MF K mount zoom lenses with non-rotating front elements?

ChrisR

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The last year or so I've been enjoying using a couple of "normal range" zooms on my Pentax MX and LX cameras. First I had the M 35-70, until I fell over on some rocks and dented it's focus ring. Now I have a Vivitar 35-70, which is lighter and nearly as nice to use. However, both of these lenses have rotating front elements.

Later this year we're going on a walking holiday in Switzerland. A zoom in the 28-80 range (roughly) could be very useful. However, I'd also like to be able to use a polariser and/or grad filters while out. This is pretty hard to do with a rotating front element (and on the Vivitar it move fairly freely). So I started looking for an alternative zoom I could take with me.

Normally the lens reviews on Pentaxforums have all the information you'd need about lenses, but it appears they don't list whether the front element rotates. In some cases I've found where reviewers have specifically mentioned that the element does rotate, and that's ruled out most of the Tamron Adaptall-2 zooms AFAICS. I've found nothing that confirms the SMC M and SMC A zoom front elements do or don't rotate, though I'm beginning to suspect they do.

Anyone know?
 
So I put a related post up on Pentaxforums, and got some responses...

There was a consensus that zoom lenses of that period were normally designed to have rotating front elements. :(

It looks like these zoom lenses have front elements that definitely do rotate:

[Lens, weight (gm), Rotate?, filter (mm), PF rating]

SMC Pentax-A 24-50mm F4, 375, R, 58, 9.5
SMC Pentax-M 35-70mm F2.8-3.5, 470, R, 58, 9.18
SMC Pentax-M 75-150mm F4, 465, R, 49, 8.55
Tamron Adaptall-2 35-135mm f/3.5-4.2 (22A), 625, R, 67, 8
Tamron Adaptall-2 35-135mm f/3.5-4.5 (40A), 547, R, 58, 9
Tamron Adaptall-2 35-70mm F3.5 CF Macro (17A), 330, R, 58, 8.5
Tamron Adaptall-2 70-150mm f/3.5 (20A), 459, R, 49, 8
Tamron Adaptall-2 SP 35-80mm F2.8-3.8 (01A), 386, R, 62, 8.91
Vivitar 24-70mm f/3.8-4.8 Series 1, 450, R, 67, 8.5
Vivitar 35-70mm F2.8-3.8 Macro Focusing Zoom, ?, R, 55, 9.14

These zoom lenses possibly (probably?) rotate; I don't know yet:

Kiron 28-105 f/3.2-4.5, 709, ?, 67, 8.25 EDIT: but see Brian's post above...
SMC Pentax 45-125mm F4, 612, ?, 67, 8
SMC Pentax-A 28-80mm F3.5-4.5, 355, ?, 58, 8.5
SMC Pentax-A 35-105mm F3.5, 615, ?, 67, 8.84
Tamron Adaptall-2 28-70mm F/3.5-4.5 (44A), 361, ?, 62, 8.14
Tamron Adaptall-2 35-70mm f/3.5-4.5 (09A), 322, ?, 58, 7.33
Tamron Adaptall-2 SP 35-105mm f/2.8 (65A,) 624, ?, 67, 8.4
Tamron Adaptall-2 SP 60-300mm f/3.8-5.4 (23A), 870, ?, 62, 9

And these zoom lenses have front elements that DO NOT ROTATE (Eureka! Or maybe not...):

Makinon MC 28-80mm f/3.5, ?, N, ?, 9
Sigma 24-135mm F2.8-4.5, 530, N, 77, 8.33
Tamron Adaptall-2 28-200mm type 171A, 508, N, 72, 7.5
Tamron Adaptall-2 SP 24-48mm f/3.5-3.8 (13A), 346, N, na?, 8
Vivitar Series 1 VMC 28-90 / 2.8-3.5 680, N, 67, 9.13
Vivitar Series 1 VMC Macro focussing zoom 28-105/2.8-3.8, 620, N, 67, 8.33

So let's have a look at that last lot. It's hard to find any information about the Makinon, and I think the rating was based on one review. There appear to be a number of Makinon lenses which don't have a particularly good rating. I'm very doubtful!

The Sigma looked promising for a while, but I think it's actually an auto-focus lens, so probably not the easiest to manual focus.

The Tamron 28-200 171A is also promising (specifically NOT the 71A, which does rotate), but the reviews and ratings are not great.

I once had the Tamron 24-48 13A (I think). It is apparently very difficult to attach filters to it, may not have a filter thread, so kind of defeats the point of this exercise! Not sure that 24-48 is a great zoom range for mountain scenery, but maybe I'm wrong. (The main thing I remember about that lens was that it metered a good stop slower than other lenses on the same scene and camera. Presumably some sort of transmission issue?

The Two Vivitar zooms (28-90 and 28-105) look very promising, both have 67 mm threads, but both are really quite heavy for all day walking at 680 and 620 gm respectively. Maybe I should try to get hold of one of these and try it out!

Any thoughts?
 
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I forgot: someone on PF linked to a MFlenses post on the same topic, which came up with some ideas...

Sorry @excalibur2 it appears I transcribed your info on the Kiron wrongly. However, it is even heavier than the Vivitars!
 
Some (maybe many?) Makinon lenses are not very good..the one I had was about 35mm -70mm and was well engineered, heavy and look as new but was crap optically so gave it away to a charity shop.....so pot luck with Makinon.
On the link you provided they all rave about the S1 Vivitars, and came across one at the bootie for £5 (Tokina)...well it was OK but I wasn't impressed so gave that to the charity shop as well, maybe I had a bad copy :(
 
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Chris, I have the Tamron 28-70 and the SP 28-80 and can confirm that the front element DOES rotate on both of them.
 
I appear to have accidentally ordered a Vivitar Series 1 24-70 in PKA mount. I'm assuming it has a rotating front element (67mm!), but can anyone confirm? Thanks
 
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