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07-02-2022, 07:03 PM   #1
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Do F lenses bang to stop ?

I came across the F 28-80mm and used on my digital camera, it was quite noisy in focusing and bang to stop at both ends, unlike modern shaft drive lenses that stop smoothly, wonder if that was the design or the film lenses not working properly on digital camera ? here's an example on Youtube, it seems all F lenses worked the same.




07-02-2022, 07:17 PM   #2
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QuoteOriginally posted by lotech Quote
I came across the F 28-80mm and used on my digital camera, it was quite noisy in focusing and bang to stop at both ends, unlike modern shaft drive lenses that stop smoothly, wonder if that was the design or the film lenses not working properly on digital camera ? here's an example on Youtube, it seems all F lenses worked the same.

https://www.youtube.com/watch?v=_BvGx6uUHA4
I switched to Canon because I loved their EF/usm lenses - better in my view than what Pentax was doing for AF {‘F’ lenses}. In recent years, I purchased a FA 28-105mm lens so I could set aperture at the lens for my K-30 {which now suffers from “Dark Image Syndrome}, so I guess I’ve never owned a ‘F’ lens, but l still doubt if Pentax’s first attempt at AF was up to their usual standards. In my case, the screw drive makes more noise than the in-lens motors do, but nothing like you describe. Back before I got a 55-300mm PLM lens, my wife used to complain about the noise made by DA 55-300mm focusing, but frankly, the lens I had then was no noiser than the ‘FA’ lens is.

Last edited by reh321; 07-02-2022 at 07:23 PM.
07-02-2022, 07:33 PM   #3
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QuoteOriginally posted by reh321 Quote
I switched to Canon because I loved their EF/usm lenses - better in my view than what Pentax was doing for AF {‘F’ lenses}. In recent years, I purchased a FA 28-105mm lens so I could set aperture at the lens for my K-30 {which now suffers from “Dark Image Syndrome}, so I guess I’ve never owned a ‘F’ lens, but l still doubt if Pentax’s first attempt at AF was up to their usual standards. In my case, the screw drive makes more noise than the in-lens motors do, but nothing like you describe. Back before I got a 55-300mm PLM lens, my wife used to complain about the noise made by DA 55-300mm focusing, but frankly, the lens I had then was no noiser than the ‘FA’ lens is.
I got the DA 55-300mm non PLM too, and it produced higher pitch noise than the old F, but did not bang to stop. If those lenses can be made using internal focus (faster focus) then the noise will not be too much of a thing,
07-02-2022, 07:36 PM   #4
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I've owned multiple copies of the F 35-70 and F 70-210, and yes, both have rather violent AF action and "bang" when focus is attained.

07-02-2022, 07:57 PM   #5
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I used to own a few F lenses for my SFXn and Z-1. Yes they have rather 'violent' AF. A little disconcerting if you are new to them.
07-02-2022, 08:08 PM   #6
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QuoteOriginally posted by sbc Quote
I used to own a few F lenses for my SFXn and Z-1. Yes they have rather 'violent' AF. A little disconcerting if you are new to them.
Yes that troubled me a bit, whether it was 'normal' by design or a flaw are not ideal.
07-03-2022, 04:14 AM   #7
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completely normal

07-03-2022, 06:23 AM - 1 Like   #8
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Yes, that is a familiar sound. Not only do they bang, they are also quite fast AF-lenses. That is what I noticed on my SFX's. And it did not bother me then and it does not bother me now. Simply because of the great the results they deliver. Take the F 50mm F1.4 and you will not believe your eyes if you see the result.
07-03-2022, 12:35 PM   #9
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It has always seemed to me that F lenses were the most obviously designed around a set of constraints the engineers didn't really know how to address gracefully.

In comparison to the first-generation 35-70 f2.8 AF lens on the ME-F, the F lenses are worlds faster, but it is obvious from everything about them they were designed around focusing fast with the camera motor.

They are generally rotten for manual focusing, with sloppy feel, but they work well in autofocus.

And all of the ones I have used have "banged" like that...
I still have a 50 f1.7, 35-70, and 70-210 in pretty common rotation...

-Eric
07-04-2022, 05:30 AM   #10
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Indeed, the lenses bang. FA lenses do the same, for the record. I remember being surprised by the torque and hard stops of the FA 100-300 F4.7. It's fine once you're used to it.
07-04-2022, 06:27 AM   #11
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QuoteOriginally posted by bdery Quote
Indeed, the lenses bang. FA lenses do the same, for the record. I remember being surprised by the torque and hard stops of the FA 100-300 F4.7. It's fine once you're used to it.
My FA doesn’t do this on my K-30. Maybe the particular camera makes a difference??
07-04-2022, 01:31 PM   #12
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I have a fair number of FA lenses. Interestingly, most "bang" on my old film SLRs and also on my (now my daughter's) K5. On the K-1ii, the focussing is far less violent and more precise.
So, I also think it's (partly) body dependent.
07-05-2022, 05:30 AM   #13
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QuoteOriginally posted by reh321 Quote
My FA doesn’t do this on my K-30. Maybe the particular camera makes a difference??
Which FA?
07-05-2022, 05:38 AM   #14
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QuoteOriginally posted by bdery Quote
Which FA?
28-105mm
07-06-2022, 05:31 AM   #15
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QuoteOriginally posted by reh321 Quote
28-105mm
A more recent model I believe. Seeing as it almost certainly has a hard stop, it comes to it slowly instead of full head-on?
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