SOLD: AO Series 10, halogen, 4 objectives - $125.00 + shipping

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dtsh
Posts: 586
Joined: Wed May 01, 2019 6:06 pm
Location: Wisconsin

SOLD: AO Series 10, halogen, 4 objectives - $125.00 + shipping

#1 Post by dtsh » Fri Jan 14, 2022 11:12 pm

It's time for me to clean out my hoard and recover some space.

This is an American Optical Series 10, Serial number 959498

For those not familiar with this series allow me a moment to prattle on about it. I admit up front that I am quite fond of the platform so there is a bias to be aware of, but I think most will agree that not only are these quite nice instuments, you'll be hard-presssed to find anything comparable anywhere near this price.

In 1961, AO decided to focus their efforts on infinity corrected optics and introduced their 34mm parfocal infinity system at a time when the rest of the industry was focused on using finite tube lengths such as the common 160mm TL microscope. It’s hard to discuss some of the features without an understanding of infinite vs finite, but I’m only going to cover some of the very basic concepts. In an infinity system, the light bundle that comes out of the back of the objective is effectively parallel and it uses a telan lens in the base of the head to convert that parallel bundle into a beam that converges to a focus to be picked up by the eyepieces. What this means is that, theoretically the objective and the head can have a variable distance between them and still work as a complete system delivering a useful image at the correct magnification. This might not seem especially useful at first, but it allows adding various analyzers and other instruments into the path without affecting the focus of the final image, a feature that finite systems struggle with, making the same product capable of a variety of advanced techniques easily by adding modules to extend functionality. There were a lot of these made with a variety of add-ons allowing brightfield, epi illumination, darkfield, phase contrast, fluoresence microscopy, and more just by adding or swapping out components.

An additional feature that’s easy to overlook at first glance is that this allows changing the way focus is achieved. With the 34mm infinity system, AO was able to alter the design so that adjusting the focus raises and lowers the nose instead of the stage while the head remains fixed. This might seem trivial, but it allows something few other systems could achieve; effectively removing the possibility of crushing a slide and objective together and destroying one or both as the nose simply comes to rest on top of the slide instead of being driven into it. Another added benefit is the ability to quickly change objectives and cycle through uniform slides while maintaining focus, requiring only minor adjustment of the fine focus to account for the minor deviations. Here’s an excerpt from the manual, describing the process.

“The autofocus stop is pre-set at the factory. It is the stop which limits the height of the stage. This setting is valid for slides anywhere from 0.50 to 2.5 mm, in thickness. Because of the highly precise tolerances held in the manufacture of the objectives, it is possible to search the slide with 10x or 45x objectives, find the required field for study under oil immersion, raise the coarse adjustment, swing to the oil immersion objective, apply oil to slide, and lower the coarse adjustment rapidly to its positive stop. The subject will be in focus within a touch of the fine adjustment with absolutely no danger of touching the slide.”

This leads to a discussion of the focus mechanism which I personally consider beautiful in it’s simple elegance. Here’s a link to the AO 10 manual (there are other versions of the manual at PS Neeley’s):
https://user.xmission.com/~psneeley/Per ... ersion.pdf

Unlike some manuals, the AO 10 manual is a pretty good resource for getting familiar with using the instrument and is worth a read. It is not a repair manual nor is it an introduction to microscopy, but it does contain exploded parts diagrams which can be quite useful, such as this one regarding the focus which I was just discussing:
AO10_focus1.jpg
AO10_focus1.jpg (94.24 KiB) Viewed 197 times
If you study the above image, you’ll see that it is effectively a very large screwform. Within the thread form of the coarse focus rides a ball that is connected to an arm which translates lateral motion of the ball into vertical motion of the arm upon which the nose and objectives are mounted, thus raising or lowering the head as the ball moves from one side to the other. A look at the parts diagram in the back of the manual shows the larger screwform with a smaller and finer screw inside it; the larger is the coarse focus and the smaller, the fine. Rotation of the fine focus moves the block which is the larger coarse focus laterally. Of note, the arm and ball are loaded by gravity; this permits largely slop-free focus and reduces the risk of damaging slides or objectives by accidentally crushing them together. That later being a feature that should stand out to anyone who’s accidentally crushed an expensive/loved slide under an objective.

This series are well built quality microscopes, usual problems with these are frozen greese in the head and focus mechanism, but this one has been cleaned and relubed so that is not a concern.

This series uses AO's 34mm parfocal infinity objectives, a product line AO used for many years over a variety of models. This particular scope is equipped with a 4x/0.12NA Cat.1017 plan achro, 10x/0.25NA Cat.1019 plan achro, 40x/0.66NA Cat.1023 plan achro, and a 100x/1.25NA Cat.1079 achromat. For those not familiar, plan objectes provide a "flat field" over most of the field of view where an achromat that isn't plan will be in focus at the center, but the periphery will become more and more out of focus.

This unit comes with a 1.25NA Aspheric condenser Cat.1084 with the optional swing-in auxilliary lens to fully illuminate the field for the 4x objective.

The stage is not the standard basic stage, but has vernier measurement scales for both the X and Y axis. The focus knobs are marked with 1 micron increments, which provides measurement in the Z axis.

The illuminator is the 6V 20watt halogen lamp with a built-in transformer and to provide variable intensity (Philips #7388) which was one of the best illuminators available for the series. The illuminator includes a built-in 10% neutral density filter (the smaller right knob) which can swing-in to reduce the light intensity when needed. It has what is known as "modified koehler" illumination, which means that there is a frosted lens after the bulb to provide diffuse and even illumination of the field and a centerable field iris. The result is that you can achieve Koehler illumination without having to adjust the lamp, but retain the adjustable field iris to reduce stray light from reducing contrast.

The head is the trinocular with the ability to flip between 100% light to the eyepieces or 100% to the photo port. The photo-tube is NOT provided, but can typically be acquired for around $50.00.

The scope comes with a pair of 10x Cat.176 eyepieces. A pair of 15x Cat.184 eyepiece can be included for an extra $35.00

This microscope is used and shows signs of wear and has a few nics and blemishes as one would expect from an instrument that's 50 years old. It's in good serviceable shape and everything works as it's supposed to. I believe in the value of these scopes enough to offer that if you aren't happy with it, you have 60 days to send it back and I'll refund your money, no questions asked (I'll eat the shipping sending, you returning). If it's damaged in shipping, that's all my expense.

Now for the images....
AO10_1031_1.jpg
AO10_1031_1.jpg (111.18 KiB) Viewed 197 times
AO10_1031_2.jpg
AO10_1031_2.jpg (88.38 KiB) Viewed 197 times
AO10_1031_3.jpg
AO10_1031_3.jpg (84.79 KiB) Viewed 197 times
AO10_1031_5.jpg
AO10_1031_5.jpg (87.51 KiB) Viewed 197 times
Last edited by dtsh on Tue Jan 18, 2022 11:52 pm, edited 2 times in total.

dtsh
Posts: 586
Joined: Wed May 01, 2019 6:06 pm
Location: Wisconsin

Re: For sale: AO Series 10, halogen, 4 objectives - $125.00

#2 Post by dtsh » Fri Jan 14, 2022 11:23 pm

Please don't judge the scope too harshly based on my abilty (or lack thereof) to take good photos.

I felt some images of a calibration slide would provide good examples of the plan objectives and be a good measure of performance. I have left the images largely unmodified, so bits of dust will show up and the banding from not having the shutter speed adjusted, but the performance of the system should be apparent. The divisions are 0.01mm

Here is the 4x Cat.1017
Cal_4x_1017.jpg
Cal_4x_1017.jpg (56.5 KiB) Viewed 195 times
10x Cat.1019
Cal_10x_1019.jpg
Cal_10x_1019.jpg (59.9 KiB) Viewed 195 times
40x Cat.1023
Cal_40x_1023.jpg
Cal_40x_1023.jpg (120.52 KiB) Viewed 178 times
100x Cat.1079
Cal_100x_1079.jpg
Cal_100x_1079.jpg (63.89 KiB) Viewed 195 times
Pay attention to the edge of the field on the 100x and you should see the difference between the plan and non-plan objectives as the focus starts to drift toward the periphery.
Last edited by dtsh on Sat Jan 15, 2022 12:30 am, edited 4 times in total.

dtsh
Posts: 586
Joined: Wed May 01, 2019 6:06 pm
Location: Wisconsin

Re: For sale: AO Series 10, halogen, 4 objectives - $125.00

#3 Post by dtsh » Fri Jan 14, 2022 11:28 pm

Please don't judge the scope too harshly based on my abilty (or lack thereof) to take good photos.
Understand that these are image stacks and not single images. I can provide photos of some other specimens if desired.

The subject is a wing of a species of Chrysops (deer fly), unprofessionally mounted by me in PVOH-G mountant.

4x Cat.1017
1017_Chrysops_stack.jpg
1017_Chrysops_stack.jpg (133.35 KiB) Viewed 194 times
10x Cat.1019
1019_Chrysops_stack.jpg
1019_Chrysops_stack.jpg (213.68 KiB) Viewed 194 times
40x Cat.1023
1023_Chrysops_stack.jpg
1023_Chrysops_stack.jpg (181.17 KiB) Viewed 177 times
100x Cat.1079
1079_Chrysops_stack.jpg
1079_Chrysops_stack.jpg (142.71 KiB) Viewed 194 times
Last edited by dtsh on Sat Jan 15, 2022 12:38 am, edited 1 time in total.

dtsh
Posts: 586
Joined: Wed May 01, 2019 6:06 pm
Location: Wisconsin

Re: For sale: AO Series 10, halogen, 4 objectives - $125.00 + shipping

#4 Post by dtsh » Sat Jan 15, 2022 12:37 am

Please don't judge the scope too harshly based on my abilty (or lack thereof) to take good photos.

These however are siingle images of a section of Rannunculus stem, commmercially prepared.

4x Cat.1017
Rannunculus_4x.jpg
Rannunculus_4x.jpg (128.55 KiB) Viewed 174 times
10x Cat.1019
Rannunculus_10x.jpg
Rannunculus_10x.jpg (205.12 KiB) Viewed 174 times
40x Cat.1023
Rannunculus_40x.jpg
Rannunculus_40x.jpg (213.26 KiB) Viewed 174 times
100x Cat.1079
Rannunculus_100x.jpg
Rannunculus_100x.jpg (122.16 KiB) Viewed 174 times

Dubious
Posts: 291
Joined: Sun May 09, 2021 7:55 pm

Re: For sale: AO Series 10, halogen, 4 objectives - $125.00 + shipping

#5 Post by Dubious » Sat Jan 15, 2022 1:14 am

PM sent.

PeteM
Posts: 2090
Joined: Tue Dec 06, 2016 6:22 am
Location: N. California

Re: For sale: AO Series 10, halogen, 4 objectives - $125.00 + shipping

#6 Post by PeteM » Sat Jan 15, 2022 3:37 am

These are nice scopes and $125 is a bargain.

Hobbyst46
Posts: 3713
Joined: Mon Aug 21, 2017 9:02 pm

Re: For sale: AO Series 10, halogen, 4 objectives - $125.00 + shipping

#7 Post by Hobbyst46 » Sat Jan 15, 2022 9:43 am

dtsh, what a beautifully arranged thread!!. Should set a standard for sellers of used microscopes, regardless of conditions.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

marqnielson
Posts: 1
Joined: Sun Jan 16, 2022 7:57 am

Re: For sale: AO Series 10, halogen, 4 objectives - $125.00 + shipping

#8 Post by marqnielson » Sun Jan 16, 2022 8:46 am

I am new here and can't send PMs just yet. Is this still available?

dtsh
Posts: 586
Joined: Wed May 01, 2019 6:06 pm
Location: Wisconsin

Re: For sale: AO Series 10, halogen, 4 objectives - $125.00 + shipping

#9 Post by dtsh » Sun Jan 16, 2022 4:51 pm

marqnielson wrote:
Sun Jan 16, 2022 8:46 am
I am new here and can't send PMs just yet. Is this still available?
It is likely sold, but if that doesn't work out I will send you a PM sometime next week.

I have another one I should be finishing in the next few weeks, with it I intend to show a tear down and reassembly of some of the common faults on the AO10, which is largely limited to grease seizing in the focus mechanism and head after many decades and basic cleaning. The simple beauty of the mechanisms in the AO10 is part of what I love about it, if one is careful to not disturb the optical alignment of various parts, there are only a few specialty tools needed to work on them. A couple of screwdrivers, allen wrenches, and a bristol spline wrench for the head.

dtsh
Posts: 586
Joined: Wed May 01, 2019 6:06 pm
Location: Wisconsin

Re: SOLD: AO Series 10, halogen, 4 objectives - $125.00 + shipping

#10 Post by dtsh » Tue Jan 18, 2022 11:52 pm

This one is gone. Thanks for the interest.

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