Search found 2901 matches

by MichaelG.
Sat Jul 24, 2021 7:19 pm
Forum: Microscopy accessories
Topic: Wired vs Geared Stages
Replies: 5
Views: 144

Re: Wired vs Geared Stages

microb wrote:
Sat Jul 24, 2021 7:13 pm

Fixed it. I changed the image format so the website likes it.
.
Thanks for that … I stand by my initial response.

MichaelG.
by MichaelG.
Sat Jul 24, 2021 5:32 am
Forum: Camera systems and imaging
Topic: 1st steps in Stereo microscopy
Replies: 9
Views: 187

Re: 1st steps in Stereo microscopy

what I meant, is that a point in the center will travel left or right when I'm zooming or focusing. Oh, yeah. That's unavoidable on a greenough. Yes … as mentioned at 11 here: http://www.alanwood.net/downloads/olympus-sz4045tr-sz6045tr-sz1145tr-instructions.pdf The camera only sees one ‘channel’ … ...
by MichaelG.
Sat Jul 24, 2021 5:06 am
Forum: Microscopy accessories
Topic: Wired vs Geared Stages
Replies: 5
Views: 144

Re: Wired vs Geared Stages

This is a tentative response, Ted … because there is nothing currently pictured in your post

A wire system can be built [at reasonable cost, and without excessive friction] to be completely free of backlash.

MichaelG.
by MichaelG.
Fri Jul 23, 2021 9:29 pm
Forum: Pictures and Videos
Topic: Diatoms in epi DIC
Replies: 18
Views: 390

Re: Diatoms in epi DIC

Scarodactyl wrote:
Fri Jul 23, 2021 5:02 pm
It's specifically the tl4000 rc […] I'll take some pictures later along with my further experiments.
If it’s not too much bother; could you please include a photo showing items 9a and 9b
The patent only has them in plan view, and the detail is not evident.

Many thanks
MichaelG.
by MichaelG.
Thu Jul 22, 2021 3:37 pm
Forum: Microscopes and optics
Topic: Please advise, please offer comments on objective lens etched specs ed specs
Replies: 13
Views: 265

Re: Please advise, please offer comments on objective lens etched specs ed specs

My guess is that it’s the work of an “industrial designer” who believes that simplification brings clarity.

MichaelG.
.

and, as if by magic, here is evidence that they are at work: https://www.nikon.com/about/technology/design/
by MichaelG.
Thu Jul 22, 2021 9:28 am
Forum: Pictures and Videos
Topic: Diatoms in epi DIC
Replies: 18
Views: 390

Re: Diatoms in epi DIC

I think this points us in the right direction:
https://worldwide.espacenet.com/patent/ ... S7394593B2
… features 9a and 9b being particularly relevant.
see text commencing column 10, line 52

MichaelG.
by MichaelG.
Wed Jul 21, 2021 12:06 am
Forum: Beginner's corner
Topic: Resoloution and Light Wavelengths
Replies: 37
Views: 596

Re: Resoloution and Light Wavelengths

I see nothing in the posted photo to demonstrate resolution of two points separated by half a micron. What's wrong with the plot crb5 posted showing ~500 nm transitions at the edges of the lines on the calibration slide? That doesn’t fit my definition of resolution Figure 6(d) here does : http://ze...
by MichaelG.
Tue Jul 20, 2021 9:33 am
Forum: Beginner's corner
Topic: Resoloution and Light Wavelengths
Replies: 37
Views: 596

Re: Resoloution and Light Wavelengths

. I believe I have the same stage micrometer. The scale is 1mm square. Divided by 100 divisions that equals 10µm per division. So 10µm/19 = 0.52µm per division Very happy with that … but I think Markus has made a ‘leap of faith’ in assuming that he therefore has 0.52µm resolution I see nothing in t...
by MichaelG.
Tue Jul 20, 2021 6:07 am
Forum: Beginner's corner
Topic: Resoloution and Light Wavelengths
Replies: 37
Views: 596

Re: Resoloution and Light Wavelengths

... I suggested using pixel pitch as a measuring scale, because all the other factors are 'nominal' values. … but then calculated sizes of features in the object plane based on pixel pitch depend on the nominal specifications of all the optics between the sensor and object... Yes, Hans; that ^^^ wa...
by MichaelG.
Mon Jul 19, 2021 5:55 pm
Forum: Beginner's corner
Topic: Resoloution and Light Wavelengths
Replies: 37
Views: 596

Re: Resoloution and Light Wavelengths

hans wrote:
Mon Jul 19, 2021 5:47 pm
pixel pitch, etc. don't affect the result.
Just to be clear ... I suggested using pixel pitch as a measuring scale, because all the other factors are 'nominal' values.

MichaelG.
by MichaelG.
Mon Jul 19, 2021 5:15 pm
Forum: Beginner's corner
Topic: Resoloution and Light Wavelengths
Replies: 37
Views: 596

Re: Resoloution and Light Wavelengths

Markus, It may be better to go ‘back to basics’ … Take a photograph of the slide and count the pixels that represent some chosen length on the scale : Then check your camera specification, which should tell you the ‘pixel pitch’ and do your sums. All other numbers in the system can happily be ignore...
by MichaelG.
Mon Jul 19, 2021 3:41 pm
Forum: Camera systems and imaging
Topic: Hard to Get Clear Image of Fibers
Replies: 12
Views: 170

Re: Hard to Get Clear Image of Fibers

Stacking should certainly help, but … to be brutally honest, I couldn’t see any plane of your image that is sharp.

I wonder if you have a vibration problem ?

MichaelG.
.
P.S. __ is the lens something like this one ?
http://download.hayear.com/wap/content/?171.html
by MichaelG.
Mon Jul 19, 2021 8:58 am
Forum: Beginner's corner
Topic: Resoloution and Light Wavelengths
Replies: 37
Views: 596

Re: Resoloution and Light Wavelengths

Hey All, I was just calibrating my microscope with a calibration slide and realised that at the highest magnification (2500 x) that one unit on the eyepiece graticule is equal to 0.5 um (or 500 nanometers). Unless I've done my sums wrong, […] I think you probably have ^^^ Could you please show us y...
by MichaelG.
Sun Jul 18, 2021 6:10 pm
Forum: Miscellaneous
Topic: How really safe is a laser pointer ? new findings
Replies: 6
Views: 200

Re: How really safe is a laser pointer ? new findings

microb wrote:
Sun Jul 18, 2021 4:07 pm
Cheap green laser will not have an IR filter. […]

This video shows how to test without a spectrometer:
Interesting and useful link …Thanks

MichaelG.
by MichaelG.
Sat Jul 17, 2021 8:39 pm
Forum: Miscellaneous
Topic: How really safe is a laser pointer ? new findings
Replies: 6
Views: 200

Re: How really safe is a laser pointer ? new findings

Always worth mentioning an article which concludes:
But it’s never going to fully heal,” Davidorf said. “There will always be scarring there.”
Thanks for sharing the link.
MichaelG.
by MichaelG.
Sat Jul 17, 2021 4:29 pm
Forum: For forum members who want to buy and sell equipment
Topic: Like to buy a Ring adapter for AO stereo zoom
Replies: 27
Views: 452

Re: Like to buy a Ring adapter for AO stereo zoom

Will do The ring light arrived safely, and appears to be good value for money. The power supply output is smoothly variable over the [nominal] range 10 to 12 Volts, which covers ‘very dim’ to ‘very bright’. … There is no obvious visible flicker but; viewed on the oscilloscope there is some high fre...
by MichaelG.
Sat Jul 17, 2021 8:10 am
Forum: Microscopes and optics
Topic: Strange flare in Nikon CF N plan apo 20/0.75 objective
Replies: 26
Views: 591

Re: Strange flare in Nikon CF N plan apo 20/0.75 objective

Interesting photo !!
Thanks for sharing it.

I really think you should try that Nikon in a stripped-down ‘HotRod’ microscope.
… When it comes to performance “Less is More” :D

MichaelG.
by MichaelG.
Sat Jul 17, 2021 6:58 am
Forum: Microscopes and optics
Topic: Simple method to test objective using laser pointer
Replies: 5
Views: 165

Re: Simple method to test objective using laser pointer

The principle works very well [maybe too well ?]
… the only problem I have found is that every lens looks dirty !

Setting a threshold of ‘acceptability’ seems to be the tricky bit.

MichaelG.
by MichaelG.
Fri Jul 16, 2021 10:49 pm
Forum: Illumination Techniques
Topic: Converting Brightfield Microscope To DIC
Replies: 30
Views: 1029

Re: Converting Brightfield Microscope To DIC

You mean that some of those entities in my last image, the moving strings of bacteria, don't really exist? Those amoebas don't exist? No, I mean some of the ‘detail’ within them doesn’t exist. MichaelG. . Edit : __ Please see p8 of the excellent paper by Michael W. Davidson and Mortimer Abramowitz ...
by MichaelG.
Fri Jul 16, 2021 8:57 pm
Forum: Illumination Techniques
Topic: Converting Brightfield Microscope To DIC
Replies: 30
Views: 1029

Re: Converting Brightfield Microscope To DIC

DonSchaeffer wrote:
Fri Jul 16, 2021 7:52 pm
The thing is, you can sometimes see things that will not be seen when the diaphragm is open.
Some of which don’t actually exist … That was my point at post #13

MichaelG.
by MichaelG.
Fri Jul 16, 2021 8:20 pm
Forum: Pictures and Videos
Topic: Better illumination and better result
Replies: 2
Views: 89

Re: Better illumination and better result

Nice clean image … What did you do to improve the illumination?

MichaelG.
by MichaelG.
Fri Jul 16, 2021 12:05 pm
Forum: Illumination Techniques
Topic: DIC Question
Replies: 202
Views: 7332

Re: DIC Question

It seems that it's possible to get 'food grade' polycarbonate without UV additives but couldn't find any sources here in the UK. . These people might be able to advise: https://www.sndsolutions.co.uk/polycarbonate-vs-petg/ It is possible to buy Food Grade Polycarbonate, however this is quite a rare...
by MichaelG.
Thu Jul 15, 2021 7:01 am
Forum: Microscopes and optics
Topic: Strange flare in Nikon CF N plan apo 20/0.75 objective
Replies: 26
Views: 591

Re: Strange flare in Nikon CF N plan apo 20/0.75 objective

Sorry … I obviously still haven’t explained myself properly I was effectively proposing that, exclusively for the purposes of checking whether the microscope body tube is the source of your flare problem , you temporarily replace that tube with something much bigger. The wooden box was the simplest ...
by MichaelG.
Thu Jul 15, 2021 6:28 am
Forum: Illumination Techniques
Topic: DIC Question
Replies: 202
Views: 7332

Re: DIC Question

LouiseScot wrote:
Wed Jul 14, 2021 10:42 pm
I can't seem to find any suppliers of non uv protected polycarbonate sheet here in the UK. Presumably it's all only made for glazing purposes.
.
Also used for machine safety guards, riot shields, and the visors on motorcycle helmets
… but it may all be UV protected : I don’t know.

MichaelG.
by MichaelG.
Wed Jul 14, 2021 5:37 pm
Forum: Microscopes and optics
Topic: Strange flare in Nikon CF N plan apo 20/0.75 objective
Replies: 26
Views: 591

Re: Strange flare in Nikon CF N plan apo 20/0.75 objective

How do you test it using a box? How do you align all the optical components? How about testing it in a darkroom by screwing all the optical components horizontally onto a table like they do in the research labs. The bore would effectively be infinitely large. But I don't have the equipment. That’s ...
by MichaelG.
Wed Jul 14, 2021 1:15 pm
Forum: Microscopes and optics
Topic: Strange flare in Nikon CF N plan apo 20/0.75 objective
Replies: 26
Views: 591

Re: Strange flare in Nikon CF N plan apo 20/0.75 objective

It would be good to see what the objective is really capable of
… I would be tempted to to test it on a much bigger-bore tube
… or maybe even use a box, for a convenient lash-up.

MichaelG.
by MichaelG.
Wed Jul 14, 2021 8:18 am
Forum: Pictures and Videos
Topic: You gotta do this.
Replies: 8
Views: 293

Re: You gotta do this.

This is cheating, because I photographed a prepared slide, but I think it worth sharing:
.
Fern Spores : downsized for forum posting
Fern Spores : downsized for forum posting
8DD262AD-1F17-4E99-B3CF-BAC460E383BD.jpeg (128.14 KiB) Viewed 179 times
.

MichaelG.
by MichaelG.
Tue Jul 13, 2021 8:58 am
Forum: Microscopes and optics
Topic: Submicron imaging : 1998 style
Replies: 4
Views: 152

Re: Submicron imaging : 1998 style

I was particularly intrigued by the mention of improved focussing [human interaction] gained by assigning false colour to a specific grey level. The facility is available on broadcast quality cameras, and also on this little monitor: https://youtu.be/JwrwsjO7Cww but … can anyone recommended a [cheap...