Search found 2688 matches

by MicroBob
Sat May 08, 2021 7:33 pm
Forum: Specimens, samples and slides
Topic: pleurosigma sword in darkfield
Replies: 4
Views: 94

Re: pleurosigma sword in darkfield

Nice photos, Doron, especially the second one. This blue just looks super. I think more diatoms show it when observed with comparatively low aperture objectives.

Bob
by MicroBob
Sat May 08, 2021 7:16 am
Forum: Specimens, samples and slides
Topic: Two-blades method - possible to improve?
Replies: 6
Views: 232

Re: Two-blades method - possible to improve?

I think the two-blade method is best for flat specimen like leaves. As soon as the specimen are round and bigger or harder the struggle will increase. So I wouldn't spend too much energy into optimising this method. If you look for alternative solutions: A well sharpened wood plane can take of chips...
by MicroBob
Fri May 07, 2021 6:03 pm
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 302

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 fa...
by MicroBob
Fri May 07, 2021 8:36 am
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 302

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 ou...
by MicroBob
Fri May 07, 2021 7:18 am
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 302

Re: Buying expired slides - hit or miss

Hi Doron, what I find interesting is that this process can take place in varying speeds. I had fairly recent slide packs go bad while some decades old are not perfect but quite okay. And I would expect the slides to deteriorate separated in boxes too. From household glassware I know this too, glasse...
by MicroBob
Thu May 06, 2021 9:01 pm
Forum: Microscopy accessories
Topic: Buying expired slides - hit or miss
Replies: 17
Views: 302

Re: Buying expired slides - hit or miss

Hi together, this is a really interesting topic. Even some really experienced microscopists are not aware of this problem and it is not discussed much. I don't like to throw things away (asky my wife) and tend to buy lifelong supplies of everything and use them up over time. I also like to make perm...
by MicroBob
Wed May 05, 2021 4:23 pm
Forum: Specimens, samples and slides
Topic: Two-blades method - possible to improve?
Replies: 6
Views: 232

Re: Two-blades method - possible to improve?

Angling the blades could improve the quality of the sections. The included angle of the micro bevels of one blade will be around 35°. So the inclination would be 17,5° plus clearance angle. For fresh sectioning it has shown that the back of the microbevel can slide above the section a bit without do...
by MicroBob
Wed May 05, 2021 8:32 am
Forum: Beginner's corner
Topic: Suggestions for Work Surface
Replies: 5
Views: 121

Re: Suggestions for Work Surface

I have this in use: My favourite:- piece of planed wood , 10cm x 25cm x 0,8cm I take notes on it if necessary and from time to time just plane the surface An 8cm x 12cm planed board on 3cm high feet - makes handling easier sometimes A sheet of glass 20cm x 25cm - easy to clean cold cuts plates from ...
by MicroBob
Tue May 04, 2021 3:02 pm
Forum: Specimens, samples and slides
Topic: Keep Dry Diatom on slide
Replies: 8
Views: 161

Re: Keep Dry Diatom on slide

Hi Suphot, nice and simple method! I think that most bacterial an fungal activity will take place in the first weeks so the slide should be more or less stable from now on. If you woulf like to go one step further you could clean the diatoms by incineration. I found it to be practical to put the cov...
by MicroBob
Tue May 04, 2021 6:11 am
Forum: Illumination Techniques
Topic: Interesting graphical description of the mathematical background of oblique lighting
Replies: 4
Views: 200

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

Hi together, the limitation of oblique was always that it was not easy to get a repeatable effect. I can imagine that in a very modern microscope with stepper motor control of the oblique stop and digital imaging the resolution enhancing effect could be put to good use. Changeing the objective by me...
by MicroBob
Sun May 02, 2021 5:34 pm
Forum: Illumination Techniques
Topic: Interesting graphical description of the mathematical background of oblique lighting
Replies: 4
Views: 200

Interesting graphical description of the mathematical background of oblique lighting

Hi together,
Hubert has looked for an explanation of the relief effect of oblique lighting and created this interesting comparison of illumination techniques (in german language):
https://www.mikroskopie-forum.de/index. ... ;topicseen

Bob
by MicroBob
Fri Apr 30, 2021 11:19 am
Forum: Specimens, samples and slides
Topic: Substitutes for Hay Infusion?
Replies: 8
Views: 241

Re: Substitutes for Hay Infusion?

Hi,
you can also set up a pond aquarium that can run stable for a long time. Hay is probably available in pet shops.

Bob
by MicroBob
Wed Apr 28, 2021 6:20 pm
Forum: Beginner's corner
Topic: My first week in microscopy.
Replies: 5
Views: 196

Re: My first week in microscopy.

Hi Jim,
nice to hear that you had such a successful and joyful start into microscopy! This is an amazing hobby but many newbies don't get past the first hurdles and give up - this can't happen to you anymore.
Enjoy your further trips into the micro world!

Bob
by MicroBob
Wed Apr 28, 2021 5:40 am
Forum: My microscope
Topic: Feeling a bit lost (buying advice / Belgium)
Replies: 25
Views: 788

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

Hi, welcome to the forum! An alternative solution could be buying used from a reputable dealer like Immel Optik in Germany. In the past year or so there has been a never ending stream of newcomers looking for microscopy buying advice. So the more experienced microscopists are a bit worn out and don'...
by MicroBob
Mon Apr 26, 2021 3:18 pm
Forum: Specimens, samples and slides
Topic: Best Practices Drymounts
Replies: 11
Views: 420

Re: Best Practices Drymounts

I bougth the pen to label a stack of slides for paraffin sections. I label them in advance and take notes in a book to make sure I know what they are. Last I used the pen to cut 20x20 cover slips in quaters. I used them for a diatom incineration cleaning method that works best with small rectangular...
by MicroBob
Sun Apr 25, 2021 8:12 pm
Forum: For forum members who want to buy and sell equipment
Topic: Is there a demand for LOMO Biolams out there?
Replies: 1
Views: 104

Re: Is there a demand for LOMO Biolams out there?

Hi, they were sold in western Germany by a mail order company in bigger numbers and they show on ebay all the time, typically nearly unused and with hardenend grease. With the wooden box in the version you describe they go for round about 60€ including inland shipping. With shipping from your countr...
by MicroBob
Sun Apr 25, 2021 4:17 pm
Forum: For forum members who want to buy and sell equipment
Topic: Need 28mm eyepieces
Replies: 16
Views: 332

Re: Need 28mm eyepieces

Hi Don, with 20x eyepieces you will get into empty magnification, bigger but not better resolved. To get twice the magnification and twice the resolution at half the free working distance you could install a 2x lens under the objective if this is possible on your model. Often there is a mounting thr...
by MicroBob
Sun Apr 25, 2021 11:53 am
Forum: Specimens, samples and slides
Topic: Best Practices Drymounts
Replies: 11
Views: 420

Re: Best Practices Drymounts

Hi John,
this is the one I bought and I like it: https://de.aliexpress.com/item/32906393 ... 4c4dSHExGM
It actually has a dark tip insert so it's not plain steel, but I can't determine whether it's diamond or carbide. It works! :D

Bob
by MicroBob
Sun Apr 25, 2021 10:02 am
Forum: Specimens, samples and slides
Topic: Best Practices Drymounts
Replies: 11
Views: 420

Re: Best Practices Drymounts

For labeling slides and cutting cover slips I have a pen that was sold as diamond tipped, might be carbide. It wasn't expensive but works well as long as used only for this fine work.
by MicroBob
Sat Apr 24, 2021 7:39 am
Forum: Specimens, samples and slides
Topic: Best Practices Drymounts
Replies: 11
Views: 420

Re: Best Practices Drymounts

Hi, I have little experience with dry mounts but my head is full of good ideas. :roll: Genereally I like to make permanent mounts to be able to come back to them with different techniques etc. For a good slide the cover slip is necessary unless your objectives are not meant for use with one (e.g. on...
by MicroBob
Fri Apr 23, 2021 1:41 pm
Forum: Pictures and Videos
Topic: Actinocyclus octonarius
Replies: 23
Views: 621

Re: Actinocyclus octonarius

Hi Wes, I had the same decision when doing this adaptation for my Phomi. I chose the second tube. A normal eyepiece is parfocal when it sits in place, no adjustment needed. I made an adapter Zeiss tube dovetail to Sony e-mount. Since the Phomi has a built in tube factor of 1,25 I want to make best u...
by MicroBob
Thu Apr 22, 2021 8:00 pm
Forum: Pictures and Videos
Topic: Actinocyclus octonarius
Replies: 23
Views: 621

Re: Actinocyclus octonarius

I compared Rolf's hybrid eyepieces ( eye lens KPL 10x, barrel KPL 8x, field lens either KPL 8x or KPL 10x) to a lifted standard KPL 8x: The hybrids give a much better image. So Rolf really had an ingenious idea here, especially since the hybrids consist of fairly common components. Neither of us has...
by MicroBob
Thu Apr 22, 2021 7:15 pm
Forum: Pictures and Videos
Topic: Actinocyclus octonarius
Replies: 23
Views: 621

Re: Actinocyclus octonarius

Wes wrote:
Thu Apr 22, 2021 7:01 pm
I get strong chromatic aberration especially around the edges when I tried direct projection without lifting the eyepiece.
Hi Wes, in this case you will have changed the objective's focus, right? This is not a good method as the objectie is not used as intended.

Bob
by MicroBob
Thu Apr 22, 2021 6:49 pm
Forum: Pictures and Videos
Topic: Actinocyclus octonarius
Replies: 23
Views: 621

Re: Actinocyclus octonarius

Hi Glen, great image! Concerning eyepiece projection: Can you post an image of an object micrometer to show how well this works towards the borders? Rolf Vossen has recently posted an article on the use of hybrid eyepieces as projectives. I have taken part in the experiments and found this to be a v...
by MicroBob
Wed Apr 21, 2021 7:21 pm
Forum: Microscopes and optics
Topic: 2x objective issue resolved
Replies: 5
Views: 270

Re: 2x objective issue resolved

Hi Michael, that sounds a lot more elegant for sure! :D Do you know of an actual use of this name by a microscope maker? It is a simple lens, so lots of other names could have been used. I know Zeiss West and Zeiss Jena used "Brillenglaskondensor", but I'm not aware of the names used by other german...
by MicroBob
Wed Apr 21, 2021 12:14 pm
Forum: Microscopes and optics
Topic: 2x objective issue resolved
Replies: 5
Views: 270

Re: 2x objective issue resolved

Hi Antoni, without condenser you get an illumination of a wide field but the colours in the image are typically much worse than with condenser in the illuminated area - don't ask me why. What helps is an improvised condenser lens, planconvex, plan side on top, focal lenght about 40mm. This placed in...
by MicroBob
Tue Apr 20, 2021 8:38 pm
Forum: Microscopes and optics
Topic: Any Bresser XPD-101 field microscope users?
Replies: 8
Views: 287

Re: Any Bresser XPD-101 field microscope users?

Hi Brian,
one drawback of the FM31 is it's low build, not really good to use for more than minutes. Other field microscopes are much better in this area.
And when you include the necessary accessories the size of the instrument might not be so important any more.

Bob
by MicroBob
Tue Apr 20, 2021 4:55 pm
Forum: Microscopes and optics
Topic: Any Bresser XPD-101 field microscope users?
Replies: 8
Views: 287

Re: Any Bresser XPD-101 field microscope users?

Hi Brian, field microscopes seem to be a tiny market nowadays and at this price it is not very appealing for occasional use. Do you have a special application in mind? There are several alternatives, some quite frequently and cheaply available. When you search for fm31 or field microscope in this fo...
by MicroBob
Mon Apr 19, 2021 1:20 pm
Forum: Resources (online, books etc.)
Topic: Micro algae database and image collection is online!
Replies: 4
Views: 307

Micro algae database and image collection is online!

Hi together, a former member of our MIKRO Hamburg group spent a lot of effort in photographing and identifying micro algae. I have had his 35mm slide collection scanned and after a lot of work with connecting image and database you can find the collection on the website of our main society: https://...
by MicroBob
Sat Apr 17, 2021 7:11 am
Forum: Microscopy accessories
Topic: Disposable blades with Cambridge rocking microtome, anybody?
Replies: 14
Views: 714

Re: Disposable blades with Cambridge rocking microtome, anybody?

Congratulations, nice sections!
The OLFA LBB blades have two bevels per side, the final micro bevels including an angle of probably 35°. So the body of the blade should be in a bit more than 17,5° to the movement plane of the block.

Bob