AO series 10 trino head cleaning

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henryr
Posts: 182
Joined: Sat Aug 29, 2015 12:29 pm

AO series 10 trino head cleaning

#1 Post by henryr » Thu Nov 19, 2020 3:53 pm

I'm very close to buying a series 10 but some have a less than clean image when looking through the eyepieces. And some have no cover over the vertical tube or the binoc tubes so could stuff have fallen on the prisms? So is it an easy or difficult task to clean the prisms? Here is an example of what I've seen.
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apochronaut
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Joined: Fri May 15, 2015 12:15 am

Re: AO series 10 trino head cleaning

#2 Post by apochronaut » Thu Nov 19, 2020 5:42 pm

What exactly are you looking at there? Down through an eyepiece with the illuminator turned on?

henryr
Posts: 182
Joined: Sat Aug 29, 2015 12:29 pm

Re: AO series 10 trino head cleaning

#3 Post by henryr » Thu Nov 19, 2020 6:14 pm

That I was told, buy the seller, that the photo is looking through the eyepieces with the light on.

apochronaut
Posts: 6268
Joined: Fri May 15, 2015 12:15 am

Re: AO series 10 trino head cleaning

#4 Post by apochronaut » Thu Nov 19, 2020 11:06 pm

So , most of what you are seeing is at or near to whatever conjugate planes the cell camera is focused on plus the plane at or near to the field stop, which is a fixed focal point of the projection lens in the ocular.

Due to the focus differential between numbers of those bits of dust and debris and the coma and lateral ca some are being distorted by, I would say that you have at least four locations that all that stuff is residing on. 1) the eyelens. at least the upper surface but based on my experience , the lower surface too. 2) the field lens , again on the exterior surface but more likely than not the upper surface too. 3) the exterior or lower surface of the telan lens in the bottom of the head. 4) the top of the upper condenser lens and probably the bottom of the condenser collector lens too.

Cleaning those surfaces should get about 90% of it and access to those surfaces is pretty easy.

Dust or film inside the head is not that visible. If it was, most microscopists would go insane fairly quickly. The greatest effect of dust, debris or film on the interior surfaces of of a head show up as a loss of contrast and illumination intensity. Under low light conditions and using a 100X oil objective on the 10, one can detect debris on the first surface of the deviating prism as a defocused smudge.
It's not unusual for a microscope that is between 40 and 55 years old to be due for a dustoff, irregardless of brand. The 10 is a good choice . The thing about the AO 10 is that it is a 10. It is hard to find another model of miroscope that can perform to it's level at the same price. The only really desirable accessory for the amateur that is off the table for a 10 or it's 100 watt big brother 20 for that matter is DIC. Oh , it exists but try to find one.
What are available are, Dark , Bright and 100X B-Minus phase , incident and trsnsmitted fluorescence , toric and cardioid oil DF, advanced planachros that perform like some competitor's planfluorites, several planapo options, 5 position nosepiece ,an easy photo option with widely available trinocular heads, very sturdy and all machined metal durable construction, a wide flat field, 4 condenser options, left and right stage options , easy to find teaching head, cheap and easy pol accessories, vertical illuminator and planachro epi objectives available.
All those options in a microscope stand that can be purchased for less than 200.00 any day of the year.
A thread ran just a couple of weeks ago about the best microscope for upgrading. The AO 10 was never mentioned I recall, because the assumption is that the endpoint of upgrading a scope is DIC. It seems that only DIC capable scopes were considered for that thread but outside of that consideration, the AO 10 has to be one of the great, inexpensive, upgradeable small footprint microscopes of all time.......and in the last 5 years, I have seen about 7 DIC components for one for sale, so that isn't an impossibility , either.
Last edited by apochronaut on Fri Nov 20, 2020 2:21 am, edited 1 time in total.

henryr
Posts: 182
Joined: Sat Aug 29, 2015 12:29 pm

Re: AO series 10 trino head cleaning

#5 Post by henryr » Fri Nov 20, 2020 1:09 am

Thanks for an in-depth description of various causes of dirty looking images. I enjoy your very enlightening and interesting posts.

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