Need help to disassemble Vivitar 28mm f/2.8.
Need help to disassemble Vivitar 28mm f/2.8.
May 10, 2012
My Vivitar 28mm f/2.8 lens has fungus inside its lens. I would like to take apart and clean the glasses inside. So far, I could only open the front side and the back side lens cover, as shown on these pictures below.
I don't know what to do next. Would you please help me...?
Thanks a lot.
The slots in the back of the black painted pieces takes a spanner for them to unscrew. Maybe the front lens unit as well.
They look like this tool, and you can snap the tips in various ways to get at them.
...and available here, among other tools:
Don't know about the fungus mess. If it has eaten through some coating, then that can be very bad. If you try and polish it out and take out the coating with it, often the lens will suffer some chromatic/refractive issues and the focus suffers and sometimes a lot. If it is between the cemented optics, then you have to separate them and deal with re-cementing them with an optics glue that sets with UV light which isn't that bad nor hard, but the coating getting attacked could be the end and generally the manufacturer just replaces it. Those optics glues can be expensive too as well as the UV light that is used to set them.
@GMack: Thanks for your advices. Yes..., I was looking the same tool that you mentioned too. I don't know how bad the fungus mess is..., but from my observation..., it doesn't look that bad.
Anyway..., I think..., I probably should start by using that tool to open the back side of lens, as shown in the picture below (See the red arrows). It seems there are nothing we can do in the front side of the lens.
If it is between the cemented optics, then you have to separate them and deal with re-cementing them with an optics glue that sets with UV light which isn't that bad nor hard, but the coating getting attacked could be the end and generally the manufacturer just replaces it. Those optics glues can be expensive too as well as the UV light that is used to set them.
+1 on that, all lenses I ever had affected by the fungus were on "glued" lens elements and the process took place on the cement, not the actual glass. That is why badly affected lenses are considered almost worthless.
Might also want to check out this forum I have bookmarked. They have a lot of people who do that sort of stuff and a lot about lens fungus issues too if you search there.
Oddly, your lens seems to have that radioactive lens coating on it that turns yellow like the old Pentax Takumars did. Some think leaving it in the sunlight will take care of it and the fungus, and maybe the "bad-for-humans" UV light too as used in EPROM erasers or biological clean hoods. Others recommend a 50/50 mix of ammonia and hydrogen peroxide for the fungus part. Others seem to like a good old vinegar douche solution for dealing with it.
Forgot. I have made those spanner tools out of old needle nose pliers that worked well too by grinding the tips down to fit. The spanner above is nicer though and is a workhorse for shop use. Coolest tool I ever saw was an Olympus camera tech's 'mirror box screwdriver.' Handle with a bunch of small gears that went out to a small crosspoint-tip to get into areas you often wonder "How did they tighten that screw where it's at?" Cost was around $45 then, and the above spanner was only $20. Best screwdriver tips seem to be those sold by the SPT organization for the crosspoints screws on cameras.
Aside, one old photographer I knew from the club often wondered why they didn't make the lens cover caps clear so it would be less friendly for fungus to begin growing there as under the current black ones we have now. Might be a new use for just leaving a clear filter on the front of the lens as a lens cap, although the glass may block enough of the UV and let the stuff grow anyway. Dunno, but that nasty stuff shows up in the bodies on the prisms and eyepieces at times too. Looks like a black spider web in the viewfinders at times.
It seems there are nothing we can do in the front side of the lens.
The front side of the lens will also likely screw out. You just need a grippy rubber/silicone pad like a jar opener. I've also used gaffer tape to make a little "handle" I can turn.
If it's a Vivitar lens made by Kiron (serial number starts with a 22), some of the 28mm's simply twist in half, although that still may not be enough to get at the fungus. That other website will probably help.
I wouldn't waste much effort on one unless you just want to pull it apart.