BebuLamar

I have a lot of old cameras and lenses and never find anything suitable for that job. I do wonder though. My cameras have lots of scratches but some how I don't have scratches on my lenses.

LDI

I am a jeweler and have used countless optical devices with black finishes that have failed. For thirty eight years I’ve wrestled with
making tiny, perfect objects using microscopes made by nearly every camera manufacturer. For those of you who are lucky enough to “just let it go and live with it”, I wish I could.
My “fixes”:
1) Sliding many small-cross-section O-rings onto cylindrical areas
2) Where that’s not appropriate, I have used
heat shrink tubing. This is trickier. You will have to trim the excess ends, and find US or EU material that looks good. AVOID VINYL.
It will dry out and as it continues to off-gas, making your fingers

RodeoMan Loc: St Joseph, Missouri

Good answer. Sometimes a good story is better than a good fix.

LDI

LDI continued:
...and make your fingers stink.
3) dismantle the equipment and sandblast it.
find a member of the “Plato-painting” industry with all technology under one roof:
anodizing, baked powder painting, and most important “hard coating”. Hard coat is an electrodeposition done in a vacuum chamber.
It used cost a fortune, and now is inexpensive. From the yellow Ti-Ni on drill bits to perfect decorative finishes, it is nearly as hard as a diamond. Tell the sales engineer the truth, but stress that there are thousands of people in your similar situation. These guys ‘are very accommodating, especially because they are looking for new markets that will able to make them a profit. Let’s see: $.05 for a US drill bit coating or competing against Chinese $.05 entire drill bits. They have sample finishes, and better yet match your sample. Hope this is helpful! I am offline for the next week, but will follow up upon return.

RodeoMan Loc: St Joseph, Missouri

siamesecatmanuk Loc: Leicestershire UK

Thank,you all,itsmobviously NOT just me then that's not doing very well,I feel a bit better knowing that,I didn't want a perfectnas new finish just back to black rather than the steel looking colour under a few very deep scratches ,I will live with it the best I can get it,not so obvious and I drought anyonemwill,inspect,close up,plus I need not worry if there s a bit of rain on bare metal.

Bill P

AH HA!! you say the scratches show a "steel color." So it is likely that the barrel is made of aluminium. That makes it a sure thing that it's not painted, but anodized. To repair that scratch, you would have to completely disassemble it from the lens, take it to an anodizer and have it done. I doubt filling the scratch is possible.
Then you would have to put it back together, done in a clean room, all in perfect alignment. Or, go to a hobby store, get a tiny brush and some flat black hobby enamel, and have at it. If unhappy, you can remove the paint with solvent, the anodized finish can take it.

Or, just look at it as a badge of honor. And remember, Robert Capa, when photographing the Marines putting the flag on the beach, never said, "Well, that photo's crap. Is scratched the outside of my lens!"

bolete

magic marker

chrissybabe Loc: New Zealand

Magic markers rub off really quickly and take on a purplish tint anyway.
Any paint you use will rub off with time. There is no finish that will look like new and will last the next few years (without repeated application anyway). Possibly your best bet might be to use one of those paints designed to apply over rust applied with a very fine brush. These paints seem to stick better than the normal stuff. Best of luck mixing a couple of them to get the right degree of finish. And they are not cheap either.
Otherwise just put up with them and make a bigger effort not to get more.