Search found 2741 matches

by MichaelG.
Thu May 13, 2021 7:58 am
Forum: Microscopes and optics
Topic: Difference between reduction lenses
Replies: 4
Views: 76

Re: Difference between reduction lenses

Thanks for posting the very informative comparison [your second pair], Bram

MichaelG.
by MichaelG.
Wed May 12, 2021 2:32 pm
Forum: Introduce yourself
Topic: Longtime lurker New User
Replies: 7
Views: 142

Re: Longtime lurker New User

A beautiful microscope, Dan ... and obviously in very capable hands !

I am green with envy [approximately the colour of your specimen]

MichaelG.
by MichaelG.
Sat May 08, 2021 8:58 am
Forum: Microscopes and optics
Topic: Spring loaded objective
Replies: 20
Views: 300

Re: Spring loaded objective

It’s scrap ... feel free to post it to me for disposal :lol: :lol: MichaelG. . But seriously ... Sorry, no experience of dismantling Please tread carefully ... we love your images !! . Edit : __ I expect that the engraved shroud will simply unscrew, exposing the spring and presumably some congealed ...
by MichaelG.
Sat May 08, 2021 7:03 am
Forum: Beginner's corner
Topic: this is amazing!
Replies: 6
Views: 273

Re: this is amazing!

You’re hooked, hebele
.. or perhaps that should be Hooke-ed

Welcome to the wonder of microscopy !

MichaelG.
.

Edit: https://www.gutenberg.org/files/15491/1 ... 5491-h.htm
The illustrations are hyperlinked in the right margin
by MichaelG.
Thu May 06, 2021 8:57 am
Forum: Illumination Techniques
Topic: This e-bay item looks familiar for some reason
Replies: 3
Views: 181

Re: This e-bay item looks familiar for some reason

https://www.microbehunter.com/microscop ... ilit=flash

Presumably it is Saul’s ebay listing
... unless someone has done a very good knock-off

MichaelG.
by MichaelG.
Thu May 06, 2021 7:46 am
Forum: Home-made microscope adaptations
Topic: Making a negative meniscus lense ?
Replies: 15
Views: 612

Re: Making a negative meniscus lense ?

Thanks for the response, Matador No, I regret that I do not have an Axioskop myself ... so this is just an interesting academic exercise for me. Frankly; it is outrageous to even try scaling a lens from a mere sketch in a patent; but I would love to see how close we can get. ... Given that this is j...
by MichaelG.
Wed May 05, 2021 6:26 pm
Forum: Camera systems and imaging
Topic: C-Mount Question
Replies: 2
Views: 136

Re: C-Mount Question

by MichaelG.
Wed May 05, 2021 9:00 am
Forum: Home-made microscope adaptations
Topic: Making a negative meniscus lense ?
Replies: 15
Views: 612

Re: Making a negative meniscus lense ?

Just bumping this, because it’s already fallen off page_1

I was hoping to prompt some wider discussion
... Does anyone actually have an example of the lens, that they could check ?

MichaelG.
by MichaelG.
Wed May 05, 2021 7:22 am
Forum: Beginner's corner
Topic: What is this part?
Replies: 4
Views: 236

Re: What is this part?

Although you probably will not need it that extra piece is some kind of camera mount adaptor which they didn't bother to define for any us. . It looks like a C-mount adapter ... which is not required because the camera is already configured to fit into the eyepiece tubes. If so, the top screw-threa...
by MichaelG.
Mon May 03, 2021 8:24 am
Forum: Pictures and Videos
Topic: Another Suctoria
Replies: 7
Views: 231

Re: Another Suctoria

A wonderful glimpse into the world of the very small.
... I was amazed that the main body stayed so still for you !

MichaelG.
by MichaelG.
Sat May 01, 2021 5:40 pm
Forum: Pictures and Videos
Topic: water lens under UV...
Replies: 6
Views: 223

Re: water lens under UV...

Fascinating image, Chris
Thanks for sharing it.

MichaelG.
by MichaelG.
Sat May 01, 2021 3:11 pm
Forum: Home-made microscope adaptations
Topic: Making a negative meniscus lense ?
Replies: 15
Views: 612

Re: Making a negative meniscus lense ?

Based on that ^^^ ... here’s a model : . E02584D4-EAF9-4191-8D10-4D85A65A2A46.jpeg . So ... allowing for many approximations, and the likelihood that Zeiss would use a higher Refractive Index glass : I think we have a nominally 20 Diopter negative lens [which could probably be produced by your local...
by MichaelG.
Sat May 01, 2021 2:47 pm
Forum: Home-made microscope adaptations
Topic: Making a negative meniscus lense ?
Replies: 15
Views: 612

Re: Making a negative meniscus lense ?

UPDATE

Assuming the glass diameter to be 24mm ... here’s my best effort at dimensioned sketch of the lens element :
.
adapted from the drawing in US patent 4,807,980
adapted from the drawing in US patent 4,807,980
59269735-1BDA-4798-967E-246F9D9B8126.jpeg (84.88 KiB) Viewed 374 times
[ if anyone knows the actual diameter, I can re-scale it ]

MichaelG.
by MichaelG.
Sat May 01, 2021 8:02 am
Forum: For forum members who want to buy and sell equipment
Topic: Need Ziess 1.25x Auxiliary lens (part number 44 52 65)
Replies: 17
Views: 791

Re: Need Ziess 1.25x Auxiliary lens (part number 44 52 65)

75RR wrote:
Sat May 01, 2021 7:19 am
Matador wrote:
Fri Apr 30, 2021 1:15 am
(too wide for the 24mm slot in the phase condenser turret):
Are you sure it fits 'in' the turret rather than as most auxiliary lens do, in a filter holder slung under the condenser?
Both the highlighted text, and the patent drawing, seem pretty explicit

MichaelG.
by MichaelG.
Sat May 01, 2021 6:04 am
Forum: Specimens, samples and slides
Topic: Substitute for Reticule
Replies: 4
Views: 218

Re: Substitute for Reticule

It’s O.K. to use a formula; if you are sure that the numbers you plug-in are valid.

The truth is that the lens markings are ‘nominal’ ... so it’s wise to calibrate what you are using.

MichaelG.
by MichaelG.
Fri Apr 30, 2021 9:05 pm
Forum: Specimens, samples and slides
Topic: Substitute for Reticule
Replies: 4
Views: 218

Re: Substitute for Reticule

It would be wise to check those dimensions physically
The first two are dead easy if you have scales on your mechanical stage
...The two higher magnifications will be trickier but you could, for example, look at the structure of a known webcam sensor or some such.

MichaelG.
by MichaelG.
Thu Apr 29, 2021 5:16 pm
Forum: Beginner's corner
Topic: Using a pair of cameras with a stereo microscope
Replies: 37
Views: 1936

Re: Using a pair of cameras with a stereo microscope

The optical arrangement looks plenty good enough for stereoscopic video ... I just need two suitable cameras. The Raspberry pi compute module supports two camera inputs […] Thanks for that ... Yes I did wonder about that module, and as the 12mm Computar works well with the Toupcam’s 1/2.5” sensor [...
by MichaelG.
Thu Apr 29, 2021 8:22 am
Forum: Microscopes and optics
Topic: Why are numerical aperture and color correction related?
Replies: 8
Views: 315

Re: Why are numerical aperture and color correction related?

That sounds like the two properties can by changed independently, but they aren't because of the generality of the expected use cases. Therefore, it would be possible to have a very high NA objective with no color correction that might be useful for specialized uses where monochromatic light is use...
by MichaelG.
Thu Apr 29, 2021 6:08 am
Forum: Beginner's corner
Topic: Using a pair of cameras with a stereo microscope
Replies: 37
Views: 1936

Re: Using a pair of cameras with a stereo microscope

MichealG -dagnamit son of a monkey spank! If it wasn’t for that extra 0 on the price...It’s good though to know ones financial limits on a experimental project unless someone else has done the hard work first to make it a working system and shares how they do it-do you have a plan B? Or dropping th...
by MichaelG.
Tue Apr 27, 2021 7:36 pm
Forum: Beginner's corner
Topic: Using a pair of cameras with a stereo microscope
Replies: 37
Views: 1936

Re: Using a pair of cameras with a stereo microscope

UPDATE: I have received a formal quote from Shodensha in Japan, and unfortunately my idea of buying a pair of UVC cameras from them is not really practical for a rather whimsical project. DN3UVC-130 cameras are 660USD each, plus a very reasonable 40USD for delivery to my UK address. 1,360USD, plus i...
by MichaelG.
Tue Apr 27, 2021 8:18 am
Forum: Home-made microscope adaptations
Topic: Making a negative meniscus lense ?
Replies: 15
Views: 612

Re: Making a negative meniscus lense ?

.

Work in progress :
.
One small step for Man ...
One small step for Man ...
BEF81C90-799A-442F-A281-A0175748818C.jpeg (84.51 KiB) Viewed 478 times
.

Now we need to scale it ... Then choose a glass

MichaelG.
by MichaelG.
Mon Apr 26, 2021 10:34 pm
Forum: Home-made microscope adaptations
Topic: Making a negative meniscus lense ?
Replies: 15
Views: 612

Re: Making a negative meniscus lense ?

Here’s a direct quote from column 3 of the patent text: For illuminating still larger objective fields, that is for the work with objectives having an imaging magnification of 1.25X, the auxiliary lens 10 is additionally switched into the beam path beneath the composite lens 7 in the immediate vicin...
by MichaelG.
Mon Apr 26, 2021 9:02 pm
Forum: Home-made microscope adaptations
Topic: Making a negative meniscus lense ?
Replies: 15
Views: 612

Re: Making a negative meniscus lense ?

Reading the patent : Yes , I am pretty confident that it is a simple meniscus lens design ... BUT No , I cannot find any reference to the glass or the curvatures Just for the sport of it ... If you can give me a useful dimension for any item clearly visible on the patent drawing: I will try to ‘reve...
by MichaelG.
Mon Apr 26, 2021 8:14 pm
Forum: Beginner's corner
Topic: can i improve the quality?
Replies: 4
Views: 295

Re: can i improve the quality?

Greetings ... welcome aboard The main limitation of that camera [ https://amscope.co.uk/products/0-3-mega-pixel-usb-live-video-microscope-imager-digital-camera?variant=32656899801223 ] will be the low resolution of 640x480 pixels. It is possible to produce useful images at that resolution ... but we...
by MichaelG.
Mon Apr 26, 2021 6:37 pm
Forum: Digital processing
Topic: Automatic whole cell organelle segmentation ...
Replies: 0
Views: 267

Automatic whole cell organelle segmentation ...

Today, I attended a webinar hosted by the RMS : Imaging ONEWORLD - 'Automatic whole cell organelle segmentation in volumetric electron microscopy' 26 April, 2021 ... My mind was truly boggled This is the stuff of dreams, but they are doing it for real. The session is already available on the RMS You...
by MichaelG.
Mon Apr 26, 2021 6:30 am
Forum: Home-made microscope adaptations
Topic: Making a negative meniscus lense ?
Replies: 15
Views: 612

Re: Making a negative meniscus lense ?

I'm looking for an "Adapter lens" (zeiss part 44 52 65) that is supposed to be mounted in the rotating turret of my phase/DIC condenser for my Zeiss Axioskop 50. . The part in question I post about here (with diaphragm and pictures, and the patent info) : https://www.microbehunter.com/microscopy-fo...
by MichaelG.
Wed Apr 21, 2021 8:13 pm
Forum: Microscopes and optics
Topic: 2x objective issue resolved
Replies: 5
Views: 289

Re: 2x objective issue resolved

MicroBob wrote:
Wed Apr 21, 2021 7:21 pm
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 ...
Try page 95 of this, Bob
http://www.science-info.net/docs/zeiss/ ... ystems.pdf

MichaelG.
by MichaelG.
Wed Apr 21, 2021 5:55 pm
Forum: Microscopes and optics
Topic: 2x objective issue resolved
Replies: 5
Views: 289

Re: 2x objective issue resolved

Zeiss sold these as "Brillenglasscondenser" = "Nose bicycle condenser". . Please excuse the intrusion, Bob ... but DeepL gave what appears to me to be a more elegant alternative translation: = Spectacle lens condenser is this reasonable ? MichaelG. . As referenced here: https://books.google.co.uk/b...