Portable microscope

[75RR]

It has got to be a contender for most practicable portable microscope at the most reasonable price. Assuming nobody else bids for it. I was tempted!

https://www.ebay.co.uk/itm/Vintage-Meop ... 3731664332

+ a little info on it

http://www.quekett.org/resources/articl ... a-portable

+ a pic

[Hobbyst46]

Nice find. A cover in the style of Wild, sturdy and reliable. No doubt it can be easily upgraded just a little bit by adding a LED light and an eyepiece USB camera, connected to a laptop. This is likely easier to do than finding a binocular head. Although, the basic small compact size of the scope is a virtue in itself.
May you win the bid.

[75RR]

May you win the bid.

Mentioned it because I am not going to bid, though I was tempted. Thought someone here might be interested. Good luck to anyone that is.

[zzffnn]

So the objectives do not have RMS thread? DIY adaptation may be possible, if thread diameters are not too far apart.

And there is no condenser (but adding a DIY one there shouldn't be difficult).

Everything else looks great for me. Too bad shipping cost will kill the deal, otherwise I would bid. I doubt it would end at 20 GBP though. Many microscopists there in UK.

[MicroBob]

The Meopta has a small revolver with 3 non-RMS objectives, the 20:1 collapses inside.
It is a nice compromise between portability and usability. I haven't tested it thoroughly enough to make a statement on its optical quality.
A true RMS revolver nosepiece wouldn't add much bulk to many portable microscopes and offer quickly changeable good objectives. But this is seldomly available.

We just today discussed the topic on our group meeting and a very experienced member who has probably had every portable microscope made since the 1930s recommended the Olympus MIC school microscope. It usually comes with a sturdy (but big) plastic box, has an inclined monocular tube and is cheap to buy. I have one and what I don't especially like is the comparatively small field of view through the small tube and eyepiece.

[zzffnn]

Thank you, Bob.

How heavy is your Olympus MIC scope?

Would you please quantify how small the viewing field is (compared to the standard 18mm field width), is it closer to 20% smaller or 30% smaller? I assume its eye tube cannot take RMS standard eyepiece? I wear strong eyeglasses, so field width smaller than 12.6mm may not work for me.

I actually have a true pocket scope that provides 100x and 400x visual magnification. Its 400x does not have enough NA (resolution) and truly sharp field width is narrow (objectives are simple lenses without RMS thread). But it comes with a RMS eye tube and wide field standard eyepiece. It is comfortle to use, but poor image at 400x (100x imagery is decent). No condenser. But hey, it is truly pocketable.

Edit: that pocket scope has been sold out. Here is my original forum thread with some photos and description: viewtopic.php?f=16&t=2246

[MicroBob]

Hi Fan,
it weighs 1750g including the box.

I'm very short sighted and have to move very close to the eyepiece so my eyelashes touch the eyepiece. With glasses I can see just a bright point in the middle. Due to the special tube diameter one can't just exchange the eyepiece. The eyepiec eitself doesn't want to screw out, but the tube does.

Bob

[MicroBob]

I forgot this:
with the total mag of 40 I can see 3mm object width, with the total mag of 150 I can see 1mm object width.

[zzffnn]

In that case, the Oly scope is too heavy for my use.

Bob, I think your modified LOMO scope would beat that Oly easily too.

I have added a condenser to a educational toy "My First Lab Duo" scope. It weight 900 grams with LED light, batteries and condenser. Its eyepiece provides decent field size and imagery is decent up to 400x (40x mini objective + 10x eyepiece).

[MicroBob]

Bob, I think your modified LOMO scope would beat that Oly easily too.

As far as I remember by "Biolamini" weighs 1,3 kg, monocular, no light, no xy-object guide. When I add a compact bino tube and battera powered LED light and object guide it isn't especially small or light any more. On the other hand side it provides nearly the same performance as a lab microscope and is ergonomically acceptable.
The heavy weight of the Olympus comes from the heavy plastic box and the microscope itself weighs only 1 kg. It includes a heavy cast foot, good for stability in school use.

What I would see as useful is a microscope that is a a real improvement over a light lab microscope like the Biolam in terms of weight and size, switchable parfocal magnifications (40x),100x and 400x, battery powered LED light, nice eyepieces, quick to setup, object guie, ergonomical to use, not too expensive. With a detatchable base weight it could serve as a good school microscope and in this way generate production numbers.

Can you show a picture of your modified microscope, Fan?

Bob

[zzffnn]

Bob, it looks almost exactly like the original:
https://www.amazon.com/My-First-Lab-Duo ... B000NOU54O

I simply removed the factory condenser diaphragms, enlarged the condenser opening and added on an old Nikon Abbe condenser with two-part epoxy clay.

And its eyetube can be unscrewed for compact storage too.

Between your Biolam mini and your Olympus MIC, I would personally still prefer the Biolam for its RMS standard mounts all around (for example, you can put on a dry darkfield condenser) and wider view field.

That is because I already have a pocket scope and a 900 gram portable upright (getting that Oly MiC would not offer me any more features, but getting a Biolam Mini like yours will offer me more features; you know I may simply modify my Biolam after yours one day).

Could you link your original forum thread for Biolam Mini here please? I could not find it now.

[MicroBob]

Hi Fan,
I wrote a bit on the Biolamini here: viewtopic.php?f=11&t=6998&p=62050&hilit ... ini#p62050

Main components are a Lomo Biolam head and a small linear guide sold for industrial applications. The rest are aluminium parts, hold together by screws, a dovetail and in case of the condenser holder just expoxy glue. I got the alignment precise enough without use of too fancy measuring tools, just ordinary machinist stuff like a precision bevel edge square and a water level and much eyeballing.
The stage can be set down with the dovetail for use of a low mag objective with longer parfocal distance, but I haven't really used this feature so far.

Bob

[zzffnn]

Beautiful! I remember it now, Bob. You were calling it "Biolamini" instead of "Biolam Mini" and it is in the FM-31 thread. No wonder why my search returned nothing.

Your focus drive mechanism looks difficult for me to replicate though. I am sure you have put lots of thoughts in its connections and joints; they look just so elegantly and deceivingly simple and efficient!

[MicroBob]

Your focus drive mechanism looks difficult for me to replicate though.
It is not dissimilar to this one: https://www.owis.eu/en/products/manual- ... view/Main/ I got mine from a car boot sale for 0,5€ and had it lying around a couple of years. My one is made up from aluminium extrusions and it doesn't move quite as well as a good classic microscope guide. There are probably better ones around. One disadvantage: Nobody else knows how to use this adjustment, so I have to explain it every time I let someone look through it.

I am sure you have put lots of thoughts in its connections and joints; they look just so elegantly and deceivingly simple and efficient!

Not really - sometimes I just want to build something any I started with only a rough concept in my head and a selection of used metal components from my lifelong collection.


Bob

[75RR]

Ouch! What does Pantone call that colour ... sick green?

color=#40FF00

[MicroBob]

I have to admit, that colour was greener than I intended!

[MichaelG.]

Reference the Meopta, recently offered on ebay

May you win the bid.

Mentioned it because I am not going to bid, though I was tempted. Thought someone here might be interested. Good luck to anyone that is.

Strangely enough ... there were no bids, and then it was re-listed
Then the seller invited offers ... and now it's mine.

As I wrote to the seller:
This is an interesting little instrument, but would probably remain no more than a curiosity on my shelves.
[non-standard objective mounts, friction-drive focus, and only a plain stage] ...

MichaelG.

[Hobbyst46]

Then the seller invited offers ... and now it's mine.

....No doubt it can be easily upgraded just a little bit by adding a LED light and an eyepiece USB camera, connected to a laptop...
May you win the bid.

My compliments, Michael.
Actually, the quotation included a practical suggestion for upgrade, but even if not, hopefully this scope will not collect dust on a shelf. Maybe a kid (whatever his/her age) wil train himself/herself to collect field data for later research with his/her senior/mentor/partner/family member in a home lab.

BTW: what is a "friction drive focus" ?

[75RR]

As I wrote to the seller:
This is an interesting little instrument, but would probably remain no more than a curiosity on my shelves.

I hope you take it out for a spin at least. You never know, it may grow on you yet.

[MichaelG.]

BTW: what is a "friction drive focus" ?

If you look at the photo posted earlier ... there is a vertical [probably chromium plated] rod: The focus wheel is spring-loaded against this, to provide traction ... No gears as such.
It's a simple but effective drive, also used on many photographic enlargers, but does not provide fine adjustment.

That is my understanding ... I will photograph some details when I receive the microscope.

MichaelG.

[MichaelG.]

I am duly chastised and/or encouraged

What I do with it will, of course, depend upon its underlying qualities
... As yet, unknown

MichaelG.

Edit: This looks quite promising
https://mikrokristalle.com/tag/schuelermikroskop/

[MicroBob]

Hi Michael,
the 20:1 objective rests in a travel position and has to be drawn out to its full length to be parfocal.
Depending on how you travel this might just be the right microscope to take when you go on a trip.
It would be great when somebody would invest the time to design a 3D-printable storage unit to fill all the unused space in the metal box.

Bob

[MichaelG.]

Thanks for that very helpful note about the 20x, Bob ... Much appreciated

I don't have a 3D printer, but may see if I can come-up with some internal storage ideas.

MichaelG.

[MichaelG.]

The Meopta arrived safely today, and is a delightful little package.
Some adjustments are required [the head assembly is loose on its fixings, and the catches on the 'can' need slight modification] but it shows great promise.

Details to follow in the next week or so.

MichaelG.

.

Head [black] is rattling loose

Meopta_.jpg (75.4 KiB) Viewed 8540 times

[MicroBob]

Hi Michael,
there should be a red rubber ring of recrangular section between base and dome.
My one wasn't ok any more and I replaced it with an O ring.
The rectsngular shape was better though.

Bob

[MichaelG.]

Thanks, Bob

That's the seller's photo of my actual microscope
As you will see, the red rubber ring is present; but hardened and cracked.
... Not as bad as my Wild M11 though.

If I manage to find a suitable ring, I will post the details.

MichaelG.

[Hobbyst46]

Thanks, Bob

That's the seller's photo of my actual microscope
As you will see, the red rubber ring is present; but hardened and cracked.
... Not as bad as my Wild M11 though.

If I manage to find a suitable ring, I will post the details.

MichaelG.

Sealable kitchen plastic packing boxes of the LOCK-LOCK species are based on square cross-section rubber "o-rings".

[MichaelG.]

Sealable kitchen plastic packing boxes of the LOCK-LOCK species are based on square cross-section rubber "o-rings".

Good thinking

[75RR]

If all else fails perhaps you can cut one out of a cork tile.

[Roldorf]

You could always use the ring from a suitable sized kilner jar. Maybe you could 'borrow one" from the wife.