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05-25-2011, 04:16 PM   #1
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Quick-shifting FA without quick-shift

What would happen if I put an auto-focus lens without quick-shift on a modern body (e.g. the K-5) and turned the focus ring with the lens set to auto-focus? Would I feel that the focus ring was stuck if I only tried to turn it very carefully, and hence be able to stop before damaging something? Or would something (what) break very easily?

I am considering buying semi-old primes with auto-focus. I currently have a couple of manual-focus primes, and a quick-shift zoom, which are all completely safe when it comes to focusing manually.

05-25-2011, 04:20 PM   #2
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QuoteOriginally posted by hjb981 Quote
What would happen if I put an auto-focus lens without quick-shift on a modern body (e.g. the K-5) and turned the focus ring with the lens set to auto-focus? Would I feel that the focus ring was stuck if I only tried to turn it very carefully, and hence be able to stop before damaging something? Or would something (what) break very easily?

I am considering buying semi-old primes with auto-focus. I currently have a couple of manual-focus primes, and a quick-shift zoom, which are all completely safe when it comes to focusing manually.
In a lens without Quickshift, the focus ring is locked in place when the camera is set to AF and can only be turned by the camera. With my 77 I notice this immediately, and the lock is quite firm -- I think you'd really have to make a deliberate effort to wrench the focus knob against this resistance before doing any damage.
05-25-2011, 04:26 PM   #3
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There is almost no chance you will break a AF lens without quick shift unless you are the Incredible Hulk. There is no give at all so you will notice it is locked in place immediately.
05-25-2011, 04:56 PM   #4
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QuoteOriginally posted by KxBlaze Quote
There is almost no chance you will break a AF lens without quick shift unless you are the Incredible Hulk. There is no give at all so you will notice it is locked in place immediately.
Mr. McGee, don't make me angry. You wouldn't like me when I'm angry.

05-25-2011, 04:57 PM   #5
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Thanks for your replies. I am now reassured that I can safely consider auto-focus lenses without quick-shift. I am not the Incredible Hulk , and I also always handle my things carefully.

/Jonas
05-25-2011, 05:00 PM   #6
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I actually found I could quite easily turn the focus ring on the DA L 18-55 in AF by accident, as it is not really locked in place but rather just has more resistance than normal. Caused no damage (and I quickly moved on from it anyway).

The only other non-QS lenses I've used are the FA limiteds, and those are quite distinctly locked in place. You'd have to put in a considerable amount of effort to turn them, and I have a hard time imagining someone doing it by mistake. I've never managed to do it, despite me often forgetting that they don't have QS and trying to turn them anyway.
05-25-2011, 05:24 PM   #7
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There is a safeway to use Quickshift on a FA lens without stripping the screw drive or the AF motor. You will need to half press and hold the lens release button while you adjust the focus. this will disengage the screw drive.

AF will resume when you release the lens release button, so its better to take the shot while the button is still half depressed.
05-25-2011, 07:59 PM   #8
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A lot of wrong replies I see.

You can turn the ring no problem, I have FA 31, 43, 77, 135. These all turn manually when in autofocus. You don't strip anything and there is no lock. These lenses don't lock and unlock, do you know how much effort that would be if the camera had to unlock before rotating and relock when finished. Remember that if it is locking then the motor isn't free to turn either. Think about it, you would burn up the system when you lens is hunting. It may seem locked but it isn't. It is coupled to a gear assembly and motor which are always free to turn. If they weren't free to turn then the camera could never autofocus. Takes extra force because you also have to rotate the gear assembly and motor inside the camera. My baby cousin can turn it, she is no incredible hulk.

05-25-2011, 08:24 PM   #9
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QuoteOriginally posted by atlnq9 Quote
A lot of wrong replies I see.

You can turn the ring no problem, I have FA 31, 43, 77, 135. These all turn manually when in autofocus. You don't strip anything and there is no lock. These lenses don't lock and unlock, do you know how much effort that would be if the camera had to unlock before rotating and relock when finished. Remember that if it is locking then the motor isn't free to turn either. Think about it, you would burn up the system when you lens is hunting. It may seem locked but it isn't. It is coupled to a gear assembly and motor which are always free to turn. If they weren't free to turn then the camera could never autofocus. Takes extra force because you also have to rotate the gear assembly and motor inside the camera. My baby cousin can turn it, she is no incredible hulk.
Ok buddy thanks for letting us know how you look after your equipment.
05-25-2011, 08:28 PM   #10
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I don't know why some people continue to perpetuate the myth about screw drive AF lens without QS. Focus ring do not 'lock' and I highly doubt turning the focus ring a few times while in AF mode will do any damage to the screw drive motor. I have turned the focus ring on my Tamron 70-300 AF lens with the K20D set to AF.S. Other than a momentary initial resistance to the turning motion, the focus ring turns quite smoothly in either direction with a bit more resistance than a lens with the QS feature. If it wasn't for the herky-jerky motion when overcoming the resistance at the start, this somewhat stiffer turning motion would be better suited as a fine tuning focus aid than the free-wheeling focus rings on the lenses with the QS feature. Of course, the screw drive motor whines when the focus ring is turned but it's not anymore alarming than turning any other motor without power.

Thanks,
05-25-2011, 08:39 PM   #11
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I just push the lens release button to MF.
05-26-2011, 12:21 PM   #12
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QuoteOriginally posted by atlnq9 Quote
A lot of wrong replies I see.

You can turn the ring no problem, I have FA 31, 43, 77, 135. These all turn manually when in autofocus. You don't strip anything and there is no lock.
Might not "strip" anything, at least not right away, but you're applying torque in places the system wasn't designed to withstand, so I doubt it's good for the camera or lens.
05-26-2011, 01:14 PM   #13
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QuoteOriginally posted by Marc Sabatella Quote
Might not "strip" anything, at least not right away, but you're applying torque in places the system wasn't designed to withstand, so I doubt it's good for the camera or lens.
He's applying torque in the same places just the power is coming from the wrong end IMO.
While I would't recommend MFing non QS AF lens whilst camera is in AF mode, I don't think ocasionally doing so would harm the gears or motor...
05-26-2011, 01:36 PM   #14
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QuoteOriginally posted by Eruditass Quote
I just push the lens release button to MF.
What?
05-26-2011, 01:40 PM   #15
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QuoteOriginally posted by axl Quote
He's applying torque in the same places just the power is coming from the wrong end IMO.
While I would't recommend MFing non QS AF lens whilst camera is in AF mode, I don't think ocasionally doing so would harm the gears or motor...
I shift my truck's manual transmission without using the clutch but I wouldn't do this.
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