I don't have easy access to the used market of the US nor Europe. I'm in South America, and haven't found any "old professional grade" €100 Olympus/Zeiss.
I've had good luck importing a couple of barely used astro items from the US (CN classifieds), but I'm unwilling to take the risk with a used microscope, not being able to test it first (nor to return it after).
Despite the lesser value, I'd be more comfortable with a brand new China am scope/swift/similar.
So I went and checked Amscope's compound options under $150 and this is what I found:
There are several different base/mount, differing in design, orientation and some lighting (halogen vs led, top vs bottom, handle vs none, batteries vs ac power, etc), all holding a monocular head, 10x eyepiece, and rotating objectives of 4x, 10x and 40x. Each of these base mounts then comes in several incarnations at increasing prices, by adding features/accessories.
The first step up in price brings adds fine focus, which I think is a must.
Next step up in price adds a rotatable head (nice to have).
Next step up seems to add an extra eyepiece of 20x or 25x, which raises the theoretical magnification specs to 800x or even above 1000x for some models, which I think is pointless, and I doubt anything above 400x will be much useful. At most, the value of that extra 20x eyepiece lies in enabling the intermediate magnification of 200x, considering that 100x to 200x is said to be the most useful power for observing pond water life (according to what I've read). Still, I do wonder how likely I'd be to swap eyepieces.
Next step up in price brings a mechanical stage (which can be had separately for $27 anyway), and some models come with sets of slides plus a book.
Next step up in price comes with a "dual head" meant for two observers (professor + student?) or maybe for a camera.
Next step up in price goes over my price range (unless I gave up the stereo microscope), with binocular (although non-stereo) heads and features like dark field, phase contrast, flux condensers and whatnot.
So, wanting to concentrate on value, not hoping to observe above 400x (but desiring the intermediate 200x) power, preferring LED over halogen, and leaving the mechanical stage for a later purchase, I end up with the the M158B-2L model as the most attractive for me, and surprisingly inexpensive: $99 (+5lb international shipping).
This leaves money for a stereo microscope, just not the nice 7-45 zoom that I fancied (which goes for $227 +18 lb international shipping).
Here the choice is basically the fixed 20x & 40x stereo for $118 vs the fixed 10 & 30x for $108. I fear as a low magnification, 20x is too high for a stereo, so I'm leaning towards the 10 & 30x.
There are ~$60 "barlows" for these, at 0.3x, 0.5x and 0.7x powers, and these even seem to be M48, making me wonder whether my 2" astro focal reducer + spacers could work here to make it more versatile (or give it more
backfocus working distance)
The compound + stereo 30x would run me $207 + shipping (~11 lb), and I'd have 10x, 30x (stereo) and 40x, 100x, 200x, 400x (mono).
Not bad, but I wish there was a "single mount, dual head" solution.
¿What do you think of my reasoning?
Edited by Adun, 04 January 2020 - 09:51 PM.