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Lenses with floating elements
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PostPosted: Sun Jun 23, 2024 11:18 am    Post subject: Lenses with floating elements Reply with quote
It is my understanding that years / decades after a lens that has floating elements was built, these floating elements can start to cause problems in terms of reduced optical quality.

First, is my understanding correct? And if yes, is there a way to determine if a lens has floating elements?

Regards, Christine


PostPosted: Sun Jun 23, 2024 1:36 pm    Post subject: Reply with quote
Iirc, floating elements if the rear element does not move as lens is focused.

Also iirc, there are problems especially with wide angle lenses that have floating elements combined with inaccurate adapters.

More info here: https://forum.mflenses.com/who-made-the-first-floating-element-design-t47591.html

Use forum search for "floating" for more topics here...such as https://forum.mflenses.com/wa-with-floating-element-and-adapter-t73811.html

The focusing mechanics of lenses with floating elements are of course more complex. Improper realignment after servicing, or through usage is also possible especially if something comes loose


PostPosted: Sun Jun 23, 2024 2:55 pm    Post subject: Reply with quote
Interesting, thank you. One of the answers in that first topic indicates this is not the issue I am/was having.

Regards, C


PostPosted: Sun Jun 23, 2024 3:42 pm    Post subject: Reply with quote
connloyalist wrote:
Interesting, thank you. One of the answers in that first topic indicates this is not the issue I am/was having.

Regards, C


What issue? Smile


PostPosted: Sun Jun 23, 2024 3:52 pm    Post subject: Reply with quote
Well, you may remember me saying at some point that my Minolta MD 35-70 (the good one) is pretty bad. Consensus on that was that I must have a bad copy. Then the other day I remembered that I used to have a Minolta MD 28mm 2.8 which is equally bad. I know it is not a generic Minolta problem because I have a 135mm 3.5 and a 200mm 4.0 that are both stellar.

So I was thinking maybe a floating elements problem? But one of the posters in the other topic listed the Minolta primes with floating elements and the 28mm 2.8 isn't one of them.

Nevertheless, I am bit hesitant to dive deeper into Minolta lenses because twice now I have had lenses that are really pretty lousy. Shorter focal lengths not working well on crop camera's? Or maybe just bad luck?

Regards, Christine


PostPosted: Sun Jun 23, 2024 4:37 pm    Post subject: Reply with quote
I remember...could be older wide lenses just aren't that good, especially on m43 sensor? How are your other older wide angles on m43? Is the small dense m43 sensor so demanding? I look forward to input from more knowledgeable members!


PostPosted: Sun Jun 23, 2024 4:50 pm    Post subject: Reply with quote
visualopsins wrote:
I remember...could be older wide lenses just aren't that good, especially on m43 sensor? How are your other older wide angles on m43? Is the small dense m43 sensor so demanding? I look forward to input from more knowledgeable members!


I will have to retest some of my wide lenses, but I as I remember the Nikon F and Olympus OM 24mm 2.8's are fine. So far for me this has been a problem specific to Minolta, oddly. And I would like to know the why and how.

Regards, C.


PostPosted: Sun Jun 23, 2024 6:34 pm    Post subject: Reply with quote
Of the Minolta manual focus SR mount 28mm lenses the f/2 is the only one with floating elements. The f/2.8 and f/3.5 do not have floating elements.

Personally I have no bad experiences with any of my Minolta lenses (approx. 250 of them), other than the odd copy here and there with haze. But I don't use them on crop cameras.


PostPosted: Mon Jun 24, 2024 2:06 pm    Post subject: Re: Lenses with floating elements Reply with quote
connloyalist wrote:
It is my understanding that years / decades after a lens that has floating elements was built, these floating elements can start to cause problems in terms of reduced optical quality.

First, is my understanding correct? And if yes, is there a way to determine if a lens has floating elements?

Regards, Christine


The Canon FD lenses with their cams + nylon bearings movements will suffer of wear on the nylon over time and with floating elements in primes and zooms that becomes even more a problem than in a simple one unit focusing scheme.


PostPosted: Sat Jul 13, 2024 6:31 pm    Post subject: Reply with quote
Generally the more complex the lens design, the more that can go wrong over time. But I don't recall reading anything that especially singles out floating elements in this regard.


PostPosted: Sat Jul 13, 2024 6:51 pm    Post subject: Reply with quote
Need to differentiate between lenses with floating elements where rear group is typicsl TC design (thanks stevemark) with front groups moving, and more complex designs of zooms where distances of internal elements move.


PostPosted: Sun Jul 14, 2024 9:20 am    Post subject: Re: Lenses with floating elements Reply with quote
Ernst Dinkla wrote:


The Canon FD lenses with their cams + nylon bearings movements will suffer of wear on the nylon over time and with floating elements in primes and zooms that becomes even more a problem than in a simple one unit focusing scheme.


Ernst, in fact the Canon FD lenses wouldn't have any longterm problems if ever they had been equipped with nylon bearings. Typically (with the only exceptions being lenses that came out at the end of the FD era...), they all have a combination of a brass core and rubber bearings - the latter turning into a sticky mess.


PostPosted: Sun Jul 14, 2024 9:43 am    Post subject: Re: Lenses with floating elements Reply with quote
Alsatian2017 wrote:
[...] with the only exceptions being lenses that came out at the end of the FD era...), they all have a combination of a brass core and rubber bearings - the latter turning into a sticky mess.


Interesting, I didn't know that. Would the exception from the brass core and rubber bearings be all the "new FD" lenses, or a subset of those?

Regards, Christine


PostPosted: Thu Sep 05, 2024 3:27 pm    Post subject: Reply with quote
connloyalist wrote:
So I was thinking maybe a floating elements problem?


robin0112358 wrote:
Generally the more complex the lens design, the more that can go wrong over time. But I don't recall reading anything that especially singles out floating elements in this regard.


...and usually zoom lens designs from the same era are more complicated still, and there are enough around today which are still working fine. However, the occasional funny designed oddball happened even in the best families, and those were either bad from the beginning (i.e. Nikkor 20/3.5 infinity) or those who cause problems after many years (Vivitar 24/2 oily aperture blades, Nikkor 135/2 stiff focusing), the net usually knows them all. Minolta was known and praised for their optical and build quality. I would put it on bad luck, even if it happened twice. Do you have the possibility to try the lens(es) in question on a different camera? The Nikkor 20/2.8 I took as a replacement for the 20/3.5 is excelling on my D610, it doesn´t impress me on the Sony Alpha due to rather soft and smeared corners. And those are both full frame. Sometimes a lens and a sensor are not to be convinced to befriend each other.

visualopsins wrote:
Iirc, floating elements if the rear element does not move as lens is focused.


I thought so too. My Zuiko 28/2 and the Nikkor Ai 35/1.4 have floating elements, at least subject literature says so. Zuiko has a moving rear element, and the rear element of the Nikkor is moving and rotating.


PostPosted: Thu Sep 05, 2024 3:34 pm    Post subject: Reply with quote
RokkorDoctor wrote:
Of the Minolta manual focus SR mount 28mm lenses the f/2 is the only one with floating elements. The f/2.8 and f/3.5 do not have floating elements.

Personally I have no bad experiences with any of my Minolta lenses (approx. 250 of them), other than the odd copy here and there with haze. But I don't use them on crop cameras.


Same here with few exceptions. You may have a crooked adapter which only shows at short focal lengths.


PostPosted: Sun Sep 08, 2024 11:46 am    Post subject: Reply with quote
As it happens I just picked up a Minolta XD-5, so I will make sure to test this lens.

Note to self: do no use Kodak ColorPlus 200 for this test. Too much grain.

Regards, C.
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