Introduction . . .

This is a brand new blog, by a brand new blogger. However, some readers may recognize this blog's title, taken from a series of books of the same name. Unfortunately, time has a way of gradually making printed material all too quickly outdated -- especially these days -- and so, this blog was created partly as an attempt to address that issue.

As we move forward from here on-going efforts will be made to transfer selected content from the Better Microscopy books series into this new format, not only to provide to provide more effective distribution, but also as a means for making timely additions and overdue updates to that material. In addition, much previously unpublished material is now planned to be released, including high-resolution color images.

The current plan is to aim for a content mix that is both interesting and educational -- perhaps even inspiring -- and which will address the needs and interests of a wide range of user levels, from beginner to semi-professional. With more decades of Microscopy experience than I care to admit, I hope I will be able to contribute something to others in terms of both knowledge and enjoyment.

I hope you find something of interest in new undertaking as it takes shape and gain much from its content, now and well into the future!

Just beware of the occasional attempts at humor...

Note -- The new e-mail for issues concerning this Blog is:

Thanks for visiting!

Saturday, October 14, 2017

UPDATE on Site Issues — F.Y.I.

Due to growing support issues, plans for major revisions to this site have temporarily  been placed on hold. Also, at least for the near term, new posts and updates may now occur slightly less frequently.

Still, the current goal is for at least one update and one significant new post per month, but as often as can be reasonably managed under these new circumstances. 

Note that this does not affect the Compendium Edition, which is planned to remain available at the current, discounted "Blog" price for at least a few more weeks. (See Jan. 20, 2017 post.)


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Saturday, September 30, 2017

'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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Sunday, September 24, 2017

'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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Tuesday, September 12, 2017

A Summer Surprise, or just one more Oddball lens?

As I struggle recover from the Summer hiatus, I offer the following as an initial return effort... 

One never knows what may bubble to the surface on a certain Internet auction site (its name rhymes with "flea-bay").  And, for those readers who believe this Blog is becoming a haven for mere 'Optical Kitsch', you will probably not be disappointed with this latest item…   

Seriously, this latest "Flea-bay find" is a quite decent example of the very rare and most unusual Carl Zeiss Jena (Germany) "Plankton-Sucher" objectiv, (or, in English, "Plankton-Searcher" objective). Based on the markings, plating and finish, the date of manufacture for this example is estimated at around 1930.

This lens was originally designed in the late-1890's(!) and persisted, basically unchanged, for four decades. It is listed as having a Focal Length of 33mm, a Working Distance of 36mm, and is designed for use with a 160mm Tube Length, giving it a Magnification of just about 6x on a standard microscope. With just minor changes, this was a standard Zeiss Jena catalog item up until at least 1937, although now it seems quite rare.

The lens was intended for use with deep-dish sample containers having a water depth of 40mm, or so. With these  only the tip of lens would be submerged and yet the lens could focus clearly to the bottom of the container. The relatively-low NA seems to have been purposely chosen to maximize depth-of-focus, without too seriously impairing image sharpness. (For comparision, the standard Zeiss Jena 6x of the same vintage was NA 0.17 and had a Working Distance of just 9mm – but in air, not water, of course.)

It may be assumed that such a lens was useful for examining and even isolating individual organisms from a large sample container, either for culturing or for detailed examination later under higher magnification, or both. Such use would seem to rationalize the lens' rather extreme Working Distance (relative to its Magnification).   

The current plan is to evaluate this lens by comparing its performance with more modern, and more commonly available alternatives – beginning with the common LOMO 6x/0.17 (a modern copy of the original Zeiss Jena design).

The results of these evaluations should appear in one or more future posts…

Now, on a separate, somewhat related (but lighter) topic, the image below depicts the home of the new "International Museum of Optical Kitsch" (a.k.a: 'IM OK'), located just outside New York City. [LOL]

Past and future material for this Blog is currently being housed there.


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Saturday, September 9, 2017

WOW — an AO Polanret, complete (For Sale on eBay)!

For those few of you who might have some interest in the very rare AO Polanret variable phase contrast unit, a complete setup (minus the microscope, of course) has just appeared for sale on eBay.

The unit appears complete, with even the proper Condenser (and top!), and seems in rather nice condition.

It is offered as a "But-it-Now/obo" (fixed price, or best offer), however, considering its cosmetic condition, completeness and rarity, it is not really possible to gauge the current market value – so your guess is probably as good as mine.. 

I have not seen this unit and have no connection with either this equipment or the Seller — this posting should simply be considered as a bit of current news.

If you'd like to take a look, the eBay Item number is: 272824055329, or you can try searching eBay's Healthcare/Lab section for "Polanret". (As eBay continues to mess with its internal software you may or may not find this, or any other specific item, on the first try – so just try again later...)

Have Fun!

[Note: Postings for the AO Polanret system may be found in the Blog Archive here (at right) under January and February 2017.]  

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Tuesday, June 27, 2017

Summer Hiatus...

Due to increased obligations in other areas, it will not be possible to update this site until sometime after Labor Day, Sept. 4, 2017

For now, you may expect normal updates to resume by mid-September... 

Also – note that the contact e-mail listed above will not be monitored during this period.

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Friday, June 9, 2017

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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Tuesday, May 9, 2017

3D Image Enhancement made EASY – Part III.

Comparing Simple Contrast Methods – cont'd.

Part I (April 25th.) of this series introduced a new method of image enhancement (simple '3D') and gave examples of its use.

Part II (May 3rd.) offered further examples of results using this method, particularly as compared to Brightfield and COL.

Part III continues this effort with examples at higher magnification and higher resolution.

Now, in casual microscopy, considerable time is often spent using the 40x ("high dry") objective. This lens offers the combined advantages of reasonably high magnification and resolution, decent working distance, and ease-of use. Also, almost every standard microscope has one. Further, more than 90% of what maybe seen (at high magnification) with Transmitted Light Microscopy may be seen using this type of lens. So, it seems only proper that we should determine just how well the 3D Mask method works with this lens…

In the first set, below, we compare results obtained using Brightfield with those using the Radial 3D mask method. This  set shows the same diatom photographed using each of these methods, with the results adjusted to approximate the actual visual appearance of the object. (If anything, these images understate the advantages of the 3D method, in part due to loss of image quality due to the use of the JPEG image format during image processing.)

Click anywhere on the above image for larger versions. 

Note that the measured width of diatom used in these photo is approximately 21 microns, which results in a calculated 'dot spacing' of about 1.0 microns. As this is reasonably within the resolution capability of the NA 0.70 objective, the performance of the objective itself should not be a limiting factor in these tests.

Not apparent in the photo set is the slight loss in overall image brightness associated with the 3D mask. However, this loss is a small penalty to pay for increased image contrast and resolution.

Radial 3D versus 'COL' – more surprises? 

In the second set, below, we compare the Radial 3D mask method with COL, a currently popular alternative method of contrast enhancement. Once again, the relative levels of image brightness are not preserved in these images, but here, COL typically suffers a much greater loss of overall brightness (typ. 3 to 4 times greater) than does the 3D mask method.

Click anywhere on the above image for larger versions. 

Here the 3D method appears to be at a disadvantage, at least initially, but only because the Condenser Iris was fully open (e.g: 100%).

However, as shown in the third photo set (below), this limitation is easily overcome by simply reducing the Iris opening.  This results in a sort of "variable contrast" mode, where the overall image contrast is readily controllable by means of the Condenser Iris. For Iris openings down to about 60%, there is very little loss in resolution, while even smaller openings (down to about 40-50%) may be used to achieve further increases in image contrast.

Click anywhere on the above image set for larger versions. 

Note that the COL method has no equivalent mode!

With COL results are fixed, as determined by the annulus diameter and opening width. To adjust contrast with COL either the entire Iris must be exchanged or a variable condenser, such as the scarce (and costly) Leitz 'Heine' Condenser, must be used. (Note that the Heine condenser will typically fit only a few older microscopes, whereas the Radial 3D mask method may be used on nearly any microscope equipped with a standard Condenser!)

Finally, remember that, with COL, usually the entire condenser annulus (or the Heine condenser setup) must be changed with every change of objective, while, with the Radial 3D mask method, only a simple Iris "tweak" is all that is typically be needed, if at all.

Next, in Part IV of this series, we will explore some of the unique possibilities for even greater image enhancement using the Radial 3D mask method…

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Wednesday, May 3, 2017

3D Image Enhancement made EASY – Part II.

Comparing Simple Contrast Methods

A recent post (April 25, below) has revealed a very simple method of optical contrast enhancement, "Radial 3D Effect", which also adds a measure of 3D-like effect to an overall contrast improvement.. The method is very easy to implement and to use, functioning with a wide range of common objectives and yet requiring no special adjustments with objective changes.

Yet, in spite of these these and other operational advantages (described below), the basic question remains, "Just how well does this new method work?"

In this post we begin to address that question, starting with a direct comparison of images from this new method with those from two common alternative methods: (a) Simple Brightfield, and (b) Circular Oblique Lighting (or, COL). (These other methods also share the traits of simplicity, ease-of-use, and of not requiring any special objectives.)

So, how do these methods actually compare? 

To see, we can begin by examining the image set below… 

Click anywhere on the above image set for larger versions. 

The top image is in Brightfield mode, with illumination by the Kohler Method, with the Condenser Iris set to about 100% of the full objective aperture. This is to serve as the "Reference" image. It reveals a reasonable amount of detail but one could hope for greater contrast. Also, the image appears "flat," revealing little of the object surface texture.

The middle image is basically identical, but with the addition of the Radial "3D" Effect mask discussed earlier. Note that this image shows not only increased object contrast and detail, but also reveals object surface contours, especially evident in the specimen on the left.

The final image was made by replacing the "3D" mask with a standard Condenser phase ring (annulus) to produce COL contrast. Note that here there is also increased contrast (relative to Brightfield), but the "3D" effect seen in the middle image is absent.  However, much unlike the Radial 3D Mask method, image results with COL can be quite dependent upon the exact choice of annulus, as well as 'annulus-specimen' matching. Thus, with COL, each objective potentially requires using a different annulus. (The 'Radial 3D Mask' technique has no such sensitivities.)

One important factor, not shown by the above images, is the difference in overall image brightness which occurs with each of these methods.

Brightfield, of course, offers the highest image brightness level, with the Radial '3D' Mask method running second with somewhat less than half that level (depending on the exact diffusion material used). The COL method, however, is far behind this with overall brightness at 15% or lower, depending upon the size and width of the Condenser annulus selected. (Note that some specially-made COL rings may support slightly higher overall image brightness levels.)

Condenser iris Effects

Both Brightfield and Radial 3D methods also support a basic level of user control over "depth-of-focus" in the specimen plane, simply by adjusting the Condenser Iris opening. Reducing the opening, even by a small amount (e.g: from 100% to 80%) can result in a significant increase in not only depth-of-focus, but also in overall image contrast. These effects are depicted in the image set  below:

Click anywhere on the above image set for larger versions. 

As expected, reducing the Condenser Iris opening in either Brightfield or 3D mode provides a slight increase in image contrast, but in the 3D mode this more significantly enhances the apparent depth-of-focus for the specimen. In general, Iris openings from 100 percent open, down to 50 or 60 percent open, can prove useful. At less than about 50% open, image resolution can begin to suffer noticeably.  

Unfortunately, the COL method (described above) does not directly support such control – with COL the only recourse is to switch to using a smaller diameter annulus, which often can have unpredictable and undesirable effects on the overall appearance of the specimen. 

Be aware that the image set presented above is not intended as definitive basis for comparing these methods, but merely as a basic indication of the results produced by each method. More precise imaging techniques for these three methods, as well as for some additional methods, will be needed to permit extending this evaluation to a more definitive level

Note that the above images are limited by minor variations in focus between modes, as well as a slight residual camera motion which may obscure finer detail. Both these issues will be addressed in the test setup before any additional comparison photos are produced.

This comparison will continue is a subsequent post, or two…

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Tuesday, April 25, 2017

3D Image Enhancement made EASY – Part I [Updated April 27]

Click on image above for larger version.

Recent posts covering the Goerz '3D' Condenser have sparked interest in creating an alternative approach suitable for use with ordinary (Abbe-type) condensers.

The goals of this new effort were: (1) Low cost and Ease of construction, (2) Improvement in image contrast and apparent object depth, and (3) Ease of construction and use..

It is important to remember that the goals here are not maximum image contrast nor maximum resolution, but rather to simply achieve meaningful improvements in both (relative to normal Brightfield imaging) by use of the simplest and most generally applicable method possible. 

The method presented here appears to satisfy these goals and results in a simple addition which may be easily applied to an ordinary microscope condenser and, unlike other methods, (e.g: oblique illumination or phase contrast) may be used without any additional/special optics or concern for adjustments during use.

Also, since the light loss is minimal, the device is suitable for use on instruments having limited illumination and/or at higher magnifications than these common alternatives.

The device is constructed as a simple disk having an array of three diffusion segments, which modify the illumination in a predetermined manner and is essentially the same for all objectives, from 10x to 40x, or more. The "radial" approach both eliminates the need for adjustments when changing objectives and also allows the Condenser Iris to remain fully usable as an additional means of image control.

The construction of this Condenser "Radial Diffusion mask" is depicted in the following diagrams:

Note: Click on any above image for a larger view. 

Installation of the mask, its preferred use and example specimen photos will be presented ASAP… 

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Basic Construction Notes:  

Most of the construction details for this mask are non-critical. If the tape intersection point is reasonably close to the optical center of the Condenser when installed, then the device should function as intended. The precise angles are also not critical – anything approaching 90-degrees should work just fine. 

The specific type of "matte tape" to be used is also not critical. Ordinary, generic "dollar store" types seem to work about as well as anything else. As long as the tape width is about 3/4" then disks up to about 37.5mm diameter would seem feasible. Scotch (brand) Matte finish tape, however, apears to be superior to their "Satin finish" variety, which seems to exhibit less desirable diffusion characteristics, at least for this use. 

The acetate disk material is also non-critical. The basic requirements are that it be basically clear, self-supporting and thin enough to be trimmed with scissors. However, if your Condenser accepts a clear Daylight filter, then this might  serve as an alternative substrate. 

The positioning of the Opaque segment was chosen so as to not create uneven illumination with objectives of less than about 40x. However, it may be positioned closer to the disk center if contrast enhancement is desired for objectives in the 16x to 25x range also. In this case, about a third, instead of halfway, from the center to the disk edge may be tried. However, if detailed examinations with 40x and greater objectives are not the primary use, then the Opaque segment may simply be omitted with minimal loss in overall performance. (It can always be added later, if desired.) 

The Opaque segment may be created with a single strip of black PVC tape (plastic electrical tape), located on the reverse side of the disk, so it does not interfere with the matte segments. This allows the opaque segment to be re-positioned, if desired, without interfering with the other segments. 

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An External Mask

One common problem with many modern microscopes is that they often use Condensers which lack any sort of proper filter holder. Naturally, this sort of shortcoming might seem to be an issue when attempting to implement even something as simple as a Radial '3D' Mask… 

Fortunately, the design of this Mask is remarkably forgiving when to comes to placement in the Condenser, even to the extent that it can be perfectly acceptable to place the mask outside the Condenser! This can be especially true for use with objectives of >10x, where the loss in Mask performance is basically trivial. (For objectives of ~10x, the loss is most typically limited to a slightly uneven background light level.) 

For Condensers which have a significant bottom flange (e.g: most base-mount types), external mounting of the mask should be possible, as long as the width of the flange's bottom surface is sufficient to allow retention of the tape strips. 

The tape strips are simply applied across the width of the flange, such that the "inside corner" formed where the strips overlap is located approximately in the center of the objective aperture, as viewed from the eyepiece position. (For the most accurate alignment, with the least difficulty, use of the 10x objective is suggested for this process.)  The two diagrams below depict both proper tape placement and proper overall mask alignment (centering).  

(Note: Click on either image above for a larger view.)

Be aware that the tape placement should be performed only after the Condenser has been properly centered in its mount, as for Brightfield use. Once the Condenser itself is centered, any centering mechanism present should not be used to correct any misalignment of the tape strips. If the overall positioning is unacceptable, then the strips should simply be removed and re-positioned properly. Just remember that exact alignment is not essential for successful use!  

The photo below shows typical results when using the External '3D' Mask method:
(Image cropped and downsized from 16Mpix JPEG original. No sharpening used.) 

(Note: Click on above image for a larger view.

Additional photos using the Radial '3D Mask' will appear in the next post – so, stay tuned…

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