Microscope reviews!

The attached document was extracted from the Practical Guide to Microscopes, a volume in the BETTER MICROSCOPY Series. It is essentially the 2010 text with only a few minor updates.

It represents the opinions of the author, based on several decades of experience in microscopy and, in most cases, considerable hands-on experience with the models discussed.

Clearly, it is not the last word on much of the material covered and does not cover all of the possible models. Coverage is limited to those models most likely to be useful today and not of "collectible" status -- roughly covering the period of the 1950's through the early 1990's. (Thus, modern Infinity models are not covered, except for American Optical (AO) and its descendants.)  

Nevertheless, for those more interested in "using" (versus merely "collecting") microscopes, the text in its present form should provide some useful guidance, and perhaps some interesting background as well.

An updated version if this work is in progress and is planned to expand the coverage to include a number of additional microscope models, as well as changes in branding and corporate names, etc.

This .pdf file is less than 1MB and only 14 pages, and so should be a 'quick read' for most users:

Microscope Reviews & Comments 

I hope you enjoy this latest release and perhaps learn a thing or two from it! 

Infinity Secrets – Part 1...

In pondering the various issues surrounding the use of Finite optics on Infinity systems it dawned on me that perhaps the most fundamental issue was simply, "Why?..." (More specifically, "Why would anyone ever want to use Finite objectives on an Infinity microscope?")
   
Of course, there was the all-too-obvious answer, Temporary Insanity, but that seemed hardly worth adding to any list. After all, that might just be the sort of thing that might very easily affect anyone with an interest in Microscopy!
   
So, the search for valid reasons continued -- and that led to the development of this:
   

The Short List of Reasons for Finite > Infinity Transitions

   
Adventure -- You want to investigate a new Infinity application area but lack Infinity lenses. 
Curiosity -- Having heard that its possible, you now want to try it out and see for yourself.
Necessity -- You find they don't make the Infinity lens you need, so it's Finite or nothing!
Desperation -- You dropped your favorite Infinity lens and need to replace it, quickly.
Economy -- You own Finite lenses and now want to re-use them on your new Infinity scope.
Stupidity -- You buy an Infinity scope without lenses and now find can't afford the real things.
Caution -- You want an Infinity scope and need to know if your Finite lenses will work on it.
Lack of Knowledge -- You heard that it was 'impossible' - but want to attempt it anyway.
Blog reading -- You read Blogs like this one and are now just dying to try this out.

Still, all kidding aside, users can have all sorts of reasons for wanting to us Finite lenses on an Infinity scope, but, for the most part, these users all have two things in common:
   
(1)  They usually have Finite lenses already, often from their current (or, "old") Finite scope, and,
(2)  They either already have access to an Infinity scope or expect to have access to one, soon.
   
And, there is yet a third possible, related reason:
    
(3)  With a large investment already in Finite lenses, some users may want guidance in choosing an Infinity scope system which will allow maximum re-use of their existing Finite lens inventory.
   
Consequently, with all this as background, it seemed perfectly logical that what was needed here was a document which could give some truly practical guidance in these various areas.

This document is in two parts, with a third one planned.
   
The .pdf file for Part 1 (for reading on-line and/or download) is here:
 

Infinity Secrets – Part 1...  

 
I hope you enjoy this release and benefit from it in many ways…

Finite & Infinity -- Updated Release

This update completes the preliminary version of this document with additional text plus graphic adjustments to the tables for added clarity. This should be adequate for any initial efforts in using Finite objectives on Infinity systems:

  Finite & Infinity -- Updated release

Now, rather than continue with incremental additions to this file it has been decided to cover further work on this subject via an entirely new file. The current document will remain as a General Introduction to the subject matter while the new document should provide further Technical Information and specific examples.

You may expect the first release of this new document in a few days, inasmuch as a good portion of it has already been written. The gating items now are basic Graphics to support the text.

It is hoped that this incremental approach will result in distributing useful information in a more timely manner than the conventional approach of waiting for everything to be completed and then releasing a hard copy publication. In other words, the choice is between having it now, or perhaps in mid-2017! 

In any case, Thank You for your interest... 

Finite-to-Infinity!

This is the long-awaited release of the Finite-to-Infinity discussion and data. If you ever plan on using Finite objectives on an Infinity scope, or have ever wondered if it can be done, this document is a Must Read!

While still in preliminary form, it was judged sufficiently complete for release at this time. Additional information and specific examples should be forthcoming over the next few weeks.

It's only four text pages (plus two charts) so it should be a fast download and an easy read!

I hope you find it useful -- here it is:

[ File removed -- see Updated Release, Sept, 21, above. ]

Now, many users seem confused or even mystified by this subject although, in reality, it is rather simple.

It has been known and recognized for decades that the objective-to-eyepiece distance on a regular ('finite') microscope should be maintained within rather strict limits. For an ordinary 40x/0.65 objective, for example, the tolerance is less than 10mm. Given this fact, why would anyone suppose that you could stretch this distance by mare than 100 times that and yet not suffer some consequences in the image quality?

The attached document discusses this matter, explains these consequences, and offers options in terms of how to deal with, or even avoid them.

The final page of the document lists various Infinity systems prevalent today, along with their primary optical characteristics. The next step will be to add discussions of how to best use this data in choosing both finite objectives for Infinity use and Infinity objectives to switch between Infinity systems.

Future releases will cover specific examples and examine application considerations in some detail.

 * * * *

And now... Darkfield and more!

This latest release is more in line with the scope and purpose of this blog than the earlier "test" releases.

Those were limited in size and scope and were primarily introductory material. With this release we move forward into more substantive discussions; more technical and more detailed:

Optical Contrast Methods.

The contents of this release were taken from Volume II of the BETTER MICROSCOPY Combined Edition, the best-selling book of the Series. It covers Darkfield Microscopy, Phase Contrast Microscopy,  and Other Contrast Methods (Oblique, Rheinberg Color Contrast and Pseudo-phase).

The full-color rear cover photo set has been retained, illustrating the methods covered in the text. Photo details are listed in "Appendix I," the next-to-last page of the release.

Although this release runs to 30 pages (a bit much for online viewing!) the file size has been kept to under 2Mb, for easy download, and the page size has been adjusted to the US standard 8.5 x 11 in, for easy printing.

 I hope you enjoy this first "real" document release, and perhaps even learn "a thing or two" from it...

More Progress -- Full-color!

One of the limitations of the publishing process is the need to restrict images to b/w (black/white). This was due to both simple economic factors and the desire for reasonable image color accuracy.

Some time ago there had been noises made about creating the capability to insert color pages into an otherwise all-b/w book -- but that never happened. So, if you want to place even one color image inside such a book, the entire book must be printed via a "full-color process", which more than triples the cost!

Also, there is the related matter of just how accurate and consistent the image colors will be, inasmuch as the books are individually printed, and not necessarily always by the same printer.

So, because of these concerns, and complaints voiced by other authors about such problems, it was decided to keep all the books in the Better Microscopy Series as black/white only.

However, with the advent of what now amounts to Internet publishing, by simply distributing files over the Web, it really makes little difference whether the images contained in the file are full-color or not.

Because of this an effort was begun to acquire the software tools necessary to replace individual b/w images in a .pdf file with their original full-color versions. This has now been accomplished.

As a test, this .pdf file now contains such a full-color replacement image:

Using Polarized Light.

Clicking on the link should open the file in a new window. If your browser lacks a ".pdf viewing" capability, you will have to download the file for viewing, or add the capability. If you are still using Windows, "PdfXchangeViewer" works quite well, loads quickly, and is Free. Just use Google Search to locate their website and the download link. I never use Adobe now that I have this!  

If you're using Chrome, there is a rather decent "PDF Viewer" app which also works quite well. (If you're using anything else, you may need Google Search to find something you can use...)

And, as a last resort, there's always Adobe's "Acrobat Reader"!

Progress -- 1st Download?

The link below should take you to a viewable/downloadable .pdf file.

The file content is a simple extract from one of the Basic Microscopy books and is included here largely as a "test case." If this linking proves reliable, then more, and better, examples should follow soon.

 Don't get nervous over the "Creative Commons" stuff -- basically, that just says the file is yours to do with as you wish, just as long as you don't try to sell the content, or change it and then re-distribute it. However, as long as you don't alter the file content, then you are free to give it (pass it along...) to anyone you wish. Also, you are free to copy the file to a CD or other memory device, or to print it, and use the result yourself or pass that along, as long as the actual content of the file is not changed. 

That said, here's the link to the first document:

Basic Optical Contrast Methods.

This .pdf test file contains three introductory-level excerpts from one of the Better Microscopy books which discuss: Oblique Illumination, Basic Darkfield, and Low-power Darkfield. (Files covering these topics at a more advanced level are in preparation and should be released soon.)

Note that the page margins have been adjusted to permit direct printing on US standard 8.5 x 11in. paper.
(If necessary, similar files can be prepared for Euro-standard A4-size paper.)

Note also that the pages in the file retain the page numbering of the original (source) document, and there are only 7 pages in this file. So, when you see the high page numbers, don't think you ate missing a lot of pages -- they simply aren't in that file! This practice will be followed in future files so that separate releases may be aggregated later and easily arranged into the same page sequence as in the original book. 

This link will be tested for a couple of days on various systems and browsers to verify that it works reliably, and then additional, more detailed, documents will be introduced, as time permits.