[RoccoStiglitz]

Hi all,

I'm trying to get catch-in focus to work with a D FA 24-70 on a K-1. Is it possible with an AF lens that doesn't have an AF/MF switch? Tried the lens release button trick but the AF just operates normally. I have everything set as instructed in the manual. Am I missing somthing? Is there a way to get it to work with this lens?

Thanks

[stevebrot]

Is it possible with an AF lens that doesn't have an AF/MF switch?

Welcome to the Pentax Forums!

Catch-In-Focus only works with the AF switch in the AF position, so it is not a feature available to you with most AF lenses. As for "lens release button trick", I would caution against attempting to operate any AF lens partially mounted.

If you really need CIF, your best option is a manual focus lens or an AF lens with an AF/MF switch on the lens body.


Steve

[Franc]

should be the MF position

[RoccoStiglitz]

Welcome to the Pentax Forums!

Catch-In-Focus only works with the AF switch in the AF position, so it is not a feature available to you with most AF lenses. As for "lens release button trick", I would caution against attempting to operate any AF lens partially mounted.

If you really need CIF, your best option is a manual focus lens or an AF lens with an AF/MF switch on the lens body.


Steve

That seems to be the case which is unfortunate as it seems like it'd be easy to implement with a focus priority before shutter release setting in the CIS menu. Bummer.

Thanks

---------- Post added 04-06-17 at 12:08 AM ----------

should be the MF position

Not according to the manual or the PF CIS tutorial. Switch on MF with CIS turned on the shutter will release at full press subject in focus or not.

[stevebrot]

That seems to be the case which is unfortunate as it seems like it'd be easy to implement with a focus priority before shutter release setting in the CIS menu. Bummer.

Yes, that is how it works, with the important provision that the lens must be manual focus. CIF (aka focus trapping) is a manual focus technique, meaning that the feature only exists when the attached lens is not coupled for AF. It might help to point out that the feature is a historic accident of design that was user-discovered and turned out to be handy for certain use cases.

What are you wanting to do that requires a focus trap when using the D FA 24-70/2.8? After all, it is a perfectly good auto-focus lens.


Steve

[RoccoStiglitz]

Yes, that is how it works, with the important provision that the lens must be manual focus. CIF (aka focus trapping) is a manual focus technique, meaning that the feature only exists when the attached lens is not coupled for AF. It might help to point out that the feature is a historic accident of design that was user-discovered and turned out to be handy for certain use cases.

What are you wanting to do that requires a focus trap when using the D FA 24-70/2.8? After all, it is a perfectly good auto-focus lens.


Steve

I was reading the tutorial here which has a picture of a humming bird approaching a feeder that was captured with a focus trap. Camera mounted on a tripod, remote release with the button locked seems like it could be a good pseudo motion sensor kind of setup.

[Na Horuk]

For CiF You need:
a) Turn off shutter priority
b) Select the right AF mode in camera (on some cameras it is AF.A, on some AF.S, check manual)
c) The lens mount must be conductive to short the AF contacts (lenses with fully plastic mount or with nonconductive coatings or lenses like Helios 44-2 that do not cover the contacts will not work)
d) Lens must be switched to MF. Lens with no AF is always MF. If lens is AF and there is no switch, like on most DA lenses, then you cannot CiF. Some users report that lenses with Focus Clamp can use CiF, as the clamp turns the lens to MF. I have not tested this personally, but it sounds interesting. Think about F or FA 100mm macro lens. Super sharp optics, decent price, and it should allow CiF, at least according to some reports
e) Camera must be set to AF (button near the lens mount). Check manual which AF setting, for those cameras that have multiple options
f) Enable CiF in Menu (near the end)

Now hold the shutter button and wait for something to get into focus, or twist the focus ring slowly until it hits something. This will trigger the shutter. You can even use burst mode with it.

CiF is great for old MF lenses. It is useless for modern lenses with no AF button. While you can push the mount release button on the camera, I would really advise against this.

Camera mounted on a tripod, remote release with the button locked seems like it could be a good pseudo motion sensor kind of setup.

Maybe you can use something like Pentax M 50mm f1.7 or Pentax M 28mm f2.8 or even one of the medium telephoto primes from the film era. Most of these are super affordable with good image quality. The M50mm f1.7 is about as good as the DA 50mm f1.8, only it has older lens coatings so it is recommended to use a good tight lens hood on it. M 50mm f2 and lens hood should cost under $60. Cheaper than motion detection sensors

[jbinpg]

1) Steve had it mixed up - the lens switch must be in manual and the body in AF for CIF to work.

2) CIF will not work with back button focus enabled.

3) AF mode must be AFS rather than AFC.

[RoccoStiglitz]

Think I've got my answer. No lens AF/MF switch means no CIS/trap focus.

Thanks for the replies everyone.

[stevebrot]

1) Steve had it mixed up - the lens switch must be in manual and the body in AF for CIF to work.

Steve said what you said. Both are mixed up


Steve

(...yes, that Steve...)

[stevebrot]

Camera mounted on a tripod, remote release with the button locked seems like it could be a good pseudo motion sensor kind of setup.

Yes! That is one of the cooler ways to use CIF and might be a good excuse to head down the path to LBA* perdition with your K-1 and manual focus lenses.


Steve

* Lens Buying Addiction (LBA) is often initiated by the innocent purchase of vintage manual focus lenses. The slope is slippery, very slippery...)

[RoccoStiglitz]

LBA...

Yeah. I'm looking at legacy lenses right now. I'm thinking a fast 85mm would be a nice addition.

[Canada_Rockies]

When I bought my SF-1 some years ago, I tried it with a 70-210 A lens. Got 3 nice hummers landing while I ate supper. Can't remember the drive mode that allowed it to take the shots with the remote (physical) locked ON.