loads of dust on 2nd element?

[Chaojesse]

Hi everyone,

I recently picked up a Minolta M-Rokkor 28mm. It doesn't have the notorious "white spots," but there is considerable amount of dust accumulated on the second element. I was wondering if anyone knows if they would affect picture quality? If so, do you think it is easy to get to the second element and would recommend a DIY?

Any ideas is much appreciated! Thanks!

 

[mdarnton]

Is that dust? Looks like evaporated and condensed oil.

 

[xxloverxx]

Might be haze.

 

[Blanc]

Looks like someone tried to spray wd40 into the helical to me, you should smell it.

Dust can hardly get in a rokkor to this ammount (I never saw this that bad) IMHO I worked on some high speed camera lenses used for shooting demolitions from the inside and even with those it wasn't that bad.

Maybe haze, but never saw it in those proportions neither.

 

[btgc]

Looks similar to how push-pull zooms can look (as they normally suck air into). It will not affect image dramatically but for peace of mind it can be cleared, it's like going out of home wearing freshly washed socks 🙂 At least I did with some lenses, but none of them were particular model.

 

[Steve M.]

It's hard to say from the photos whether it's evaporated lube, dust, or both. You'll get some flare if there's some sun in your shots I'd think. Put a hood on it and take some photos. It might not be too bad. If it's dust I'd leave it be, assuming the photos turn out OK. If it's out-gassed lube, I'd want to get it CLA'd.

 

[Chaojesse]

Looks like someone tried to spray wd40 into the helical to me, you should smell it.

Dust can hardly get in a rokkor to this ammount (I never saw this that bad) IMHO I worked on some high speed camera lenses used for shooting demolitions from the inside and even with those it wasn't that bad.

Maybe haze, but never saw it in those proportions neither.

Thanks everyone for the suggestions. If I were to open the lens from the front, what kind of tool would fit in those two notches opposite of each other?

 

[shadowfox]

Search online for "lens spanner."

 

[Phil_F_NM]

The front element is part of a cemented group so you don't have access to it unless the particles are actually behind the group. Removing it with a spanner should be easy.

If it's between the elements in the first group, this may be the final throes of the white spot issue though.

Good luck.

Phil Forrest

 

[KoNickon]

Uh oh, that looks almost exactly like my sample of this lens. I sent it to John Van Stelten at Focal Point, who is familiar with the white spot problem, and he said it's not worth his opening up the lens. So I fear that you, like me, have a "flare king" Rokkor.

 

[clayne]

Not worth opening up? Nonsense. That's simply condensed lubricant from the helical that's evaporated onto the inner surfaces of the each group facing the iris. Open the lens, separate the front and rear cells, and then clean the 2 inner exposed elements with naphtha or 99% isopropanol and a pec pad. This should not require removing any elements from their retaining rings unless it's truly between groups - which I doubt it is. Oil doesn't usually evaporate onto elements secured with retaining rings. 99/100 times it's the elements facing the iris.

 

[Chaojesse]

Minolta 28mm f2.8 successfully repaired!

Minolta 28mm f2.8 successfully repaired!

I finally bit the bullet and sent it to John Van Steltan in Colorado. After 5 weeks of seemingly endless waiting (but only 3 of those weeks were the actual repair time), I got it back.

I haven't this roll of film yet, but the lens looks pristine. I can see some paint loss around the perimeter of the first lens group housing (which is a metal barrel that makes removing the first lens difficult, if not impossible), but the rest of the lens is intact.

It wasn't a cheap repair, but considering how well it turned out, and given the reputation of this lens, I think it's worthwhile.