[cyclone3d]

I am working on an old Sigma 135mm 2.5 preset lens that is long overdue to be reassmbled.

I noticed that some of the flat black paint is gone in the area right above where the iris is.
It first looked like it may have been oil, but after trying to clean it off, it became more apparent that either it wasn't painted properly in the first place or the paint just came off at some point.

I was just wondering if anybody had any experience with what type of paint would work good for re-blacking the inside of lenses.

I've also got the Vivitar AT-22 extension tube set and for some reason they used gloss black paint on the ridges in the center of the tubes.
Wouldn't it tend to work better if it was flat black in order to avoid light bouncing around?

[hcarvalhoalves]

I guess you can use matte black spray paint that's made of nylon. Dries fast and doesn't reflect light at all.

[Enigmaticca]

Sort of on topic (sorry to hijack thread cyclone3d);

What type of paint is used on the externals of K, M and A series lenses? I have a few I would like to touch up.

Cheers

[wlachan]

What type of paint is used on the externals of K, M and A series lenses? I have a few I would like to touch up.

Those are plating I believe, and there is no effective way of touching up.

[gp1806]

Sort of on topic (sorry to hijack thread cyclone3d);

What type of paint is used on the externals of K, M and A series lenses? I have a few I would like to touch up.

Cheers

A black Sharpie pen can minimize the silver look on the worn areas, but it is not permanent and you will need to reapply as it wears off. I believe these were anodized black aluminum, not a finish that can be duplicated in the average home.

[excanonfd]

I am working on an old Sigma 135mm 2.5 preset lens that is long overdue to be reassmbled.

I noticed that some of the flat black paint is gone in the area right above where the iris is.
It first looked like it may have been oil, but after trying to clean it off, it became more apparent that either it wasn't painted properly in the first place or the paint just came off at some point.

I was just wondering if anybody had any experience with what type of paint would work good for re-blacking the inside of lenses.

I painted cars for a living along time ago, quit for health reasons just as the colour coat/clear coat paint system became the norm (same as what's on your vehicles today). Painting inside of a cylinder is impossible with conventional spray system in an assembly line set up. Someone with an airbrush system might be able to custom paint inside of a cylinder that's 3 inch diameter or less, but no manufacturer is ever going to do this if they hope to sell their lenses at a competitive price.

I've also got the Vivitar AT-22 extension tube set and for some reason they used gloss black paint on the ridges in the center of the tubes.
Wouldn't it tend to work better if it was flat black in order to avoid light bouncing around?

Have you had any problems when using your AT-22 that you think can be attributed to the gloss paint on the tubes? If you haven't had any trouble I would leave it alone - the same for your Sigma lens, painting near moving parts can be difficult and may even make your lens unusable.

Thanks,

[thazooo]

Flat black paint for model cars. Won't match but will keep the light from bouncing.
Use a fine brush and apply thinly.

[cyclone3d]

I guess you can use matte black spray paint that's made of nylon. Dries fast and doesn't reflect light at all.

Any specific brand you would recommend?

I painted cars for a living along time ago, quit for health reasons just as the colour coat/clear coat paint system became the norm (same as what's on your vehicles today). Painting inside of a cylinder is impossible with conventional spray system in an assembly line set up. Someone with an airbrush system might be able to custom paint inside of a cylinder that's 3 inch diameter or less, but no manufacturer is ever going to do this if they hope to sell their lenses at a competitive price.


Have you had any problems when using your AT-22 that you think can be attributed to the gloss paint on the tubes? If you haven't had any trouble I would leave it alone - the same for your Sigma lens, painting near moving parts can be difficult and may even make your lens unusable.

Thanks,

It may be time to break out my airbrush then.

Not really sure if the gloss in the tubes has given me any problems, but it makes sense that it would. I do get some weird lighting sometimes when i do use them though.

I have the Sigma lense completely dissasembled. It had multiple issues when I bought it.

[Just1MoreDave]

To the original point, I think the most important point is that the paint should stick really well. You don't want to disassemble the lens to redo it. It doesn't even need to be smooth, except for looks, since the idea is a non'reflective surface.

Sort of on topic (sorry to hijack thread cyclone3d);

What type of paint is used on the externals of K, M and A series lenses? I have a few I would like to touch up.

Those are plating I believe, and there is no effective way of touching up.

I have an M40/4 macro lens that was missing a lot of the original exterior finish. It is some sort of anodized or plated thing, not paint. I can't find a paint that doesn't look too thick and doesn't chip off eventually. I'm not exactly a paint expert.

[Lowell Goudge]

I had a Ricoh lens where there was a shinny black Ron holding the rear group in place but causing a serious reflection off the sensor. I used acrylic flat black craft paint. Using a sharpie won't work if the surface is smooth because the pen will leave a shiny black surface

[wlachan]

Just airbrush the whole thing matt black when needed.
Hobby paints don't stick too well btw. Better find those in hardware shops.

[excanonfd]

Any specific brand you would recommend?



It may be time to break out my airbrush then.

Not really sure if the gloss in the tubes has given me any problems, but it makes sense that it would. I do get some weird lighting sometimes when i do use them though.

I have the Sigma lense completely dissasembled. It had multiple issues when I bought it.

If you have an airbrush, any solvent based paint thinned enough to go through the spray tip should suffice. Any flat black paint should do but for high strength and best adhesion, high temperature paint meant for refinishing Propane BBQ might be the best available.

If your Sigma is completely disassembled, give it a go. I no longer have the AT-22 but an AT-23 seem to share that somewhat shiny ridged ring. I haven't noticed any ill effect from that, I'll have to pay attention when I use the extension tubes next time.

Thanks,

[slip]

Sort of on topic (sorry to hijack thread cyclone3d);

What type of paint is used on the externals of K, M and A series lenses? I have a few I would like to touch up.

Cheers

you might want to try one of these, they have different sizes of tips and colors. You can get them at a local industry supply store like this MARKAL CO./LA-CO INDUSTRIES INC. Marking Products | Fastenal

[MRRiley]

Try Birchwood Casey's 'Aluminum Black'... this is a product which effectively "stains" the aluminum (similar to "bluing" used on firearms) so it is less likely to flake off and make a worse mess inside the lens.

Aluminum Black Metal Finish

They also make similar products for brass and steel... Birchwood Casey - Finishing List

A light sanding may be necessary after treatment to reduce reflectivity, but the gloss depends mostly upon the smoothness of the underlying metal... slick as glass equals glossy... rough as sandpaper means matte or flat...

Mike

[The Jannie]

I've recommended elsewhere that a good model railway shop - not a toy shop - will have the answer. Paints are available in clean black, dirty black, shiny black, not-too-shiny black, track black, wheel black, etc etc . . . the list is almost endless. I'm sure you'll find a match there.