Lost Secrets, continued — Ideal Magnification

This post extends the prior discussion into the realm of the User's Vision, showing how a proper choice of Eyepiece Magnification is necessary for optimum visual performance:

Lost Secrets of Microscopy – Ideal Magnification 

I hope you find this bit helpful...

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A New Direction — Lost Secrets of Microscopy!

With this post we shift this Blog into a new dieection – a series examining "lost" historical concepts ("secrets") in the light of modern microscopy needs and practice...

This first posting of this new series covers the "Sharpness Index" — a simple means for comparing the relative performance potential for objectives of differing Magnification and NA.

The method presented is more inclusive of important optical parameters (e.g: both Magnifiction and NA) and is thus potentially more useful than the simpler "Rayleigh criterion," which has become so over-used and mis-applied these days. ("Rayleigh," and more modern alternatives, will be covered in a future post.)

As before, the document itself is presented as a .pdf file, to facilitate downloading, printing and off-line archiving.

I hope you enjoy this information and benefit from it...

Lost Secrets of Microscopy — the Sharpness Index

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Finally — New Book Downloads (Free!)

The popular Better Microscopy Compendium Edition is now available for download as a set of .pdf files.

Previously, this book was an aggregation of four separate volumes, merged to maximize publishing economy for a printed format. However, at well over 300 pages (total) it seemed best to split the complete book into the original separate volumes, for easier downloading and/or online reading. 

Consequenlty, the downloads offered below (.pdf files) have been orgainzed as follows:

    Compendium Edition (Intro.) — F/R covers (art), basic Table of Contents... (6pp.)

    Volume I: Transmitted Light Microscopy — Full text with Combined Index. (104pp.)

    Volume II: Optical Contrast Techniques — Full text, with Index. (44pp.)

    The Practical Guide to Microscopes — Full text with tables. (98pp.)

    Notes on Microscopy — Original Notes collection and graphics. (56pp.)

    (Total of above downloads = 308pp.)  Just click the individual links to the .pdf files!

Note that since the download text retains the formatting for the original book page size (~7.5 x 9.6 in.) you may wish to adjust your printer settings to achieve a printed page output format most appropriate to your needs.

Also, note that while original page numbering has been retained, a few extraneous (blank/'filler') pages have been deleted, resulting in some numbering "gaps" within the separate volumes. If this bothers you, please feel free to restore these blank pages in your printouts. . . (lol)

Thank you!

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Secrets of the Leitz Heine — Part 3.

The saga of Leitz Heine "Secrets..." continues with this latest release – Part 3.

In this Part, we find that the iconic Heine Condenser can actually (and easily!) be fitted to many of the newest generation  (1980's) Leitz scopes. (Often referred to as "Wild-Leitz" scopes, because of the 1980's Wild-Leitz corporate merger.)

Leitz ceased production of their Heine condensers in the 1970's and no new version was ever made for the new scopes. So, if you have (or want) one of these scopes, and wish to mount a Heine on it, the methods in this Part may be your best bet!

Note that this Part continues the shift towards increased use of graphic illustrations, instead of lengthy descriptions.

Secrets of the Leitz Heine — Part 3 (.pdf). 

Parts 1 and 2 of this series were released in an earlier post (October 22, 2018).

I hope you find this latest release useful and informative!

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Secrets of the Leitz Heine Condenser — Part 2

Part 1 covered technical details of the famous Leitz Heine condenser and its use.

Part 2 extends this coverage to show how the Heine can easily be used with many non-Leitz scopes!

The attached .pdf file contains Part 2 plus an updated Part 1 (with minor revisions).

Secrets of the Leitz Heine — Parts 1 &2

I hope you find this material interesting and useful!

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Secrets of the Leitz Heine Condenser — Part 1

Here, finally, is the long-awaited release of current work on the Leitz Heine condenser. This Part discusses the basics of the condenser and its use.

Secrets of the Leitz Heine Condenser — Part 1

As usual, the file is in ".pdf" format and should be easily viewable online, as well as also downloadable and printable, if desired. 

The next release is planned to cover detailed Heine application information and discuss means for adapting the Leitz units to other, more modern scopes! 

I hope you find this useful. . .


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Camera Coupling Methods (from Vol. III)

With this post we continue the incremental release of content from the 2016 edition of Volume III of the Better Microscopy book series.

This release is contains app Notes Nos. 10-13, discussing the most common forms of Optical Coupling Methods for a Camera to a Microscope. (This is a .pdf file of about 700KB, formatted for printing on US Standard Letter (8.5 x 11in) size, 18pp.)  

Vol. III – Camera Coupling Methods, etc.

Depending upon your browser options and settings, you may need to download the file for reading. It should be compatible with most versions of Adobe Acrobat Reader, as well as most alternatives.

 Additional content from the 2016 edition of Vol. III should become available soon . . . 

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'Heine-IPC': COLOR Phase Contrast... [UPDATE]

Note: For the Original post, see Post of Sept. 24, 2017, immediately below...

One of the more significant justifications for developing something like the current "Heine-IPC System" is the potential for producing high-definition phase contrast images (either with or without color enhancement) using objectives for which no "genuine" phase contrast version is available, or which may never have existed... 

One good example of this is the Nikon 60x/0.85 CF Plan Achromat (non-phase only), used for the next two Heine-IPC images, shown immediately below:

Click on either of the above images for larger views.

The sample image below shows a different color adjustment for the IPC unit, as well as a diatom having greater fine detail in its structure... (Note that the focus in this image is on the fine detail, not on the diatom's overall structure. Click on the image for a larger version.)

Click on any of the above images for larger views.

For discussion of the Nikon IPC system itself, see the post of Feb. 25, 2017, in the Blog Archive. 

Development of the 'Heine-IPC System' is, of course, continuing... 


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'Heine-IPC': A New COLOR Phase Contrast System?

One incredibly rare bit of microscope technology is the near-legendary Leitz 'Color Heine' phase contrast condenser, shown below, for reference, in comparison with its "common" (non-color) cousin:

Supposedly, only 300 of these very specialized devices were ever made and only a very few are thought to survive today in working condition. Asking prices for working examples today are in the many thousands of dollars – one measure of their uniqueness, and scarcity. Few in microscopy have ever actually seen one, let alone actually used one, and even documentation is almost non-existant. Puplished photos taken through the unit are also extremely rare.

Yet, one benefit of the Color Heine is the knowledge that it is technically possible to achieve Color Phase Contrast using an otherwise ordinary microscope, resulting an underlying desire to achieve this elusive end – somehow!

Now, the simultaneous availability of both an "ordinary" Leitz Heine phase contrast condenser, as well a working example of the not-quite-so-rare Nikon Interference Phase Contrast (IPC) unit, has resulted in an uncommon opportunity to experiment with the combination of these two disparate devices, in the hope of creating a practical and truly flexible 'Color Phase Contrast' System.

The main limitation of the Nikon unit is the matter of finding a condenser with phase rings which acceptably match the phase plates inside the unit – in practice, something much easier said than done... In this light [sic] it was hoped that the Heine condenser could address this problem, resulting in a wider range of optics which could function usefully with the IPC.

As mentioned in a much earlier post, the Nikon IPC was apparently intended to function solely with the old Nikon S-series (short barrel) Achromat objectives, even though much better Nikon optics were readily available, even back then! This odd design limitation seems to have killed the sales of the unit, at least in the US. Still, anone who has one of these systems no doubt has lusted, at least at some time, for the chance to use it with a good Nikon Apo or other fine objective! Thus, the desire to find some practical way to enable this sort of usage, and the subsequent choice of the Leitz Heine condenser as a possible solution... 

But, as the Heine was designed to fit only Leitz microscopes, and the Nikon IPC unit only Nikon  microscopes, a certain amount of "Frankenscope" engineering is to be expected in "marrying" these two separate pieces in the hope of creating a new, viable (and practical) Color Phase Contrast system.

The initial phases of this development effort are now nearing completion and the results should be posted here in the very near future.

Until then, the image set below shows a limited sample of the sort of initial results that may be obtained from this new, "Heine-IPC System", using just ordinary (e.g: non-phase) optics on an unidentified diatom:

Note: Click on the above for larger images. 

As with any development effort of this sort, improvements in both image color and image quality are expected soon... . 

[ NOTE: For the UPDATE to this Post – see Post of Sept.30, 2017.] 

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3D Image Enhancement made Easy – Part IV.

Combining contrast methods

In prior posts we described a simple method, "Radial-3D Masking," for microscope image enhancement with could produce both contrast enhancement and a perception of "3D" (relief effect).

However, while useful on its own, it is also possible to combine this method with at least one other popular contrast method, namely, "Circular Oblique Lighting", ("COL"). This new method has the potential to not only further improve contrast levels in the COL image, but also to add a 3D effect.

Unfortunately, the results of this combination, in some instances, can become a bit excessive. For this reason we will introduce a more moderate version of the Radial-3d Method, termed here the "Diffuse Half-Mask" ("DHM") method.

This is. basically, little more than half of the Radial-3d Method, using only a single diffusion strip, rather than two. It produces results that are a bit less dramatic than the Radial-3d Method, but which may be better-suited for combining with other optical contrast methods. Details of this method, as well as the original Radial-3d Method are shown below:

Examples of just how simple and effective these "combo" contrast methods can be are depicted in the photo set immediately below.

The image set on the left depicts increasing levels of "3D" effect, beginning with 'Brightfield' (no 3d enhancement), then 'DHM' (moderate 3D enhancement) and, finally, 'Radial-3D' (full 3D enhancement).

The image set on the right depicts the same series, but now in combination with COL.

Click anywhere on the above image for larger versions. 

In general, these methods appear to be most effective when applied to subjects which exhibit fine structural detail. Still, they may also be useful with less demanding specimens, as shown in the next photo set:  

Click anywhere on the above image for larger versions. 

Note that when the image contrast is already high (e.g: Phase Contrast) additional contrast enhancement using these methods is likely to be rather limited, if at all. 

In any case, thoughtful experimentation is highly recommended! 



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