Search found 179 matches
- 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.
- 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 ...
- 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.
- 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.
- 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...
- 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.
- 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...
- 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?
- 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 ...
- 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...
- 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...
- 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)?
- 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?
- 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...
- 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 ...
- 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...
- 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 ...
- 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
Then the 'shadows' of the edge would have been off screen..?!apochronaut wrote: ↑Sun Oct 30, 2022 9:26 pmLooking at the last picture you supplied, what appear to be the two linear branches of the angle, portray more than 90° .
- 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...
- Mon Oct 31, 2022 9:16 am
- Forum: Specimens, samples and slides
- Topic: swimming spores
- Replies: 11
- Views: 2664
- 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 pmHi
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
- 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.
"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.
- 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...
- 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...
- 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...
- 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...
- 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...
- 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...
- 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 ...
- 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.