Search found 3154 matches

by MicroBob
Fri Jan 11, 2019 9:35 pm
Forum: Specimens, samples and slides
Topic: Radiolaria observations
Replies: 19
Views: 9998

Re: Radiolaria observations

Hi Doron,
I took you image from the neofluar and used the green colour channel to get a b/w image and sharpened a bit. For me this looks better than the colour image.

Bob
by MicroBob
Fri Jan 11, 2019 11:33 am
Forum: My microscope
Topic: Zeiss Standard 14
Replies: 61
Views: 34353

Re: Zeiss Standard 14

The centering mechanism works with two screws that work against one spring loaded plunger.
The screws usually move, but the plunger often is stuck due to hardened grease. So you should check wheter the condenser actually moves when you turn the screws out.

Bob
by MicroBob
Thu Jan 10, 2019 8:24 pm
Forum: Specimens, samples and slides
Topic: Radiolaria observations
Replies: 19
Views: 9998

Re: Radiolaria observations

Hi Doron,
in bright field you can just use white light and take the photo. Then just use one colour channel in the image editor and convert to gray scale. I get somewhat better diatom images this way.

Bob
by MicroBob
Thu Jan 10, 2019 3:47 pm
Forum: Specimens, samples and slides
Topic: Radiolaria observations
Replies: 19
Views: 9998

Re: Radiolaria observations

Hi Doron, nice images! Since radiolaria have no colour you might just use one colour channel (I think green is best) of your image so you effectively come close to the image quality of an apochromat. I like to use round cover slips for permanent slides because it is much easier to get a good looking...
by MicroBob
Thu Jan 10, 2019 2:38 pm
Forum: Microscopes and optics
Topic: My new (old) microscope and a couple of questions
Replies: 30
Views: 13114

Re: My new (old) microscope and a couple of questions

On the german used market newer dark field condensers (like Zeiss Standard ring dovetail mount) can be found much less frequently than older ones. The method was not used as much after the second word war and the introduction of phase contrast. A dark field condenser has to be centered precisely so ...
by MicroBob
Thu Jan 10, 2019 9:11 am
Forum: Microscopes and optics
Topic: My new (old) microscope and a couple of questions
Replies: 30
Views: 13114

Re: My new (old) microscope and a couple of questions

Hi José, cemented lens groups are used to reduce the number of glass-air surfaces where light loss and stray light is produced. They are necessary for high performance optics. I try a little to keep my microscopes from quick temperature changes and avoid hard knocks on the objective barrels. You hav...
by MicroBob
Wed Jan 09, 2019 9:31 pm
Forum: Microscopes and optics
Topic: My new (old) microscope and a couple of questions
Replies: 30
Views: 13114

Re: My new (old) microscope and a couple of questions

Hi José, you bought a verry nice microscope there. It is a Zeiss Standard from western Germany, 160mm tube length, all original objectives calculated to be used with correction eyepieces. Your eyepieces and the black achromatic objectives and the silver Neofluar match perfectly. The black achromats ...
by MicroBob
Sun Jan 06, 2019 9:34 pm
Forum: My microscope
Topic: Zeiss Jena Lu Wd microscope
Replies: 15
Views: 12081

Re: Zeiss Jena Lu Wd microscope

The nosepieces of LG and NF are the same. This means that the darkfield incident condenser of the NF could fit the LU. I have the NF and condenser but no LU so I can't test it. The darkfield incident condenser of the NF comes in a big heavy box with about 5 ring mirrors and infinity objectives with ...
by MicroBob
Sun Jan 06, 2019 7:24 pm
Forum: My microscope
Topic: Zeiss Jena Lu Wd microscope
Replies: 15
Views: 12081

Re: Zeiss Jena Lu Wd microscope

Hi Javier,

i happened to stumble upon this Zeis Jena LU document:https://docplayer.org/56846662-Abteilun ... -3641.html

Bob
by MicroBob
Sun Jan 06, 2019 11:40 am
Forum: Specimens, samples and slides
Topic: Some Of My Homemade Permanent Slides
Replies: 31
Views: 18230

Re: Some Of My Homemade Permanent Slides

Hi Rick, I'm sure it would be very useful if you could post this list here. I would not include stuff the supplyer isn't supposed to sell to the local public into a public available list though. There have been examples where limitations have not been cared for and big problems resulted from it, not...
by MicroBob
Sat Jan 05, 2019 9:09 pm
Forum: Introduce yourself
Topic: Hello from a beginner
Replies: 10
Views: 6869

Re: Hello from a beginner

Hi, welcome to the forum! Your topic is really interesting an of great importance today. In most places micro plastic is not highly concentrated so you might have to look for a way to concentrate it. Most plastics have a density of around 1 while sand has one of around 2. Plastics can withstand some...
by MicroBob
Sat Jan 05, 2019 8:02 pm
Forum: Specimens, samples and slides
Topic: Some Of My Homemade Permanent Slides
Replies: 31
Views: 18230

Re: Some Of My Homemade Permanent Slides

Hi Rick, thank you for posting your preparation method for the hydra! I like experimental microcopy methods a lot and I also think that they are very worthwhile: When you look what problems microscopists, especially beginners have, you frequently find that one of the main problems is that they know ...
by MicroBob
Fri Jan 04, 2019 12:48 pm
Forum: Microscopy accessories
Topic: Slotted screwdriver blade thickness
Replies: 24
Views: 14850

Re: Slotted screwdriver blade thickness

Unless of course they were made specifically for Zeiss This sounds so much like Zeiss, it has to be true. Lagrely they had the attitude to do things as good as ever they could, forget the cost. They also used whatever thread or screw head they tought best without much regard towards standards. This...
by MicroBob
Fri Jan 04, 2019 10:09 am
Forum: Microscopy accessories
Topic: Slotted screwdriver blade thickness
Replies: 24
Views: 14850

Re: Slotted screwdriver blade thickness

For screw drivers a small bench grinder is just right, 125 to 150mm wheel diameter. This cost just 15€ and doesn't take up much space. This wheel diameter gives the right amount of hollow grind. A proper screw driver is made from hardened steel and shouldn't be warmed to much more than 200 °C. This ...
by MicroBob
Thu Jan 03, 2019 4:19 pm
Forum: Specimens, samples and slides
Topic: Interesting topic: Sylvester fireworks particles
Replies: 1
Views: 2794

Interesting topic: Sylvester fireworks particles

Hi together, an interesting topic is treated in german Mikroskopie-Forum: Fireworks particles. Jon Larsen has pictured many of them in his book "In Search of Stardust" (very interesting - buy it!) because you can easily think they were micro meteorites. Gerd made the suggestion to specifically have ...
by MicroBob
Thu Jan 03, 2019 4:11 pm
Forum: Microscopes and optics
Topic: Field of view coverage, plan/non plan comparison
Replies: 4
Views: 2254

Re: Field of view coverage, plan/non plan comparison

Hi Doron,

as ever a nice and conclusive comparison!

You could optimize you field of view by using a pancake 40mm lens like the old Pentax-M 40 1:2,8 from the late seventies.
This an be found on a Pentax ME camera that nobody pays much money for.

Bob
by MicroBob
Thu Jan 03, 2019 3:48 pm
Forum: Microscopy accessories
Topic: Slotted screwdriver blade thickness
Replies: 24
Views: 14850

Re: Slotted screwdriver blade thickness

These thin blades are damaged easily so you need a bench grinder anyway.
Grinding screw driver tips is a nice beginner training task by the way.

Bob
by MicroBob
Mon Dec 31, 2018 11:43 am
Forum: Miscellaneous
Topic: Lomo MBD-1 Field Microscope
Replies: 3
Views: 4086

Re: Lomo MBD-1 Field Microscope

These MBD-1 come with an additional 40:1 0,75 water immersion objective. One drawback of these instruments is that you are supposed to remove all objectives before storing the intrument in the box. For long travels in extreme regions this might just be fine, but for use as a quick-to-grab garden mic...
by MicroBob
Sun Dec 30, 2018 7:29 pm
Forum: Microscopes and optics
Topic: Leitz 63x 170 mm dry objective
Replies: 11
Views: 5289

Re: Leitz 63x 170 mm dry objective

Hi Jan,
when asking for the uses of objectives or eyepieces it is advisable to post an image of the component or a link to the offer or the complete and precise text on the component. With Leitz ist is for instance a big difference whether it is a Periplan 10x eyepiece or a Periplan 10x18.

Bob
by MicroBob
Sat Dec 29, 2018 7:37 am
Forum: Miscellaneous
Topic: Mounting needle
Replies: 7
Views: 6765

Re: Mounting needle

For diatom mounting a seal hair works well.
by MicroBob
Sat Dec 29, 2018 7:34 am
Forum: Microscopes and optics
Topic: carl zeiss jena coarse focus mechanism?
Replies: 6
Views: 4344

Re: carl zeiss jena coarse focus mechanism?

Nyogel 795A, is too light. Some microscope stands have an adjustable coarse focus mechanism - you might be able to adjust it. Coarse forus is not that important as you don't use it that much. As long as it is not too hard to move so the gears would suffer it might not be necessary to dismantle it c...
by MicroBob
Sat Dec 29, 2018 7:07 am
Forum: Pictures and Videos
Topic: Birefringence of Ice
Replies: 10
Views: 5356

Re: Birefringence of Ice

Hi Rob,
thank you for showing these beautiful images! Ice really is an interesting topic.

Bob
by MicroBob
Fri Dec 28, 2018 2:28 pm
Forum: Microscopes and optics
Topic: Leitz 63x 170 mm dry objective
Replies: 11
Views: 5289

Re: Leitz 63x 170 mm dry objective

It depends on your need and preferences. When you spend a lot of time with one objective and one single slide you can just as well use oil. If you have to scan through a 1000 slides a day and look for a medical detail you would be happy to see enough with a dry objective. 200€ is a lot of money for ...
by MicroBob
Fri Dec 28, 2018 2:19 pm
Forum: Microscopes and optics
Topic: carl zeiss jena coarse focus mechanism?
Replies: 6
Views: 4344

Re: carl zeiss jena coarse focus mechanism?

Hi Peter, I can't help you here but with Zeiss Jena there is one general tip: They used grease that had an unusual tendency to harden. This can be a problem when dismantling because things just don't move when you loosen a screw. It helps a lot to soak the microscope micus optical components in warm...
by MicroBob
Fri Dec 28, 2018 7:59 am
Forum: Beginner's corner
Topic: What does x:1 mean on an objective?
Replies: 2
Views: 2181

Re: What does x:1 mean on an objective?

Generally a 10:1 objective is part of a finity system like your old Leitz. A 10x objective is for infinity systems. There is a logic behind this nomenclature but I couldn't explain it. In case of Leitz optics you have to look for a Leitz NPL Fluotar 100/1,32 Oel and not a Leitz NPL Fluotar 100x/1,32...
by MicroBob
Fri Dec 28, 2018 7:55 am
Forum: Microscopes and optics
Topic: Leitz 63x 170 mm dry objective
Replies: 11
Views: 5289

Re: Leitz 63x 170 mm dry objective

Hi Jan, these strong dry objectives are not very common. In use they have the problem that the image quality depends very much on the cover slip thickness and this varies a lot. For a high quality universally usable high power dry objective it is necessary to have a cover slip thickness correction c...
by MicroBob
Sun Dec 23, 2018 10:56 pm
Forum: Beginner's corner
Topic: First microscope
Replies: 135
Views: 51452

Re: First microscope

With a budget of 1000€ you can expect to buy a great microscope. A budget of this size also needs more planning to be used right. There are some used microscope dealers in Europe that would ship to France - this is an option too. Here a first microscope was sought and found recently: For sure an int...
by MicroBob
Sun Dec 23, 2018 9:11 am
Forum: Beginner's corner
Topic: First microscope
Replies: 135
Views: 51452

Re: First microscope

One general problem with the Zeiss Standard Junior is the optical design of the condenser: It is designed to work with mirror and a microscope lamp ca. 250mm away. When used with the oven lamp or a small LED light directly on the base the condenser can't offer ist full n.a.. This can be overcome by ...
by MicroBob
Sat Dec 22, 2018 11:42 pm
Forum: Beginner's corner
Topic: First microscope
Replies: 135
Views: 51452

Re: First microscope

Hi Enzo, this is an old Standard Junior course microscope with a kitchen oven lamp. They are very nice and high quality but not especially valuable since there are so many used ones around and they are somewhat limited. When you would sell it on german ebay you wouldn't get more than 250€, but his i...