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07-20-2010, 01:19 PM   #16
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QuoteOriginally posted by JeffJS Quote
The AF/MF switch on the camera engages and disengages the AF by retracting the screw drive on the camera. There's probably a switch inside the mechanism that tells the camera to shut off the screw drive when retracted (so the motor doesn't spin randomly). I'd love to be able to focus trap (CIF) my FA limited lenses.
The cheat for AF lenses without a MF switch is to hold the lens lock button in. The lens lock button disengages the screw drive from the lens and so the screw drive simply spins in its socket. The draw back to this method is of coarse the AF is spinning, but if you are only using it in short bursts, you probably aren't going to drain the battery any more than you normally would.

Thank you
Russell

07-20-2010, 08:54 PM   #17
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QuoteOriginally posted by Russell-Evans Quote
The cheat for AF lenses without a MF switch is to hold the lens lock button in. The lens lock button disengages the screw drive from the lens and so the screw drive simply spins in its socket.
Oh wow! An undocumented cheat! And it works! Now I can use my 5 AF lenses just like my 70 MF ones! But really, THANKS for this tip. These forums are an ongoing seminar, endless and profound.
07-20-2010, 11:28 PM   #18
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Well feed me nails and call me Rusty!! A little awkward but it works. Focus trap the 31.... yum! Just hold the lens lock button with the Johnny Cash finger, press the shutter release and twist the focus ring..

01-10-2011, 06:50 PM   #19
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Well, I can't get the CIF function to do a durn thing on my K200D. Using a 50mm 1.7 manual focus lens, AF-S selected, camera in AF mode, stabbing or holding the shutter release, but no joy. Anyone get this to work on a K200D?

01-10-2011, 07:05 PM   #20
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QuoteOriginally posted by nosliwmit Quote
Well, I can't get the CIF function to do a durn thing on my K200D. Using a 50mm 1.7 manual focus lens, AF-S selected, camera in AF mode, stabbing or holding the shutter release, but no joy. Anyone get this to work on a K200D?
Yep, do it all the time with A 28, A 50, and M100 on my K200D.

It is most effective using the center focus point, and I just hold the shutter release half-way down while focusing. I will say it isn't incredibly precise, and it helps to slowly rotate the focus ring, going past the target, then back to it.

I will admit though, most of the time with manual focus lenses I just set to F8 and the hyperfocal distance and forget about it.
01-11-2011, 01:55 AM   #21
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QuoteOriginally posted by nosliwmit Quote
Well, I can't get the CIF function to do a durn thing on my K200D. Using a 50mm 1.7 manual focus lens, AF-S selected, camera in AF mode, stabbing or holding the shutter release, but no joy. Anyone get this to work on a K200D?
Did you enable CIF? On my K20D, that's item [34] on the Custom Settings menu. (Wait, now that I think about it, you *must* have enabled CIF, else you wouldn't have this problem. Ignore that question.)

What is the mount of the lens you've tried? If it's a screwmount lens in a PK adapter, the lens base probably doesn't short out the contacts on the camera mount. If it's a nice bright shiny K-mount, it *should* safely short those contacts. The contacts *must* be shorted for CIF to work.

I use CIF extensively. I often use longish weirdish glass in bellows, the bellows base being a nice bright shiny PK-M mount. The last couple days, I've concentrated on a 127/1.8 projector lens (no diaphragm, aperture is always wide-open) for dreamy shots. Aim at the subject, hold the shutter down, slowly rack the lens till focus is achieved, and SNAP!

That reminds me: CIF needs light, and contrast. CIF won't actuate if you're aiming at a bland surface. It also won't work with an M-type lens with the aperture stopped down. I find that f/8-11 is usually the limit. It's best to keep the aperture at f/5.6 or wider, and to focus on something with a contrast gradient, especially an edge. Good luck!
01-13-2011, 11:18 PM   #22
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QuoteOriginally posted by nosliwmit Quote
Well, I can't get the CIF function to do a durn thing on my K200D. Using a 50mm 1.7 manual focus lens, AF-S selected, camera in AF mode, stabbing or holding the shutter release, but no joy. Anyone get this to work on a K200D?
I eventually got this to work. Not sure if it's because I put the camera in "P" mode or if that's just a coincidence. I think I just wasn't patient enough--it's not lightning-fast...
01-21-2011, 07:47 PM   #23
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It is unfortunate to hear that the "Catch in Focus" function operates only with the shutter release depressed. When I first read about CIF in camera reviews I thought - Yea! Finally after years of waiting, someone else has finally caught up with the Yashica 230, 270, and 300 AF SLR bodies that had "Trap Focus".

Then after reading this thread and the manual I was then left thinking - Drat! They still fall short.

The Yashicas I mention (made approximately between 1987-1997) had what is called Trap Focus. It operates much the same way except for one important difference. You only need to depress the shutter release once (if you are using AF) to establish focus and prep the body to work. After that is done you can walk away from the camera and just let it do its thing.

It's great! One good example for me was when I set my 300 up to take pictures of hummingbirds. After I had it prepared I went inside, ate lunch, and then took a nap. When I figured the roll might be done and the lighting had changed significantly, I simply went back outside and retrieved the camera. Low and behold while I was sleeping, it was happily taking pictures of the birds for me.

That is why when I post my most interesting hummingbird shot, I tell folks that I have to be honest. I didn't take this photo, my camera did.

01-21-2011, 08:30 PM   #24
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Never had to stand "body side" of my K20 with my finger on shutter button,
let my thumb do the talkin, via locked remote. Have heard of folks using rubber band and
a marble with a "flat" ground on it to do the same, when lockable remote wasnt
handy. AC/DC converter saves recharge cycles on batteries if a AC source is near by.

NOTE: If a AC/DC converter is used outdoors or wet location AC source used SHOULD have
an GFCI (Ground Fault Circut Interrupter) integral. Lets keep everything safe,and fun.

Last edited by BillM; 01-25-2011 at 08:05 PM. Reason: life essential safety considerations
10-09-2015, 05:44 AM   #25
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Sorry to dig up this 5 years old topic but I have a very similar issue.
I'd like to use catch-in focus on a K20D with some M42 lenses (Tokina 135/2.8 and Takumar 55/1.8) used with the infinity adapter (third party i.e. not Pentax). I've set custom menu #34 Catch-in focus to 2 (On) and of course #36 Using aperture ring to 2 (Permitted).
Middle focus point only is selected, focus mode is set to AF-S and I do get focus confirmation (I get it in M mode as well).
I focus manually with the expo button pressed halfway to get the confirmation then I reposition the camera (tried with and without the expo button pressed halfway) so the scene in the focus zone is out of focus and press the expo button fully. The camera takes the shot right away.
I also tried changing custom menu #14 AF with the shutter button half pressed to 2 (Off) and getting the focus confirmation with the AF button. Confirmation works, I recompose and press the shutter button, camera takes the picture right away again.

My understanding of the above is that I need to short some contact(s?) on lens mount. My question is which one(s)? There are 7 on the outer side of the lens mount (6 to 8 o'clock) and two more inside at 5 o'clock.
10-09-2015, 07:54 AM   #26
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QuoteOriginally posted by gazdi Quote
Sorry to dig up this 5 years old topic but I have a very similar issue.
I'd like to use catch-in focus on a K20D with some M42 lenses (Tokina 135/2.8 and Takumar 55/1.8) used with the infinity adapter (third party i.e. not Pentax). I've set custom menu #34 Catch-in focus to 2 (On) and of course #36 Using aperture ring to 2 (Permitted).
Middle focus point only is selected, focus mode is set to AF-S and I do get focus confirmation (I get it in M mode as well).
I focus manually with the expo button pressed halfway to get the confirmation then I reposition the camera (tried with and without the expo button pressed halfway) so the scene in the focus zone is out of focus and press the expo button fully. The camera takes the shot right away.
I also tried changing custom menu #14 AF with the shutter button half pressed to 2 (Off) and getting the focus confirmation with the AF button. Confirmation works, I recompose and press the shutter button, camera takes the picture right away again.

My understanding of the above is that I need to short some contact(s?) on lens mount. My question is which one(s)? There are 7 on the outer side of the lens mount (6 to 8 o'clock) and two more inside at 5 o'clock.
Just use a piece of aluminum foil to short them all (on the right side near the lens removal button).
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