 07:27 AM	#7
reeftool Pentaxian Join Date: Dec 2007 Location: Upstate New York Photos: Gallery \| Albums Posts: 9,554	The camera gets lens information through the pin connections. It will ask for lens info if it doesn't receive it regardless whether the pins are shorted or open which is the case with most Takumars. There have been discussions in the past as to whether or not catch in focus was a planned feature or an accidental benefit of the design of the auto focus system. I never remembered reading anything about it in the K10D manual and first heard about it from other users here in the forum a few years ago. Newer camera bodies document it in their manuals.

12-13-2010, 11:14 AM	#9
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521	Originally posted by newarts Aluminum duct tape is a good alternative until Pentax fixes the firmware (if ever.) Is that working stable? Will it not become loose from the bajonet locking pin and the AF Pin? It seems that one has to shorten just one pin, any pin, to get it to work.

12-13-2010, 12:52 PM	#10
newarts Inactive Account Join Date: Dec 2008 Location: Ames, Iowa, USA Photos: Albums Posts: 2,965	Originally posted by blende8 Is that working stable? Will it not become loose from the bajonet locking pin and the AF Pin? It seems that one has to shorten just one pin, any pin, to get it to work. In my experience aluminum duct tape lasts well. I typically have used it only in the region of the pins to be shorted. At least once I covered an entire m42 base and held up well.

12-13-2010, 01:16 PM	#11
jolepp Veteran Member Join Date: Oct 2010 Location: Finland Photos: Albums Posts: 3,196	CIF is not the only difference when no pins are shorted, on green button press in M-mode the k-x releases the aperture lever and flips the mirror with an M-lens (chromed base, some pin(s) shorted), but leaves both alone with no lens (no pins shorted as with a coated base M42). Again, no obvious reason for the difference in operation.

12-13-2010, 06:14 PM	#13
0rangepeel Senior Member Join Date: Nov 2009 Location: Vancouver Photos: Gallery Posts: 111	I think I know what's wrong, I had this problem and posted in another thread. Like someone mentioned, it is not set in AF.S Basically, what happens is when you put on an AF lens on, it lets you choose between AF.S/AF.C/AF.A on a K-x. But, when you take off the AF lens, and put on a manual lens, you cannot change this mode anymore. When you stick a manual focus lens on, it is stuck no whatever mode you last set it to. So, if you want CIF to work again, you will have to mount the AF lens back on, switch the mode back to AF.S, then put your manual lens back on, and voila it will work again. This is a lame software error, but for the higher end bodies, switching between AF.S/AF.C is done with a dedicated button, and not a menu, so it was probably thought few users with an entry level dslr would be dabbling with MF lenses and switching AF modes at the same time. Cheers!

03-02-2011, 10:17 PM	#14
tdannar New Member Join Date: Jul 2010 Location: Sand Springs Photos: Gallery Posts: 11	I cannot get the CIF to work on my K-x. I have tried all the above and it will not automatically fire. I will focus on something, press the shutter release, move into the area that I focused and nothing happens. If I focus on my hand and hold down the shutter release, it will fire when my hand comes back into focus, but it will not fire again unless I release the shutter and press it again, hold it, and move my hand back into focus. This sounds like a feature that I would like to use........

03-02-2011, 11:22 PM	#15
crewl1 Site Supporter Join Date: Jul 2010 Location: Los Angeles, CA Photos: Gallery \| Albums Posts: 9,807	@tdannar It is working as designed, the problem is the K-x does not have the ability to enable constant shutter press since it does not have a wired remote facility. This is where building a mechanical device to do what you are doing with your finger is required. You also need to set drive mode to continuous if you want it to repeatedly take pictures once something comes into focus. See https://www.pentaxforums.com/forums/pentax-camera-field-accessories/132847-d-...lease-k-x.html