I wanted to have a 20x microscope objective with a decent WD (for extreme macro photography with a FF DSLR), and ended up ordering this one:
https://www.ebay.ca/itm/183165843330
This is Olympus ULWD Neo Splan 20 0.40 inf/0 f=180mm metallurgic objective. It was surprisingly cheap given the ULWD designation. According to this link (http://www.alanwood.net/photography/oly ... tives.html), the objective is "Metallurgical achromat, brightfield/darkfield, superwide flat field up to F.N. 26.5". The PDF datasheet I found on Olympus metallurgic objectives provides the following numbers:
WD = 11.0mm, focal length = 8.99mm
The working distance is great for such a high magnification and fast lens.
I have no experience with infinity corrected objectives (my only objective so far was Nikon 10x/0.25 210mm), so I'm trying to figure out what setup I'll need. I believe the designation "?/0 f=180mm" means I'll need an 180mm lens to be used as a tube lens - correct? I have Canon f4L 70-200mm zoom - will this work well?
Another question - can I use AF of the tube lens to shift focus, for focus stacking? According to this link (http://extreme-macro.co.uk/extreme-macro-tube-lenses/) image quality goes down if AF is moved away from infinity - is it your experience as well? If that does work, then I can use the focus stacking feature of Magic Lantern (alternative firmware for Canon DSLRs). If not, I'll end up using my own design Fast Stacker rig (https://pulsar124.wikia.com/wiki/Fast_Stacker).
Finally - the thread on this objective is "Neo Thread". Apparently it is a 26mm thread. Do you know if this step-down 30-26mm adapter will work with the objective:
https://www.ebay.ca/itm/RISE-UK-30mm-26 ... 1820044885
I'll also need two more step down rings to get to the Canon 70-200mm f4 thread size (67mm) - 52-30, and 67-52:
https://www.ebay.com/itm/RISE-UK-37mm-3 ... 1829289118
https://www.ebay.com/itm/RISE-UK-37mm-3 ... 1829289118
Do you think this 3-ring setup will work well?
Olympus ULWD Neo Splan 20/0.40 inf/0 - any tips for usage?
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