different ways AF lenses work

jayartibee · 07-06-2019, 01:17 PM

probably being a bit dense here but as far as I can tell the 'standard SLR kit lens' when using MF seems to disengage from the body focus system but the DA 35 millimetre lens remains in gear so that when you use the focus ring it appears to turn the whole focus motor gearing system of the camera body. Is this normal?

**jatrax** · 07-06-2019, 01:36 PM

Yes. The difference is called "Quick Shift". Some lenses have it, some do not. If the lens has quick shift then you may use the auto focus and then use the manual focus ring to fine tune or adjust your focus.

However, if the lens does not have quick shift then turning the manual focus ring while the auto focus is engaged turns all of the gears back to and including the AF motor in the camera. This is generally viewed as possibly damaging to the camera and it is suggested that you disengage the camera AF motor by placing the camera in manual focus mode before using the manual focus ring on any lens without quick shift.

**monochrome** · 07-06-2019, 01:37 PM

The DA35/2.8 Macro does have QuickShift. The focus ring should disengage for manual touch up.

The DA35/2.4 AL ‘Plastic Fantastic’ does not have QuickShift and remains coupled to the AF motor at all times unless you mechanically place the camera body in MF.

Adam · 07-06-2019, 01:41 PM

This should go without saying, but just in case you don't know: if your lens doesn't have quick shift, you should never turn the focusing ring manually when in AF mode. Be sure to disengage the gears by putting the camera in MF first.

Adam
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07-06-2019, 01:17 PM	#1
jayartibee New Member Join Date: May 2019 Posts: 4	different ways AF lenses work probably being a bit dense here but as far as I can tell the 'standard SLR kit lens' when using MF seems to disengage from the body focus system but the DA 35 millimetre lens remains in gear so that when you use the focus ring it appears to turn the whole focus motor gearing system of the camera body. Is this normal?

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07-06-2019, 01:36 PM	#2
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Yes. The difference is called "Quick Shift". Some lenses have it, some do not. If the lens has quick shift then you may use the auto focus and then use the manual focus ring to fine tune or adjust your focus. However, if the lens does not have quick shift then turning the manual focus ring while the auto focus is engaged turns all of the gears back to and including the AF motor in the camera. This is generally viewed as possibly damaging to the camera and it is suggested that you disengage the camera AF motor by placing the camera in manual focus mode before using the manual focus ring on any lens without quick shift.

07-06-2019, 01:37 PM	#3
monochrome Loyal Site Supporter Join Date: Mar 2008 Location: Working From Home Photos: Gallery \| Albums Posts: 26,276	The DA35/2.8 Macro does have QuickShift. The focus ring should disengage for manual touch up. The DA35/2.4 AL ‘Plastic Fantastic’ does not have QuickShift and remains coupled to the AF motor at all times unless you mechanically place the camera body in MF.

07-06-2019, 01:41 PM	#4
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	This should go without saying, but just in case you don't know: if your lens doesn't have quick shift, you should never turn the focusing ring manually when in AF mode. Be sure to disengage the gears by putting the camera in MF first. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers: