Search found 2571 matches

by Hobbyst46
Thu Mar 01, 2018 12:55 pm
Forum: Illumination Techniques
Topic: Dark field illumination: Questions and answers
Replies: 65
Views: 13990

Re: Dark field illumination: Questions and answers

Hello Bob Thanks for opening the new post and for the as-always help and good will. I think your microscope has a frosted lens before the mirror in the base. So probably the distance between frosted lens and lamp has not much influence on the illumination, except for the brightness. Yes, indeed ther...
by Hobbyst46
Thu Mar 01, 2018 9:49 am
Forum: Microscopes and optics
Topic: New objective dusty inside... Amscope poor quality control
Replies: 15
Views: 1998

Re: New objective dusty inside

Crater Eddie - I wonder, had you asked the seller of this brand new objective to post close-up photos of this objective before buying it, would these speckles or dust or scratches be visible in the photos? would they show apriori that it could be suspect of defects ?
by Hobbyst46
Wed Feb 28, 2018 10:33 pm
Forum: Illumination Techniques
Topic: 43x very dim
Replies: 38
Views: 5543

Re: 43x very dim

Apochronaut: Just to answer the previous question - this GFL has the light bulb inside the round base plate, under the arm, not below the condenser. the distance (and base of course). The distance is roughtly 11+5=16 cm. I would like high NA darkfield, though. Also, below are some photos of 100x oil...
by Hobbyst46
Wed Feb 28, 2018 7:24 pm
Forum: Illumination Techniques
Topic: 43x very dim
Replies: 38
Views: 5543

Re: 43x very dim

When nothing works read the manual !!! Following the previous discussions I opened the original instruction manual of my scope, in a page that I have never noticed before, and so it says: "For dark-field investigations with immersion objectives we produce an ultra-condenser... in conjunction with an...
by Hobbyst46
Wed Feb 28, 2018 6:11 pm
Forum: Illumination Techniques
Topic: 43x very dim
Replies: 38
Views: 5543

Re: 43x very dim

Thanks MichaelG.
by Hobbyst46
Wed Feb 28, 2018 5:56 pm
Forum: Illumination Techniques
Topic: 43x very dim
Replies: 38
Views: 5543

Re: 43x very dim

Apochronaut: Thanks a lot for the great info. I understand from it that the DF issue arises from the distance. It agrees with the decay of intensity of radiation with the squared distance to the condenser. So if I could place the source nearer to the condenser the problem will be diminished ? The co...
by Hobbyst46
Wed Feb 28, 2018 4:21 pm
Forum: Illumination Techniques
Topic: 43x very dim
Replies: 38
Views: 5543

Re: 43x very dim

Is German eBay a separate site from "English/American" eBay?
by Hobbyst46
Wed Feb 28, 2018 4:19 pm
Forum: Illumination Techniques
Topic: 43x very dim
Replies: 38
Views: 5543

Re: 43x very dim

MicroBob I am very glad that you are pursueing this subject. I only have two condensers. One is the simple brightfield condenser with a swing out lens, NA 1.3. I do not use it, The other one is thd Achromat aplanat 1.4 condenser, model 7z if I recall correctly. It has BF, DF, PH2, PH3 and three empt...
by Hobbyst46
Wed Feb 28, 2018 12:59 pm
Forum: Beginner's corner
Topic: Word to the Wise: Lessons Learned
Replies: 18
Views: 4154

Re: Word to the Wise: Lessons Learned

I read them end to end after having read several articles about the subject in peer-review journals related to paleontology, ecology etc.
by Hobbyst46
Tue Feb 27, 2018 10:08 pm
Forum: Beginner's corner
Topic: Word to the Wise: Lessons Learned
Replies: 18
Views: 4154

Re: Word to the Wise: Lessons Learned

Actually, it is easier to reach the posts from the Google's search engine - just input the post name and it will find it
Either I do not know how to search inside the forum or the search engine ignores scripts - even when I put two words between "" marks.
Age takes its toll.
by Hobbyst46
Tue Feb 27, 2018 9:13 pm
Forum: Illumination Techniques
Topic: 43x very dim
Replies: 38
Views: 5543

Re: 43x very dim

AS mentioned above, I cannot do 100x DF as yet.
I can try phase contrast in addition to BF. Within a couple of days.
by Hobbyst46
Tue Feb 27, 2018 8:30 pm
Forum: Pictures and Videos
Topic: Euglena, Algae, Diatom and Cyano
Replies: 16
Views: 1678

Re: Euglena, Algae, Diatom and Cyano

MicroBob:

I have a Canon EOS-M10, also a "crippled" camera with respect to tethering
Looks like camera manufacturers copy from each other the downgrades of their new compact cameras! :?
by Hobbyst46
Tue Feb 27, 2018 6:03 pm
Forum: Illumination Techniques
Topic: 43x very dim
Replies: 38
Views: 5543

Re: 43x very dim

I'm guessing you have never tried this 10 watt option from retroDiode? A 10 watt led is absolutely wimpy, in comparison to 100 watt halogen and completely useless for high resolution DF, despite what their adds say. I challenged them on their claims and they admitted that their retrofits were not a...
by Hobbyst46
Tue Feb 27, 2018 5:33 pm
Forum: Beginner's corner
Topic: Word to the Wise: Lessons Learned
Replies: 18
Views: 4154

Re: Word to the Wise: Lessons Learned

A tip to would-be diatom collectors: Read two 2016 posts "Doing Diatoms" and "Doing diatoms a Different Way". First, they are examples of scrupulous, methodical, creative labor that yielded remarkable results. Second, IMHO, the challenges of collecting, cleaning and purifying diatoms, as described i...
by Hobbyst46
Tue Feb 27, 2018 3:59 pm
Forum: Illumination Techniques
Topic: 43x very dim
Replies: 38
Views: 5543

Re: 43x very dim

While I fully agree with Apochronaut on every aspect and potential issue with LEDs, for my scope a LED source was the only option when the ancient tungsten lamp became problematic. So in the case that you nevertheless want a LED here is my experience. A DIY LED illumination may involve some electric...
by Hobbyst46
Tue Feb 27, 2018 12:24 pm
Forum: Pictures and Videos
Topic: Well I didn't see this coming...
Replies: 18
Views: 1547

Re: Well I didn't see this coming...

hkv - Very impressive, thanks for posting!
by Hobbyst46
Tue Feb 27, 2018 9:59 am
Forum: Pictures and Videos
Topic: Well I didn't see this coming...
Replies: 18
Views: 1547

Re: Well I didn't see this coming...

It certainly has eight legs, not seven. So it is not an insect.
It is not a bug either. A BUG is something that infests computer software, especially when fresh... :lol:
by Hobbyst46
Sun Feb 25, 2018 6:59 pm
Forum: Miscellaneous
Topic: Sometimes my focus knob doesn't seem to work.
Replies: 10
Views: 2156

Re: Sometimes my focus knob doesn't seem to work.

Lilly If this "snaps into focus" is detected through the viewing eyepieces, the focusing mechanism is defective. But this is unlikely IMO. If you see it only on the camera monitor, it may be related to the camera or software. Another possibility: the specimen slide is slightly lifted off the stage, ...
by Hobbyst46
Sun Feb 25, 2018 1:47 pm
Forum: Pictures and Videos
Topic: Sprossquerschnitt einmal anders
Replies: 6
Views: 802

Re: Sprossquerschnitt einmal anders

Sehr schoen
by Hobbyst46
Sun Feb 25, 2018 9:47 am
Forum: Camera systems and imaging
Topic: Experiments with afocal photomicrography: illuminations, spider threads...
Replies: 53
Views: 13242

Re: Experiments with afocal photomicrography: illuminations, spider threads...

About the fine scratched lines: This was invented by Friedrich Adolph Nobert. He invented machines that were able to make line patterns that first could be seen in the 1960s under the then perfected electron microscopes. https://de.wikipedia.org/wiki/Friedrich_Adolph_Nobert So my curiosity about th...
by Hobbyst46
Sun Feb 25, 2018 9:17 am
Forum: Camera systems and imaging
Topic: Experiments with afocal photomicrography: illuminations, spider threads...
Replies: 53
Views: 13242

Re: Experiments with afocal photomicrography: illuminations, spider threads...

Micro-Bob: Thanks for the input. According to the following citation from Wikipedia: "In physics, Babinet's principle[1] states that the diffraction pattern from an opaque body is identical to that from a hole of the same size and shape except for the overall forward beam intensity". Likewise, I thi...
by Hobbyst46
Sun Feb 25, 2018 12:03 am
Forum: Camera systems and imaging
Topic: Experiments with afocal photomicrography: illuminations, spider threads...
Replies: 53
Views: 13242

Re: Experiments with afocal photomicrography: illuminations, spider threads...

Hi MicroBob Thanks a lot. I thought that the diffraction pattern from a dark object is the same as from a bright object except for intensity (if I state it correctly, I no expert on optics), but I have already ordered a micrometer like the one in the link. So, I will follow your suggestion about the...
by Hobbyst46
Sat Feb 24, 2018 8:59 pm
Forum: Beginner's corner
Topic: What scope for freshwater plankton
Replies: 6
Views: 1422

Re: What scope for freshwater plankton

On the used items market there are mostly two types - either a compound microscope, aka biological microscope, or a stereoscope, that is used for inspection of larger specimens - electronic components, minerals, gems, whole insects. Stereoscopes are often used by goldsmiths and jewelery designers/cr...
by Hobbyst46
Sat Feb 24, 2018 5:21 pm
Forum: Miscellaneous
Topic: How can I get them to hold still???
Replies: 8
Views: 1797

Re: How can I get them to hold still???

I only meant to slow them somewhat, not freeze their motion on the spot
by Hobbyst46
Sat Feb 24, 2018 4:52 pm
Forum: Miscellaneous
Topic: How can I get them to hold still???
Replies: 8
Views: 1797

Re: How can I get them to hold still???

You may try adding some viscous liquid that will slow the swimmers down, although it might shorten their life span as well. like draw out just al little bit - say a few percent -of the water from under the cover slip by means of a piece of blotting paper (or even a paper towel), and topping up with ...
by Hobbyst46
Sat Feb 24, 2018 12:56 pm
Forum: Camera systems and imaging
Topic: Experiments with afocal photomicrography: illuminations, spider threads...
Replies: 53
Views: 13242

Re: Experiments with afocal photomicrography: illuminations, spider threads...

1) Many components we use today are more or less compatible but come from completely different points of time. The Zeiss Winkel Standard and Zeiss Standard Systems have been made from the late 40s until the late 80s, one model even until the mid 90s. So it has to be expected that not all components...
by Hobbyst46
Thu Feb 22, 2018 8:53 pm
Forum: Camera systems and imaging
Topic: Experiments with afocal photomicrography: illuminations, spider threads...
Replies: 53
Views: 13242

Re: Experiments with afocal photomicrography: illuminations, spider threads...

Following my struggling with afocal photography with a stage micrometer as test specimen, I was frustrated by the chromatic aberrations. Then I discovered the Peter Hubel Mikroskopie-ph.de site. Among fascinating high resolution photos of diatoms, I found a thorough investigation of the performance ...
by Hobbyst46
Wed Feb 21, 2018 4:23 pm
Forum: Beginner's corner
Topic: need help buying a new microscope
Replies: 10
Views: 2710

Re: need help buying a new microscope

Nergiz Olympus scopes are usually excellent, this model is not too old so I believe you will be very happy with the CX31!!. Halogen illumination is very ubiquitous among microscopes, including high end ones, and the more power the better especially for darkfield and other special effects. You can al...
by Hobbyst46
Wed Feb 21, 2018 4:03 pm
Forum: Camera systems and imaging
Topic: Understanding the capabilities of microscope cameras
Replies: 6
Views: 2901

Re: Understanding the capabilities of microscope cameras

In the case that you opt for a Canon EOS camera, if it is a mirrorless of the series EOS-M series, they do not support live view with a desktop computer - no matter which software. They do support tethering with smartphone or tablet. I do not know if they support tethering with a laptop computer. I ...
by Hobbyst46
Wed Feb 21, 2018 3:45 pm
Forum: Beginner's corner
Topic: USB digital microscope
Replies: 6
Views: 4537

Re: USB digital microscope

Luis I looked at the specs of the scope mentioned in the link above this one. As hkv and others remarked, you need good optics to see bacteria. And it may be important to have good contrast, e.g. phase contrast and more. I am not sure that this scope can be upgraded in this sense. Moreover, its illu...