Search found 3356 matches

by Hobbyst46
Mon May 10, 2021 10:00 pm
Forum: Microscopes and optics
Topic: The argument for plan.
Replies: 6
Views: 217

Re: The argument for plan.

What was the slide of? Planar corrections are much more noticeable on planar subjects. Typical histological slide (4-5 micron tissue thickness). Matador I think that 4-5 um range of non-flatness is not a good indicator. The thickness of the stage micrometer lines is IMHO much smaller. According to ...
by Hobbyst46
Mon May 10, 2021 10:08 am
Forum: Pictures and Videos
Topic: Polarized live Diatom (Pleurosigma sp)
Replies: 6
Views: 210

Re: Polarized live Diatom

Thanks, I added a short video link that may help with the ID, also run a BF stack I have to work with it, but the diatom had broke by then under the coverslip pressure Nice video. I tentatively identified from the pattern of dots in the polarized image. From my experience of handling individual Ple...
by Hobbyst46
Mon May 10, 2021 8:59 am
Forum: Pictures and Videos
Topic: Polarized live Diatom (Pleurosigma sp)
Replies: 6
Views: 210

Re: Polarized live Diatom

Wonderful image, and it looks like a Pleurosigma species.
Would be nice to know the appearance without polarization, since the color of the diatom organic parts is green and/or orange/yellow.
by Hobbyst46
Sun May 09, 2021 5:04 pm
Forum: Specimens, samples and slides
Topic: Alboran Sea Diatoms
Replies: 17
Views: 724

Re: Alboran Sea Diatoms

Charles, I tried punching the spacers from an aluminum foil (as per your post), but it did not work for me. MicroBob has suggested flat stainless shim rings. I bought some, 18x12x0.1 mm, to try. More for dry mounts, but maybe it will work with Pleurax as well. The only problem I see with rings are ...
by Hobbyst46
Sun May 09, 2021 6:45 am
Forum: Specimens, samples and slides
Topic: Alboran Sea Diatoms
Replies: 17
Views: 724

Re: Alboran Sea Diatoms

Charles, I tried punching the spacers from an aluminum foil (as per your post), but it did not work for me.
MicroBob has suggested flat stainless shim rings. I bought some, 18x12x0.1 mm, to try. More for dry mounts, but maybe it will work with Pleurax as well.
by Hobbyst46
Sun May 09, 2021 6:35 am
Forum: Pictures and Videos
Topic: melosira + pleurosigma
Replies: 11
Views: 269

Re: melosira + pleurosigma

The 63x1.4 must be rescued and returned to use, for us to see the lovely images !
by Hobbyst46
Sun May 09, 2021 6:33 am
Forum: Specimens, samples and slides
Topic: pleurosigma sword in darkfield
Replies: 4
Views: 118

Re: pleurosigma sword in darkfield

Thanks a lot MicroBob, Sciencematters.
I believe that blue is preferred by the photosynthetic process which takes place in the live diatom.

Thanks Timemaster1212. Yes, the blue glow must mean orcs are near by.
by Hobbyst46
Sat May 08, 2021 7:04 pm
Forum: Specimens, samples and slides
Topic: pleurosigma sword in darkfield
Replies: 4
Views: 118

pleurosigma sword in darkfield

This is a 200um long Pleurosigma that forms an Oriental sword, made of blue steel... the hilt is a broken Enontia. Isolated and mounted in Pleurax. Imaged with 40x0.75 Neofluar, and a drop of water between the condenser top and the slide bottom. Slight shifts of the condenser enhance the blue glare....
by Hobbyst46
Sat May 08, 2021 9:24 am
Forum: Microscopes and optics
Topic: Spring loaded objective
Replies: 20
Views: 306

Re: Spring loaded objective

Edit : __ I expect that the engraved shroud will simply unscrew, exposing the spring and presumably some congealed lubricant on the bearing surface. One by one I am trying to unscrew the shrouds on my Zeiss objectives, and the only one who yielded was the 16X0.40. It simply shows the longitudinal g...
by Hobbyst46
Sat May 08, 2021 8:44 am
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 351

Re: Buying expired slides - hit or miss

Hi Doron, your photos 4 and 5 show patterns that could go as fungus or bacterias. And some glass fungi emit acidous substances that can etch glas, typically the fungi that spread like a bizarre spider web. So to me fungus infction would be a possible explanation to look into. The damages I had so f...
by Hobbyst46
Sat May 08, 2021 7:35 am
Forum: Illumination Techniques
Topic: First try at Fluorescence!
Replies: 3
Views: 114

Re: First try at Fluorescence!

A long-pass interference filter will remove most of the blue background.
by Hobbyst46
Fri May 07, 2021 1:35 pm
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 351

Re: Buying expired slides - hit or miss

(continued)
by Hobbyst46
Fri May 07, 2021 1:30 pm
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 351

Re: Buying expired slides - hit or miss

So, is this the prevalent hypothesis: hygroscopic slides absorb water which enable fungus growth. Fungus then eats the glass and/or excrete corrosive metabolites which degrade the slides. When cleaning, you can remove the fungus but not the marks of corrosion? From what I have read, it is rather a ...
by Hobbyst46
Fri May 07, 2021 10:30 am
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 351

Re: Buying expired slides - hit or miss

I think this problem is often overlooked and some people just don' t experience it. The hazy surface comes from a degradation of the slide surface, like small pits. When using a mountant that has a refractive index near that of glass the might be less visible. In thick mounts they might be safely o...
by Hobbyst46
Thu May 06, 2021 9:10 pm
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 351

Re: Buying expired slides - hit or miss

Thanks for the link, Bob.
Indeed, the deteriorated slides I described were compactly packed without any separation between two neighboring slides.
by Hobbyst46
Thu May 06, 2021 7:15 pm
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 351

Re: Buying expired slides - hit or miss

...Leica, Fisher Scientific, Globe Scientific and none have expiration dates. They do have catalog and lot numbers and date manufactured, but none with expiration dates. The ones I bought are wrapped with cellophane in 50-piece cardboard boxes; there are lot numbers and an hourglass symbol for 2006...
by Hobbyst46
Thu May 06, 2021 3:24 pm
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 351

Buying expired slides - hit or miss

I still use quality slides that expired ~30 years ago. I thought that expiration was due to the loss of sterility, since some of them had been originally sterile. And today, I do not need sterile slides. These slides look and feel like new, and are crystal clear. Recently I was tempted to buy qualit...
by Hobbyst46
Tue May 04, 2021 7:11 pm
Forum: Microscopes and optics
Topic: Eyepiece diameter
Replies: 10
Views: 231

Re: Eyepiece diameter

The eyepiece shown by ImperatorRex above is 10x/20 eyepiece, which was apparently more modern than those 10x/18 (or 12.5x/18) shown in the catalogue.
by Hobbyst46
Tue May 04, 2021 2:58 pm
Forum: Specimens, samples and slides
Topic: Keep Dry Diatom on slide
Replies: 8
Views: 183

Re: Keep Dry Diatom on slide

For a simple fix, you could seal the edges with varnish or fingernail polish. That way, you wouldn't need the tape. I do it stepwise: First, I put the smallest possible amount of nail polish or varnish around the coverslip, otherwise the sealant tends to crawl (by capillary) inside, under the cover...
by Hobbyst46
Tue May 04, 2021 10:23 am
Forum: Microscopes and optics
Topic: Eyepiece diameter
Replies: 10
Views: 231

Re: Eyepiece diameter

These Zeiss eyepieces vary so there might be some ambiguity. Here are my two own eyepieces, type A and type B as marked, and the yellow lines give diameters measured with calipers. One looks like the catalogue picture and the other bears a catalogue number as in the catalogue. On top of that, there ...
by Hobbyst46
Tue May 04, 2021 8:28 am
Forum: Microscopes and optics
Topic: Eyepiece diameter
Replies: 10
Views: 231

Re: Eyepiece diameter

Since I do not have that eyepiece, just a rough estimate for a start. The 12.5W eyepiece " 12.5x Br Kpl wide-angle eyepiece 12.5x 1 5 20.3 1 8 50" 464142 " in the catalog: I have that very eyepiece, and the diameter of the black top section is 28.1mm (calipers). Assuming that the photos of these eye...
by Hobbyst46
Mon May 03, 2021 10:02 pm
Forum: Illumination Techniques
Topic: Interesting graphical description of the mathematical background of oblique lighting
Replies: 4
Views: 227

Re: Interesting graphical description of the mathematical background of oblique lighting

Bob, It would be nice reading the full article, it there is an English version; the text is too long for DeepL sessions...
I would add that Oblique illumination is quite vivid in recent academic research, decorated with complex (pun) math equations...
by Hobbyst46
Mon May 03, 2021 6:03 pm
Forum: Beginner's corner
Topic: eyepiece camera vs phone
Replies: 7
Views: 317

Re: eyepiece camera vs phone

1. I would prefer a trinocular head if possible. Whatever camera. But the following comments apply anyway. 2. The eyepiece camera (at least the inexpensive ones) has three main disadvantages: a) only a fraction of the FOV is covered, even if a 0.5X reduction lens is supplied with the camera (even wo...
by Hobbyst46
Sat May 01, 2021 6:19 pm
Forum: Pictures and Videos
Topic: water lens under UV...
Replies: 6
Views: 223

Re: water lens under UV...

Curious what a "water lens" means, as photographed here? Is it just a drop of water with pond scum underneath and further magnified 400x? Tiny floating water plants, a circular leaf with tiny root, named "water lens". Often seen in aquaria and serve as shelters for newborn Guppy/Zebra fish. Easily ...
by Hobbyst46
Sat May 01, 2021 8:53 am
Forum: For forum members who want to buy and sell equipment
Topic: Need Ziess 1.25x Auxiliary lens (part number 44 52 65)
Replies: 17
Views: 799

Re: Need Ziess 1.25x Auxiliary lens (part number 44 52 65)

75RR wrote:
Sat May 01, 2021 8:19 am
...Seems a shame to use up a slot though.
Not to mention only 4 slots in the condenser of such a modern microscope...
by Hobbyst46
Fri Apr 30, 2021 11:27 am
Forum: Specimens, samples and slides
Topic: Substitutes for Hay Infusion?
Replies: 8
Views: 269

Re: Substitutes for Hay Infusion?

A banana peel in a small jar filled with tap water has always worked for me. Especially for Paramecia. It remains productive for a week at least.
by Hobbyst46
Thu Apr 29, 2021 11:34 am
Forum: My microscope
Topic: Feeling a bit lost (buying advice / Belgium)
Replies: 25
Views: 872

Re: Feeling a bit lost (buying advice / Belgium)

3. A simple 5MP eyepiece camera (less than $100) and simple adapter Do you mean a generic eyepiece camera rather than one offered by the manufacturer? What type of adapter are you referring to, please? Yes, even an unbranded generic 5MP can do a decent job. At least for documentation. They go into ...
by Hobbyst46
Thu Apr 29, 2021 11:08 am
Forum: Microscopes and optics
Topic: Why are numerical aperture and color correction related?
Replies: 8
Views: 317

Re: Why are numerical aperture and color correction related?

Note, that there are other important features of the objective, such as working distance, depth of focus, number of glass elements, correction for coverslip thickness, which are taken into consideration.
by Hobbyst46
Thu Apr 29, 2021 10:30 am
Forum: Pictures and Videos
Topic: Grammatophora oceanica
Replies: 10
Views: 290

Re: Grammatophora oceanica

Fascinating (as usual... :) ) !
by Hobbyst46
Wed Apr 28, 2021 8:41 am
Forum: My microscope
Topic: Feeling a bit lost (buying advice / Belgium)
Replies: 25
Views: 872

Re: Feeling a bit lost (buying advice / Belgium)

May I suggest you have a look in a local version of ebay (most countries have one) for a used microscope from one of the resellers (Euromex, Amscope, Bresser etc) Thank you, I'll recheck, there is next to nothing locally but I do see some offers for mostly Amscope from other countries in the EU. I'...