Love My Balplan

[H Jay Margolis]

Here’s WHY:

I am H Jay Margolis, president of Infinity Photo-Optical
www.infinity-USA.com. My LinkedIn gives all particulars.

WHY DO I LOVE MY BALPLAN?
Well, I may be the only one left WHO HAD ANYTHING TO DO WITH IT!

In 1970, at 24, I went to Rochester, NY to overnight at one certain company’s request at the UNIVERSITY CLUB. This was an historic experience out of traditional Americana.
Here, BAUSCH & LOMB put me up in this quaint setting along with others first joining Rochester companies. It was fascinating and I realized I had been lucky enough to get a job at a company that stood for something great.

After signing up and getting a physical I easily passed then but would FLUNK today, I was escorted the sandy third floor and shown my desk and introduced around. One of the guys was Dave Collins and we soon turned out to be the most technically able of the Product Administrators.
I got the DynaZoom line. That was just what I wanted!
Then, I was shown the worst part: each day, a pile of papers would await my approval or not as to whether repairs should go forth for people claiming warranty corrections. My piles were high, but SOMEHOW, they dwindled quickly. Everyone else looked at me like some kind of WUNDERKIND. Some started to resent me.
I had no idea why. I did NOTHING wrong. I offended no one.

ONE DAY, though, I got a call from top—I mean TOP management. Wow, I first thought! Am I doing so well they want to make me an executive already?!?!

HARDLY. It was an irate call from (H)erbert J
(M)Ossian, VP OF THE SCIENTIFIC INSTRUMENT DIVISION
who angrily asked why I was using HIS NAME TO GET MY
WORKLOAD GO THROUGH ahead of everyone else’s.
Well, it all turned right when I told him my name is (actually) (H)arvey (J)ay (M)argolis. We both had a good laugh. If anything, when we’d (rarely) pass in the hall, it was a good thing to see the VP SMILE to see me. But, all of a sudden, my pile started to go up and not everything went through like it had.

Part of my job introduction was being asked a question about my thoughts on the new LEITZ microscope since it was the first to be square rather than round—especially like the Zeiss or even our own DynaZoom. I quickly figured that they were asking me this for a BIG reason. So I said that I thought that was where the look of microscopes was headed. RIGHT ON!...

Then, I was shown LAB 3. LAB 2 was the in-house name for the DynaZoom. So it was clear that this was the prototype for its proposed successor. It was an angled black painted MONSTROSITY. Oh, no...this was a MISTAKE, surely. And thanks to LEITZ, B&L saw the light: this would not come out. BUT THERE WAS A BIG PROBLEM: They had already made the commitment to produce it. What to do?

Soon, one of the fellows I came to respect most,
Harold Rosenberger came up with the idea: LAB IV!
And there it was: put a BOX over LAB III! Make the BOX
support observation tubes and above and have the (former) Lab III support the objective nosepiece down.
So in WHAT BECAME BALPLAN, there’s a LAB III “lurking”
inside. And there never was anything more said about there ever being LAB III.

Well, I’ve got a lot more stories—like the REAL REASON why the Flat Field system was created by James Benford,
Harold Rosenberger, Dick Seidenberg and George Aklin.

Aklin became my mentor. He was a cousin of the composer Alan Hovanness and he and his wife had me (a lone “kid” over to listen to the music and have a dinner now and then. He was a character. But he was also a true optical genius. I am about to name a new product I am developing as “GA” to his memory. There were, as they say, “Giants” at B&L in the early 1970’s. But the seeds of it all coming to an end were evident to me.
——-
More to come. I am THRILLED to be involved with all of you. Also, it pleases me to tell of people who should be remembered. They made a beautiful product and we’ve lost something with the end of B&L. What Soflens did was what had to be, I suppose. But when a machine can take $0.38 of plastic and turn it into (1971) $137/pair contacts
can make more in a day than building precision instruments can do in months.
M

[PeteM]

Welcome. Did you stay long into the Leica years?

[apochronaut]

I'm sure you have some interesting stories. The Balplan has always been an interesting but somewhat confusing microscope for me. It never really reached it's potential. I always figured that it was probably due to the fact that it arrived close to the time things were winding down what by then had become merely one of a parent company's three microscope companies.
Any idea why they only ever catalogued 3 low power flat field apochromats for it? Was it that there was no impetus to develop a condenser that could carry the higher N.A. lenses?

[BramHuntingNematodes]

Amazing! I use a flat field Dynazoom very frequently, outfitted with the B&L plan lenses. My first example had a clouded shared rear objective lens, and it was an incredible time I had taking it apart to try to figure out what was going on, and then to fix it. Some of the fellows and I were looking at old patent drawings, taking apart Balplans, sharing pictures and basically just having a big time. I would love to hear some stories.

Been too long since I gave Mysterious Mountain a spin, thanks for reminding me!

[Charles]

Welcome. It's great to have someone who has worked with B&L. Although I have never been a fan of the Balplan, I have collected a lot of the B&L microscopes from the all brass, brass & black and black era scopes. Here are some of my favorites in the black era. Would you be able to give me some info on the trinocular B&L scope?

B&L Trinocular.jpg (77.97 KiB) Viewed 9783 times

The DDE is probably my most favorite of the B&L research line:

B&L DDE.jpg (102.76 KiB) Viewed 9783 times

[hans]

Looking forward to your insights into microscope development.

This is interesting: https://www.infinity-usa.com/infocus/ Is the effect equivalent to changing tube length?

I have so far resisted temptation to buy one of the surplus Balplans that occasionally show up cheaply on eBay but have enjoyed reading some of the threads about them, for example: viewtopic.php?t=3712

[BramHuntingNematodes]

dang chuck that's some plush gear say does that trinocular have an intrinsic barlow lens looks like a Dynoptic stand

[MichaelG.]

Looking forward to your insights into microscope development.

This is interesting: https://www.infinity-usa.com/infocus/ Is the effect equivalent to changing tube length?

[…]

.

+1 Welcome from me !!

We both like a good patents, Hans ... I think this is the one: US 7,869,139
https://worldwide.espacenet.com/patent/ ... S7869139B2

MichaelG.

[Charles]

dang chuck that's some plush gear say does that trinocular have an intrinsic barlow lens looks like a Dynoptic stand

Here is a comparison photo between the trinocular and Dynoptic. There are differences from the base up and the heads do not swap out. The trinocular head can also be rotated.

B&L Research Right Compair.jpg (89.82 KiB) Viewed 9765 times

[Charles]

There seems to be a few versions of the Dynoptic. There are even ones with the fine focus high on the limb. The version with the blue background does look like the trinocular and probably is the same base?

B&L Comparison.jpg (98.81 KiB) Viewed 9746 times

[BramHuntingNematodes]

They still called them Dynoptic. The Dynazoom without the zoom feature was a Dynoptic too.

[Charles]

Thanks BramHuntingNematodes.

[apochronaut]

The high fine focus Dynoptics were earlier, made in the 40's. Low focus with chrome on brass knobs came later, then low focus with machined aluminum knobs. Although all called Dynoptics, each incarnation had a different model #. The newer aluminum knobbed binocular I'm pretty sure takes the trinocular head but the earlier versions don't.

Hans. The big limiting factor in buying a used Balplan is the problem they got into with optical cement but replacement objectives can be found fairly easily still. The 100X planachro w./iris is a difficult find. There are patterns associated with the optical cement breakdown. Certain eras and the 20X planachromats seem to be badly affected. It may be related to light. It seems that unused objectives may be o.k. or at least I've observed that any I have come across are. I. Miller ( Microscope Central) might know more about that since they have been selling off their existing stock for about 10 years now. I recall that they went through an entire box if 12.5X Flat Field apochromats to find a good one and there was not a single one, although I don't know if they were new. Most likely trade-ins or warranty returns? I.Miller was the largest B & L dealer and when the factory closed, they purchased a considerable amount of the stock, if not all of it.
Bad cement or not, I just bought a 100 watt trinocular with the coveted 100X planachro w./iris and oil D.F. parabaloid condenser and all is good with it.
They sold a lot of those 100 watt 5 objective research stands into the live blood analysis market throughout the 80's. They had an edge over the AO 20 because the trinocular had a beam splitter and supported visual and video simultaneously. AO onlybhad a moving prism. They then lost that market subsequently to the BX-40, I suspect largely due to a simple thing like lousy glue plus the fact that you could outfit a BX- 40 with 3 planapos for about $10,000 and there was no reputation for optical cement failure. It doesn't take too many clients at 200.00 a pop to pay for it.

[H Jay Margolis]

Wow! I got quite a response.
Let me first say that by the time I got to B&L the Dynazoom had already gone from its early 60’s gray to “professional black.” There were NO 50’s Dynoptics to be found! I never even got my hands on one. Perhaps they kept one in the room where they kept competitive scopes, but again, never did I even see one. So I can’t help much with dating models.

It came down to Dynazoom being zoom and Dynoptic being without. BOTH used the Rosenberger-Seidenberg flat field system. You could special-order the old non-FF optics—while they still had any. Brass housing denoted Apochromatic, brass and metal, fluorite, and metal, achromatic. Those were the ways the scopes were classified.

Now: Bet nobody here knows WHY they came out with the Flat Field system? Yes, it was fast becoming clear that Zeiss and Leitz had a hit with planachromats, and AO had just confused the world with INFINITY correction (which was instantly conflated to mean INFINITELY CORRECTED, the REAL REASON was:
Their skilled assemblers either retired or
died out. They could not get new people to
apprentice. By using lenses that were 1/5 as
powerful and then amplifying them 5x by a negative
lens in the nosepiece, LARGER DIAMETER OPTICS
COULD BE USED. They even had it that they would
in the near future use jigs and machines to aid
assembly, with a final astigmatic correction made at
the very last with a rotation on a jig.
SO THERE YOU HAVE IT! This was GENIUS.
And, even today, why are objectives so long?
They just don’t place the negative in the nosepiece!

YES: I worked with (it turns out) unsung GENIUSES who were: Harold Rosenberger, Richard Seidenberg, George Aklin—and one more—who has not been mentioned yet because he worked on the stereo microscope end—and his story will come later. That was Paul Nothnagel. As to the other founder of FF, James Benford, I unfortunately never met him as he had retired about three years before I got there, Harold succeeding him.

The problem at B&L which I detected and realized my days were numbered, was that the ENGINEERS were incredible. But MARKETING was PATHETIC. My bosses could detect (as hard as I tried to hid it) my ADMIRATION for the engineers and my CONTEMPT for them. I soon decided I would save up and get back into graduate school. The problem with marketing was, they did not realize that they had a BETTER research potential than even Zeiss. They had optics—particularly with the FF system—that blew away the competition. Instead, they directed BALPLAN to the hospital and clinical markets. They were still bogged down fighting the equally backward thinking AO guys and not realizing that the real way to market BALPLAN was to make it pre-eminent. And they got caught up in trying to be cute. They put black plastic inserts on the knobs. The base is a disaster I always thought killed it by trying to look to “modern.” Yet, I told them that the flip-in lever for the ND filter should have had a round ball on top. My girl friend at the time told me it hurt her to feel it’s sharp edges (a lesson I learned to try to anticipate the female feelings to use an instrument that I try to take I to account with my own products to this day).

But I still love my BALPLAN. No child is perfect, but you can still find love in your heart.

[H Jay Margolis]

The idea for InFocus BEGAN with BALPLAN and my LinkedIn tells the story.

I have put on my www.infinity-USA.com site the patent info under the OEM section. If the InFocus were mated to the Rosenberger-Seidenberg system in a specific way...
I have Zemax shown there.

I pretty well think this DYNAMIC System COULD make for great things. But at 74, I have set my sights no longer on microscopes, but Cine.

Thanks for your interest.

[apochronaut]

Wow! I got quite a response.
Let me first say that by the time I got to B&L the Dynazoom had already gone from its early 60’s gray to “professional black.” There were NO 50’s Dynoptics to be found! I never even got my hands on one. Perhaps they kept one in the room where they kept competitive scopes, but again, never did I even see one. So I can’t help much with dating models.

It came down to Dynazoom being zoom and Dynoptic being without. BOTH used the Rosenberger-Seidenberg flat field system. You could special-order the old non-FF optics—while they still had any. Brass housing denoted Apochromatic, brass and metal, fluorite, and metal, achromatic. Those were the ways the scopes were classified.

Now: Bet nobody here knows WHY they came out with the Flat Field system? Yes, it was fast becoming clear that Zeiss and Leitz had a hit with planachromats, and AO had just confused the world with INFINITY correction (which was instantly conflated to mean INFINITELY CORRECTED, the REAL REASON was:
Their skilled assemblers either retired or
died out. They could not get new people to
apprentice. By using lenses that were 1/5 as
powerful and then amplifying them 5x by a negative
lens in the nosepiece, LARGER DIAMETER OPTICS
COULD BE USED. They even had it that they would
in the near future use jigs and machines to aid
assembly, with a final astigmatic correction made at
the very last with a rotation on a jig.
SO THERE YOU HAVE IT! This was GENIUS.
And, even today, why are objectives so long?
They just don’t place the negative in the nosepiece!

YES: I worked with (it turns out) unsung GENIUSES who were: Harold Rosenberger, Richard Seidenberg, George Aklin—and one more—who has not been mentioned yet because he worked on the stereo microscope end—and his story will come later. That was Paul Nothnagel. As to the other founder of FF, James Benford, I unfortunately never met him as he had retired about three years before I got there, Harold succeeding him.

The problem at B&L which I detected and realized my days were numbered, was that the ENGINEERS were incredible. But MARKETING was PATHETIC. My bosses could detect (as hard as I tried to hid it) my ADMIRATION for the engineers and my CONTEMPT for them. I soon decided I would save up and get back into graduate school. The problem with marketing was, they did not realize that they had a BETTER research potential than even Zeiss. They had optics—particularly with the FF system—that blew away the competition. Instead, they directed BALPLAN to the hospital and clinical markets. They were still bogged down fighting the equally backward thinking AO guys and not realizing that the real way to market BALPLAN was to make it pre-eminent. And they got caught up in trying to be cute. They put black plastic inserts on the knobs. The base is a disaster I always thought killed it by trying to look to “modern.” Yet, I told them that the flip-in lever for the ND filter should have had a round ball on top. My girl friend at the time told me it hurt her to feel it’s sharp edges (a lesson I learned to try to anticipate the female feelings to use an instrument that I try to take I to account with my own products to this day).

But I still love my BALPLAN. No child is perfect, but you can still find love in your heart.

I've been on record a number of times as lauding the flat field optical system, even going so far as to say that their later versions, marked planachromat, were the best planachromats up until the mid-80's. Fully up to the standards of many planfluorites, which may be the reason that except for the ñewly evolved 50X .80 oil planfluorite in the 80's, they discontinued the flat field fluorites.
As a Balplan user and not just looking at one by virtue of observation or casual use, here are a few comments, all in view of my also having used many other microscopes , both old and new.

I don't like the nosepiece. It requires that you grasp the objectives to turn it and the ball race is noisy. I realize that it is a well made and precise device but those are just aspects of it's function that I find bothersome. The necesdity to wrap ones hand around the objectives is in keeping with a practice many users employ but with the advent of the painted objectives, the specs. on those would be lost quickly.p

The substage is a bit crowded. A little more room would have been nice. Changing from one condenser to another is a bit of a tightrope walk, since the top lens of both is vulnerable.

The base doesn't bother me. It is utilitarian and functional, with all necessary controls easily at hand and feels precise. Yes, the neutral density lever is a bit industrial but it works smoothly with not too much pressure and seems like it will work that way for the next century. I can see that it's thin rigid nail-like profile could pressure very delicate skin. Just a little rubber sleeve would have been nice. They did do that with the condenser lever. Some have a bare metal bar and others have a little rubber grip attached.

It would have been nice if B & L had seen fit to expand their phase contrast system a little. The dark phase system they did employ works well enough, excellent actually but the addition of bright phase would have been welcome, especially since AO only produced their bright phase as an achromat system. The B & L flat field optics would have made a perfect bright phase and no doubt a better one than the AO achromat bright phase.

Pity they did not embrace transmitted DIC. I guess semi-conductors ruled the decisions somewhat.

A three way trinocular would have been the ticket. By 1985 AO had that and the Balplans fate was sealed.

[H Jay Margolis]

Hi,
I appreciate all your comments as they are right on. B&L could not get the license for Nomarski DIC.
They had it on their bench metallographs. That turned out to be a killer in the research market and, come to think of it NOW, may have played a part in restricting their efforts in the research market. Nomarski had become a requirement. I still do not know why they could not get a license. Did Nomarski have a thing against them?

I should explain that I left B&L in 1973. All I know about BALPLAN ends there. I proposed a lot of things to try to get it going, such as trying to put a Jackson Tubelength Corrector in it and still have my proposal from 1971. But
I did not know that the FF system required a specific distance to the tube lens INSIDE the binocular. Duck Seidenberg pulled me aside at a sales meeting to tell me they had looked into it but it would have aberrated things.
I had always thought he was not being candid with me, but years later, I read the FF patents when I developed InFocus. I had to study every infinity system extant and right now, probably am the single person who can explain and correct every strength used today. I then realized he was right and found out how to solve this by using afocal variation.

I put so many proposals out that one day, in anger I put one in the SUGGESTION BOX! That did it! I was called in to my boss’s office and PROMOTED out of Rochester to assist the New York sales office. I got 30% more salary and a big Chevy Impala. Since I came from New Jersey, I lived home, paid my parents a modest rent and saved BUNDLES
to go back to Colorado for grad school at CSU!

But all that I learned at B&L was critical to what was to become the establishment of Infinity Photo-Optical!

[H Jay Margolis]

Well, that’s what I know up until 1973. Actually, I am stunned by the knowledge you guys have about things after that. I never knew of the glue problems, for example, since the glues had not aged yet.

I didn’t know that they came out with the 50/0.80 oil but I WATCHED George Aklin go over the printouts after waiting for time on a main frame. What he’d have done on Zemax!

By the way, if anyone (I checked with Miller) knows where I could get one or of the other later planapos, bear in mind that I KNOW they were designed by him just before he retired in 1973. B&L brought him in from Kodak. He was the first to use lanthanim glass and his TESSAR stands as the best ever. See Modern Lens Design by Smith, p.204.
And Loveland’s Photomicrography gives a great account of the FF system. Loveland knew Shilaber, Benford, Aklin, Rosenberger and Seidenberg as part of the Rochester crowd.

It all turns out that I was at B&L at just the right time. The best of times. The brightest of times—just as the candle flickered before it burned out.

So, if anyone has any of my friend Aklin’s last best designs to part with, let me know...

And except for personal stories from my days at B&L, that is as much as I know. As I said, I left in 1973. By 1983, I had formed Infinity.

[BramHuntingNematodes]

Ha yeah if anyone knows where to get those planapos I would be interested too!

[hans]

I have put on my www.infinity-USA.com site the patent info under the OEM section. If the InFocus were mated to the Rosenberger-Seidenberg system in a specific way...
I have Zemax shown there.

Lots of interesting background, thanks. There is something I have been wondering about but not had time to experiment with yet, which maybe you would know off the top of your head... when photographing with camera lens through a microscope eyepiece ("afocal") there is similar adjustment possible, although presumably not as wide a range as the InFocus gives, by focusing the camera lens. Any idea roughly what the focus range of a typical camera lens (for example DX NIKKOR 35mm f/1.8G which I have been using goes 30 cm to a bit past infinity) would correspond to in terms of cover glass thickness variation?

...when I developed InFocus. I had to study every infinity system extant and right now, probably am the single person who can explain and correct every strength used today. ...

Seems like a lot of hobbyists (myself included) become interested in reverse engineering while trying to figure out how to best retrofit modern cameras onto older microscopes, both for fun, and to avoid paying for proper, commercial solutions like yours.

Hans. The big limiting factor in buying a used Balplan is the problem they got into with optical cement but replacement objectives can be found fairly easily still. ...

Thanks, just what I needed... encouragement... Gotta wait at least until after I get around to cleaning up and mixing and matching parts from all the 10 and 110 stuff I have accumulated already.

[H Jay Margolis]

You come across as highly intelligent. But it is not as simple as focusing a camera lens. But you just committed the worst thing you could do by telling me you want to try to make something around the sweat and hard work of others. I am quite Randian.

[BramHuntingNematodes]

Interesting talk from someone that made something after studying every infinity system. Maybe you're more like daniel plainview and don't like competition.

[hans]

But it is not as simple as focusing a camera lens.

The InFocus is no doubt a more sophisticated implementation. From your literature I understood the basic idea to be modification of objective working distance, to compensate for sample preparations differing from what the objective was originally designed, as you mention was done with drawtubes on older microscopes. Would focusing a camera lens that is imaging through a microscope eyepiece not produce a similar, if cruder and possibly with adjustment range too small to be useful, effect?

I am quite Randian.

It certainly shows.

[H Jay Margolis]

Interesting talk from someone that made something after studying every infinity system. Maybe you're more like daniel plainview and don't like competition.

You are RIGHT! I ow you and the other fellow a SERIOUS APOLOGY. I hope you will accept it

It is all too easy to forget that I did the same things once.
Recently, I had to defend some intellectual property and I may have simply wound up too much energy and some must have been left over.

OF COURSE, you Fellows need to have FUN looking at stuff and trying out how you can do things privately.
You have taught me a lesson for which I THANK YOU.

Now, let me direct you to the infinity site where you will see in DOWNLOADS the patent application for dynamic microscopy. (It is low on the page, scroll down).
I have decided to share it freely. Anyone who wishes to build it, can do so.

To answer quickly why a camera lens set to infinity and then defocused won’t work: consider all the major companies that would have done that with their commercial camera adapters. The amount of correction would never be enough to change the front focus working distance of the high power objectives. I could go into it more, but you can see that the depth of FOCUS is tremendous for low power objectives by pulling up the eyepiece. A high power hardly changes even if the eyepiece is pulled out inches. But the reverse happens to depth of FIELD; a low power has great and high have much less. To affect high powers, A LOT OF CHANGE is needed.
Even the InFocus must work within these limits.
__
Again, sometimes we need to remember when we wanted to do the same things.

[H Jay Margolis]

[quote="H Jay Margolis" post_id=93940 time=<a href="tel:1607981728">1607981728</a> user_id=2870]
But it is not as simple as focusing a camera lens.

The InFocus is no doubt a more sophisticated implementation. From your literature I understood the basic idea to be modification of objective working distance, to compensate for sample preparations differing from what the objective was originally designed, as you mention was done with drawtubes on older microscopes. Would focusing a camera lens that is imaging through a microscope eyepiece not produce a similar, if cruder and possibly with adjustment range too small to be useful, effect?

[quote="H Jay Margolis" post_id=93940 time=<a href="tel:1607981728">1607981728</a> user_id=2870]
I am quite Randian.
[/quote]

It certainly shows.
[/quote]

Looking forward to your insights into microscope development.

This is interesting: https://www.infinity-usa.com/infocus/ Is the effect equivalent to changing tube length?

I have so far resisted temptation to buy one of the surplus Balplans that occasionally show up cheaply on eBay but have enjoyed reading some of the threads about them, for example: viewtopic.php?t=3712

I want to apologize. As I wrote to the other fellow,
it is easy to forget that I once liked to do the same.
I appreciate being taken to task.

I may have gotten you guys mixed up in responding. I’m new to how this works. And I have hardly ever joined a forum.

But you guys are impressive in your knowledge and enthusiasm.

I think in time, I might be of some help. You see, I have one of the greatest optical Erector sets at my fingertips.
In my stock room are parts for this, parts for that. For example, I got a great 1960’s Zeiss Achromatic condenser.
But it was to short to work with my Zeiss AxioStar (which I use in both DIN or ICS. In five minutes, I found the dovetails and sockets to make an adapter. Works great—and if anybody out there has the problem—let’s talk.


I believe you asked about why a camera lens couldn’t work over an eyepiece. Before even thinking about it, it would have been a no brained for manufacturers to have offered spherical correction as commonplace. But the real reason has to do with what it takes to change the objective’s frontal Gauss particulars. It takes a lot more than can be effected by focusing a camera lens to force the objective to find a new working distance.

You might like to go to DOWNLOADS on the Infinity site anc scroll down to read about how moving the InFocus with activation can create an adaptive optic scope. I decided to give it away. Anybody can make it who CAN make it.

Again, I’m not usually so hotheaded.

[BramHuntingNematodes]

No worries friend, and I think I am beginning to see the principle behind these scopes. It is certainly a unique approach to construction.

[H Jay Margolis]

Thanks. I’ll be glad to discuss things, anytime.

[apochronaut]

Well, that’s what I know up until 1973. Actually, I am stunned by the knowledge you guys have about things after that. I never knew of the glue problems, for example, since the glues had not aged yet.

I didn’t know that they came out with the 50/0.80 oil but I WATCHED George Aklin go over the printouts after waiting for time on a main frame. What he’d have done on Zemax!

By the way, if anyone (I checked with Miller) knows where I could get one or of the other later planapos, bear in mind that I KNOW they were designed by him just before he retired in 1973. B&L brought him in from Kodak. He was the first to use lanthanim glass and his TESSAR stands as the best ever. See Modern Lens Design by Smith, p.204.
And Loveland’s Photomicrography gives a great account of the FF system. Loveland knew Shilaber, Benford, Aklin, Rosenberger and Seidenberg as part of the Rochester crowd.

It all turns out that I was at B&L at just the right time. The best of times. The brightest of times—just as the candle flickered before it burned out.

So, if anyone has any of my friend Aklin’s last best designs to part with, let me know...

And except for personal stories from my days at B&L, that is as much as I know. As I said, I left in 1973. By 1983, I had formed Infinity.

I have never seen any objectives marked planapo or planapochromat. Only Flat Field Apochromat. My catalogues go from 1973 to 1977 then jump to 1986. Everything is Flat Field until 1975. Then planachromats and a different barrel conformation appear. The 20X lingered a little longer as a Flat Field. Throughout, the apochromats stay as Flat Field with the older straight sided barrels, going back to the Dyna days. There was also a 50X .80 planachromat, which I have only seen in a catalogue.. In the 1986 catalogue, it is gone as are the apochromats.
They only catalogued 7.5X , 12.5X and 25X Flat Field Apochromats. In discussions with Michael Miller some time ago, he also confirmed that they only made the 3 apochromats for the Balplan. However, I have seen 2 and own 1, 75X 1.2 oil Flat Field Apochromats ; own a 125X 1.4 oil Flat Field Apochromat and have seen a 100X Flat Field Apochromat. I think I may have seen a 50X as well. My assumption is that those are all objectives made for the Dyna series Flat Field microscopes. The question that I have had for years is ; why did they not continue with those objectives for the Balplan? Did they just keep on with the three low power objectives because they hadn't developed a high N.A. achromat condenser for the Balplan systems, and then the whole program changed direction?

The Flat Field Fuorites too. I once owned a 100X 1.30. There was a 50X .80 dry. I think perhaps an 80X too. I do own an 80X .90 Flat Field Fluorite epi seeno cover objective with a 24mm thread from a metallograph. Used with an R.M.S. adapter it corrects perfectly on a Balplan. None if these were catalogued for the Balplan but the aforementioned 50X .80 oil planfluorite was manufactured for it but in my catalogues it is missing. Perhaps it superceded the 50X planachromat in the late 70's early 80's but by 86 had been dropped.

I don't think there were too many of those objectives made. Partly because the planachromats are so good. I have only ever seen the 7.5X in multiples of more than 2, 2- 25X, 2- 75X, 2- 50X planfluorites in quite a few years of keeping an eye peeled for them. Pretty rare items.
In the last little while there have been a few of the l.w.d. 10X .25 planachromats on ebay, all from the same seller. If you have a Balplan, one of those is worth having, with it's 9mm working distance.

[BramHuntingNematodes]

I have also seen some flat field epi darkfield objectives-- I don't reckon they made any of those in plan?

[hans]

No worries and thank you for taking time to explain, not common to hear from someone actually involved in the design of optics like this, will definitely take a closer look at your website as time allows.

What had me thinking about spherical correction was this thread a few months ago, viewtopic.php?f=14&t=10361, trying to understand why a cover-glass-corrected water immersion objective would be beneficial.

Given one has a method to vary working distance over a useful range, the other part of the equation which I don't really understand at all yet, is how exactly changes in the sample preparation (change in cover glass thickness with a dry objective, adding water layer between sample and cover glass, etc.) relate to changes in working distance necessary to compensate.

You might like to go to DOWNLOADS on the Infinity site anc scroll down to read about how moving the InFocus with activation can create an adaptive optic scope. I decided to give it away. Anybody can make it who CAN make it.

Yes, I had seen the adaptive version mentioned, very impressive. Too bad typical camera lenses do not provide enough range, otherwise an autofocus camera tethered to a computer might be convenient actuator for a DIY attempt.