If you work on this, before you screw out the spring holder of the USD unit (9:30) make a mark. If you lose the factory adjusted spring pressure for rotor and stator, you'll may have trouble with the autofocus later - ranging from intermittently failing, over moving too slow, to not moving at all. Dis- and assembling the lens multiple times to find the ideal spring pressure again is a pain. Ideally wear gloves when touching the stator and rotor part of the USD unit just to be sure you don't leave fat, dirt and debris from your fingers that could also affect the USD unit negatively. If you don't need to work specifically on the USD unit, I'm not even sure if you have to disassemble the unit piece by piece. Can't you just lift off the focus ring first thing after 9:14 and get to the screws directly? As always, thanks for the great tutorial.
Hello friend, thank you very much for your video. I'm in Brazil and here I can't find technical assistance that can help me, no one works with Tamron. Well, my Tamron lens had focus “slipping” intermittently. I decided to follow your video on how to disassemble it. I suspect that the problem is in the lens movement gears where there are plastic bushings that surround the screw to facilitate the mechanical movement of the crystals' position. Now, to my dismay, I can no longer assemble all the crystal drum equipment. In your current video you begin assembling the lens with the barrels aligned and screwed together. Could you make a video showing it even more in depth and please, without skipping any part. All the screws are messed up now.
There is a lens element inside which is hold by three eccentric screws, so it can be tilted. The front lens element just changes the distance from the other parts of the lens, and can't be tilted.
@@CamerasLensesEtc thanks for the reply! i have a high res camera and know how lenses work (cus spend time with large format, movements, blabla bla) should I try to get in there, or it's too hard for a commoner? nobody really has any videos on THAT
@@sunlbx If you have experience with disassembling / assembling lenses, then you can give it a try, but it is quite hard to do the calibration: most likely you have to remove the USM motor or other lens cover collars of tubes to get access to the calibration screws, do the calibration then you have to put everything back. It would be easier to buy and sell used lenses of this, test them and keep the best.
@@CamerasLensesEtc goddamit, I heard that any mistake when removing the USM might render it inoperable. too bad however, I was able to calibrate tamron 70-200 VC G1 by tilting the front group. Perhaps something was out of alignment inside. So I was able to misalign the front group in just the required way to cancel out wrong tilt somewhere inside. was hoping it would be doable with 24-70
I have a question, I got the same lens use, the previous owner said sometimes he was getting soft images, I found out after following your guide I clean the lens its pretty much perfect all the way to around 65mm at 70mm at f2.8 is softer than the rest of the barrel No bad like just softer and like halation. Now do you think this is something wrong with the lens or I just nature of the beast because ones I step down to f3.5 its sharp all the way. Can the firmware of the lens be updated if you can you point me to a tutorial? Thank you so much!
Generally, the lenses are the softest at the widest aperture, and the sharpest when closed down by 2 apertures. I would compare the lens to the other, same lenses, and see if the softness of your lens is normal or not. Mine is sharp at 2.8, and I have tested several of them, and they are sharp at the widest aperture. The firmware can be updated at Tamron service center.
If you work on this, before you screw out the spring holder of the USD unit (9:30) make a mark. If you lose the factory adjusted spring pressure for rotor and stator, you'll may have trouble with the autofocus later - ranging from intermittently failing, over moving too slow, to not moving at all. Dis- and assembling the lens multiple times to find the ideal spring pressure again is a pain. Ideally wear gloves when touching the stator and rotor part of the USD unit just to be sure you don't leave fat, dirt and debris from your fingers that could also affect the USD unit negatively.
If you don't need to work specifically on the USD unit, I'm not even sure if you have to disassemble the unit piece by piece. Can't you just lift off the focus ring first thing after 9:14 and get to the screws directly? As always, thanks for the great tutorial.
Thank you for the info!
You have to remove the parts of the USM motor to get access to the screws underneath it to continue with the disassembly.
Hello friend, thank you very much for your video.
I'm in Brazil and here I can't find technical assistance that can help me, no one works with Tamron.
Well, my Tamron lens had focus “slipping” intermittently. I decided to follow your video on how to disassemble it. I suspect that the problem is in the lens movement gears where there are plastic bushings that surround the screw to facilitate the mechanical movement of the crystals' position.
Now, to my dismay, I can no longer assemble all the crystal drum equipment.
In your current video you begin assembling the lens with the barrels aligned and screwed together. Could you make a video showing it even more in depth and please, without skipping any part. All the screws are messed up now.
What do you mean by "crystal drum equipment"? Can you give me a timecode?
Hello! Is the front element there calibrated / adjustable?
I have field tilt, must be it
..
There is a lens element inside which is hold by three eccentric screws, so it can be tilted. The front lens element just changes the distance from the other parts of the lens, and can't be tilted.
@@CamerasLensesEtc thanks for the reply!
i have a high res camera and know how lenses work (cus spend time with large format, movements, blabla bla)
should I try to get in there, or it's too hard for a commoner? nobody really has any videos on THAT
@@sunlbx If you have experience with disassembling / assembling lenses, then you can give it a try, but it is quite hard to do the calibration: most likely you have to remove the USM motor or other lens cover collars of tubes to get access to the calibration screws, do the calibration then you have to put everything back. It would be easier to buy and sell used lenses of this, test them and keep the best.
@@CamerasLensesEtc goddamit, I heard that any mistake when removing the USM might render it inoperable.
too bad
however, I was able to calibrate tamron 70-200 VC G1 by tilting the front group. Perhaps something was out of alignment inside. So I was able to misalign the front group in just the required way to cancel out wrong tilt somewhere inside.
was hoping it would be doable with 24-70
I have a question, I got the same lens use, the previous owner said sometimes he was getting soft images, I found out after following your guide I clean the lens its pretty much perfect all the way to around 65mm at 70mm at f2.8 is softer than the rest of the barrel No bad like just softer and like halation. Now do you think this is something wrong with the lens or I just nature of the beast because ones I step down to f3.5 its sharp all the way.
Can the firmware of the lens be updated if you can you point me to a tutorial?
Thank you so much!
Generally, the lenses are the softest at the widest aperture, and the sharpest when closed down by 2 apertures.
I would compare the lens to the other, same lenses, and see if the softness of your lens is normal or not.
Mine is sharp at 2.8, and I have tested several of them, and they are sharp at the widest aperture.
The firmware can be updated at Tamron service center.
@@CamerasLensesEtc Thank you!
@@LimaVideoProductions at 70 mm wide open it really is at its weakest