Search found 1975 matches

by MicroBob
Mon Apr 06, 2020 5:43 pm
Forum: Miscellaneous
Topic: Repository of exotic diatoms?
Replies: 15
Views: 516

Re: Repository of exotic diatoms?

Hi Daroush and Doron, I have no background in laboratory work and never searched for a used electric centrifuge due to the space problem. Our group has one that is intended for quite small Eppendorf tubes. So my market overview is full of bling spots. But the centrifuges you have and describe would ...
by MicroBob
Mon Apr 06, 2020 2:25 pm
Forum: Microscopes and optics
Topic: Intriguing objective
Replies: 10
Views: 451

Re: Intriguing objective

Here in Germany the Zeiss Standard line is loved by the amateurs. Especially good objectives are common knowledge and they hold their price to some extent. I have heard of this objective before but never had the impression that anybody were on the lookout for one and would pay a lot of money for it....
by MicroBob
Mon Apr 06, 2020 1:19 pm
Forum: Miscellaneous
Topic: Repository of exotic diatoms?
Replies: 15
Views: 516

Re: Repository of exotic diatoms?

Enclosed a picture of my centrifuge. The rotor shaft is supported right up to the top and the tolerances are tight. This is no rocket science but good traditional workmanship is needed for good performance. The ukranian model won't really work properly. "Hettich" would be a good brand: https://www.e...
by MicroBob
Mon Apr 06, 2020 12:03 pm
Forum: Miscellaneous
Topic: Repository of exotic diatoms?
Replies: 15
Views: 516

Re: Repository of exotic diatoms?

Hi Glen, I have a hand centrifuge that looks very similar to Daruosh's but is a couple of decades old. They are better for the diatomist than electric centrifuges for the tiny Eppendorf tubes because the glass tubes hold 15ml of fluid. For some diatom cleaning methods it is necessary to remove a che...
by MicroBob
Sun Apr 05, 2020 7:47 pm
Forum: Pictures and Videos
Topic: Epistylis
Replies: 5
Views: 271

Re: Epistylis

Great video! The movement of the cilia is nearly visible - did you film this with an exceptionally high frame rate?

Bob
by MicroBob
Sun Apr 05, 2020 7:43 pm
Forum: Pictures and Videos
Topic: Pine needle-safranin,fast green staining.
Replies: 10
Views: 368

Re: Pine needle-safranin,fast green staining.

BTW: The documentary images of your sectioning process are exceptional, Seb!
by MicroBob
Sun Apr 05, 2020 7:35 pm
Forum: Pictures and Videos
Topic: Diatom from Nova Scotia, Silica Lake High power dark field
Replies: 5
Views: 208

Re: Diatom from Nova Scotia, Silica Lake High power dark field

And the character of the images is very different: My single shot is more a grim looking diatom, the SEM images have a detatched and neutral character. Stacking helps with sharpness but in some cases it gives a much too flattenend result, like in my epi darkfield image. In this case the SEM image is...
by MicroBob
Sun Apr 05, 2020 6:25 pm
Forum: Pictures and Videos
Topic: Diatom from Nova Scotia, Silica Lake High power dark field
Replies: 5
Views: 208

Re: Diatom from Nova Scotia, Silica Lake High power dark field

I don't have a bright field image ready but here is a stacked epi dark field image of raw material of a similar species. In bright field ist looks very special: Not so much a grid of pores but a shimmering surface with superficial dents. The shimmering look and the highly curved form make it difficu...
by MicroBob
Sun Apr 05, 2020 4:08 pm
Forum: Pictures and Videos
Topic: Pine needle-safranin,fast green staining.
Replies: 10
Views: 368

Re: Pine needle-safranin,fast green staining.

Hi Seb, that is a very interesting technique - I have never heard of anybody doing this! Typically people who embed into some media do the cutting with a real microtome. People who do freehand sections don't embed. Your method makes hand sectioning usable for several more applications. I recently st...
by MicroBob
Sun Apr 05, 2020 2:43 pm
Forum: Specimens, samples and slides
Topic: reflected light silicon chip die
Replies: 39
Views: 8920

Re: reflected light silicon chip die

Hi Michael, your microscope can be set up for different incident light methods and the right mix of components (so you have them) will do the trick. If you have specific questions about the automatic translations I'm happy to help. Of cause I don't know the quality of the translation from russian in...
by MicroBob
Sun Apr 05, 2020 10:29 am
Forum: Pictures and Videos
Topic: Diatom from Nova Scotia, Silica Lake High power dark field
Replies: 5
Views: 208

Diatom from Nova Scotia, Silica Lake High power dark field

Hi together,
here two images of a diatom from Nova Scotia, Silica Lake with dark field contrast.
Zeiss West cardioid condenser, Zeiss West 100:1 with iris, second image Leitz NPL Fluotar 50:1 1,0.
32W LED at full power.

Bob
by MicroBob
Sun Apr 05, 2020 7:52 am
Forum: Specimens, samples and slides
Topic: reflected light silicon chip die
Replies: 39
Views: 8920

Re: reflected light silicon chip die

Hi Michael, here is the link to the right manual in I'm right: http://www.mikroskopfreunde-nordhessen.de/dateien/Lomo-M.pdf There is an image of the box of accessories, front left are some kind of stops, I guess that there will be one with a dot in the middle. On page 7 the epi darkfield setup is de...
by MicroBob
Sun Apr 05, 2020 1:48 am
Forum: Specimens, samples and slides
Topic: reflected light silicon chip die
Replies: 39
Views: 8920

Re: reflected light silicon chip die

Hi Michael, epi brightfield usually gives a very hazy image. In the Olympus brochure you linked there is an opaque stop mentioned to block direct brightfield light through the objective and acheive true epi dark field. This stop might be missing in your setup. Also a directed light source, not a dif...
by MicroBob
Sun Apr 05, 2020 1:36 am
Forum: Pictures and Videos
Topic: Pine needle-safranin,fast green staining.
Replies: 10
Views: 368

Re: Pine needle-safranin,fast green staining.

Hi Seb, that is a nice looking section! What like especially at pine needles ist that you often have clearly visible stomata in the image. I have no experience with PEG embedding - how do you use this and how are your experiences? Does it section well without crumbling? With what type of microtome d...
by MicroBob
Sun Apr 05, 2020 1:24 am
Forum: Beginner's corner
Topic: Kohler Trouble
Replies: 40
Views: 1457

Re: Kohler Trouble

Hi, your insect wing has quite a depth and it is not possible to have it sharp top to botton at the same time and maintain the full resolution. You probably have seen great images of insects, these are made with a fairly wide opened condenser aperture from a stack of lots of images. The images are c...
by MicroBob
Sat Apr 04, 2020 7:55 pm
Forum: Specimens, samples and slides
Topic: reflected light silicon chip die
Replies: 39
Views: 8920

Re: reflected light silicon chip die

I am deeply disappointed [albeit unsurprised] by the softness of the image Hi Michael, I don't know your microscope but with epi setups there are often special tube length part of the clculation. May be you have the wrong mix of components? Also with used epi objectives I have had much more trouble...
by MicroBob
Sat Apr 04, 2020 2:53 pm
Forum: Pictures and Videos
Topic: Two ciliates from my plancton aquarium in phase contrast
Replies: 9
Views: 362

Re: Two ciliates from my plancton aquarium in phase contrast

Hi Don,
the cilia are accentuated by the phase contrast. Also I edited the image which increased their visibility.
You might try olbique illumination to enhance the visibility.

Bob
by MicroBob
Sat Apr 04, 2020 9:25 am
Forum: Home-made microscope adaptations
Topic: Tiny field microscope specifically for diatom sampling
Replies: 8
Views: 479

Re: Tiny field mcroscope specifically for diatom sampling

Hi together, thank you for your comments! The Swift FM31 and its clones are small but heavy and unwieldy to use. But they offer 400x magnification and can replace a normal microscope on a holiday trip to some extent. For this specific purpose I wouldn't use it. The fibre optics microscopes could be ...
by MicroBob
Fri Apr 03, 2020 7:21 pm
Forum: Home-made microscope adaptations
Topic: Tiny field microscope specifically for diatom sampling
Replies: 8
Views: 479

Tiny field microscope specifically for diatom sampling

Hi thogether, photomicro-Mike had posted a link to a booklet of the Amateur Diatomist series: http://www.microscopy-uk.org.uk/diatomist/ADvol43.pdf Beginning with page 4 an interesting design of a field microscope is shown that has proven well in practical use. The design specialty is that there is ...
by MicroBob
Fri Apr 03, 2020 6:30 pm
Forum: Specimens, samples and slides
Topic: Apple Twig Hand Section, Stain & Mount
Replies: 9
Views: 468

Re: Apple Twig Hand Section, Stain & Mount

What I always find funny: We aim at making a tiny object observable, a couple of mm at max. And we devastate at least a whole desk surface, maybe a whole room, each time! :lol: I now have the added problem of working in home office or better office/lab. This brings a lot of additional stuff that has...
by MicroBob
Fri Apr 03, 2020 11:41 am
Forum: Introduce yourself
Topic: diatoms
Replies: 11
Views: 651

Re: diatoms

Just this february we had a group meeting on diatom strew slide making and it was very well attended (19, I can only remember two meetings with more people attending) and the members and guests were very keen on trying their hand at strew slide making. We even overran the set time to work on one mor...
by MicroBob
Fri Apr 03, 2020 5:58 am
Forum: My microscope
Topic: My first successful use of a microtome
Replies: 8
Views: 805

Re: My first successful use of a microtome

Hi Don,
I actually sell these holders from time to time: viewtopic.php?f=16&t=7065&p=62601&hilit ... der#p62601
Very good blades are the ones from OLFA,Japan, the inventor of this kind of knifes with break-off blades.

Bob
by MicroBob
Fri Apr 03, 2020 5:33 am
Forum: Introduce yourself
Topic: diatoms
Replies: 11
Views: 651

Re: diatoms

Hi Mike, thank you for the link! This booklet also contains the description of the little field microscope that would be useful for diatom collecting. Here is a link to a detailed research on diatom refractive indices: http://www.mikroskopie-ph.de/Mikrokosmos,%20Band%2098%282%29,%20S.%2098%20%282009...
by MicroBob
Fri Apr 03, 2020 5:06 am
Forum: Resources (online, books etc.)
Topic: R.M.S. die.
Replies: 21
Views: 9085

Re: R.M.S. die.

apochronaut wrote:
Thu Apr 02, 2020 7:30 pm
I posted a link on March 3 and the link seems to work. Does it not work for you, Bob?
Hi Phil, now it does but then it didn't. Maybe the shipping options have been changed for Germany inbetween?

Bob
by MicroBob
Fri Apr 03, 2020 4:46 am
Forum: Specimens, samples and slides
Topic: Apple Twig Hand Section, Stain & Mount
Replies: 9
Views: 468

Re: Apple Twig Hand Section, Stain & Mount

Hi John, thank you for this interesting report! It really is no bad idea to do free hand sections here and there as it is quite a productive method and easier to fit in a busy schedule. A while ago I have made my first paraffin sections and liked it a lot. But I also had a lot of fun with my free ha...
by MicroBob
Thu Apr 02, 2020 7:48 pm
Forum: Pictures and Videos
Topic: Spirogyra glabra algae
Replies: 9
Views: 301

Re: Spirogyra glabra algae

When you do contact him be sure to tell him that many members of the Microbehunter forum have been impressed by the quality of the images and his ability to capture critical moments. This is my intention. When used in the right way, such a collection can really move something in our time of decline...
by MicroBob
Thu Apr 02, 2020 6:12 pm
Forum: Pictures and Videos
Topic: Spirogyra glabra algae
Replies: 9
Views: 301

Re: Spirogyra glabra algae

Hi Glen, I think Walter had a very high standard for his work and must have discarded lots of bad or average slides. Of cause it is much more fun to work on a collection of this quality than on the usual (e.g. mine) wild mix. He also prepared his database very well with good explanations how which i...
by MicroBob
Thu Apr 02, 2020 5:58 pm
Forum: Microscopes and optics
Topic: DIY epi-DIC
Replies: 8
Views: 318

Re: DIY epi-DIC

I have an epi condenser for single objectives mounted in a "monkel". Reflectors "D" and "H-Pl" too. I'm not quite shure about the objective lenghts here as Zeiss had more than one on their epi stuff. The two epi DIC prisms look as if they were made for objectives of different lenght and design. Epi ...
by MicroBob
Thu Apr 02, 2020 4:10 pm
Forum: Introduce yourself
Topic: diatoms
Replies: 11
Views: 651

Re: diatoms

And this is cleaned diatom material photographed with incident light dark field contrast. When you think of them as made from glass you get the right idea.
by MicroBob
Thu Apr 02, 2020 4:05 pm
Forum: Introduce yourself
Topic: diatoms
Replies: 11
Views: 651

Re: diatoms

Hi Frank, diatoms are basically transparent and have a refractive index around 1,45. To get a contrasty image a difference of the refractive index of the mountant of 0,1 is recommended. This doesn't necessarily mean that it has to be higher though. Diatoms in air give lots of contrast but you can't ...