imagesintime Loc: small town, mid-America

Ask the kind folks at lensrental.com.

Kissel vonKeister Loc: Georgia

Right; they're called crosspoint screws.

Harvey Loc: Pioneer, CA

Thanks for the tip : however I found this kit https://www.amazon.com/gp/product/B0064PUJUG/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 on amazon and ordered it. - Friday I'll know if one of them works.

Harvey

pounder35 Loc: "Southeast of Disorder"

The normal effect of a really dirty lens will be a loss of contrast. But it'll have to be really, really dirty. More than the average shooter will ever experience. If you have fingerprints and smudges all over your front and rear elements then use common sense and clean the lens. Some dust on internal lens elements is not worth the trouble to try to clean. Especially for a novice. By the time you reassemble the lens you normally end of worse than before you tried to clean it. Have you ever seen a diagram of the construction of a modern lens? Especially a zoom. There are multiple groups of elements. And if you accidentally flip a concave or convent element you won't know it until the lens is completely reassembled. Then the possibility of having to readjust the focus and diaphragm is likely. I'm just trying to share what I know from my years of camera repair and save Harvey a lot of work for nothing.

pounder35 Loc: "Southeast of Disorder"

I got a little off track and went back and noticed your were complaining about mold instead of dust. The same things I described still apply. One thing I will add is that often mold will etch into the coating of an element and be permanent.

Harvey Loc: Pioneer, CA

Thanks for this tip -I ordered a set of these JIS as my first thoughts were I could just use a tiny single blade screwdriver "BUT" if the screws have tapered slots - like I am now sure they have , I would just mess up the head - these look like a sharp square cut philips "type" driver with no blunt point.
Any way I canceled my precision flat blade set and will be waiting for these to come after the first of the month. I think I will photo this mold cleaning project as it is getting interesting.
Harvey

Harvey Loc: Pioneer, CA

This lens has been shelved for 17 yrs the mold could be etched in the permanent like you say.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

Excellent. I am relieved to hear that. If I can help, you know where to find me!

Take care!

Harvey Loc: Pioneer, CA

"YES" Just as I visualized them - I have a set ordered.

skipnord Loc: Corcoran, Minnesota

Many places - grocery stores, etc. - have eyeglass repair kits for sale near the checkout counter. They include a very small phillips screwdriver. This may work for you.

brucebc Loc: Tooele, Utah

sir tools part #ST 9009 It is a great set. Has straight, phillips, allen, and Torex total of 22 bits and sizes.
https://www.walmart.com/ip/Sir-Tools-ST9009-23-in-1-Mini-Uni-Drive-Kit/16551238?wmlspartner=wlpa&selectedSellerId=1413&adid=22222222227016731078&wl0=&wl1=g&wl2=c&wl3=52590729551&wl4=pla-84471337031&wl5=9029685&wl6=&wl7=&wl8=&wl9=pla&wl10=113139785&wl11=online&wl12=16551238&wl13=&veh=sem

jct842

On jis screws one can get a better fit using a std. Philips if you grind off the point on the philips. If you take one of the jis screws and put a philips in it and look real close you can see the philips does not seat all the way into the jis screw. It doesn't take very much grinding to remove the point on the philips. On jap motorcycles when people keep stripping the screw what is happening is they are using the wrong driver.

Jim Plogger Loc: East Tennessee

I bought these at The Home Depot a few years ago. I think this is what you are looking for.

(Download)

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

OK, so why not just get JIS precision tools? Can you make better beer, wine, or whisky than the professionals? Cheaper, for sure, better? That's a matter of taste!

Oh, and I have had some excellent moonshine in Appalachia!

amfoto1 Loc: San Jose, Calif. USA

Those screwdrivers are widely available at hardware stores or any place that tools are sold. They typically come in small sets.

You also can get them online... search for "precision screwdrivers" and "jewelers screwdrivers" at Amazon or elsewhere and you'll find a wide selection.

More of a concern, some camera gear uses Phillips head screws, others use JIS (Japanese Industry Standard) cross point. Phillips are the most common type you'll find being sold. If the screw isn't too tight, they're relatively interchangeable. But because they're slightly different, it can be a problem using the wrong one when a screw is particularly tight. (Note: I see some other folks have suggested modifying Phillips to make them fit JIS better. I haven't tried this because I have sets of both.)

Sometimes you may find screws are secured with Locktite, too. The weaker holding blue type is no problem. But the stronger red type requires heating to get it to release. If you happen to come across any of those, heat the screwdriver while it's held snugly in the screw head, rather than trying to directly heat the screw.

Another important thing is to set up a work space where you can be certain not to lose tiny parts... anything that ends up on the floor or in the carpet might disappear forever and be hard to find an exact replacement.

Not sure what particular lens you are working on, but many you have to be careful of certain things.... disassembled focusing helicoids can be very difficult to reassemble correctly. Also watch for tiny shims used to precisely adjust lens fit, such as under the bayonet mounting screws. Note their locations carefully and be sure to put them back in the same place... or you might need specialized optical equipment to test the lens and re-calibrate it.