Bruce, Thank you. An electronic contact cleaner spray might be a good idea. I didn't think about it.
Just a quick comment about isopropanol. You brought up an important point that can be overseen often. However, for the purpose of "full disclosure", err. information: The amount of residue left behind by an evaporating solvent depends on the solvent, but even more depends on the purity of the solvent. The 70% isopropanol that is sold at a pharmacy as "rubbing alcohol" probably has plenty of impurities that don't evaporate. High purity (e.g. spectroscopic grade) solvents leave very small residue (between 1ppb and 1ppm, depending on the solvent). Isopropanol of high purity grades is frequently used for cleaning Ultra-high-vacuum (UHV) components for the reason that it leaves very small amount of residue on the surface, and also that it can be removed by baking the surface. Methanol that is used for the same purpose, while being more volatile overall, IIRC, may leave a bit more impurities behind. Many typical wafer cleaning procedures include IPA (isopropanol) or methanol as the last step, - to remove residues left by other solvents, e.g. acetone. Igor Tue Nov 13 12:29:00 EST 2012 Bruce Walker wrote: I use an electronic contact cleaner spray which I apply with a Q-tip. Hosa D5S-6 DeoxIT, by Caig Laboratories. Dirty hotshoe contacts (and battery contacts too; don't forget those) are the source of practically all my flash misfires. It similarly affects the radio trigger devices. I'd be leery of using isopropanol though. Better than nothing, but I have found it may leave a non-conductive residue. On Tue, Nov 13, 2012 at 12:09 PM, Igor Roshchin <str at komkon.org> wrote: > > > In the recent past, my flash (Metz AF58-1) in combination with K-7 > developed a problem. In some cases, I do not get the flash-ready > confirmation symbol in the viewfinder. In other cases, even if I do > get that confirmation at first, the flash (in PTTL mode) goes off full > capacity, as if the PTTL did not work, yielding extremely overlit > images. In those cases, often, on the subsequent shots, there is > no flash confirmation symbol. > > All those problems can be fixed by tweaking the hotshoe in the socket > (sliding it slightly in or out), but it takes a few times to find the > "right" position. > I am thinking if this can be fixed by cleaning the contacts. > > What are the options of cleaning the contacts besides the obvious of > using a q-tip soaked in isopropanol? > > Any other thoughts on what else might be causing such hot-shoe issues? > > Igor -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
