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12-03-2017, 03:02 PM   #1
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Quick Shift Focus

I've just purchased my first lens with quick shift focus, a DA*300. I did a search on this forum and have consulted the operators manual but didn't find an answer to this question. Is there any way to disable or turn off the quick shift? I can foresee some situations where I would not want it on.

A second question. It's also my first lens that is compatible with the lens correction feature in my K-1. Is there any downside to leaving on all four lens correction settings in C4 or are there some situations where it is best turned off? Or is it meant to be on only for on demand or intermittent use? Obviously I don't have an understanding of this feature yet.

Thanks for any help.

12-03-2017, 03:04 PM   #2
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QuoteOriginally posted by wanderer2 Quote
I've just purchased my first lens with quick shift focus, a DA*300. I did a search on this forum and have consulted the operators manual but didn't find an answer to this question. Is there any way to disable or turn off the quick shift? I can foresee some situations where I would not want it on.
Simply refrain from touching the focusing ring and you won't interfere with the camera's AF.

QuoteOriginally posted by wanderer2 Quote
A second question. It's also my first lens that is compatible with the lens correction feature in my K-1. Is there any downside to leaving on all four lens correction settings in C4 or are there some situations where it is best turned off? Or is it meant to be on only for on demand or intermittent use? Obviously I don't have an understanding of this feature yet.
Distortion corrections add about 2 seconds of processing time per shot, so you wouldn't want to use this in burst mode as it will severely cripple your framerate and buffer. The others don't add much overhead, but remember that they only apply to JPEGs.

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12-03-2017, 06:28 PM   #3
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Thanks for the info. It the corrections only work in jpg there isn't much point in my using them. Although I do use simultaneous RAW and jpg the latter is only for emailing a file.

As far as refraining from touching the focusing ring, that's my worry. I can envision being all set up with camera on a tripod, carefully focused, and inadvertently brushing against the focusing ring, getting the focus off without realizing it, which is a major problem in a landscape I hope to use for a large print. So I assume there is no way to disable quick shift focus?

Thanks again, I appreciate the feedback.
12-03-2017, 08:02 PM   #4
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It is apparent you do not understand what "quick shift" focus is. It simply means a designed-in mechanism for temporarily over-riding AF to instantly manually focus the lens, without having to switch the camera or lens to the MF mode. It is a MF "touch-up" or a fine-tuning correction after AF has been achieved. To engage this capability, after the AF has achieved its focus, you continue to hold down the half-press of the shutter release button, or the AF button, while you operate MF on the lens's focusing collar in the usual manner to get focus as you want it to be, then fire the shutter immediately without letting up on the half press. As soon as you do let up, the quick shift feature disappears. It only operates in AF mode, for which it is an over-ride.

As with any lens, when on a tripod, you must take care to not inadvertently touch the lens's focusing collar to throw it off-focus.

12-03-2017, 08:35 PM   #5
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QuoteOriginally posted by mikesbike Quote
It is apparent you do not understand what "quick shift" focus is. It simply means a designed-in mechanism for temporarily over-riding AF to instantly manually focus the lens, without having to switch the camera or lens to the MF mode. It is a MF "touch-up" or a fine-tuning correction after AF has been achieved. To engage this capability, after the AF has achieved its focus, you continue to hold down the half-press of the shutter release button, or the AF button, while you operate MF on the lens's focusing collar in the usual manner to get focus as you want it to be, then fire the shutter immediately without letting up on the half press. As soon as you do let up, the quick shift feature disappears. It only operates in AF mode, for which it is an over-ride.

As with any lens, when on a tripod, you must take care to not inadvertently touch the lens's focusing collar to throw it off-focus.
I think I understand what quick shift focus is - my understanding is the same as you describe. The difference between what you describe and they way it seems to me it works for me is that I use BBF focusing with the camera on a tripod and I do not want to change that focus whatsoever until I'm done photographing that scene. With all other AF lenses I use (none of them have quick shift capability), if the lens is set on AF mode the focus ring will not change the focus when focus has been achieved with BBF - the ring isn't engaged, it just moves without altering the focus. What I'm concerned about is what you describe in your last sentence, accidentally contacting the focus ring on the DA* 300 and changing the focus - even a small amount would ruin the photo. I think this could happen since I'm unaccustomed to this feature and may forget about it when I'm absorbed in taking the photo.

That's why I'm asking if there is a way to turn off quick shift focus. It appears that there isn't.

Last edited by wanderer2; 12-03-2017 at 08:40 PM.
12-03-2017, 09:31 PM   #6
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I haven't found it an issue with any quick shift lens, including the DA*300mm which has a generously sized ring. If I've bumped it enough to shift the focusing ring I've probably bumped it enough to shift the tripod and I have to reset anyway.

You could always apply a piece of gaffers tape once you've set the focus. This might count as turning quick shift off
12-04-2017, 05:54 AM   #7
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I think you’ll find in use it doesn’t pose an issue. All the lenses I use for weddings have quick shift focus and I’ve never had an incident of accidentally throwing the focus off. With the DA* lenses, the focus ring tends to be quite generous in size and I’ve not had a problem with how I hold the lens.
12-04-2017, 08:55 AM   #8
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In reflecting further on the Quick Shift feature I guess it was a dumb question. Since this feature appears to be entirely mechanical and not related to the electronics of the camera or lens there would have to be a switch on the lens to turn it off, one like the AF/MF switch. Since there isn't any such thing that answers my question. As I said before this is my first lens with this feature and I didn't thoroughly think about it.

I hope you all are right that it won't be a problem for me. But, I am quite clumsy. ) I will try to be careful.

Thanks for all the responses.

12-04-2017, 02:59 PM   #9
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You are welcome- do not think any question is a dumb one. Modern DSLRs are complex, even though well-designed and easy to use, once it is understood. You now understand that it is only while holding down the BBF that quick-shift could be employed, during which it should be an easy matter as to the proper handling of the lens collar. In lenses not having this feature, where the focusing collar turns during AF, which is common, you want to be careful not to touch the focusing collar during AF anyway, since that puts a strain on the AF focusing motor. So you build a good habit for handling. Once AF has been achieved and you let up on the button, the quick shift option is gone in lenses so equipped.
12-05-2017, 01:34 PM   #10
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<<You now understand that it is only while holding down the BBF that quick-shift could be employed, during which it should be an easy matter as to the proper handling of the lens collar. >>

Actually it doesn't seem to work this way, if I understand the sentence above. I checked this with the new DA*300 on my K-1 and after BBF focus and then releasing the BBF button the lens collar will still rotate and refocus. So it appears to me that care will have to be taken not to avoid any contact with the lens focusing collar throughout the shooting process, not just when the BBF (AF) button is depressed.
12-05-2017, 01:44 PM   #11
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It's not a dumb question at all! Yes, it works as you've suggested, you do have to avoid turning the ring when you've released the AF button. On the plus side, quick shift makes it dead easy to go from AF to full time manual focus when using back button focus.

It's maybe worth pointing out that the two macro lenses, dfa50mm and dfa100mm (non-WR model), both have focus clamps to lock the ring down which would be the feature you'd like on your DA*300mm. In practice though, I virtually never find I need to use these clamps.
12-05-2017, 09:22 PM   #12
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QuoteOriginally posted by BrianR Quote
It's not a dumb question at all! Yes, it works as you've suggested, you do have to avoid turning the ring when you've released the AF button. On the plus side, quick shift makes it dead easy to go from AF to full time manual focus when using back button focus.

It's maybe worth pointing out that the two macro lenses, dfa50mm and dfa100mm (non-WR model), both have focus clamps to lock the ring down which would be the feature you'd like on your DA*300mm. In practice though, I virtually never find I need to use these clamps.
Thanks Brian. I'll watch for that focus ring lock with future lens purposes, although I don't think it's an absolute necessity for me. Sometimes it just difficult for awhile to adapt to the idea of something new (to me).
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