AO Spencer 15 with Pol or is it an Interference?

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Charles
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AO Spencer 15 with Pol or is it an Interference?

#1 Post by Charles » Thu Nov 26, 2015 10:52 pm

I have an AO Spencer 15 Pol on the way. The serial number dates it to late 1955 to early 1956. This is the first I've seen the Pol version of this model, so just had to get it. :D It has a rotating analyzer built into the single objective holder instead of the normal 3-4 objective turret as well as a 1/4 wave plate. Even the mono tube has a special 'notch' to fit over the analyzer piece. Comes with a circular rotating mechanical stage but doesn't seem to have objectives or the condenser with polarizer and the eyepieces do not look like AO, but I have all the extras which should fit.
Spencer 15 Pol Left2.jpg
Spencer 15 Pol Left2.jpg (63.16 KiB) Viewed 5356 times
Spencer 15 Pol Head and Stage2.jpg
Spencer 15 Pol Head and Stage2.jpg (56.87 KiB) Viewed 5356 times
Spencer 15 Pol Back All2.jpg
Spencer 15 Pol Back All2.jpg (94.27 KiB) Viewed 5356 times
Last edited by Charles on Sat Dec 05, 2015 4:37 pm, edited 1 time in total.

apochronaut
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Re: AO Spencer 15 with Pol

#2 Post by apochronaut » Thu Nov 26, 2015 11:56 pm

Very nice microscope , Charles. That stage was in use since the early 20's and this must have been about it's last gasp. It is a nice stage, though. When in good shape and well set up, they work beautifully. The microscope also has the machined aluminum knobs, previously discussed, which are consistent with the 1955/56 date. It is not catalogued in the 1955 catalogue.
The polarizing microscopes made up until this time had objectives that looked very, much like the standard Spencer objectives but had a centering type mount, were strain free and were corrected for 166.4mm. They were marked S.F. This was possibly the first Spencer binocular polarizing microscope.
The eyepieces in this one are Olympus and would not likely work well for polarizing. The polarizing eyepieces up until that time were focusing type, with crosshairs.
In the 1955 catalogue, they did branch out from the cast iron bodied, monocular polarizing scopes they had catalogued for about 20 years by offering a modified series 78/79 polarizing microscope. The 78/79 was a fantastic little student microscope with a 110 volt 10watt illuminator in the base. The good one had standard 10X, 43X and 97X lab microscope objectives and for a cheap bakelite based student microscope , produces fantastic images. Probably, very shortly afterwards they brought out your binocular polarizer.

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KurtM
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Re: AO Spencer 15 with Pol

#3 Post by KurtM » Fri Nov 27, 2015 12:53 am

Charles, I was eyeballing that one myself, but passed on it in part because I was unsure what it even was. I thought probably a POL scope, but had never seen one with bino head, and thought it odd a POL scope would be applicable to cancer research? Glad to see you got it, and still want to tour your basement someday. :shock:
Cheers,
Kurt Maurer
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Charles
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Re: AO Spencer 15 with Pol

#4 Post by Charles » Fri Nov 27, 2015 2:49 am

Thank you Phil for the additional information. I have the individual adjustable objective holders and a 1.0 NA polarized condenser which should fit. Don't know if I have any SF objectives but some regular objectives should be okay to use.

Kurt, This was originally listed as a regular auction starting at $80 and I asked if he would consider a BIN price and we came to an agreeable price. :D

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gekko
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Re: AO Spencer 15 with Pol

#5 Post by gekko » Sun Nov 29, 2015 1:41 pm

Very nice find!

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Re: AO Spencer 15 with Pol

#6 Post by Charles » Sat Dec 05, 2015 4:15 pm

Thank you Gekko!

I got this scope yesterday and was pleasently surprised at what I have. It appears to be an AO Interference microscope. The only problem is that it doesn't have it's various interference condensers as shown here for a Baker Interence here:
http://www.ebay.com/itm/AO-Cooke-C-Bake ... 7675.l2557
I have seen a couple of these for sale before but never needed one but now I do, so the search is on! :)

Overall condition and all mechanics seem excellent and works very well, and just a minor cleaning was needed. The stage also has a blank which slides on over the 'rack' when the mechanial slide holder is taken off (shown in the fourth picture, which is kind of neat. The bino and mono viewing bodies swap out with loosening a large screw on top instead of on the bottom like the regular 15. The top analyzer is in great shape but the lower polarizer is somewhat delaminated but still functional. The various condensers slide into the holder as can be seen on the 'Front' view. I've seen Reichert interference condenser like these which might fit if the dimensions are right:
http://www.ebay.com/itm/361369821115?_t ... EBIDX%3AIT

Pictures!:
AO 15 Interference.jpg
AO 15 Interference.jpg (47.35 KiB) Viewed 5301 times
AO 15 Interference Mono.jpg
AO 15 Interference Mono.jpg (51.29 KiB) Viewed 5301 times
AO 15 Interference Condenser.jpg
AO 15 Interference Condenser.jpg (64.35 KiB) Viewed 5301 times
AO 15 Interference Stage Blank.jpg
AO 15 Interference Stage Blank.jpg (48.47 KiB) Viewed 5301 times
AO 15 Interference Front.jpg
AO 15 Interference Front.jpg (49.7 KiB) Viewed 5301 times
Last edited by Charles on Sat Dec 05, 2015 4:18 pm, edited 1 time in total.

Charles
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Re: AO Spencer 15 with Pol

#7 Post by Charles » Sat Dec 05, 2015 4:17 pm

Here is a top view of the rotating analyzer:
AO 15 Interference Off.jpg
AO 15 Interference Off.jpg (55.41 KiB) Viewed 5301 times

apochronaut
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Re: AO Spencer 15 with Pol or is it an Interference?

#8 Post by apochronaut » Sun Dec 06, 2015 2:40 pm

That makes perfect sense, Charles. They weren't connected to Reichert, though, so the kit on ebay has the the parts you need. The AO interference microscope was adapted from Baker . AO's relationship to Reichert didn't begin until 1962.

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Re: AO Spencer 15 with Pol or is it an Interference?

#9 Post by Charles » Sat Apr 28, 2018 1:16 am

I found the missing pieces for this AO Interference microscope I got over two years ago. It is missing one of the condensers (I think the 10X DF). Will be fun to play with this! :D
AO Baker Interference Set2.jpg
AO Baker Interference Set2.jpg (52.31 KiB) Viewed 4025 times

desertrat
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Re: AO Spencer 15 with Pol or is it an Interference?

#10 Post by desertrat » Sat Apr 28, 2018 1:28 am

Great find! Is this interference system similar to the DIC systems of today?

I'm wondering if those parts would fit a 4 Series stand?
Rick

A/O 10 Series Microstar
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Several old monocular scopes in more or less decrepit but usable condition

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Re: AO Spencer 15 with Pol or is it an Interference?

#11 Post by Charles » Sat Apr 28, 2018 2:16 pm

There are a couple of documents on PS Neeley's site:
http://www.science-info.net/docs/Smith-Baker/
The second document shows the Smith-Baker Interference system on an AO 2 stand.

I believe the Interference system was the precursor to the DIC systems.

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zzffnn
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Re: AO Spencer 15 with Pol or is it an Interference?

#12 Post by zzffnn » Sun Apr 29, 2018 1:11 am

Charles,

Would it be difficult to show us an interference image made by the 40x(43x?) or 100x(97x?) objective/condenser combo? I wonder how different it looks from DIC. Thank you.

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coominya
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Re: AO Spencer 15 with Pol or is it an Interference?

#13 Post by coominya » Sun Apr 29, 2018 9:30 am

Yes a beautiful piece of engineering from an era where quality was forefront in the minds of the creators.

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Re: AO Spencer 15 with Pol or is it an Interference?

#14 Post by MicroBob » Sun Apr 29, 2018 4:06 pm

desertrat wrote:Great find! Is this interference system similar to the DIC systems of today?
These were my thoughts too...

apochronaut
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Re: AO Spencer 15 with Pol or is it an Interference?

#15 Post by apochronaut » Sun Apr 29, 2018 6:47 pm

desertrat wrote:Great find! Is this interference system similar to the DIC systems of today?

I'm wondering if those parts would fit a 4 Series stand?
Some of them will, since the same concept of microscope was also used to make a version based on the series 2. AO called it the series 7. The parts that are unique to the series 7 are the sliding dovetail condenser mount , the 240 degree analyzer and double slider dovetail attachment, fitted between the standard series 2/4 viewing body dovetail and the viewing body above the nosepiece, and probably the nosepiece mount itself.

For the series 7, the 6 condensers; 3 double focus and 3 shearing are still Cooke-Baker and the 6 objectives ; 10x, 40x and 100x double focus(DF) and the same complement as shearing(S), are too. They are all water immersion.

Additionally there is a standard abbe 1.25 condenser with a sliding dovetail mount available and the telescope and eyepieces( cat.# 146) are all standard AO.

The microscope is a polarizing microscope + a two beam interferometer. Selection of the condenser and matching objective type allows for the possibility of a longitudinal separation of the two polarized beams( DF) or a lateral separation( S). One is for qualitative imaging, allowing for superior 3-D imaging of cells etc. and the other is quantitative, allowing for measurements, such as the refractive index of liquids.

The recommended illuminators are all 100 watt and since much of the technique with the microscope is done by "reading" intensity gradations in monochromatic light( qualitative system), each is used with a group of filters. For maximum precision in the qualitative mode, the unusual AO #390B illuminator, a #397 100 watt AH4 mercury arc illuminator powered from a purpose built transformer, provides an ideal 546 millimicron wavelength of monochromatic light. It is used with a filter and water cell.
Alternately the # 600 filtered ortho-illuminator can be used, or the # 735C filtered illuminator. Both can be filtered to approximate 546 millimicrons. These same illuminators existed at the time of the manufacture of the series 15 version, so would also be the illuminators of choice for it. Baker, also made an Ortho illuminator of very similar design to the AO model.

Those optics are a great find , Charles. There can't be too many sets like that around, so you have really put a puzzle together well. I hope this works up to it's promise. I have seen the complete Baker version for sale in England....entire system with the case, at a good price too. Unfortunately the shipping was a killer, since it weighed over 20 kg.

A couple of more details for you. You've already gleaned that DF doesn't stand for dark field in this case but it stands for double focus. The settings on the analyzer are apparently anywhere for DF and 110 degrees +- 15 for the Shearing system.

The PZO Polarizing Interference Microscope, sometimes erroneously referred to as a PZO DIC Microscope, also has some functions in common with the Baker system, while additionally incorporating a Nomarski type DIC. I have a copy of the operating manual for that scope and there is quite a bit devoted to it's use in shearing function. They do not use the term "double focus", only various terminologies of types of "interference". There is a possibility that one of the interference systems incorporated into the PZO system, matches closely the technical functions of the baker system. At over 90 pages, the manual is quite detailed. If you needed any info. from it that might be relevant, p.m. me. I intend to copy the manual at some point and make it available but so far, I still can't quite see it as an individual log, in the log jam.

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Re: AO Spencer 15 with Pol or is it an Interference?

#16 Post by Charles » Sat Jul 07, 2018 3:55 pm

Speaking of the AO7...look what I found! An AO Baker Interference Model 7BG-QSW. The interference system is on an AO model 2 with an intermediate piece which houses the interference prism with two slide in filters, a 1/4 plate and a slide with a green filter. The bottom has the 100X Baker Interference condenser with a polarizer/interference disk on the bottom. The objectives, and condensers are interchangeable with the AO Model 15.

Pictures:
AO2 with Interference.jpg
AO2 with Interference.jpg (46.43 KiB) Viewed 3516 times
AO2 with Interference Left.jpg
AO2 with Interference Left.jpg (50.47 KiB) Viewed 3516 times
AO2 with Interference Right.jpg
AO2 with Interference Right.jpg (50.03 KiB) Viewed 3516 times
AO2 with Interference Back.jpg
AO2 with Interference Back.jpg (42.35 KiB) Viewed 3516 times
AO2 with Interference 2.jpg
AO2 with Interference 2.jpg (50.81 KiB) Viewed 3516 times
I need to start using these to see what they can do. :roll:

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Re: AO Spencer 15 with Pol or is it an Interference?

#17 Post by Hobbyst46 » Sat Jul 07, 2018 5:04 pm

Apochronaut wrote:and the other is quantitative, allowing for measurements, such as the refractive index of liquids.
For such measurement, the common wavelength is the sodium emission line of 589nm, perhaps such a filter is included to be used with a mercury 100W lamp.
Today, I would have preferred a LED for interference as well as refractive index. The monochromaticity of modern LEDs is better than that of non-dichroic color filters.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

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Re: AO Spencer 15 with Pol or is it an Interference?

#18 Post by MichaelG. » Sat Jul 07, 2018 5:55 pm

Hobbyst46 wrote:... For such measurement, the common wavelength is the sodium emission line of 589nm, perhaps such a filter is included to be used with a mercury 100W lamp.
I think that might be a rather 'extravagant' use of a Mercury lamp.
... Would it not be 'better value' to simply use a Sodium source ?

MichaelG.
.
Mercury lamp spectrum:
http://zeiss-campus.magnet.fsu.edu/arti ... ryarc.html

Low pressure Sodium:
http://www.edisontechcenter.org/SodiumLamps.html
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Re: AO Spencer 15 with Pol or is it an Interference?

#19 Post by Hobbyst46 » Sat Jul 07, 2018 6:54 pm

@MichaelG
Sorry about that, my mistake...the 589nm is not an Hg lamp line. A Sodium lamp was indeed included with Zeiss refractometers.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

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Re: AO Spencer 15 with Pol or is it an Interference?

#20 Post by MichaelG. » Sat Jul 07, 2018 6:57 pm

Hobbyst46 wrote:@MichaelG
Sorry about that, my mistake...
No problem at all, my friend.

MichaelG.
Too many 'projects'

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Re: AO Spencer 15 with Pol or is it an Interference?

#21 Post by Radazz » Wed Jul 25, 2018 3:13 pm

Beautiful scope, congratulations.
I looked at that one as well, but I’ve been collecting the Buffalo NY logo Spensers and shying away from the AO logos for some reason. Personal taste I guess.
The only AO branded scopes I’ve got are an AO 120 and an AO 1030? both infinitely corrected.
Radazz
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apochronaut
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Re: AO Spencer 15 with Pol or is it an Interference?

#22 Post by apochronaut » Wed Jul 25, 2018 3:25 pm

That is really quite a find. There can't be too many of those around. I have the 100x DF water immersion objective for it, if you are interested...but not the condenser. I also have a 9 page catalogue and an April 1961 price list. I have to scan and PDF another catalogue, someday for someone else and I could do this one for you as well, if you like.

The price list, presumably is complete, so it should include everything available for that instrument.

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