Search found 505 matches

by microb
Wed Mar 03, 2021 10:17 pm
Forum: Microscopes and optics
Topic: Olympus U-DICT versus U-DICTS
Replies: 16
Views: 172

Re: Olympus U-DICT versus U-DICTS

I believe the condenser prisms has a pin that fits in a groove or hole, which ensures that they are positioned the right way, no? You're right. I should have just looked. That answers my questions. I had mentally painted myself into a corner there, but yes there is an alignment pin. For some reason...
by microb
Wed Mar 03, 2021 8:52 pm
Forum: Microscopes and optics
Topic: Olympus U-DICT versus U-DICTS
Replies: 16
Views: 172

Re: Olympus U-DICT versus U-DICTS

One of the other orientations may be close, and that's usually when you flip it upside down, if I remember correctly. But flipping it so that it is inserted backwards becomes way off and results in a BFP with a large number of narrow interference stripes. But the condenser prism are in a ring. They...
by microb
Wed Mar 03, 2021 7:17 pm
Forum: Microscopes and optics
Topic: Olympus U-DICT versus U-DICTS
Replies: 16
Views: 172

Re: Olympus U-DICT versus U-DICTS

Sorry, I'm not sure what you are saying here. This is the situation you are after: If you look at the green box above, note the outward pointing optical axis is on the left not the right as in the original. Technically I guess a rotation would make the green box have the optical axis point in, but ...
by microb
Wed Mar 03, 2021 4:22 pm
Forum: Microscopes and optics
Topic: Olympus U-DICT versus U-DICTS
Replies: 16
Views: 172

Re: Olympus U-DICT versus U-DICTS

Is rotating the top prism on the vertical axis like this still a valid set up?

Come to think of it, the condenser discs can rotate freely, so the top prism, even though it's locked in a slider could rotate that way too.
by microb
Wed Mar 03, 2021 7:28 am
Forum: Microscopes and optics
Topic: Olympus U-DICT versus U-DICTS
Replies: 16
Views: 172

Re: Olympus U-DICT versus U-DICTS

So does the U-DICTS centered knob (unlike the U-DICT screw which moves the prism in and out) rotate the prism? And the side lever moves the assembly in and out?

I don't have a U-DICTS slide to check that.
by microb
Wed Mar 03, 2021 7:20 am
Forum: Microscopes and optics
Topic: Olympus U-DICT versus U-DICTS
Replies: 16
Views: 172

Re: Olympus U-DICT versus U-DICTS

I hadn't noticed it before, but isn't the patent diagram wrong? Shouldn't the optical axis of the Nomarski prisms mirror each other? The wedge with the axis pointing out of the drawing should be the top wedge for the objective prism and be the bottom wedge for the condenser prism. The figures show t...
by microb
Tue Mar 02, 2021 8:18 pm
Forum: Microscopes and optics
Topic: Olympus U-DICT versus U-DICTS
Replies: 16
Views: 172

Re: Olympus U-DICT versus U-DICTS

In the one ebay side picture, it looks like a vertical track, so the slider lever must wedge the prism up to the top.

Any diagrams and measurements would be appreciated just to get an idea. I assume at some point I'll have to buy one.
by microb
Tue Mar 02, 2021 8:14 pm
Forum: Microscopes and optics
Topic: Olympus U-DICT versus U-DICTS
Replies: 16
Views: 172

Olympus U-DICT versus U-DICTS

I have U-DICT slides, but for the U-DICTS which has not only a rotating knob but also a "lateral adjustment" shift hence the S. So some objectives have back focal planes at -19.1mm and some are at -25.0mm. So the pull lever, I believe, in Normal (pulled out) has the prism raised 6.1mm. For BFP1, pus...
by microb
Fri Feb 26, 2021 11:42 pm
Forum: Microscopes and optics
Topic: DIC Prisms
Replies: 3
Views: 111

Re: DIC Prisms

I'm not doing lens assemblies. I just need to test wedge prisms, so I'm putting together Python with matplotlib and some of the different math packages.
by microb
Fri Feb 26, 2021 10:03 pm
Forum: Microscopes and optics
Topic: Back Focal Plan of Olympus BX Objectives
Replies: 7
Views: 98

Re: Back Focal Plan of Olympus BX Objectives

https://www.researchgate.net/post/Is_there_a_rule_of_thumb_to_determine_the_back_focal_plane_of_objective_lens I've used the method described by Paolo Pizza with good results. It's much harder at 40x and above. Thanks. I'll take a look. I hadn't thought about get a linear set of position points. I ...
by microb
Fri Feb 26, 2021 10:01 pm
Forum: Microscopes and optics
Topic: Back Focal Plan of Olympus BX Objectives
Replies: 7
Views: 98

Re: Back Focal Plan of Olympus BX Objectives

I'm still trying to figure out a bunch of this as well.
by microb
Fri Feb 26, 2021 9:23 pm
Forum: Microscopes and optics
Topic: Back Focal Plan of Olympus BX Objectives
Replies: 7
Views: 98

Re: Back Focal Plan of Olympus BX Objectives

Forgive me if I am missing the point, but; surely [ when in use as intended ] the back focal plane of an infinity-corrected objective is at infinity. It is only when either used incorrectly, or used in combination with the tube lens, that there is an identifiable plane. MichaelG. . . https://www.mi...
by microb
Fri Feb 26, 2021 7:54 pm
Forum: Microscopes and optics
Topic: Back Focal Plan of Olympus BX Objectives
Replies: 7
Views: 98

Back Focal Plan of Olympus BX Objectives

Does anyone have a table of the back focal plane positions of the following objectives? Also does anyone have pointers to the best procedure to measure the back focal plane position? Thanks. Olympus Objectives: 37543 UPLFL 20x 0,5 37553 UPLFL 20x PH 0,5 37557 UPLFL 20x PH/NH 0,5 UPLFLN20x 0,5 LUCPLF...
by microb
Fri Feb 26, 2021 6:02 pm
Forum: Microscopes and optics
Topic: Quartz Birefringence
Replies: 15
Views: 341

Re: Quartz Birefringence

So c-axis and z-axis are the same when looking around for things about quartz. Z-cut means a flat optic with the z as the normal.
by microb
Fri Feb 26, 2021 5:55 pm
Forum: Microscopes and optics
Topic: DIC Prisms
Replies: 3
Views: 111

DIC Prisms

Working through finding Python code to ray trace through glass surfaces to get some DIC prism designs hammered out.

This code is tracing through an aspherical lens:
by microb
Wed Feb 24, 2021 10:03 am
Forum: Microscopes and optics
Topic: Quartz Birefringence
Replies: 15
Views: 341

Re: Quartz Birefringence

It looks like the I can count on a consistent atomic crystal structure. I was worried it grew with at least four merging. The left blue and left red are letting some light through, but it is cross-polarized and the same light level shows without the prism, basically very dark – and black if the LED ...
by microb
Sat Feb 20, 2021 1:46 pm
Forum: Microscopes and optics
Topic: Quartz Birefringence
Replies: 15
Views: 341

Re: Quartz Birefringence

Quartz's doubling is much more subtle, nothing like calcite's. A thick line like that, especially with subtle texturing, will obscure the doubling effect pretty well. You need sharp details with sharp edges, and better yet would be viewing it through a microscope. Believe me, the doubling will defi...
by microb
Sat Feb 20, 2021 6:26 am
Forum: Illumination Techniques
Topic: Anyone try one of these LED setups?
Replies: 3
Views: 1226

Re: Anyone try one of these LED setups?

hans wrote:
Sat Feb 20, 2021 6:16 am
I bought a few things from that seller (the WF10X/22 eyepieces Scarodactyl reviewed, calibration slide, some reticles) and the quality seemed fine.
I have that light source now. I'm just trying to figure out the best way to test it.
by microb
Sat Feb 20, 2021 6:00 am
Forum: Microscopes and optics
Topic: Quartz Birefringence
Replies: 15
Views: 341

Re: Quartz Birefringence

Do you have a pair of linear polarizing filters? Assuming there is a chance of a good continuous structured crystal, put the crystal in between to cross-polarized filters that are extinguishing the light. If there is birefringence, there should light showing again as if a quarter waveplate were ins...
by microb
Sat Feb 20, 2021 5:48 am
Forum: Microscopes and optics
Topic: Quartz Birefringence
Replies: 15
Views: 341

Re: Quartz Birefringence

Scarodactyl wrote:
Sat Feb 20, 2021 5:24 am
Do you have a pair of linear polarizing filters?
I have to hunt them down. Microscope stuff is in boxes right now.


But you see the seed in the center. So I don't think I can cut out a flat blank of any useful size.
by microb
Sat Feb 20, 2021 4:53 am
Forum: Microscopes and optics
Topic: Quartz Birefringence
Replies: 15
Views: 341

Re: Quartz Birefringence

That is a single synthetic crystal pictured in the last image. How are you detecting birefringence? The short piece is cut out of one of those large ones. The seed is in the center, so at best I have four long crystals grow off the seed's four sides. Yet I'm wondering if the structure is even messi...
by microb
Sat Feb 20, 2021 3:35 am
Forum: Microscopes and optics
Topic: Quartz Birefringence
Replies: 15
Views: 341

Re: Quartz Birefringence

So I cut and polished a section from a synthetic quartz rod. Problems: 1) I don't see any blatantly visible birefringence. After basically making a box shape out of it with polished sides, you'd think there would be some visible doubling. (I'll get polarizers back out, my microscope set-ups are in b...
by microb
Thu Feb 18, 2021 5:37 pm
Forum: My microscope
Topic: My Zeiss
Replies: 9
Views: 423

Re: My Zeiss

wstenberg wrote:
Thu Feb 18, 2021 12:49 am
100% Carl Zeiss.
Any else have one like this?
Toolmakers microscope?
by microb
Thu Feb 18, 2021 5:36 pm
Forum: Microscopes and optics
Topic: Quartz Birefringence
Replies: 15
Views: 341

Re: Quartz Birefringence

Also remember that there are no perfect crystals in nature so you may have to play with it a bit. I usually do. Greg I'm going to polish opposite surfaces at a right angle to this. This is a piece I cut off a synthetic quartz, 8 inch long and 1 inch diameter. It's just that I had assumed that the a...
by microb
Mon Feb 15, 2021 10:19 pm
Forum: Microscopes and optics
Topic: Quartz Birefringence
Replies: 15
Views: 341

Quartz Birefringence

If I'm looking perpendicular to the optical axis, I thought I would see more birefringence -- actually any.

Supposedly this is optical quartz. It has a hexagonal cross section, so that should define the optical axis as being perpendicular to the hex.

Am I missing something here?
by microb
Sun Feb 14, 2021 7:17 pm
Forum: For forum members who want to buy and sell equipment
Topic: VANOX Stand Needs a Home
Replies: 0
Views: 269

VANOX Stand Needs a Home

Would like to find an enthusiast for this: I have a Vanox stand. If you’ll cover packaging and shipping, I’ll send it to you. Otherwise, I guess I’ll break it down for parts. The masking tape is to protect it from dust. It should come off easy, and any residue can be cleaned off with alcohol. This i...
by microb
Thu Feb 04, 2021 4:24 am
Forum: Illumination Techniques
Topic: Comments on LED set up here appear useful
Replies: 3
Views: 326

Comments on LED set up here appear useful

For this video, I'm finding the comment section useful: https://www.youtube.com/watch?v=RtV_uPmhCNg
by microb
Thu Jan 28, 2021 1:07 am
Forum: For forum members who want to buy and sell equipment
Topic: Olympus MX80 Epi
Replies: 1
Views: 1064

Re: Olympus MX80 Epi

So I separated it from the base. There are a bunch of beam splitters, and Phase Contrast disk, and a laser autofocus assembly inside. If some one wants this, let me know. It's way lighter without the huge cast iron frame, and one could learn a lot -- and maybe Arduino it. Unless you need for a real ...
by microb
Wed Jan 27, 2021 11:40 pm
Forum: Illumination Techniques
Topic: Arc Lamp to Fiber
Replies: 12
Views: 668

Re: Arc Lamp to Fiber

[ what size is your LED array ? ] I want a 100mm by 300mm aluminum mount of an array of star LEDs. Each gets a condenser lens aimed at the light mixing rod, or a fiber that is then aimed at the light mixing rod. Basically the captured light is run through a mixer of some sort and all done in a way ...
by microb
Wed Jan 27, 2021 10:58 pm
Forum: Illumination Techniques
Topic: Arc Lamp to Fiber
Replies: 12
Views: 668

Re: Arc Lamp to Fiber

b. It is possible and fairly easy to couple a LED to a 1mm diameter quartz fiber without a lens. Moreover, removal of the integral epoxy lens of the LED such that the fiber end nearly touches the die enhances the amount of light that reaches the fiber. I'm trying to apply this to 24 LEDs. I'd like ...