SDM in general


cbrog

Link Posted 21/02/2020 - 17:16
Sometimes I wonder how Pentax managed to survive at all. I own four Star lenses - supposedly professional standard lenses and now only my 60-250 is working as it should. The sdm drive in the others either doesn't work or only works occasionally and one will not even manually focus within a certain focal lengths.
All these lenses are otherwise in mint condition. If I still worked as a photographer I simply would not (could not) tolerate that level of unreliability.
Last Edited by cbrog on 21/02/2020 - 17:17

JohnX

Link Posted 21/02/2020 - 17:36
I still don't see why there hasn't been a class action against Pentax, over what is an inherent product fault

ronniemac

Link Posted 22/02/2020 - 13:52
I'm really sorry to hear about your SDM * lenses, Cborg, you've been unlucky and are right to say that this is an issue that Pentax should have addressed a long time ago. Fortunately the new range of D-FA* SDM lenses have a completely different ring motor SDM mechanism which I understand if far stronger.

I have the 7 original SDM DA lenses and have been lucky - no failures to date. There is a debunked theory that if you keep the lenses on a charged camera and give them a spin every so often, that they will keep working. Like I say, it's a theory which has been refuted so take it with a pinch of salt.

B.t.w. I keep mine attached to some old K-01s, and give the focus motors a spin quite frequently, but I accept that this is nothing to do with the fact that they all work perfectly.

pschlute

Link Posted 22/02/2020 - 15:59
I at one time owned three of the DA* lenses. 16-50; 60-250; and 300. The 16-50 was troublesome in that it needed me to manually focus a few times throughout the range, then AF throughout the range after which it behaved normally. The 60-250 and 300 both worked perfectly. I only own the 300 now and it is still going strong despite its age.

I think it was the early SDM motors that had issues. As has been said the more modern lenses use a different design.
Peter



My Flickr page

Gwyn

Link Posted 22/02/2020 - 16:10
I own two star lenses - the 60-250 and the 50-135 plus the 17-70 which is also a SDM lens.
I haven't had a problem with the SDM on any of them. The 17-70 hunts for focus and seems to have got worse as it gets older, but that isn't an SDM problem.
It sounds like you have been really unlucky with yours.

smudge

Link Posted 22/02/2020 - 16:23
In my experience replacement SDM motors are a waste of money. I had 2 replacements for my 16-60 and 1 for my DA 200. None of the replacements lasted more than a year before they failed. In each case the replacements were supposed to be a new upgraded version.
Regards, Philip

pschlute

Link Posted 22/02/2020 - 17:40
Screwdrive conversion is the best approach and will be mine if the 300 ever goes west.
Peter



My Flickr page

cbrog

Link Posted 22/02/2020 - 20:11
Yes I think that will have to be my next move(s) too..!

Jonathan-Mac

Link Posted 22/02/2020 - 20:51
I don't touch the SDM lenses for this reason. Better off with Sigma or Tamron alternatives where available.
Pentax hybrid user - Digital K3 & K200D, film 645 and 35mm SLR and Pentax (&other) lenses adapted to Fuji X digital
Fan of DA limited and old manual lenses

mr.mellow

Link Posted 23/02/2020 - 13:49
I had the motor on a Sigma AF 120-400 APO DG HSM fail. I returned it to Sigma and had the motor replaced, this was done in under 2 weeks and cost £109.99. I delivered to and collected it myself at Sigma in Welwyn. Great service.
So other makes do fail occasionally.
The older I get the faster I was.
Dave
K-3 II, K10D, DA16-85, DA*50-135, DA12-24, DA18-55, DA 50, Sigma EX DG 70mm Macro, Sigma 70-300mm, Sigma DG 120-400mm APO HSM.
Metz 58 AF-1.

My Flickr link

Daronl

Link Posted 24/02/2020 - 10:44
I have owned all the SDM (DA*) lenses and still have the 200mm and 300mm

1. I had SDM problem with the 16-50 eventually changing the motor .

2, I had the 50-135 replaced twice (once in the UK and once in the States), BUT to no avail the second replacement failed within a year - They all simply played up very early) on before failing. (changed SDM)

3. 60-250 was identical - unreliable from Day 1 before failing totally (Changed SDM )

4. 300 mm failed - but was a well used and a superb optic - Changed SDM after 4 years (still have it - wouldn't part with it until I have completed my gradual move to NIKON,

5, The 200 mm has never failed and is simply a superb optic (like the 300mm), however as I had several SDM's being changed at Brentford Radio Control Models for 50% less than the Pentax approved repairers wanted - I went ahead and put a new SDM in the 200.

Why do we bother is a good question but the answer is not so clear:

I take care of all my equipment which in general could be described as in perfect condition (as anyone who has bought items off me can vouch for) but I have had problems with the Silver Edition K3 when it came out and also the K1

I waited for so long for a Pentax full frame so when the K1 I bought the camera came out I bought all the new Lenses - The Autofocus Block needed replacing on the K1 after 3000 actuations

I started out with Pentax 50 years ago when the brand was #1 and the iconic bodies were literally "Rolls Royce quality "supplemented by literally a multitude of pro Lenses - It all changed with the advent of Digital SLRs.

The K10 D and K20D were "solid" good tools, as were the K5 and K7 which induced me to increasingly to a battery of premium lenses and accessories but my second K3 totally failed after six months and the K1 also failed . ( my K3 II is a rock by the way)

Frankly speaking I really am struggling to persevere with the brand as I see no real evolution strategy that will provide us with cameras like the Nikon D500, which is modestly priced and outperforms cameras five times the price.

Because I have so much Pentax glass I am waiting for the next iteration of the K3 II which we are being led to believe will have similar AF performance to the Nikon D500 - if that turns out to be BS then I will sell off all my Pentax gear and fully move to Nikon.

I already have a Nikon D500 (bought 2nd hand) it is remarkable as regards Autofocus and continuous tracking etc but I must say the available and affordable big zooms are not as good as the Pentax 150-450 HD D-FA F4 I use it on the K3 II and occasionally the K1 - on either the image quality is amazing but the AF on the cameras is at best pedestrian and at worst unusable in some fast action shooting.
Daronl

johnriley

Link Posted 24/02/2020 - 15:52
I shoot a lot of pictures and very rarely does anything fail, but anything man made does have the potential for failure and will eventually give up of course if used long enough. All makes suffer a failure rate and price is no guarantee of a better or a worse product.

As regards SDM, there has been an evolution of SDM motors, just as there has been an evolution of Super Multi Coating, so I wouldn't let the label put me off new products.
Best regards, John

JohnX

Link Posted 24/02/2020 - 16:47
ronniemac wrote:
There is a debunked theory that if you keep the lenses on a charged camera and give them a spin every so often, that they will keep working. Like I say, it's a theory which has been refuted so take it with a pinch of salt.

I'm interested so please tell me more, as it's something I do and I'd hate to be wasting my time!

HarisF1

Link Posted 24/02/2020 - 16:57
JohnX wrote:
ronniemac wrote:
There is a debunked theory that if you keep the lenses on a charged camera and give them a spin every so often, that they will keep working. Like I say, it's a theory which has been refuted so take it with a pinch of salt.

I'm interested so please tell me more, as it's something I do and I'd hate to be wasting my time!

I don't know about the charged camera but regular use of the lenses definitely keeps the motors running from my experience.

womble

Link Posted 25/02/2020 - 07:21
From my small sample of 3, I've never had a SDM failure. I don't use them that often, mainly using primes or my older glass. Mostly, I struggle to take the FA31 off my K-3 (which has also worked flawlessly for 5 1/2 years).

The only repairs I have had to any of my more modern equipment have been user induced (e.g., the tripod falling over and dumping my gear in the sea).

K.
Kris Lockyear
It is an illusion that photos are made with the camera… they are made with the eye, heart and head. Henri Cartier-Bresson
Lots of film bodies, a couple of digital ones, too many lenses (mainly older glass) and a Horseman LE 5x4.

My website
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