<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><blockquote type="cite" class="">On Aug 21, 2019, at 4:00 AM, Roman Sowa <<a href="mailto:modular@go2.pl" class="">modular@go2.pl</a>> wrote:<br class=""><br class="">The lens themselves are not the problem, this can be wiped easily, although multiple cleans may damage anti-reflex coating. But it gets inside through gaps and sits on the prism. That causes gradual degradation in view that you cannot notice, but at some point you get the feeling "I can't remember being it so foggy" and have to clean.<br class=""></blockquote><div class=""><br class=""></div>Pressurize the inside of the 'scope and have air blowing on the objectives. An aquarium pump may suffice although the air coming out of it may not be clean and dry enough.<div class=""><br class=""><br class=""><blockquote type="cite" class="">I used to read 0603 markings without any optical aid, also soldered 0.4mm pitch QFN and alikes with bare eyes. Now I can barely see strips on THT resistor. But the microscope makes it possible to pretend I'm 17 again.<br class=""></blockquote><div class=""><br class=""></div>I wish there were something that would take 40 years off of mine.</div><div class=""><br class=""></div><div class=""><br class=""><div class="">Terry Bowman, KA4HJH<br class="">"The Mac Doctor"<br class=""><br class="">Nately: "...it's better to die on your feet, than to live on your knees."<br class="">Old Man: "You have it backwards: it is better to live on your feet, than to die on your knees."—<i class="">Catch-22</i></div><br class=""></div></body></html>