After catching Titan, Rhea, Dione and Tethys in my C90 Mak at 208X tonight, I figured I would try for the craterlets in Plato. In 45+ years of serious observing, I've never looked for these, so I thought I would try after reading a post here on CN about them. Not a trace, even after waiting until the moon got reasonably high. One thing I became acutely aware of was all the stuff I can see in my eye and any traces of dirt on the eyepiece (I assume) field lens. After a little experimenting with eyepieces I found that 165X was about all I could do on the moon without being seriously aggravated by floaters, other unworldly looking things, etc in my eye. I assume that this is due to the small exit pupil caused by the combo of the 90mm aperture and magnification. It appears that a 0.5 mm exit pupil is about all I can tolerate on the moon. This is not an issue on Saturn or Jupiter, but neither is the glare/brightness factor. I may have picked the wrong moon phase also to look for these craterlets. I think I read that the optimum time is around a 12 day old moon. Then again, maybe a 90mm aperture is just not adequate for visual detection. Comments from you seasoned lunar observers are definitely welcome.