how barlow lens

[Tiny-James]

So my Microscope is a mx2 brundel I would like to fit a barlow lens to increase the working distance but I'm unsure how it fits I see the barlow lens has a 48mm thread but I have no thread on the bottom of my object lens

https://www.ebay.co.uk/itm/262634214422 ... 0667.m2042

[Hobbyst46]

If the microscope objective has no m48 female thread, the Barlow lens will not simply fit.
All the more so if the objective plastic sleeve is tapered (conical) because it is tapered on the inside as well, so a straight tube adapter will not fit by friction.

These m48, WD165mm barlow lenses can be taken apart. The glass lens is a doublet, outer diameter 39-40mm, about ~8mm thick, retained by means of a threaded ring.
Disclosure - I am facing the same problem and did not find a solution yet. Thinking of an empty, cylindrical, hard plastic toothpicks container, of a 44-48mm outerdiameter, that might be push-fitted into the objective from below.

Also note that the 165mm WD might be a problem on a small microscope...

[dtsh]

Depending on dimensions of the objective, if it were mine I'd consider 3D printing a part to glue onto the end of the objective sleeve which could accept the barlow, either with its native threads or with a separate 3D printed ring (and perhaps a few small neo magnets to make adding/removing easy).

An alternative would be the aforementioned ring to glue on wth the barlow on a separate ring to pivot out, similar to the AO Cat.264 swing out barlow for the Cycloptic, it's mighty handy having a barlow that's easy to add/remove as needed.

[Tiny-James]

I was thinking of buying a 48mm skylight filter and gluing it to the out part of the object lens as most skylight filters have a male and female thread would this work?

[Hobbyst46]

I was thinking of buying a 48mm skylight filter and gluing it to the out part of the object lens as most skylight filters have a male and female thread would this work?

Sounds a great idea !!
I only have a 49mm filter ring (cheapo from China), not 48mm. Yes, it does have male and female threads. It wo'nt fit the m48 of course but a 48mm filter probably would. The only issue would be centration. Perhaps experiment with cellotape first.

I now see that whereas cheap 49mm UV filters are in masses, 48mm filters are rarer and expensive. Why ?

[Phill Brown]

49mm was a popular and over produced size for SLR and DSLR.

[Tiny-James]

I do believe cannon has a lens that is 48mm
and you can buy 48mm here is a link
https://www.ebay.co.uk/itm/263219150994
my object lens outer bit is 46mm so it will glue in I think?

[Hobbyst46]

A bit away from your idea but still - I see an m48 Female to m42 Male adapter, at around 12$ shipping incl. I think the m42 will just slide into the objective sleeve, and the wider shoulder will support the glueing. My microscope is not a Brunel MX2, it is a cheap noname 20X-40X from the far east, bought for kids.