Search found 179 matches

by iconoclastica
Tue Mar 07, 2023 3:11 pm
Forum: Miscellaneous
Topic: Jewelers tool to move small items (sticky pen?)
Replies: 10
Views: 1828

Re: Jewelers tool to move small items (sticky pen?)

We used cat whiskers glued to a stick to pick up individual nematodes.
by iconoclastica
Thu Dec 01, 2022 1:49 pm
Forum: Beginner's corner
Topic: Cleaning lenses
Replies: 14
Views: 2900

Re: Cleaning lenses

Zeiss or Bausch & Lomb lens cleaning solutions are generally available. https://www.zeiss.com/content/dam/Vision/Vision/International/Pdf/en/data-sheet-for-zeiss-lens-cleaning-spray.pdf Are you sure this is the proper stuff? According to Zeiss it is for spectacles and should be used in combination ...
by iconoclastica
Thu Dec 01, 2022 10:17 am
Forum: Illumination Techniques
Topic: Optiphot: Centering the epi-illuminator
Replies: 6
Views: 2001

Re: Optiphot: Centering the epi-illuminator

What you see in the photo is the projection of the field iris. The lamp can be adjusted indeed. It does do a lot for the contrast, but nothing to the positioning.
by iconoclastica
Wed Nov 30, 2022 8:52 pm
Forum: Illumination Techniques
Topic: Optiphot: Centering the epi-illuminator
Replies: 6
Views: 2001

Re: Optiphot: Centering the epi-illuminator

Thanks Jose, but i don't think it is that issue. I cannot make the location move by manhandling the illuminator. I think it is the mirror.
by iconoclastica
Wed Nov 30, 2022 7:18 pm
Forum: Illumination Techniques
Topic: Optiphot: Centering the epi-illuminator
Replies: 6
Views: 2001

Optiphot: Centering the epi-illuminator

The field of light descending from my epi-illuminator is not well-centered. I would like to correct this, but the question is: How? I don't see any obvious screws that would allow to centre it. Here is how it looks like now: _0001.jpg The illuminator does not bear any type designation, only a serial...
by iconoclastica
Sat Nov 26, 2022 10:10 pm
Forum: Beginner's corner
Topic: Cleaning lenses
Replies: 14
Views: 2900

Re: Cleaning lenses

Last week I saw this video at iBiology. I tried their method on my objectives and it worked well and looks super safe.
by iconoclastica
Mon Nov 21, 2022 3:51 pm
Forum: Microscopy accessories
Topic: L900C
Replies: 2
Views: 1418

Re: L900C

I use other filters of the same make and I do know where they go. Notwithstanding that, I appreciate your reply, for the text included in the picture. At the bottom left it says "LEMON SKIN", which is a new term to search for: Use of the lemon skin filter is effective for low magnification photograp...
by iconoclastica
Sun Nov 20, 2022 9:03 pm
Forum: Microscopy accessories
Topic: L900C
Replies: 2
Views: 1418

L900C

With my Nikon optiphot epi-illuminator, I got a filter marked "L900C" in a box labeled "MBN12400". It looks like it's a diffuser only. What is it used for?
by iconoclastica
Tue Nov 15, 2022 9:32 pm
Forum: Camera systems and imaging
Topic: Full electronic shutter vs. normal shutter
Replies: 20
Views: 4400

Re: Full electronic shutter vs. normal shutter

OK the mirror slap at the beginning of DSLR cameras is the major cause of shutter shock. Many cameras (with mirrors) offer EFCS which raises the mirrors already before taking any photo. But, at the end there is still a mechnical shutter to end the exposure. If we compare EFCS cameras (still having ...
by iconoclastica
Tue Nov 15, 2022 9:06 pm
Forum: Home-made microscope adaptations
Topic: can I use the Labophot's intenal power supply for LED etc?
Replies: 2
Views: 1592

Re: can I use the Labophot's intenal power supply for LED etc?

Hmm, was suspecting something like that. My project is a bit more complex than just replacing the bulb with a led. In fact, for the time being at least, the original lamp should continue to be usable. I was hoping to read the pot meter indirectly to mimic its setting with the led's brightness, and/o...
by iconoclastica
Tue Nov 15, 2022 6:57 pm
Forum: Home-made microscope adaptations
Topic: can I use the Labophot's intenal power supply for LED etc?
Replies: 2
Views: 1592

can I use the Labophot's intenal power supply for LED etc?

When I remove the lamphouse of the Nikon Labophot, I measure the voltage at its contacts as a constant 17.2V. It does not change while turning the power wheel (except off). Does this mean that the halogen bulb is regulated by current at constant voltage, or that this is not the correct way to measur...
by iconoclastica
Thu Nov 10, 2022 4:12 pm
Forum: Illumination Techniques
Topic: Adding Simple Darkfield to a Nikon Labophot Condenser
Replies: 22
Views: 12960

Re: Adding Simple Darkfield to a Nikon Labophot Condenser

From the photos, the MXA20495 seems a pretty simple thing, not worth the money nor the trouble to get it in this era of 3d-printing. Could someone please draw how exactly it attaches to the condenser (and possibly its dimensions)?
by iconoclastica
Thu Nov 03, 2022 7:23 pm
Forum: Microscopes and optics
Topic: the scale on the condenser's aperture
Replies: 27
Views: 4888

Re: the scale on the condenser's aperture

Is there a way to find that out?
by iconoclastica
Thu Nov 03, 2022 1:16 pm
Forum: Microscopes and optics
Topic: the scale on the condenser's aperture
Replies: 27
Views: 4888

Re: the scale on the condenser's aperture

In order to figure that out, one needs to determine if the aperture that is being viewed at the bfp of the objective equals the full aperture of the objective. So: inspect the BFP make sure the condenser's aperture is focused make sure neither field aperture not the objective's aperture (if any) ar...
by iconoclastica
Thu Nov 03, 2022 1:08 pm
Forum: Microscopes and optics
Topic: the scale on the condenser's aperture
Replies: 27
Views: 4888

Re: the scale on the condenser's aperture

on any objective, start with an open aperture and slowly close the aperture until you see contrast begin. If you look at the back aperture of the objective you will find that the aperture will be about 7/8 th of the aperture of the objective. Optimum contrast with optimum resolution. Excellent! We ...
by iconoclastica
Wed Nov 02, 2022 9:10 pm
Forum: Specimens, samples and slides
Topic: swimming spores
Replies: 11
Views: 2664

Re: swimming spores

It seems that there's nothing to it than making a new slide for observation at the highest magnification. So be it then, comaperd with all the hassle of viewing 100x making an addional slide isn't that much work after all. I am having some succes now with pre-made water-gelatin as mounting medium. I...
by iconoclastica
Mon Oct 31, 2022 1:15 pm
Forum: Microscopes and optics
Topic: the scale on the condenser's aperture
Replies: 27
Views: 4888

Re: the scale on the condenser's aperture

NA is not affected by the media applied to the condenser if the the selected NA is less than the RI of the media. I don't think I can understand that statement. The NA is the product of the RI and the sine. Mathematically it is easy to prove that NA <= RI * sin(theta) is always true, so the NA can ...
by iconoclastica
Mon Oct 31, 2022 12:58 pm
Forum: Microscopes and optics
Topic: the scale on the condenser's aperture
Replies: 27
Views: 4888

Re: the scale on the condenser's aperture

apochronaut wrote:
Sun Oct 30, 2022 9:26 pm
Looking at the last picture you supplied, what appear to be the two linear branches of the angle, portray more than 90° .
Then the 'shadows' of the edge would have been off screen..?!

Θ  = approx. 60°
Θ = approx. 60°
file.jpg (41.55 KiB) Viewed 4587 times
by iconoclastica
Mon Oct 31, 2022 9:30 am
Forum: Specimens, samples and slides
Topic: swimming spores
Replies: 11
Views: 2664

Re: swimming spores

Also had a stab with cooking oil olive oil: 1.46-1.48 (dependent on wavelength) coconut oil: 1.45-1.46 Peanut oil: 1.460 – 1.465 Corn oil: 1.465 – 1.468 Sesame oil: 1.465 – 1.469 Sunflower oil: 1.461 – 1.468 Palm oil: 1.449 – 1.455 Sabah oil: 1.4633 ± 0.0021 ref: Refractive-index-of-virgin-olive-oi...
by iconoclastica
Mon Oct 31, 2022 9:16 am
Forum: Specimens, samples and slides
Topic: swimming spores
Replies: 11
Views: 2664

Re: swimming spores

EYE C U wrote:
Sun Oct 30, 2022 9:11 pm
you talking about these? `
Nope. Those are the sporangia or spore capsules.
The spores are inside them:


HF19113 spore 100x.jpg
HF19113 spore 100x.jpg
HF19113 spore 100x.jpg (29.75 KiB) Viewed 2406 times
by iconoclastica
Sun Oct 30, 2022 4:36 pm
Forum: Microscopes and optics
Topic: the scale on the condenser's aperture
Replies: 27
Views: 4888

Re: the scale on the condenser's aperture

LouiseScot wrote:
Sun Oct 30, 2022 3:38 pm
Hi
The animation on that page doesn't run in my Edge browser so I've no idea what it shows! I was really only linking to the text anyway.
Louise
shifting the slider turns the ring and narrows the bundle
shifting the slider turns the ring and narrows the bundle
flash.jpg (89.78 KiB) Viewed 4653 times
by iconoclastica
Sun Oct 30, 2022 3:37 pm
Forum: Specimens, samples and slides
Topic: swimming spores
Replies: 11
Views: 2664

Re: swimming spores

The label on my oil excells in being non-informative...
"Labtek immersion oil R.I. 1.518"


---------

First attempt with olive oil moderately unsuccesful: not too transparent, that's good, but very few spores in the sample, so none within focus reach. Wll try again.
by iconoclastica
Sun Oct 30, 2022 3:34 pm
Forum: Microscopes and optics
Topic: the scale on the condenser's aperture
Replies: 27
Views: 4888

Re: the scale on the condenser's aperture

I ... can't remember if I posted this link [url]https://zeiss-campus.magnet.fsu.edu/tutorials/basics/condenserlightcones/indexflash.html[/url A beautiful animation, but plain wrong. Here is the same in reality: NA0.2.jpg NA0.7.jpg NA1.0.jpg Their mistake is that theta is to be taken from the normal...
by iconoclastica
Sun Oct 30, 2022 12:48 pm
Forum: Microscopes and optics
Topic: the scale on the condenser's aperture
Replies: 27
Views: 4888

Re: the scale on the condenser's aperture

I think the numerical aperture on the condenser scale is just indicative of the setting to use with a given objective. The scale on my T720 displays objective magnification rather than NA. So goes 4, 10, 20, 40, 60, 100. Exactly what I was given to think by I don't recall what textbook. I even have...
by iconoclastica
Sun Oct 30, 2022 11:48 am
Forum: Specimens, samples and slides
Topic: swimming spores
Replies: 11
Views: 2664

Re: swimming spores

Thanks Chas, those are useful remarks. I definitely will try oily media, it's easy enough to obtain them ;) But I am afraid it will make the spores to transparent. In an oil, pollen grains become more clear and transparent and the structures can be better observed That is exactly the problem I get w...
by iconoclastica
Thu Oct 27, 2022 10:33 am
Forum: Microscopes and optics
Topic: the scale on the condenser's aperture
Replies: 27
Views: 4888

Re: the scale on the condenser's aperture

These are tha lat steps of the Köhler-instrucions if routinely follow: • Remove one of the eyepieces or replace it with a centering telescope. You can now observe the objective’s BFP in the tube. • Close the aperture diaphragmwhich is visible within the objective’s BFP, until its diameter is about 3...
by iconoclastica
Wed Oct 26, 2022 8:10 pm
Forum: Microscopes and optics
Topic: the scale on the condenser's aperture
Replies: 27
Views: 4888

the scale on the condenser's aperture

s-l500.jpg Often the aperture rings of the condensers are provided with a scale. The figures on those scale at least suggest that setting it by the scale would more or less be the correct setting given the system's NA. However, whe I close the aperture until it starts showing in the periphery of th...
by iconoclastica
Tue Oct 25, 2022 6:21 pm
Forum: Specimens, samples and slides
Topic: swimming spores
Replies: 11
Views: 2664

swimming spores

Fern spores are much like pollen. They vary in size, but typically they're about 50 µm long. Often I need to take a quick look at them to see whether they're spiny, wartly, smooth or whatever. I stress the word 'quick' in the previous sentence because at such moments I am not busy with microscopy bu...
by iconoclastica
Mon Oct 24, 2022 1:00 pm
Forum: Home-made microscope adaptations
Topic: stereomicroscope illumination for less than $10
Replies: 5
Views: 2116

Re: stereomicroscope illumination for less than $10

Nice job! The ones I got were not as bright as I would like, but they work fairly well. Here's a thread where I designed one for use with the Cycloptic. There are some changes I would make were I to build another, but last I spoke with it's caretaker it was still working fine for her. I was fairly ...
by iconoclastica
Sun Oct 23, 2022 2:46 pm
Forum: Resources (online, books etc.)
Topic: Nikon Labophot & Optiphot manuals etc.
Replies: 3
Views: 2318

Re: Nikon Labophot & Optiphot manuals etc.

I do have a few more of them, such as the repair manual. If there's any permanent site to store them, I'd be happy to pass 'm on.