Assembling a Field Microscope (Some Help?)

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Sure Squintsalot
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Assembling a Field Microscope (Some Help?)

#1 Post by Sure Squintsalot » Fri Jul 29, 2022 8:44 pm

I thought it'd be fun, useful, and interesting to have a field microscope when out camping, at the beach, and going to the restaurant with friends.

Anyway.

I ended up with this fine petrographic unit which mostly works save for the fact that three of the objectives and the analyzer have delaminated and are pretty useless. Other than a few rusted screws, everything else is in OK shape; even the grinding sounds coming out of the rotating stage are likely repairable.
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I'll need a box, a battery operated LED light source, and 4 decent objectives that'll make me the most popular person at Denny's Monday Night Seafood Special.
  • Will AO 160 objectives work? Should I look for the lowest magnification range in a quality optic? What do you do when in the woods?
  • How about that analyzer? I suspect that here's no way I'll find a replacement, but I have the tools to cut one out of a camera lens polarizer filter. Should I bother?
  • A ready-made, bolt-in light source would be nice, but I can certainly modify something cheap, easy, and effective. Any recommendations?
  • An age-appropriate box would be nice, but I'd settle for an old ammo box or, DIY plans for making my own. Waddya got?
I'm a noob when it comes to the whole field biology thing. So, any tips for interesting pieces of gear that would make having a scope in the woods awesome, would be appreciated!

Thanks!

apochronaut
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Re: Assembling a Field Microscope (Some Help?)

#2 Post by apochronaut » Sun Jul 31, 2022 2:19 pm

Maybe you can pull it out at Denny's, right at the same time the health inspector is there for a check.

lorez2
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Re: Assembling a Field Microscope (Some Help?)

#3 Post by lorez2 » Sun Jul 31, 2022 3:42 pm

You may find that Denny's has a problem with a microscope on one to their tables.

I delivered a microscope to a client, long ago, and when I took it out of the box to show him some things Denny's people were close-by with many questions... such as, "are you from the health department"?

Just for more fun, I took out my kit and prepared to swab the table top.

lorez
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MicroBob
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Re: Assembling a Field Microscope (Some Help?)

#4 Post by MicroBob » Tue Aug 02, 2022 4:07 pm

Hi,
this is a Zeiss Standard Junior in Pol version. It has 160mm tube lenght, 10mm placement of the intermediate image and 45mm parfocal objectives. The AO objectives are probably too short to focus and optically different. The Junior is a very nice microscope, bullet proof mechanics and finely made, contrary what "Junior" would suggest today. There are chinese microscope LED lamps that can be used quite well. There used to be a "Bundeswehr" version in a sturdy box. I have one that apparently has been upgraded to a rare foot with built in illumination. Some Junior condensers expect the light source ca. 25cm away and don't offer their full numeric aperture when illuminated directly from below. There are Leitz condensers that do a better job in this case.
Is this a trinocular head?

Bob
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Sure Squintsalot
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Re: Assembling a Field Microscope (Some Help?)

#5 Post by Sure Squintsalot » Tue Aug 02, 2022 5:11 pm

Thanks Bob!
Yes, this is a trinocular, also, the manual (!) calls it a "Standard KF". I expect to use it to full capacity when out car camping and have everything I need, including microtome and slide prep fit neatly into a smartly outfitted box.

Turns out the objectives hadn't delaminated but were caked with Canada balsam. A little chiseling, solvent bathing, disassembly, and deeper cleaning, and now they look good as new.

I have to believe, though, if I'm looking at low contrast stuff, I'd need phase contrast objectives and condenser , no?

Thanks for the super useful photos! I'm on the hunt for a strong battery operated substage LED light.

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Re: Assembling a Field Microscope (Some Help?)

#6 Post by MicroBob » Tue Aug 02, 2022 5:18 pm

What do you plan to observe? Stained sections won't profit from phase contrast. If you want to observe plancton life brightfield is a good starting point, adding a little oblique or DIC - lookalike oblique. It also depends whether you want to observe or photograph: I like phase contrast for observation but don't find the image especially beautiful.
In my experience the basic Zeiss Achromats don't tend to delaminate and offer a good image for the usual objekts. Are the eyepieces ok and do you like them?

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Re: Assembling a Field Microscope (Some Help?)

#7 Post by Sure Squintsalot » Tue Aug 02, 2022 6:29 pm

What do I plan to observe?

Well... I'm taking the time I spend in the woods into an entirely different direction to focus more on that "invisible world" that we ignore. So, things like pond and stream life, fungus swabs, plant pollens, cross sections of plant stems, seeds, leaves, bug debris on the front of the car, things that live in animal scat, on pine tips, under tree bark, and on the north side of rocks. The usual stuff.

Having the optics and the sample prep to do a lot of that would really nice. But I'm coming at this from the "reflected light" and petrography world. I don't even know what I don't know when it comes to transmitted light techniques.

I haven't yet looked at anything through this microscope. I've only just removed the useless analyzer, and re-assembled the objectives. I plan on a first viewing later this evening, but I have to get a light under this thing before any of that happens.

I like that printed drawer!

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Re: Assembling a Field Microscope (Some Help?)

#8 Post by MicroBob » Tue Aug 02, 2022 7:33 pm

A typical characteristic of microscopy is that you need different equipment for each new topic, and usually there is something needed that is unavailable, expensive, dangerous or must not be talked about. :roll: This can lead to a heap of equipment, much more than the instrument itself. With experience it will be possible to single out a few topics and assemble a compact kit with acceptable limitations. For the newbie this willl be difficult.
Some fairly simple methods:
- Plancton life (and life in moss)
- fresh samples from small objects that need no sectioning

Microtomy and preparation of stained permanent slides is a more advanced technique. Unless you have a sound background in biology you will probably no see much in an unstained section.

Sure Squintsalot
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Re: Assembling a Field Microscope (Some Help?)

#9 Post by Sure Squintsalot » Wed Aug 03, 2022 12:56 am

Finally re-assembled this Zeiss Standard KF after a major clean-up. Used a high-end headlamp for illumination. I'm generally pleased with how well this scope works for what I'm planning, but....
  1. The Zeiss oculars are in worse shape than I thought and don't hold a candle to the Nikon 10x wide fields I threw in, just to see;
    Screenshot 2022-08-02 183209.jpg
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    The difference was pretty astounding, but, the comparison may be a little unfair.
  • Looking at an experimental plankton strew that dried up in a petri dish, yielded the following at 400x and 1,000x (shot through eyepiece with Pixel phone, no retouching- this and all other photos):
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  • The 40x objective yielded crisper viewing than the 100x:
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These objectives were not designed for this kind of "look-see" viewing, nonetheless, I think they did OK, especially when coupled to the wide field oculars. In fact, they performed almost as well the much more modern Nikon M Plan objectives on my Optiphot in this kind of viewing.

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Re: Assembling a Field Microscope (Some Help?)

#10 Post by Sure Squintsalot » Wed Aug 03, 2022 1:13 am

  • When looking at a petrographic thin section, simply covered here with a cheap plastic polarizing film crossing the condenser polarizing element, I was very impressed with the flatness of the field across the FOV:
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    I think I'll invest the time in grinding out a new glass analyzer to put back into the headpiece.
  • Here's my very first mounted slide: some concentrated plankton strew allow to dry on a cover slip, then mounted using Permount, showing 25x, 100x, 400x and 1,000x:
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  • The fine focus doesn't work great and walks out of focus when racked in and out; a finger has to hold the coarse focus knob to keep it from moving. I'm guessing grease is sticking somewhere in that mechanism. At highest magnification, it is possible to see some of the finest details in that diatom, though I really don't know how fine that detail actually is. I expect that with better oculars and a legitimate substage light, it'll be fun to take this unit out and re-discover the outdoors!

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Re: Assembling a Field Microscope (Some Help?)

#11 Post by MicroBob » Wed Aug 03, 2022 10:53 am

This looks very promising and you already found a nice diatom colony!
In well serviced state the focus of this microscope work well dampened and and smooth. The grease deteriorates and either binds up or dries out. The microscope won't die from being used in the state for a while as it is a very bullet proof mechanism but it would be advisable to service it at one point of time.
One of the big inventions Zeiss presented with the Standard line was that all objectives were designed to have the same residual colour error and work with the same set of correcting eyepieces. As far as I can tell the Nikon eyepieces don't have this correction and will show colour fringes towards the borders. The stripes on the photos might result from a PWM controller in the lamp. Have you already encountered the condenser aperture and set it right?

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Re: Assembling a Field Microscope (Some Help?)

#12 Post by MicroBob » Wed Aug 03, 2022 12:46 pm

By the way: Did you use immersion oil with the 100:1 objective?

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Re: Assembling a Field Microscope (Some Help?)

#13 Post by Sure Squintsalot » Mon Sep 19, 2022 11:03 pm

Nope... I did not use immersion oil for the 100x; I'll get around to a legitimate oil once I have my mounting technique nailed down. Right now, I'm losing my mind trying to get bubble-free mounts of stained plant sections using Permount.

Having an uncentered light path isn't helping either! How does one adjust this condenser in the x-y plane?!

In the field. With empty gin & tonic:
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BramHuntingNematodes
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Re: Assembling a Field Microscope (Some Help?)

#14 Post by BramHuntingNematodes » Tue Sep 20, 2022 3:25 am

All of.my Zeiss pol objectives are specd to have no coverslip. If that's the case for yours you might want to keep an eye out for a 40x plan lens in the usual coverslip friendly format.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

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Re: Assembling a Field Microscope (Some Help?)

#15 Post by Hobbyst46 » Tue Sep 20, 2022 11:14 am

Squintsalot wrote:...
1. On Zeiss Standards (e.g. my GFL), there is a sleeve, coaxial with the focussing knobs and residing on the left side of the microscope (when you face the field aperture), that is used to increase or decrease the tension on the coarse focus. Perhaps there is one on the KF too.

2. The main issues with your 10X KPL eyepieces are their narrow field of view and low eyepoint of about 7mm.

Here are alternatives, arranged according to my personal preference:

a) Wide field Zeiss 12.5X KPL eyepieces. For eyeglass wearers. There are at least two slightly different shape models of this type.
b) Wide field Zeiss 10X KPL eyepieces. For eyeglass wearers. There are also 10X SKPL but their are rare and expensive.
c) Olympus WHK 10X20 eyepieces.
Note that Zeiss eyepieces are prone to delamination !!

Whatever you choose, please note that your present narrow field 10X KPLs have value and should not be neglected or used as paper holders. They can serve very well in the photo tube, either for afocal photography or for direct projection photography. For the latter, they can be hybridized with 8X eyepieces as shown by Rolf Vossen.

3. Indeed, the bands in your photos are caused by the LED light source. They can be avoided by longer exposure time - typically longer than 1/250 sec.

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Re: Assembling a Field Microscope (Some Help?)

#16 Post by Sure Squintsalot » Tue Sep 20, 2022 5:17 pm

Thanks, Hob...
I've replaced those Zeiss oculars with a set of Nikon wide fields; it was a huge improvement. I'm also taking your advice and not using those KPLs as paper holders and might use them as fishing weights instead.

Fine focus tension is definitely a thing. Unfortunately, I forgot to put a fine screwdriver in my kit. Pictures above were taken through an ocular with a Pixel 4a; the bands disappear with the Sony Nex5 mounted on the photo tube, though between the crop sensor and the 10x projection eyepiece, the FOV has little in common with the ocular FOV. I'll have to replace it with a WF 5x.

Bram... Oddly, except for the 100x oil, all of the objectives are spec'd for 0.17 coverslips. They must be a later replacement? I'd like to replace that 100x with a 20x but, for some reason, they're hard to find.

I'm still looking for a way to center everything below the objectives. I'm wondering if this scope didn't fall off a table in a previous life.

Here's my phone-shot of a stained plant stem under a coverslip fixed with heated (and semi-crystallized and bubbled) Permount, showing how off-center the stage and condenser are:
PXL_20220920_172126128~2_edited.jpeg
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FOV= 1.8mm

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Re: Assembling a Field Microscope (Some Help?)

#17 Post by Sure Squintsalot » Tue Nov 08, 2022 6:06 am

After a tense standoff at the Philippine Airlines check-in counter, I managed to get my field microscope as a carry-on. Being 2kg overweight will get you the serious stink-eye. Some 24 hours later, me, 25 other scuba divers, and my microscope were in Puerto Galera, effectively on the other side of the planet from where I live.

I hired a local and his pantang for an hour of dragging my plankton net around the bay at night. I'll bet he thought it was the strangest 20 dollars he ever made. Plankton kit with reel, isopropyl alcohol, and sample vials:
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When I wasn't underwater being shocked stupid by the abundance of sea life, I was on the top deck with this view:
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...nursing a Red Horse beer with my kit:
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Checking out plankton:
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Copepods:
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Re: Assembling a Field Microscope (Some Help?)

#18 Post by Sure Squintsalot » Tue Nov 08, 2022 6:12 am

The living velcro that is the arms of a Feather Star:
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Weird oddities:
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More copepods:
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and nematocytes....spring loaded poison darts that make up an anemone's sting:
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Re: Assembling a Field Microscope (Some Help?)

#19 Post by imkap » Tue Nov 08, 2022 8:16 am

Planktonic tourism, nice...

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Re: Assembling a Field Microscope (Some Help?)

#20 Post by Sure Squintsalot » Wed Nov 09, 2022 3:40 am

I feel like that microscope is capable of better, more interesting imaging. Is a phase contrast kit worthwhile, or even possible? Can I slip those cool oblique or colored Schadenfreud filters into the condenser?

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Re: Assembling a Field Microscope (Some Help?)

#21 Post by zzffnn » Wed Nov 09, 2022 4:06 am

Sure Squintsalot wrote:
Wed Nov 09, 2022 3:40 am
I feel like that microscope is capable of better, more interesting imaging. Is a phase contrast kit worthwhile, or even possible? Can I slip those cool oblique or colored Schadenfreud filters into the condenser?
Just block 2/3 of light under the the condenser, using a coin, a piece of cardboard of whatever opaque flat object; you will get nice oblique up to 40x NA 0.65 objective.

DIY phase is not that easy to implement.

While you are in Philippines (Cebu?) you may check out their (micro)seashells, in the 1mm-15mm size range (you don’t have to use a microscope), their deep sea specimens are amazing. They have very interesting regular sized seashells too. Rare deep water shells, such as Cypraea valentia, can cost several hundreds of USD each, even if you buy directly from local fishermen.

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Re: Assembling a Field Microscope (Some Help?)

#22 Post by zzffnn » Wed Nov 09, 2022 4:16 am

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Re: Assembling a Field Microscope (Some Help?)

#23 Post by zzffnn » Wed Nov 09, 2022 4:37 am

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Here is my 3 lb (weight) water immersion field microscope in action. It is actually usable with LOMO 65x NA 1.1 water immersion objective. Apochronaut helped me made this DIY scope (it is not easy available, unless you find another Schutz mini scope).

I used magnets above glass slide and beneath stage to provide friction to move slide with my fingers. It is doable with practice. Otherwise the Schutz stage is too small for regular slide holder.

I added a small condenser and used a L shape LED flashlight as light source, along with DIY oblique filters.

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Re: Assembling a Field Microscope (Some Help?)

#24 Post by apochronaut » Wed Nov 09, 2022 1:02 pm

Very nice job on that little jewel, Fan. Is that an AO #146 eyepiece up top? How close to the .90 aperture are you getting with the

For a bit of background on that microscope. I think Bausch & Lomb originally imported those into North America and sold them as a hobby scope. The original objective was a single stacking type : an achromat with two additional lenses stacked on for , if I recall 192X max. However it is R.M.S., so it accepted a diminutive Spencer 3 position nosepiece. There were a few models marked Schutz, Cassel and then Schutz, Kassel : after a spelling change of the city's name in 1926.
It is a very sturdy little scope of solid cast iron and brass with a robust 1/8" thick steel plate stage, allowing for the use of a magnetic slide carrier but it does carry very nice slide clips. Yet is surprisingly light. It's notable feature is a very smooth central micrometer screw for fine focus enabling the use of fairly high magnification objectives.k That one had a decent fitted mini wooden cabinet too.
If anyone is interested, I have a partial one I would sell cheap. It just needs a drawtube for the eyepiece, otherwise fully functional.
Over the years I have seen perhaps 5 of them on ebay for sale. I imagine quite a few of them got trashed by Children ove r the years.

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Re: Assembling a Field Microscope (Some Help?)

#25 Post by Sure Squintsalot » Wed Nov 09, 2022 5:33 pm

Thanks zzfffnn....that sounds like useful advice!

Small and light are definitely the way to go for portability (and getting past the carry-on weight limit). I personally draw the line at binocular over monocular, especially if part of the experience is to share viewing.

I suppose if the goal were to verify sample collection in remote, difficult locations, a minimalist scope would be the way to go.

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Re: Assembling a Field Microscope (Some Help?)

#26 Post by zzffnn » Wed Nov 09, 2022 11:55 pm

Thank you, gents.

Apochronaut: I think I used an AO #147 15x at that time. Not ideal for CA, but more comfortable to use (for my eyes) than LOMO K10x / 18. For field use, I am not being critical.

I DIY adapted a NA 1.25 condenser there, which was mounted almost flush with stage surface and can accept water immersion (above and beneath slide). So it can get very close to (if not pass by) NA 1.1 actually. I have verified this at back focal plane of my LOMO 65x NA 1.1 objective.

Its focus drive is actually good enough (in my hands) for 65x NA 1.1, after applying some thick NyoGel 767A lubricant. Before NyoGel, it wasn’t smooth enough. After NyoGel, it is quite usable.

Sure Squintsalot: I also vastly prefer angled binocular over straight tube monocular. However, after using that straight monocular purposely and continuously for an hour or so, I felt that my brain / eyes can adapt reasonably well. It surely isn’t as comfortable as an angled binocular, but it is (for me) good enough for portable use.

I would love to find a small and light binocular scope for portable use. However, as my LOMO scope is pretty light at around 8 lbs, it gets hard to find something even lighter.

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Re: Assembling a Field Microscope (Some Help?)

#27 Post by apochronaut » Thu Nov 10, 2022 4:08 pm

The #147 are excellent eyepieces. Nice wide field covering about the equivalent of a 17 or maybe 18mm f.o.v. at 10X but with 1.5X the magnification.

If you decide to eliminate the lateral ca,, the Olympus Bi W.F.10X , like these https://www.ebay.com/itm/324753471428?h ... R4SZmKSMYQ will likely work and probably the 15X equivalent as well.
I use them with Lomo planapos on my PZO Biolar, and they are perfectly corrected and flat across the field. Much better than the Lomo K. eyepieces. I can check them with the 30X .90 water objective for you and see how they work. They are also a quite high eyepoint and pairs are quite cheap, since they are shorty objective vintage.

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Re: Assembling a Field Microscope (Some Help?)

#28 Post by apochronaut » Thu Nov 10, 2022 10:44 pm

Sure Squintsalot wrote:
Wed Nov 09, 2022 5:33 pm
Thanks zzfffnn....that sounds like useful advice!

Small and light are definitely the way to go for portability (and getting past the carry-on weight limit). I personally draw the line at binocular over monocular, especially if part of the experience is to share viewing.

I suppose if the goal were to verify sample collection in remote, difficult locations, a minimalist scope would be the way to go.
This is one I have had on the back burner for a bit but it is getting there. The next step is to install the condenser, sliders and rechargeable led in the base. It is a hybrid between an AO 78 Scholar's microscope and an AO 15. The 78 and 15 have the same focusing rack and pinion so moving the 15 head with a 4 place nosepiece over to the 78 turned it into a binocular candidate for a portable scope. It takes a mini XY slide control nicely.
The objectives are all 37mm parfocal : 10X .30 Conrad Beck & Son, 30X .55 CBS, 60X .85 Leitz and 80X .90 Hacker ; the latter, a dry objective. The best eyepieces I found that give a decent planar 18mm field with those objectives were old Leitz periplans from the 37mm parfocal era.

The set of phase sliders are 80's or so B&L with 4 inserts ; 10X, 40X , 100X and DF which I am going to try to use mostly as DF and oblique stops, installed in the base and on a centerable and orbital mount. The condenser will be fitted to the underside of the stage.
The basic series 78 scope and 15 head are easily available and you can use any 160mm or even 170mm objectives you want to although shorter ones take a little fiddling with the focusing travel because of a slight difference in that between the 78 and 15. The focus itself has only one pair of knobs. A nifty clock gear in the arm is comprised of a coarse focus for
most of the travel, which gives way to fine focus for the last 10% of travel or thereabouts, so you are always fine focusing in proximity to the slide.

Fitted the way it is with the condenser and mechanical stage it is right around 6 lbs.and only 11" tall.
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Location: Georgia, USA

Re: Assembling a Field Microscope (Some Help?)

#29 Post by BramHuntingNematodes » Fri Nov 11, 2022 2:32 am

That's a tidy bit of kit there apo
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

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