Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

General lens repair reference?
Post new topic   Reply to topic
Home   Equipment Care and Repairs
View previous topic :: View next topic  


PostPosted: Fri Apr 01, 2016 1:17 am    Post subject: General lens repair reference? Reply with quote
As I quickly (alarmingly so it seems!) build my MF lens collection I've already got a couple in need of some attention. My Minolta 300mm f/4.5 needs the helicoid greased and I found a YouTube video showing a complete breakdown of the lens. But I also have a Vivitar 55mm f/2.8 Macro that also needs re-greasing. I found a parts list online but can't find a "how to." Is there some reference material anyone can point me to that would give a generic education on how lenses are assembled and can be repaired?


PostPosted: Fri Apr 01, 2016 1:34 am    Post subject: Reply with quote
That is a secret! Wink EQUIPMENT CARE & REPAIRS


PostPosted: Fri Apr 01, 2016 4:54 am    Post subject: Reply with quote
visualopsins wrote:
That is a secret! Wink EQUIPMENT CARE & REPAIRS


That's what I get for only hanging out in one forum. Embarassed

Thanks for pointing these out!


PostPosted: Fri Apr 01, 2016 10:22 am    Post subject: Reply with quote
I've repaired quite a few lenses, and to be honest, I've learned mostly just by doing.

There are certain steps that usually must be taken to separate a lens's helicals. These usually involve peeling off the rubber sleeve on the focusing collar and then removing the screws that you find underneath. There may be a few more screws on the lens body that will also have to come out. You'll want to have on hand a set of small screwdrivers to remove these screws. Those sets of jewelers screwdrivers that come in the little box are good for this. For the cross-head screws, don't use Phillips screwdrivers -- they're too pointy. The ones you want are called "cross point." They have a blunter tip and they are the ones you usually find in these small screwdriver sets.

I've never dismantled a macro lens. On the one hand, I'm thinking it might be fairly easy because a macro has relatively few elements, but on the other hand, because the helicals extend so far on a macro, there may be a more complex helical arrangement with a macro than with a regular lens.

Only one way to find out, unless you have a repair manual.

At any rate, as you unscrew the helicals, you'll want to have something sharp that you can scratch some light reference marks into the two helicals in an unobtrusive area. I do this right at the point that they separate from each other, scratching marks in each piece that coincide with each other, so I know what the correct orientation should be when it's time to screw the helicals back together. This step can be tricky. I've often missed the right thread engagement, and had to go back and redo it, sometimes even by trial and error. You'll know you're off if, after you've rescrewed your lens all the way in, your infinity marks don't line up. No big deal -- just try again until they do.


PostPosted: Fri Apr 01, 2016 7:44 pm    Post subject: Reply with quote
cooltouch wrote:
I've repaired quite a few lenses, and to be honest, I've learned mostly just by doing.

There are certain steps that usually must be taken to separate a lens's helicals. These usually involve peeling off the rubber sleeve on the focusing collar and then removing the screws that you find underneath. There may be a few more screws on the lens body that will also have to come out. You'll want to have on hand a set of small screwdrivers to remove these screws. Those sets of jewelers screwdrivers that come in the little box are good for this. For the cross-head screws, don't use Phillips screwdrivers -- they're too pointy. The ones you want are called "cross point." They have a blunter tip and they are the ones you usually find in these small screwdriver sets.

I've never dismantled a macro lens. On the one hand, I'm thinking it might be fairly easy because a macro has relatively few elements, but on the other hand, because the helicals extend so far on a macro, there may be a more complex helical arrangement with a macro than with a regular lens.

Only one way to find out, unless you have a repair manual.

At any rate, as you unscrew the helicals, you'll want to have something sharp that you can scratch some light reference marks into the two helicals in an unobtrusive area. I do this right at the point that they separate from each other, scratching marks in each piece that coincide with each other, so I know what the correct orientation should be when it's time to screw the helicals back together. This step can be tricky. I've often missed the right thread engagement, and had to go back and redo it, sometimes even by trial and error. You'll know you're off if, after you've rescrewed your lens all the way in, your infinity marks don't line up. No big deal -- just try again until they do.


Thank you for this posting! It helped convince me that trial & error are probably the way to go. Luckily most of my lenses were purchased cheap enough that it wouldn't be a catastrophe if I totally messed up. I do have a set of those small screwdrivers and even recently picked up a lens spanner wrench that will come in handy. Now I just have to take a deep breath and start in Very Happy
Post new topic   Reply to topic
Home   Equipment Care and Repairs
Page 1 of 1