Looking for opinion(s): We just purchased a used optical comparator. For the most part its in really good condition. And we paid for that, so...
The glass where the mylar sits... the "projection screen" I think is it's official name. I know they don't have dimensions scribed on them, that's what your various mylars are for. But they do have an
X ... or a
+, however you look at it, they all do, and you use this to line up your mylar to the glass. OR, you could even use it to line up a part and inspect it using a DRO.
The one I have the x / + is non-existent anywhere near the inner part, only existing on the very outside edges. Like it's been cleaned with Ajax too many times. So without a mylar, even though we have a DRO, its not usable.
Thoughts???
unless you're just gonna slap a mylar up there and use it to check form...then you're good...if you need to use the mylar for location as well you need to be able to see the screen lines to square things up