Vickers Microplan 4 objective puzzle - how to solve it?

Everything relating to microscopy hardware: Objectives, eyepieces, lamps and more.
Post Reply
Message
Author
MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Vickers Microplan 4 objective puzzle - how to solve it?

#1 Post by MicroBob » Sat Sep 18, 2021 8:57 am

Hi together,
I have a Vickrers Microplan 4 0,12 objective. It came with some other objectives that had severe damages, perhaps maltreatment by bored students or so. This objective is not damaged, but the inside lens groups are mixed up. All together give the right length to fill the barrel, but how to arrange them?

Barrel
Screw cap, towards the slide
Small diameter lens group in funnel + shim, belongs onto the small brim
Flat big diameter lens group
Tall big diameter lens group 1
Tall big diameter lens group 2
Spacer

Taking into account that the elements can be placed in two directions this gives a fairly time consuming puzzle - unless someone has an idea where to start. Does someone have a cross section view of this or a similar plan achromat objective? Does someone have this objective and dares a peek inside?
The other Vickers Microplan objectives are quite good so I would be happy to get this one going again.

Bob
Attachments
Vickers Microplan 4 0,12 in parts.jpg
Vickers Microplan 4 0,12 in parts.jpg (111.07 KiB) Viewed 6500 times
Last edited by MicroBob on Sat Sep 18, 2021 7:58 pm, edited 1 time in total.

User avatar
patta
Posts: 402
Joined: Sun May 10, 2020 6:01 am
Location: Stavanger Norway
Contact:

Re: Vickres Microplan 4 objective puzzle - how to solve it?

#2 Post by patta » Sat Sep 18, 2021 3:15 pm

Not exactly but let's guess it may have "double gauss" plan design, like the 50mm camera lenses, just inverted.

So order should be, from bottom
1- small lens, most convex down
2- tall group, concave side up
3- tall group, concave side down
4- large flat, most convex up

so are left just 2 possibilities, swapping the two tall groups

Edit
maybe the flat under the two tall groups instead
880px-Double_gauss.png
880px-Double_gauss.png (89.69 KiB) Viewed 6484 times

Chas
Posts: 422
Joined: Tue Jan 19, 2021 3:11 pm

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#3 Post by Chas » Sat Sep 18, 2021 9:17 pm

front group out. On this one the bevelling on outer face doesnt go all the way to the glass , but the bevelling on the inward facing end goes all the way to the glass.
(there is also a faint circular witness mark on the outer glass where it has been cleaned/scratched with the nose shroud on)
Attachments
microplan 4x front 640 480.jpg
microplan 4x front 640 480.jpg (51.28 KiB) Viewed 6435 times

Chas
Posts: 422
Joined: Tue Jan 19, 2021 3:11 pm

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#4 Post by Chas » Sun Sep 19, 2021 5:35 pm

I am having a really bad photograph day, but maybe there a some pointers in this;
Vicker 4x microplan 1 012 640 480.jpg
Vicker 4x microplan 1 012 640 480.jpg (38.89 KiB) Viewed 6393 times
I have not been able to unscrew the rear disc, but I can see that the back of the lens's metal has a pronounced chamfer
rear microplan 640 480.jpg
rear microplan 640 480.jpg (72.07 KiB) Viewed 6391 times
Last edited by Chas on Sun Sep 19, 2021 5:44 pm, edited 1 time in total.

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#5 Post by MicroBob » Sun Sep 19, 2021 5:43 pm

Hi Chas,
thank you very much for taking the trouble of dismantling your microscope objective! Your pictures reduce the room speculation to a handable measure. Tomorrow I will try to assemble my objective in the order as in your objective and will see how it works. The design of our objectives seems to be the same even if your lens groups are black on the outside and mine bare brass.
Thank you Patta too, the diagram might help to solve details of the puzzle!

I will report back tomorrow.

Bob

Chas
Posts: 422
Joined: Tue Jan 19, 2021 3:11 pm

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#6 Post by Chas » Sun Sep 19, 2021 5:48 pm

Bob, the washer is hardly visible in my photograph... but it sits between the the second and third item from the tip.

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#7 Post by apochronaut » Sun Sep 19, 2021 9:45 pm

The shim ( washer) is most likely in the same location as it is in Chas's objective. If you get it together and it is a little fuzzy or has unusual peripheral ca however, it is possible the shim is the culprit. I have seen instances where two objectives that looked identical from the outside had slightly altered cell dimensions on the inside and shims were installed between different cell pairs. The shim(s) thickness(es) are unique to an objective and are installed during the process of adjusting the objective to bring it into spec. Shimming is a spherical aberration adjustment mostly but when not inserted accurately will cause anything from uncharacteristic s.a., c.a. to poor parfocality.

If there is ever doubt of a shim's location, sometimes you can see mirror marks on the shim. Long brass to brass contact will often leave tiny corrosion marks on the shim and a mirror of them on the mating surface of the adjoining lens cell. They are seldom exact mirrors but a pattern can often be seen to locate the contact surfaces. One exact one is all you need.

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#8 Post by MicroBob » Mon Sep 20, 2021 2:03 pm

Hi together,
I have the objective back together now. The image is good on superficial inspection and planarity is good. But it in not parfocal with other Vickers objectives, below 45mm but closer to 45 that to Vickers parfocal lenght. It tried it with differnt eyepieces designed for intermediate image from 10 to 18mm down the tube. Bigger alteration tho this arrangement led to no or a very hazy image, changeing shim position didn't change much. It my not have been parfocal from production on as many low power objectives are not. Is your Microplan 4 parfocal with e.g. a Microplan 10, Chas?
Does someone know the official parfocality lenght, tube lenght and position of intermediate image of the Vickers objectives?

Bob

tgss
Posts: 223
Joined: Wed Jan 25, 2017 3:48 am
Location: Ontario, Canada

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#9 Post by tgss » Mon Sep 20, 2021 11:06 pm

Hi MicroBob
Vickers and their subsidiaries have used a variety of parfocality lengths: 24mm, 34mm, 44mm and, after their change to DIN specification 45mm. My guess is that your 4x Microplan is 44mm; pretty close to DIN spec. Tube length is 160mm. Location of the intermediate image was 10mm down the tube after the change to DIN, but 0.8 inches (20.32mm) prior to that; again I'm guessing that your Microplan is intended to produce its primary image 0.8 inches down the tube. Oculars were produced to suit the 0.8 inch primary image location, and of course the 10mm location after the change to DIN spec, but it is not always clear which arrangement a given ocular is designed to suit. I have Vickers Complan eyepieces that are designed for each primary image arrangement, but there is no indication on the oculars themselves that they are different!
Cheers
Tom W.

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#10 Post by apochronaut » Tue Sep 21, 2021 2:43 pm

I believe that while Vickers owned Cooke Troughton and Simms since the 20's, it wasn't until after they acquired Baker that they started branding objectives with the Vickers name, at least for coverslip corrected objectives. The latter Baker objectives were branded as Vickers after about 1963. Were these not already 45mm parfocal D.I.N. objectives?

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#11 Post by MicroBob » Tue Sep 21, 2021 6:11 pm

Hi Tom,
thank you for the detailed information. I think I have to redo my parfocality test as I'm not sure any more of my method. 0,8'' intermediate image position will probably be among the highest values of all. Perhaps carried on from huge old english microscopes? I don't think I have one of these eyepieces so will have to make do with the closest I have.
I believe to remember to have used a Vickers 50:1 fluorite parfocal next to 45mm DIN objectives but I'm not absolutely sure. This is a good reason to get the Vickers objectives out of the drawer and do some tests. For me as a german they are fairly exotic compared to my usual Zeiss West, Zeiss Jena and Leitz stuff.

@Apochronaut: I think I have a 40:1 Cooke too and will check it too.

Bob

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#12 Post by apochronaut » Tue Sep 21, 2021 6:50 pm

If the objective is marked 40:1, it may then be an older shorty. Prior to the Vickers brand being engraved on the objectives , the very same objectives were engraved Cooke-Baker. They had 40X on them.

tgss
Posts: 223
Joined: Wed Jan 25, 2017 3:48 am
Location: Ontario, Canada

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#13 Post by tgss » Tue Sep 21, 2021 6:54 pm

Hi apochronaut
I have always found the history of Vickers microscope development to be pretty darn confusing, largely because of the miscellany of instruments inherited from their predecessors. In my post above I have largely relied on "The History of Vickers Instruments' Microscopes", published in The Microscope in 1980, and written by A. John Munro who was a director of Vickers Instruments at the time. This history too is rather confusing since its presentation is by no means linear in time. But he does state that the rationalization of their optics, from the hodge-podge of specifications they inherited, to the DIN specification, was started when the replacement for their M15 instrument was being conceived. That was in 1966. The resulting replacement was the M17 (their model numbers also jump all over the place!), which was first marketed in 1976. From this I am deducing, possibly incorrectly, that their conversion to DIN spec occurred no later than 1976, but no earlier than 1966. Certainly the 1965 Vickers brochure "Optics for the Microscope" categorically states that "all objectives listed have a body length of 44 mm". "Body length" seems to be Vickers speak for parfocal length as it is used consistently. There is a reference in the same document to earlier objectives with a 45mm body length, but they appear to belong to another specification in which the intermediate image is formed 15 mm down the eyetube.

My understanding could certainly be wrong in some of the above and if you have further information on this confusing history I'd certainly welcome it, though perhaps in a separate topic to avoid usurping MicroBob's topic. I guess the message to MicroBob in all this is that he should definitely take everything with a big pinch of salt.
Tom W.

Edit: When I said "...reference in the same document to earlier objectives..." I meant the John Munro document, not the "Optics for the Microscope" brochure.
Last edited by tgss on Tue Sep 21, 2021 8:10 pm, edited 1 time in total.

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#14 Post by MicroBob » Tue Sep 21, 2021 7:03 pm

tgss wrote:
Tue Sep 21, 2021 6:54 pm
though perhaps in a separate topic to avoid usurping MicroBob's topic.

No problem for me but this rare information might be easier to find in a thread with an appropriate titel like "Vickers, Cooke, Throughton& Simms objective design values" or so.

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#15 Post by apochronaut » Tue Sep 21, 2021 8:58 pm

I read that history and remain puzzled regarding the lengths, since I have a set of Vickers/Cooke-Baker objectives, all Microplans and despite the name difference, one could easily view them as a matched set. The Cooke-Baker 10X .25 is not spring loaded and measures 42mm from thread base to tip. The 40X .70 Cooke-Baker and the 100X 1.25 Vickers are both a snudge over 44mm, parfocal with each other and clearly 45mm parfocal length. I can't see any difference between the Cooke-Baker objective body and the Vickers body, except for the diameter.

Chas
Posts: 422
Joined: Tue Jan 19, 2021 3:11 pm

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#16 Post by Chas » Tue Sep 21, 2021 11:53 pm

-Is it possible that all the internals of the 4x Microplan can be shifted up and down inside the objective's body by adjusting the rear the disc and then tigthening all the parts using the nose shroud ?? (or maybe better; set their position with the nose shroud and then tighten them up with the rear disc?)
The internals on mine seem to project out forward, a little, from the tip of the body.
Sadly I do not have any other Microplan lens to compare it to.
Last edited by Chas on Wed Sep 22, 2021 9:01 am, edited 1 time in total.

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#17 Post by MicroBob » Wed Sep 22, 2021 6:09 am

Chas wrote:
Tue Sep 21, 2021 11:53 pm
The internals on mine seem to project out forward, a little, from the tip of the body.
In my case the stack of lens groups also protrudes a little. Which the screwed in ring at the back it will be possible to secure it in a range of about 1mm, which can help a lot - good idea!
Two 10:1 Vickers objectives I compared were clearly not 45mm DIN, maybe 45mm + 0,8'' intermediate image eyepiece.

Varying objective design dimensions will probably have led to a lot of user frustration. Many users and even "maintenance people" are not that experienced with microscope technics and would mix up thing badly. In this case the Zeiss West system was very modern, one parfocal length, one set of eyepieces fiting for all objectives.

tgss
Posts: 223
Joined: Wed Jan 25, 2017 3:48 am
Location: Ontario, Canada

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#18 Post by tgss » Wed Sep 22, 2021 2:49 pm

apochronaut wrote:
Tue Sep 21, 2021 8:58 pm
I read that history and remain puzzled regarding the lengths, since I have a set of Vickers/Cooke-Baker objectives, all Microplans and despite the name difference, one could easily view them as a matched set. The Cooke-Baker 10X .25 is not spring loaded and measures 42mm from thread base to tip. The 40X .70 Cooke-Baker and the 100X 1.25 Vickers are both a snudge over 44mm, parfocal with each other and clearly 45mm parfocal length. I can't see any difference between the Cooke-Baker objective body and the Vickers body, except for the diameter.
I have checked the lengths of a number of my Microplans, and a couple of Vickers achromats, and must admit it is not easy to do in a casual way while expecting an accurate result. I simply used a digital caliper, but because of the design it is not normally possible to measure the shoulder to tip directly but involves measuring the overall length and subtracting the thread length, not to mention the fact that I guess we really want the length from the shoulder to the surface of the front lens element, which is often recessed. Also I was reluctant to measure across the front lens on the 100x since the front surface is not well protected, so guesstimated the length of the projection on the front of the lens - was it enough to exceed 44mm or not?
My results were inconclusive but I was not convinced that any of the objectives I checked were more than 44mm working distance. I thought that the Vickers brochure on their optics included working distances but unfortunately it does not, except for some LWD objectives, merely stating that Microplans have a shorter working distance than their equivalent achromats.
Yes, barrel diameters, and the diameters of the barrel front portions, do seem to vary despite the objectives being nominally the same: same power, NA, Microplan designation - more confusion :?
I also find it interesting that the 1965 Optics brochure lists only three magnifications in the Microplan range: 10x, 20x and 40x, though I have 2.5x, 25x, 100x in addition??
I would like to do some more research on this, and probably make a more accurate measurement of the lengths of the objectives I own, since the difference between 44mm an 45mm is pretty small when you take into account confounding factors like measurement error and working distance variations, but it will have to wait I'm afraid.
Tom W.

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#19 Post by apochronaut » Wed Sep 22, 2021 3:31 pm

Maybe old Cooke-Baker catalogues would help. The early Vickers objectives appear to be identical but then there was a change, later? I have noticed that some Vickers objectives have D.I.N. marked on them. One would wonder why, unless they needed to differentiate them from an earlier format?

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#20 Post by MicroBob » Wed Sep 22, 2021 4:04 pm

Some former microscope objective makers started to buy objectives from suppliers like Seibert. Do the DIN-marked Vickers look like Vickers?


MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#22 Post by MicroBob » Wed Sep 22, 2021 7:48 pm

It looks very Vickers like to me, no question. Interesting screw above the "/"

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#23 Post by apochronaut » Wed Sep 22, 2021 8:48 pm

They seem to have liked moving that screw around. Maybe one of the mechanical engineers had one loose.
The Cooke-Baker 40X .70 Microplan has it going through the back diaphragm, down into the innards. The Vickers 100X 1.25 Microplan has one right at the bottom of the main thick part of the shroud and that ebay one near the top of the shroud.
I'm guessing they are all stop screws?

tgss
Posts: 223
Joined: Wed Jan 25, 2017 3:48 am
Location: Ontario, Canada

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#24 Post by tgss » Thu Sep 23, 2021 12:01 am

And then there are these, with a more "modern" aesthetic?
From: https://www.ebay.com/itm/2653166790654
From: https://www.ebay.com/itm/2653166790654
Vickers DIN.jpg (73.79 KiB) Viewed 6131 times
I seem to remember being told that Vickers did start sourcing objectives "out of house" at some point late in their life.
Tom W.

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#25 Post by apochronaut » Thu Sep 23, 2021 1:35 pm

There were also the black infinity corrected objectives that Bio Rad sold. Not sure if the Vickers factory actually continued to make those but I have seen them advertised as Vickers. The lettering looks suspiciously Vickers.
https://www.ebay.com/itm/5642-BIO-RAD-S ... ect=mobile

MichaelG.
Posts: 3976
Joined: Mon Apr 10, 2017 8:24 am
Location: North Wales

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#26 Post by MichaelG. » Thu Sep 23, 2021 9:46 pm

tgss wrote:
Thu Sep 23, 2021 12:01 am
I seem to remember being told that Vickers did start sourcing objectives "out of house" at some point late in their life.
I have some 10x 0.25 objectives with the Vickers logo, which were made in Japan

MichaelG.
.

PostScript:
McConnell (ref. 2) records that by 1983 Vickers decided to “...reduce its range....” of optical microscopes and direct attention to “.....highly sophisticated scientific and defence instrumentation”. At some stage, Vickers started importing Vickers-badged compound microscopes from Japan. Designated as ML1300 and ML3000 they look similar to Meiji Instruments of the same period. Perhaps this was a prelude to the eventual demise of Vickers Instruments as a microscope manufacturer and its subsequent sale to Bio-Rad Laboratories in 1988.
Ref. http://www.microscopy-uk.org.uk/mag/ind ... s-m75.html
Too many 'projects'

tgss
Posts: 223
Joined: Wed Jan 25, 2017 3:48 am
Location: Ontario, Canada

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#27 Post by tgss » Thu Sep 23, 2021 11:12 pm

I think you are correct apochronaut, the engraving does look decidedly Vickerish, and the objectives look familiar. I think I have seen them listed specifically as Vickers infinity objectives, or perhaps mounted on a Vickers 'scope.

MichaelG. wrote:
Thu Sep 23, 2021 9:46 pm
tgss wrote:
Thu Sep 23, 2021 12:01 am
I seem to remember being told that Vickers did start sourcing objectives "out of house" at some point late in their life.
I have some 10x 0.25 objectives with the Vickers logo, which were made in Japan

MichaelG.

PostScript:
McConnell (ref. 2) records that by 1983 Vickers decided to “...reduce its range....” of optical microscopes and direct attention to “.....highly sophisticated scientific and defence instrumentation”. At some stage, Vickers started importing Vickers-badged compound microscopes from Japan. Designated as ML1300 and ML3000 they look similar to Meiji Instruments of the same period. Perhaps this was a prelude to the eventual demise of Vickers Instruments as a microscope manufacturer and its subsequent sale to Bio-Rad Laboratories in 1988.
Ref. http://www.microscopy-uk.org.uk/mag/ind ... s-m75.html
Thanks for the microscopy-uk link, I had completely forgotten this article.
Tom W

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Vickers Microplan 4 objective puzzle - how to solve it?

#28 Post by apochronaut » Fri Sep 24, 2021 12:30 pm

Bio Rad also sold a 15X reflecting objective for UV applications. Although the objective itself looks very much like the Vickers 15X reflecting objectlive, the mount is a small type of dovetail. I recall the Vickers probably had R.M.S. mounts for those.

Post Reply