Have anyone fixed stiff zoom ring?

Maksat Tutan · 04-13-2014, 10:37 PM

Hello Pentaxians,

I just bought the k5iis and ordered two lenses for it. Sigma 17-50 EX DG and Pentax F 50mm f2.8 macro.
Lenses arrived later than the body and flash and a grip.

So I went to local Camera shop and saw Sigma 24-70 EX DG Macro (older Version). And Asked shop owner that If I could bring the lens to home and try out for few days. He gave me, because he knew me enough.

The lens was used and in poor condition. But glasses are clean. the Only and biggest issue was stiff zoom ring. It must be dropped and got mechanical issue inside.

Zoom ring is rotates normally if camera is portrait position. So it is enough to check its abilities. And used it at two events.

It is way too soft at f2.8 for an EX lens. but it brings EX quality sharpness at f4.
So I am interested in this lens. Now what I consider is that if I can fix the stiff zoom ring issue.

Have any one fixed this kind of Zoom ring stiffness?
Many says that I could lubricate the ring with gun oil, many says that I could open the lens from front element and reach to the location where zoom ring slides and lubricate with synthetic oil.

Please help me, I have two more days to bring the lens back to the shop. I have to decide to buy or not.

---------- Post added 04-14-14 at 01:38 PM ----------

Of course the other lenses came and day work OK. Sigma 17-50 EX DG HSM is the sharpest lens I have ever held.

OregonJim · 04-13-2014, 11:44 PM

Originally posted by Maksat Tutan

Zoom ring is rotates normally if camera is portrait position.

So, are you saying that the zoom ring is only stiff when the camera body is in 'landscape' position? If so, then lubrication is (probably) not the answer. Something is (again, probably) broken inside and moving to the wrong position due to gravity when the lens is rotated. My guess is that it can only get worse, not better.

Maksat Tutan · 04-14-2014, 12:44 AM

Originally posted by OregonJim

So, are you saying that the zoom ring is only stiff when the camera body is in 'landscape' position? If so, then lubrication is (probably) not the answer. Something is (again, probably) broken inside and moving to the wrong position due to gravity when the lens is rotated. My guess is that it can only get worse, not better.

Yes, that is what I thought also.

But

You Tube

this video raised my hope.
Exactly same as this lens on video.

around 24-35mm, it is stiffest range.

OregonJim · 04-14-2014, 01:55 AM

Originally posted by Maksat Tutan

Yes, that is what I thought also.

But Nikon 24-70 f2.8 Zoom Ring Fix Repair - YouTube this video raised my hope.
Exactly same as this lens on video.

around 24-35mm, it is stiffest range.

Up to you if you want to spend money on the lens and risk a repair like this. If it were me, and I suspected the lens had been dropped, I would put it in a vise and GENTLY try to squeeze the barrel back into round in order to remove the friction.

EDIT: (assuming it's a metal-barrel lens - if plastic, then forget it)

Imageman · 04-14-2014, 11:03 AM

It isn't your property yet so don't try to do anything until you have bought it.

I would not buy any lens that was malfunctioning like this unless it was a cheap deal or I knew I could fix it for sure. You don't know this so don't just buy it.

Show it to the shopkeeper show the problem and ask what he wants to do. Nobody else will want to buy this lens off him so maybe he will do you a deal.

If it were me I wouldn't buy this lens given this fault, and I have stripped adjusted and reassembled lenses, it sounds unlikely to be fixable at home.

Lubrication and lens element clean adjust and reassemble are about as much as most people can do. but this sounds like broken or bent parts.

What is this lens worth? I think the cost of a lens tech repairing it could cost 100 dollars, given I don't know whats wrong with it, it may not even be fixable.

Speak to the shop owner before you do decide to do anything.

Maksat Tutan · 04-14-2014, 06:54 PM

hi friends,

I gave him the lens back yesterday. I hope that we could make a deal at lower price (on a very first day, he was meaning 150,000 tugriks which equals approximately $80 for the lens). But he changed his mind a little. He raised a price too much to 500,000 tugriks, which equals $300.
It is much higher price for me to spend on defective, not sharp at wide open lens.

04-13-2014, 10:37 PM	#1
Maksat Tutan Junior Member Join Date: Jan 2011 Posts: 45	Have anyone fixed stiff zoom ring? Hello Pentaxians, I just bought the k5iis and ordered two lenses for it. Sigma 17-50 EX DG and Pentax F 50mm f2.8 macro. Lenses arrived later than the body and flash and a grip. So I went to local Camera shop and saw Sigma 24-70 EX DG Macro (older Version). And Asked shop owner that If I could bring the lens to home and try out for few days. He gave me, because he knew me enough. The lens was used and in poor condition. But glasses are clean. the Only and biggest issue was stiff zoom ring. It must be dropped and got mechanical issue inside. Zoom ring is rotates normally if camera is portrait position. So it is enough to check its abilities. And used it at two events. It is way too soft at f2.8 for an EX lens. but it brings EX quality sharpness at f4. So I am interested in this lens. Now what I consider is that if I can fix the stiff zoom ring issue. Have any one fixed this kind of Zoom ring stiffness? Many says that I could lubricate the ring with gun oil, many says that I could open the lens from front element and reach to the location where zoom ring slides and lubricate with synthetic oil. Please help me, I have two more days to bring the lens back to the shop. I have to decide to buy or not. ---------- Post added 04-14-14 at 01:38 PM ---------- Of course the other lenses came and day work OK. Sigma 17-50 EX DG HSM is the sharpest lens I have ever held.

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04-13-2014, 11:44 PM	#2
OregonJim Veteran Member Join Date: Mar 2009 Location: Willamette Valley, Oregon Posts: 1,327	Originally posted by Maksat Tutan Zoom ring is rotates normally if camera is portrait position. So, are you saying that the zoom ring is only stiff when the camera body is in 'landscape' position? If so, then lubrication is (probably) not the answer. Something is (again, probably) broken inside and moving to the wrong position due to gravity when the lens is rotated. My guess is that it can only get worse, not better.

04-14-2014, 01:55 AM	#4
OregonJim Veteran Member Join Date: Mar 2009 Location: Willamette Valley, Oregon Posts: 1,327	Originally posted by Maksat Tutan Yes, that is what I thought also. But Nikon 24-70 f2.8 Zoom Ring Fix Repair - YouTube this video raised my hope. Exactly same as this lens on video. around 24-35mm, it is stiffest range. Up to you if you want to spend money on the lens and risk a repair like this. If it were me, and I suspected the lens had been dropped, I would put it in a vise and GENTLY try to squeeze the barrel back into round in order to remove the friction. EDIT: (assuming it's a metal-barrel lens - if plastic, then forget it)

04-14-2014, 11:03 AM	#5
Imageman Veteran Member Join Date: Dec 2013 Photos: Albums Posts: 461	It isn't your property yet so don't try to do anything until you have bought it. I would not buy any lens that was malfunctioning like this unless it was a cheap deal or I knew I could fix it for sure. You don't know this so don't just buy it. Show it to the shopkeeper show the problem and ask what he wants to do. Nobody else will want to buy this lens off him so maybe he will do you a deal. If it were me I wouldn't buy this lens given this fault, and I have stripped adjusted and reassembled lenses, it sounds unlikely to be fixable at home. Lubrication and lens element clean adjust and reassemble are about as much as most people can do. but this sounds like broken or bent parts. What is this lens worth? I think the cost of a lens tech repairing it could cost 100 dollars, given I don't know whats wrong with it, it may not even be fixable. Speak to the shop owner before you do decide to do anything.

04-14-2014, 06:54 PM	#6
Maksat Tutan Junior Member Join Date: Jan 2011 Posts: 45 Original Poster	hi friends, I gave him the lens back yesterday. I hope that we could make a deal at lower price (on a very first day, he was meaning 150,000 tugriks which equals approximately $80 for the lens). But he changed his mind a little. He raised a price too much to 500,000 tugriks, which equals $300. It is much higher price for me to spend on defective, not sharp at wide open lens.