Disassembly and reassemly a Minolta MD Zoom 35-70mm 1:3.5 lens. This is the 3rd generation with macro. Multiple parts of the lens have fungus so need to be thoroughly cleaned.
No two lens models are the same, but these two (28-85 and 35-70 III with macro) are released around the same time, so chances are they are mechanically similar. Looking at the optical formula on lensQAworks, the 28-85 seem to also have 3 groups, so you might find a lot of similarities. Good luck.
Thank you for a most informative and detailed lens disassembly. Question for you. On my copy of this lens, when the camera/lens is horizontal, the macro setting is stable as I focus. When I aim the camera/lens straight down, the macro setting drifts from 1:7 to 1:4. Is this normal for the lens or is there an adjustment that can be made to prevent this? Otherwise, I am very pleased with this lens and it stays on my camera 90% of the time.
Mine only shifts if you shake the lens. It should be possible to mitigate this by re-lubricating the zoom helicoid (the cylinder with a lot of tracks carved in it), but I don't think it's worth the effort of taking the entire thing apart.
Thanks for the detailed teardown. I too attempted the disassembly for basic cleaning but now i cant get a sharp image across the frame. The image is sharp in center while the area in mid is smudgy and the corners & edges gets very blurry. This is most apparent on 35 mm. Also on 35 mm i am not able to focus anything closer than 4-5 meters. I am confused what wrong did i do. This makes me so sad, have i screwed up the lens beyond repair ? Any tips on troubleshooting will be so much helpful 🙏
I have the 2nd generation 35-70 and the entire focusing part is loose. I tried to fix it, but found a ring on the inside of the focusing part seen fromt the front, that can't be made to sit in one position without eventually moving when I focus. Thus the focusing assembly can be move back and forth a littke bit by just pulling/pulling throwing it out of focus. Any suggestions?
diediemustdive.wordpress.com/2016/12/03/minolta-md-zoom-35-70mm-f3-5-disassembly-and-cleaning/ This tutorial deals with a second gen 35-70. I think it might be the setscrews on the focusing ring.
Hi there, do you know if this same procedure is valid for the MD Zoom 28-85?
No two lens models are the same, but these two (28-85 and 35-70 III with macro) are released around the same time, so chances are they are mechanically similar. Looking at the optical formula on lensQAworks, the 28-85 seem to also have 3 groups, so you might find a lot of similarities. Good luck.
The mount mechanism is most likely the same across the two lenses. I've taken apart a few Minolta lenses and they have been pretty easy.
Thanks for the reply, and for mentioning that source. My 28-85 has a sticky aperture mechanism, so I'll see if I can fix it
@@elteuben For sticky aperture you might only need to go in from the mount end of the lens and see if the lubrication is sticky or the spring is old.
Thank you for a most informative and detailed lens disassembly. Question for you. On my copy of this lens, when the camera/lens is horizontal, the macro setting is stable as I focus. When I aim the camera/lens straight down, the macro setting drifts from 1:7 to 1:4. Is this normal for the lens or is there an adjustment that can be made to prevent this? Otherwise, I am very pleased with this lens and it stays on my camera 90% of the time.
Mine only shifts if you shake the lens. It should be possible to mitigate this by re-lubricating the zoom helicoid (the cylinder with a lot of tracks carved in it), but I don't think it's worth the effort of taking the entire thing apart.
Thanks for the detailed teardown. I too attempted the disassembly for basic cleaning but now i cant get a sharp image across the frame. The image is sharp in center while the area in mid is smudgy and the corners & edges gets very blurry. This is most apparent on 35 mm. Also on 35 mm i am not able to focus anything closer than 4-5 meters. I am confused what wrong did i do. This makes me so sad, have i screwed up the lens beyond repair ? Any tips on troubleshooting will be so much helpful 🙏
See if you put in any elements backwards. There are a couple elements on this lens that are kind of symmetric and easy to get wrong.
@@atlantisq I cross checked couple of times & all elements have been placed in the required orientation.
@@PoonamKumari-l5k1y The issue as you described definitely looks like the optics are not assembled correctly, so it may very likely be fixable.
@@atlantisq Okay, i will let you know if i get to fix this out.
Hi bro. My lens is not focus at infinity correct. How to fix it? At 35, 70 to. im trying my best. All the time it out focus
I have the 2nd generation 35-70 and the entire focusing part is loose. I tried to fix it, but found a ring on the inside of the focusing part seen fromt the front, that can't be made to sit in one position without eventually moving when I focus. Thus the focusing assembly can be move back and forth a littke bit by just pulling/pulling throwing it out of focus. Any suggestions?
diediemustdive.wordpress.com/2016/12/03/minolta-md-zoom-35-70mm-f3-5-disassembly-and-cleaning/
This tutorial deals with a second gen 35-70. I think it might be the setscrews on the focusing ring.
no one can unscrew the front lens.😢