Search found 114 matches
- Thu Sep 14, 2023 9:52 am
- Forum: Specimens, samples and slides
- Topic: why lugol solution becomes transparent
- Replies: 2
- Views: 1619
Re: why lugol solution becomes transparent
Thanks for the info, good to know. I got rid of that one so I cannot try heating, I started using a glass dropper now. If it never happens again, I guess it was due to plastic.
- Tue Sep 12, 2023 1:39 pm
- Forum: Digital processing
- Topic: measuring psf without fluorescence
- Replies: 12
- Views: 3305
Re: measuring psf without fluorescence
Thanks for mentioning wavelength-dependency, I was also wondering this. So it actually makes a lot more sense for fluorescence than for (white-)light microscopy. I already tried psfgenerator and deconvolutionlab2. There still is a PSF with white light, its just that it is not as defined as with flu...
- Mon Sep 11, 2023 3:29 pm
- Forum: Digital processing
- Topic: measuring psf without fluorescence
- Replies: 12
- Views: 3305
Re: measuring psf without fluorescence
PSF's are wavelength-dependent, so unless you're imaging with light through a fairly tight notch filter, you're probably not going to be able to measure a PSF very effectively as each wavelength of light passing through your subject will create its own PSF, which will overlap with the PSF of the ot...
- Thu Sep 07, 2023 3:29 pm
- Forum: Camera systems and imaging
- Topic: Stupid new comer question
- Replies: 14
- Views: 3265
Re: Stupid new comer question
It is much easier to think about this with the concept of field of view. With a micrometer slide on the stage, you can check how much of that you see on the camera (this may mean on the sensor, on the display, on the paper depending on your aim). That is basically your magnification. I think your mi...
- Sun Sep 03, 2023 5:34 pm
- Forum: Resources (online, books etc.)
- Topic: rapid-tome, 3d printed microtome
- Replies: 4
- Views: 16579
Re: rapid-tome, 3d printed microtome
Some notes after I finished printing all the parts: Printing is pretty straight-forward (I used 0.2mm layer height), some part requires supports but it is easy to remove them. Only the small section catcher part has thin walls so it can get broken. The largest part is sled, the text over the it mak...
- Sat Sep 02, 2023 4:24 pm
- Forum: Resources (online, books etc.)
- Topic: rapid-tome, 3d printed microtome
- Replies: 4
- Views: 16579
Re: rapid-tome, 3d printed microtome
Some notes after I finished printing all the parts: Printing is pretty straight-forward (I used 0.2mm layer height), some part requires supports but it is easy to remove them. Only the small section catcher part has thin walls so it can get broken. The largest part is sled, the text over the it make...
- Sat Sep 02, 2023 6:00 am
- Forum: About the website, the magazine and this forum
- Topic: internal server error
- Replies: 4
- Views: 16805
Re: internal server error
I sometimes receive the same error. Refreshing the page has worked in each case. My assumption - others would know better - is that the server is temporarily overloaded with requests. As someone who's run webservers, that is my assumption as well. Could be a failure at various ends, database, disk ...
- Fri Sep 01, 2023 11:55 am
- Forum: About the website, the magazine and this forum
- Topic: internal server error
- Replies: 4
- Views: 16805
internal server error
When I am browsing the forum, very often I receive this error:
The server encountered an internal error or misconfiguration and was unable to complete your request. Your administrator may not have enabled CGI access for this directory.
The server encountered an internal error or misconfiguration and was unable to complete your request. Your administrator may not have enabled CGI access for this directory.
- Thu Aug 31, 2023 8:59 am
- Forum: Resources (online, books etc.)
- Topic: rapid-tome, 3d printed microtome
- Replies: 4
- Views: 16579
rapid-tome, 3d printed microtome
I have come across with a quite recent (Oct 2022) paper describing a 3d printed microtome. I think it is not shared here before, so here it is. The Rapid-Tome, a 3D-Printed Microtome, and an Updated Hand-Sectioning Method for High-Quality Plant Sectioning https://www.biorxiv.org/content/10.1101/2022...
- Tue Aug 29, 2023 5:01 pm
- Forum: Digital processing
- Topic: measuring psf without fluorescence
- Replies: 12
- Views: 3305
Re: measuring psf without fluorescence
I understand that the fluorescent beads are used to measure psf. They are around 200nm in diameter I think. Is there a common method to measure psf without fluorescence ? The minimum pinhole I see is 1um (thorlabs etc.). Wouldn't a pinhole create diffraction? Which you would not want. And what is a...
- Tue Aug 29, 2023 6:14 am
- Forum: Microscopes and optics
- Topic: inverted suggestions ?
- Replies: 11
- Views: 1417
Re: inverted suggestions ?
Not only related to this topic; is Nikon or Olympus objectives and optional parts like prisms cheaper compared to Zeiss and Leica ? Is it only due to availability ?
- Mon Aug 28, 2023 6:12 pm
- Forum: Digital processing
- Topic: measuring psf without fluorescence
- Replies: 12
- Views: 3305
Re: measuring psf without fluorescence
I wonder if this has some similarities with the old 'Star test' which I seem to think was done with either pinholes that appear in nigrosin or by bashing globules of mercury with a broad corset stay, for reflected light. Here is someone using silvered sellotape to make larger holes (not what you ar...
- Mon Aug 28, 2023 5:31 pm
- Forum: Illumination Techniques
- Topic: dark field condenser NA
- Replies: 13
- Views: 17336
Re: dark field condenser NA
It is very difficult to achieve DF with DF stops above about .65. Theoretically possible but practically unlikely. The higher you raise the N.A. , the harder it is to center the stop. As well the larger the stop, the useful illumination circle is entirely in the uncorrected or more poorly corrected...
- Mon Aug 28, 2023 5:28 pm
- Forum: Illumination Techniques
- Topic: dark field condenser NA
- Replies: 13
- Views: 17336
Re: dark field condenser NA
Is the top lens of the condenser in contact or near as can be with the slide? Not sure if you mean something else but I align Kohler first, so it is at the place it should be. But yes it is quite close to the slide. Is the condenser perfectly centred. I realized it was not perfect (although it was ...
- Sun Aug 27, 2023 7:42 pm
- Forum: Illumination Techniques
- Topic: dark field condenser NA
- Replies: 13
- Views: 17336
Re: dark field condenser NA
Thanks for the explanation. It seems I have to try this, it would be nice to have DF at NA=0.75.
- Sun Aug 27, 2023 3:44 pm
- Forum: Microscopes and optics
- Topic: inverted suggestions ?
- Replies: 11
- Views: 1417
Re: inverted suggestions ?
OK, I learned a bit more about Olympus and Nikon models. I am always looking at infinite optics (and plan achromat or flour). At minimum something like Zeiss Axiovert 40, Olympus CKX41 or Nikon TS100. It seems to me after these models the prices jump because of DIC, FL etc.
- Sun Aug 27, 2023 2:51 pm
- Forum: Specimens, samples and slides
- Topic: rain water vs. distilled water
- Replies: 9
- Views: 3106
Re: rain water vs. distilled water
For quite a few years, we have used 'artificial pond water' for keeping crayfish. The high death rates we were getting when we used tap water disappeared. We weren't specifically considering protozoa, but there were often healthy clusters of peritrichs on the crayfish. Artificial pond water might b...
- Sun Aug 27, 2023 2:47 pm
- Forum: Illumination Techniques
- Topic: dark field condenser NA
- Replies: 13
- Views: 17336
dark field condenser NA
I have the current Zeiss achromatic-aplanatic condenser including the dark field stop in the turret. The condenser is 0.9 H/BF, and 0.75 DF. The DF works fine on an objective with NA=0.5, but on an objective with NA=0.75, it does not work, some part of the view is dark other part is not etc. So a fe...
- Sun Aug 27, 2023 6:19 am
- Forum: Microscopes and optics
- Topic: inverted suggestions ?
- Replies: 11
- Views: 1417
Re: inverted suggestions ?
Thanks for the suggestions. Is there a compiled list of all microscopes models of the big 4 somewhere ? I am having trouble figuring out which model is before or after which one and their launch date or active years.
- Sun Aug 27, 2023 12:02 am
- Forum: Microscopes and optics
- Topic: inverted suggestions ?
- Replies: 11
- Views: 1417
inverted suggestions ?
Not sure if I want one yet (I have a good stereo and a good upright with kohler and DF, PH etc. but without FL and DIC), but I would like to keep an eye on second hand market of inverted microscopes. I only checked Axiovert 40 C/CFL until now, and have almost no idea about the models. What would be ...
- Sat Aug 26, 2023 5:31 am
- Forum: Specimens, samples and slides
- Topic: rain water vs. distilled water
- Replies: 9
- Views: 3106
Re: rain water vs. distilled water
I asked this to the company. They said about minerals and rain being isotonic. Not sure if this also indicates it is buffered. Apparently, what they mean with "rain water" is not pure rain drops collected during rainfall into an inert container, but freshly accumulated rain water on the ground - am...
- Fri Aug 25, 2023 7:01 pm
- Forum: Specimens, samples and slides
- Topic: rain water vs. distilled water
- Replies: 9
- Views: 3106
Re: rain water vs. distilled water
I asked this to the company. They said about minerals and rain being isotonic. Not sure if this also indicates it is buffered.
- Fri Aug 25, 2023 4:26 am
- Forum: Digital processing
- Topic: measuring psf without fluorescence
- Replies: 12
- Views: 3305
measuring psf without fluorescence
I understand that the fluorescent beads are used to measure psf. They are around 200nm in diameter I think. Is there a common method to measure psf without fluorescence ? The minimum pinhole I see is 1um (thorlabs etc.).
- Thu Aug 24, 2023 6:22 am
- Forum: Specimens, samples and slides
- Topic: rain water vs. distilled water
- Replies: 9
- Views: 3106
rain water vs. distilled water
In a document (of Carolina biological supplies), about culturing or maintaining hydra, it writes: "Fill the containers almost to the top with springwater, filtered pond water, well water, or rain water. Do not use distilled water or tap water." Why for example rain water is preferred over distilled ...
- Sat Aug 19, 2023 7:32 pm
- Forum: Specimens, samples and slides
- Topic: Where do y’all get your Mounting medium?
- Replies: 5
- Views: 3075
Re: Where do y’all get your Mounting medium?
I have the same situation, is it possible to find a lab supplier that sells to individuals ? It took me some time to find one but it is pretty useful for many things. Glycerol (or glycerine) should be available in some hobby stores, it is used for other things as well. For PVA or PVOH, Elmers water ...
- Fri Aug 18, 2023 9:19 am
- Forum: Specimens, samples and slides
- Topic: why lugol solution becomes transparent
- Replies: 2
- Views: 1619
why lugol solution becomes transparent
I have a Sigma Aldrich lugol solution (in a brown glass bottle). I had a small amount from that in an opaque plastic (with dropper cap). I was not using it for some time and I realized it turned into a transparent liquid. I thought maybe there is a precipitation and I did shake the plastic bottle a ...
- Fri Aug 18, 2023 9:17 am
- Forum: About the website, the magazine and this forum
- Topic: chemicals? board suggestion
- Replies: 0
- Views: 1410
chemicals? board suggestion
It seems there is no specific board regarding the various chemicals used. If it is a stain, I guess "Specimens, samples and slides" is the appropriate space but I think a particular board for the chemicals might be useful for the topics not directly related to slide preparation (e.g. the use of the ...
- Sat Dec 18, 2021 10:34 am
- Forum: Camera systems and imaging
- Topic: Adapters for Zeiss AxioSkop and Canon 35 mm
- Replies: 12
- Views: 3834
Re: Adapters for Zeiss AxioSkop and Canon 35 mm
I also think it is a good solution to use an MFT camera without phototube magnification, for infinity corrected systems. Two more things to check if someone decides to buy such a camera: 1) pixel pitch of the sensor, smaller is better for resolution, larger better for light gathering but this may no...
- Sat Dec 18, 2021 10:26 am
- Forum: Camera systems and imaging
- Topic: Adapters for Zeiss AxioSkop and Canon 35 mm
- Replies: 12
- Views: 3834
Re: Adapters for Zeiss AxioSkop and Canon 35 mm
60N-T2 is 426103 at the moment, I dont know maybe there was a different part number in the past. Also I dont know if your microscope is 60N, you need to be sure about that. If you use 1.6x or 2.5x, you will see a part of image, so yes it will be an optical zoom but I dont know, with an MFT camera, i...
- Fri Dec 17, 2021 6:25 pm
- Forum: Camera systems and imaging
- Topic: Adapters for Zeiss AxioSkop and Canon 35 mm
- Replies: 12
- Views: 3834
Re: Adapters for Zeiss AxioSkop and Canon 35 mm
Thinking loudly… normally if you want to see more close, naturally you want to use optics, so higher power microscope objectives, which is a meaningful magnification without losing resolution. But if you mean for some reason to pay attention to a section of the digital image, you can crop the image ...