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08-31-2017, 04:30 AM   #1
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Catch In Focus on AF lenses, is it ok to do?

Yes, I'm well aware that the CIF is meant for MF lenses only, and that some AF lenses that have a AF/MF switch can do CIF also, but I read somewhere that you can actually manage this trick as well on a AF lens by depressing down on the Lens lock/release button whilst taking the shot. What i wanted to know is if it is ok to do so, does it cause any damage, can anything bad happen and what is the worst case scenario from using this 'hack' from time to time? I'm a pretty careful guy, with the K-1 switched off I find my right hand pinky is easily placed to perform this trick and it feels as tho even with the button pressed down you'd have to be a real numpty whilst shooting to still manage to twist the lens off (ie it feels still quite stiff to swivel when holding for shooting).

Thoughts?

You see... I now have a FA 50mm 1.4 that I am quite happy with, there are times however I wish I could use this CIF trick, AF.C and AF in general on the K-1 I find a bit hit or miss. There have been plenty of scenarios whereby if I could have used a CIF trick for a particular shot and toggle back to AF quickly (without lens swapping), that would have been ideal!

Cheers,

Bruce

08-31-2017, 05:26 AM   #2
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Don't see why you should start fumbling around with the lens release button? Simply switch the camera to MF, use the lens like any other manual focus lens. That is what the switch is there for. I wonder what you thought it would do. This will allow you to use catch in focus, there is no "trick" behind it and there's nothing to worry about. If you should use a lens that has an additional AF/MF switch, make sure to switch that to MF, too to disengage any mechanical connections that might not take manual operation too well.
08-31-2017, 05:31 AM - 1 Like   #3
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QuoteOriginally posted by Arvid Quote
That is what the switch is there for.
No. Catch in Focus requires camera to be set to AF, lens to be set to MF, and lens must have conductive mount base. There are some differences between cameras throughout the generations regarding the CiF conditions, so check your camera model manual for details
Pressing the lens release button can trick the camera into believing the lens is in MF mode, despite the lens being AF and not even allowing MF mode (since it has no swtich)
QuoteOriginally posted by BruceBanner Quote
What i wanted to know is if it is ok to do so, does it cause any damage, can anything bad happen and what is the worst case scenario from using this 'hack' from time to time
I think the main fear is that you might rotate the lens and damage the AF screw drive or even drop the lens. I think you have to press lens release and also rotate the lens a little so the lens contacts are no longer recognized. Its just a little fiddly and you have to be really careful.
I totally agree with you that it is pretty annoying that CiF is only available with AF lenses that have MF switch, and most modern FA and DA lenses do not have that switch. One thing you can do is purchase a fairly affordable M 50mm f1.7 or even splurge for an A 50mm f1.4. That way you get a lens that is different from the one you have and gives you additional features (CiF, faster aperture). Later you can decide which lens to sell or whether to keep both. Fortunately, you have lots of options between 35mm and 60mm. Many 50mm primes are very affordable. Just be careful not to get one that has plastic mount or anodized mount! That can also prevent CiF. But people usually scratch off the insulating coating or add some conductive foil as a workaround

Last edited by Na Horuk; 08-31-2017 at 05:36 AM.
08-31-2017, 05:37 AM   #4
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QuoteOriginally posted by Na Horuk Quote
No. Catch in Focus requires camera to be set to AF, lens to be set to MF, and lens must have conductive mount base. There are some differences between cameras throughout the generations regarding the CiF settings, so check your camera model manual for details
Pressing the lens release button can trick the camera into believing the lens is in MF mode, despite the lens being AF and not even allowing MF mode (since it has no swtich)
Ok, I see. Thanks for correcting that!

Edit.
Yup, I went and did what I should have done before posting: I checked it on my camera and of course it's the way Na Horuk said. I just remembered it differently, never used CiF much although I mostly use manual lenses. It limits you to the center focus point only and that's not really useful for me most of the time. Anyway, apoligies if my first comment came off a little rude, I will try to think at least twice and check once before hitting "post reply" next time.


Last edited by Arvid; 08-31-2017 at 06:02 AM.
08-31-2017, 08:56 AM   #5
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QuoteOriginally posted by Na Horuk Quote
Pressing the lens release button can trick the camera into believing the lens is in MF mode, despite the lens being AF and not even allowing MF mode (since it has no swtich)
Pressing the button retracts the AF pawl, but does not trick the camera into anything. For that one must block the data pin on the mount.

Addendum: Rotating the lens in the mount to disconnect the contacts carries the risk of poor exposure since the aperture actuator will not be properly engaged.

QuoteOriginally posted by BruceBanner Quote
Thoughts?

You see... I now have a FA 50mm 1.4 that I am quite happy with, there are times however I wish I could use this CIF trick, AF.C and AF in general on the K-1 I find a bit hit or miss. There have been plenty of scenarios whereby if I could have used a CIF trick for a particular shot and toggle back to AF quickly (without lens swapping), that would have been ideal!
Using CIF is the same as using AF.S, center point only. There is no advantage to either accuracy or precision. Both use exactly the same mechanism and share the same shortfalls. Where CIF comes into its own is for focus trapping where the subject moves into focus to trigger the shutter.

If one has an AF lens mounted and detected as such, there is seldom any valid use case for CIF.


Steve
08-31-2017, 01:07 PM - 1 Like   #6
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QuoteOriginally posted by Na Horuk Quote
No. Catch in Focus requires camera to be set to AF, lens to be set to MF, and lens must have conductive mount base. There are some differences between cameras throughout the generations regarding the CiF conditions, so check your camera model manual for details
Pressing the lens release button can trick the camera into believing the lens is in MF mode, despite the lens being AF and not even allowing MF mode (since it has no swtich)

I think the main fear is that you might rotate the lens and damage the AF screw drive or even drop the lens. I think you have to press lens release and also rotate the lens a little so the lens contacts are no longer recognized. Its just a little fiddly and you have to be really careful.
I totally agree with you that it is pretty annoying that CiF is only available with AF lenses that have MF switch, and most modern FA and DA lenses do not have that switch. One thing you can do is purchase a fairly affordable M 50mm f1.7 or even splurge for an A 50mm f1.4. That way you get a lens that is different from the one you have and gives you additional features (CiF, faster aperture). Later you can decide which lens to sell or whether to keep both. Fortunately, you have lots of options between 35mm and 60mm. Many 50mm primes are very affordable. Just be careful not to get one that has plastic mount or anodized mount! That can also prevent CiF. But people usually scratch off the insulating coating or add some conductive foil as a workaround
Ah, ok. That might be a tad more fiddly and tricky to master then. I read here for example first and then thought I should post the question on these forums. The user says;

"YOU CAN USE IT WITH ANY LENS. JUST SET AF-S, THEN USE YOUR FINGER TO PUSH DOWN THE LENS-RELEASE BUTTON AND.. YEEEAH! THE FEATURE IS HERE!

Ok, camera motor rotates wildly, but you just use your hand do focus. When camera detects focused image, it starts shooting.

SIMPLE.

And on K-5 remember to set AF priority to LOCKED focus otherwise it takes pictures even without being focused."

I wanted to see if any others here on these forums actually uses this trick frequently and can report back any more information or tips on mastering it.

Oh, and I have plenty of Manual lenses to test this feature on, such as a 50mm 1.7 and 24mm F2.8 etc, it works excellently, the downfall is lens swapping time when you want to toggle back to needing AF.


QuoteOriginally posted by Arvid Quote
Ok, I see. Thanks for correcting that!

Edit.
Yup, I went and did what I should have done before posting: I checked it on my camera and of course it's the way Na Horuk said. I just remembered it differently, never used CiF much although I mostly use manual lenses. It limits you to the center focus point only and that's not really useful for me most of the time. Anyway, apoligies if my first comment came off a little rude, I will try to think at least twice and check once before hitting "post reply" next time.
That's ok

QuoteOriginally posted by stevebrot Quote
Pressing the button retracts the AF pawl, but does not trick the camera into anything. For that one must block the data pin on the mount.

Addendum: Rotating the lens in the mount to disconnect the contacts carries the risk of poor exposure since the aperture actuator will not be properly engaged.



Using CIF is the same as using AF.S, center point only. There is no advantage to either accuracy or precision. Both use exactly the same mechanism and share the same shortfalls. Where CIF comes into its own is for focus trapping where the subject moves into focus to trigger the shutter.

If one has an AF lens mounted and detected as such, there is seldom any valid use case for CIF.


Steve
That's interesting Steve, did you try it for yourself or read that somewhere, or is that just following logic and reason to that point because yer... well... knowledgeable 'n' stuff lol.

Personally I have been in lots of scenarios whereby CIF works better than me using AF.S (center point only). Here's a few examples;

Example One; On Wednesday, parents were invited to 'sit & watch' week for those of us whom have daughters (and some son's) that do ballet. Normally the parents aren't allowed to watch but occasionally they permit a sit in week, usually once a term (and they are ok with photos being taken). It can be a quiet studio, and even with the sound effects off, the constant shutter clicking of the camera could become annoying to others, so it's something I am aware of, I want to take the least amount of shots possible to avoid being annoying to others.
At times the ballerinas are stationary, using MF or AF is fine in these instances, but often they are on the move, jumping and leaping towards us parents. Now, even with AF.C selected, I think we can all agree that a fast moving target coming towards us AF.C just can't keep up, and if I toggle to MF only, by the time my focus indicator is up it's too late to take the shot as it will be out of focus, I just can't anticipate or react quick enough for those shots, nor do I want to spam the shutter. Having a CIF moment for these scenarios would be the best work around.

Example Two; Kid on a swing, yer taking pictures of them as they either swing towards you or away and you want the shot to fire off in focus, AF.S and AF.C cannot cope properly enough for these scenarios, CIF works best. But now the kid is off the swing and is now doing something else in the playground that AF.S or AF.C is suitable to use.

I don't want to have to swap a FA50mm 1.4 for a A series 50mm 1.7, and with kids and trying to 'capture the moment' by the time you've swapped they are probably stopped doing that CIF movement and are now onto something else! Hence the purpose to this thread. It maybe that I feel so strongly about CIF that I sell my brand new FA50mm 1.4 and try and hunt down a prime portrait AF lens that has a AF/MF switch on it.

I'm aware of tricks like applying foil to the connectors bla bla, but that obviously is not the solution that I need.

Cheers,

Bruce
08-31-2017, 01:28 PM   #7
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QuoteOriginally posted by BruceBanner Quote
That's interesting Steve, did you try it for yourself or read that somewhere, or is that just following logic and reason to that point because yer... well... knowledgeable 'n' stuff lol.
Tested it with my K-3 in hand just before I posted and the K-3, operationally, is about 80% similar to your K-1. What happens is that the AF motor goes herkey jerkey crazy.


Steve

Last edited by stevebrot; 08-31-2017 at 01:37 PM.
08-31-2017, 01:33 PM   #8
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QuoteOriginally posted by BruceBanner Quote
At times the ballerinas are stationary, using MF or AF is fine in these instances, but often they are on the move, jumping and leaping towards us parents. Now, even with AF.C selected, I think we can all agree that a fast moving target coming towards us AF.C just can't keep up, and if I toggle to MF only, by the time my focus indicator is up it's too late to take the shot as it will be out of focus, I just can't anticipate or react quick enough for those shots, nor do I want to spam the shutter. Having a CIF moment for these scenarios would be the best work around.
QuoteOriginally posted by BruceBanner Quote
Example Two; Kid on a swing, yer taking pictures of them as they either swing towards you or away and you want the shot to fire off in focus, AF.S and AF.C cannot cope properly enough for these scenarios, CIF works best. But now the kid is off the swing and is now doing something else in the playground that AF.S or AF.C is suitable to use.
Yes, those are good cases and both are examples of focus trapping, the one case I suggested where CIF is useful.* FWIW in both cases, the part of the subject that trapped focus will likely have moved beyond the plane of focus by the time the shutter opens.


Steve

* As opposed to CIF using the focus ring, the more common method.

08-31-2017, 01:39 PM   #9
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QuoteOriginally posted by stevebrot Quote
Tested it with my K-3 in hand just before I posted and the K-3, operationally, is about 80% similar to your K-1.


Steve
I'm not looking for any guarantees, but if it's given that the user is careful when trying this 'hack' can you foresee any damaging problems arising from using this technique on AF lenses? For example, the lens release button is depressed, the lens twisted slightly, and now shooting 'CIF' style, if there is a good grip on the lens itself (which there should be as it's being MF, and is a light lens such as a 50mm), then really what harm can it do (other than a possible bad exposed image, whereby I prolly would prefer that as I can correct somewhat that in PP but not a out of focus shot).

I just wanted to know if there were any horror stories from doing this hack lol
08-31-2017, 01:46 PM - 1 Like   #10
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QuoteOriginally posted by BruceBanner Quote
I don't want to have to swap a FA50mm 1.4 for a A series 50mm 1.7,
Sure. Lots of things to consider. Pentax announced a new DFA 50mm lens, and it looks like it has AF MF switch:
What to expect from new DFA 50mm f/1.4 and DFA 85mm - PentaxForums.com
It will also have QS and WR and silent AF, most likely. DFA* and that big size imply this will be a top tier lens, so it won't be cheap. And we don't know exactly when it will come out, we only have some concept images

Regarding the lens dismount button press.. I think lots of people have been doing that with their DA lenses. I don't think you risk much by trying it once to see if you are comfortable with it. There were other threads about this method in the past, so if you search you might get more info
08-31-2017, 02:19 PM   #11
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QuoteOriginally posted by Na Horuk Quote
Sure. Lots of things to consider. Pentax announced a new DFA 50mm lens, and it looks like it has AF MF switch:
What to expect from new DFA 50mm f/1.4 and DFA 85mm - PentaxForums.com
It will also have QS and WR and silent AF, most likely. DFA* and that big size imply this will be a top tier lens, so it won't be cheap. And we don't know exactly when it will come out, we only have some concept images

Regarding the lens dismount button press.. I think lots of people have been doing that with their DA lenses. I don't think you risk much by trying it once to see if you are comfortable with it. There were other threads about this method in the past, so if you search you might get more info
I just gave the hack a go with my K-1 and FA 50mm 1.4. What I can confirm is it works, but you need to;

a) press the lens release button
b) slightly twist the lens in the only direction it can go i.e towards being released
c) pay attention to the LCD screen on the back, there is a 'sweet spot' whereby it gets some information back such as shutter speed and aperture etc.
d) now it works
e) HOWEVER, I cannot get it to shoot properly, that is as stevebrot says, the shot is underexposed and aperture off etc. Compare the two images; one is using AF, 50mm focal, ISO 160, F1.4 1/50th shutter speed (TAv mode), the other using the same settings this time adopting the hack as outlined above, now it has no DOF and ISO 6400 :/

EDIT: Also those new lenses look promising. I was actually trying to use the Lens Database feature of this forum to just try and find any lens that has AF/MF switch, I couldn't come up with much tho... Anyone know how to filter a search for this? Or know any off the top of their heads?
Attached Images
View Picture EXIF
PENTAX K-1  Photo 
View Picture EXIF
PENTAX K-1  Photo 

Last edited by BruceBanner; 08-31-2017 at 02:54 PM.
08-31-2017, 05:02 PM   #12
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The solution is simple.
Buy another K1 and put the MF lense on it. Surely a back up body would be essential
Don't tell your wife I put you up to it
08-31-2017, 06:35 PM   #13
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QuoteOriginally posted by BruceBanner Quote
Also those new lenses look promising. I was actually trying to use the Lens Database feature of this forum to just try and find any lens that has AF/MF switch, I couldn't come up with much tho... Anyone know how to filter a search for this? Or know any off the top of their heads?
The DA* 55 has a MF/AF switch and is extremely good on the K1. A lightly used one popped up at a price I couldn't refuse, so I bought it with the aim to move it on at a profit, but after testing it on my K1 I'm not letting it go anywhere. It's so good that the new up coming D FA 50 will need to be something extra special for me to replace it.

Glenn
09-01-2017, 02:37 AM   #14
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QuoteOriginally posted by BruceBanner Quote
EDIT: Also those new lenses look promising. I was actually trying to use the Lens Database feature of this forum to just try and find any lens that has AF/MF switch, I couldn't come up with much tho... Anyone know how to filter a search for this? Or know any off the top of their heads?
I think only some * lenses have that feature and the new DFA zooms. In the 50 range you have DA* 55mm with the switch and DFA 50mm f2.8 macro
09-01-2017, 03:30 AM   #15
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QuoteOriginally posted by Na Horuk Quote
I think only some * lenses have that feature and the new DFA zooms. In the 50 range you have DA* 55mm with the switch and DFA 50mm f2.8 macro
Really? I tried to have a good look at the DFA 50mm 2.8 Macro on google images, and no image could I find had a good image of the AF/MF switch, I think I vaguely saw a 'clutch' button or summin, and I didn't know what that meant

I saw the DA 55*, tempted. However, with the newer DFA on the horizon I also holding back. Perhaps even we'll see a few DA* 55's on the marketplace
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