Hello, thank you for this very informative video. Before embarking on a repair I would like to know if there is not a manipulation to be done, I rarely use this objective, each time the AF was slow at the beginning then ended up working normally. This time the AF does not move at all, sometimes I see a very slight movement, I tried to manually manipulate the focus several times but it does not come. I don't think the engine is dead because by putting my ear against the lens I can hear it, I'm thinking more of the drive train slipping. Do you have an idea?
@@CamerasLensesEtc Thank you for helping, by watching your video, i disassembled only the focus tube and turn manually the black gear whitch hard at the begining an became easier, then i made a sucessfull test. I reassembled the focus tube on the lens which works well again now. Thank you once again for showing us so well how to disassemble this lens.🤩👍
When this lens AF slows down in normal orientation, but turned upside down it works almost as fast as new, where the problem can be? When it is stored in cabinet for few days it usually needs some time and focusing attempts to start autofocusing.
Try to move the manual focus back and forth, and focus domething close and far, and do this 10-20 times to move the lens elements, and the mechanical grease inside the lens between the lens tubes. If it doesn't help, I think the HSM motor should be replaced.
@@CamerasLensesEtc I have this lens with the Nikon mount (I assume thats why your mount has pads instead of bumps as the connection to the camera?) and after not using it for a LONG while I just noticed that it doesn't react AT ALL the to trying to auto-focus via buttons on the camera (Nikon D800) does this mean the motor is dead or could I be lucky and its something simpler? (also do you have trusted store for buying replacements, hopefully one that isn't extra expensive?((I mean I kind of prove I'm cheap/frugal since I have this instead of the Nikorr version.))) edit: I haven't opened it yet (I've fixed smart phones and similar electronics so I think I might be competent enough tho) I'm considering if its worth it to open it since I'm afraid of adding issues by unsealing it since it hasn't been opened since it was assembled at the factory.
@@jim0_o Have you tried manually move the focusing motor a few times? I had lenses which was not use for a while and the focusing was very sticky at the beginning and gave squeaky noise, but after moving the focus manually from one end to the other solved the problem. If not, then I'm afraid that the motor should be replaced.
@@CamerasLensesEtc There I finally got back home to try this and it didn't work for me, the only thing that happens when I click the focus button is the display blinks(but that probably just proves the button works), there is no mechanical noise or shake or anything so you are probably right about the motor being dead. Now I guess I'll just have to decide if I'm good enough to do it myself or if I should just use the lens manually etc. Thank you :)
I have the same lens, but in Pentax mount. I bought it new, and the AF worked fine. One day the AF simply didn't work. No movement, no sound. I have testet other lenses and other cameras, it is this lens. Manual focus works fine. What can it be? Maybe a loose flex-cable? Is is so easy I can do it myself? I'm pretty good with mechanics.
Most likely the HSM motor is not working, and it needs to be replaced. I saw for sale on aliexpress, and ebay. The flex cable is not moving during focusing or zooming, so it is extremely unlikely that is it broken.
@@CamerasLensesEtc You can revive these motors by polishing the mating surface of both the gold hsm ring and the black ring it faces with a polishing compound. Then reassemble and lock the two rings together by rotating the rings until you hear a high pitched ringing. Works wonders.
I have the same exact lens . But it’s not focusing well from f2,8 till f5 what could be the problem and how can it be fixed . When i see thru the view finder the picture will be in focus but once i take a picture it will be out of focus between those two focal lengths
Perfect...Thanks you so much !!!!
You're welcome!
Hello, thank you for this very informative video. Before embarking on a repair I would like to know if there is not a manipulation to be done, I rarely use this objective, each time the AF was slow at the beginning then ended up working normally. This time the AF does not move at all, sometimes I see a very slight movement, I tried to manually manipulate the focus several times but it does not come. I don't think the engine is dead because by putting my ear against the lens I can hear it, I'm thinking more of the drive train slipping. Do you have an idea?
I would start with cleaning the elements of the HSM motor, if that doesn't help, the motor should be replaced.
@@CamerasLensesEtc Thank you for helping, by watching your video, i disassembled only the focus tube and turn manually the black gear whitch hard at the begining an became easier, then i made a sucessfull test. I reassembled the focus tube on the lens which works well again now.
Thank you once again for showing us so well how to disassemble this lens.🤩👍
please where can i get the first front glass of this lens mine is broken
I don't think that Sigma sells that, check out ebay, maybe there is used ones for sale.
When this lens AF slows down in normal orientation, but turned upside down it works almost as fast as new, where the problem can be? When it is stored in cabinet for few days it usually needs some time and focusing attempts to start autofocusing.
Try to move the manual focus back and forth, and focus domething close and far, and do this 10-20 times to move the lens elements, and the mechanical grease inside the lens between the lens tubes. If it doesn't help, I think the HSM motor should be replaced.
@@CamerasLensesEtc I have this lens with the Nikon mount (I assume thats why your mount has pads instead of bumps as the connection to the camera?) and after not using it for a LONG while I just noticed that it doesn't react AT ALL the to trying to auto-focus via buttons on the camera (Nikon D800) does this mean the motor is dead or could I be lucky and its something simpler? (also do you have trusted store for buying replacements, hopefully one that isn't extra expensive?((I mean I kind of prove I'm cheap/frugal since I have this instead of the Nikorr version.))) edit: I haven't opened it yet (I've fixed smart phones and similar electronics so I think I might be competent enough tho) I'm considering if its worth it to open it since I'm afraid of adding issues by unsealing it since it hasn't been opened since it was assembled at the factory.
@@jim0_o Have you tried manually move the focusing motor a few times? I had lenses which was not use for a while and the focusing was very sticky at the beginning and gave squeaky noise, but after moving the focus manually from one end to the other solved the problem. If not, then I'm afraid that the motor should be replaced.
@@CamerasLensesEtc Thanks, I think I did but I'll try again to make sure.
@@CamerasLensesEtc There I finally got back home to try this and it didn't work for me, the only thing that happens when I click the focus button is the display blinks(but that probably just proves the button works), there is no mechanical noise or shake or anything so you are probably right about the motor being dead.
Now I guess I'll just have to decide if I'm good enough to do it myself or if I should just use the lens manually etc.
Thank you :)
I have the same lens, but in Pentax mount. I bought it new, and the AF worked fine. One day the AF simply didn't work. No movement, no sound. I have testet other lenses and other cameras, it is this lens. Manual focus works fine. What can it be? Maybe a loose flex-cable? Is is so easy I can do it myself? I'm pretty good with mechanics.
Most likely the HSM motor is not working, and it needs to be replaced. I saw for sale on aliexpress, and ebay.
The flex cable is not moving during focusing or zooming, so it is extremely unlikely that is it broken.
@@CamerasLensesEtc You can revive these motors by polishing the mating surface of both the gold hsm ring and the black ring it faces with a polishing compound. Then reassemble and lock the two rings together by rotating the rings until you hear a high pitched ringing. Works wonders.
I have the same exact lens . But it’s not focusing well from f2,8 till f5 what could be the problem and how can it be fixed . When i see thru the view finder the picture will be in focus but once i take a picture it will be out of focus between those two focal lengths
Is the problem still exist when you focus with liveview? Maybe your lens has a back-, or front focus issue, I would check that first.
@@CamerasLensesEtc What is the procedure to adjust a front focus problem on a Sigma objective not able to use USB dock? (50-150 2.8)