Cambridge Instruments (Bausch & Lomb) Stereo Zoom 7 teardown

[muvideo]

Hello,
it's passed a bit of time from my last teardown.
Recently I scored a pair of interesting used devices on ebay.
I was searching for an electrometer, just for the fun of having one in my 'home' lab,
I stumbled accross a seller that had a nice keithley 616 (that will be part of a another thread)
and also a stereo inspection microscope. I couldnt pass on them so I bought both, and here is it :


a Cambridge Instruments (Bausch and Lomb) StereoZoom 7 in very good ahestetic conditions.
Unfortunately the seller didnt had the stand or the eyepieces, but it's is enough fot the price.
This instrument is a “Greenough” microscope, i.e. a the light path that arrives to each eye is
fully separated, no optics are shared between the two paths.
This is different from “Common Main Objective” device, like my other microscope, 
a Lomo MBC-10 where the last optic is shared.
There are some benefits and downsides for each configuration.



The unit has a coaxial illuminator, that injects light directly in the light path, illuminating the
field through the same optics that are used to pick up the image. The illuminator is easily
separated from the unit,


but it seem that each illuminator is adjusted to the main unit


The illuminator itself contains a colored filter wheel and a pair of prisms that deflect
the light in the mai path, while letting pass trough the image that goes to the oculars

[muvideo]

Time to take a look inside, top removed:


Interpupillary distance can be set simply moving the oculars, the prisms will pivot around
the optical axis



The optical assebly can be removed entirely removing 3 screws




Another difference between this scope and the Lomo is the fact that the SZ7 is a continuous
zooming microscope, while the Lomo's magnification factor can be varied in fixed steps.
The variable magnificaition is obtained moving part of the optics, a top set will move
downwards while a bottom set will move upwards, the movement is actuated by the rotation
of the central shaft:

[muvideo]

Here can be appreciated the position that the illuminator assumes in the microscope:




The light generated from the right will be deflected towards the bottom of the scope
where it will light up the sample, the reflected light will then go back upwards to
the eyepieces.

Unfortunately I still dont have the eyepieces to try it out, and cannot use Lomo's ones
since these are strangely 1.25” (more common in telescopes)  while SZ7 are standard
0.975” or 24.5mm diameter  edit: these are 23.2mm diameter, I'm more familiar
with telescope eyepieces than with microscope ones.
 
Now I'm considering buyin this set of eyepieces: ebay #301032060351
http://www.ebay.it/itm/301032060351?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
but any recomendation is welcome, also now I need a stand.

[radhaz]

That's quite the quality scope you have there. I use stereo zooms at work quite a lot, I find them indispensable.

[KJDS]

Those eyepieces have very small viewing holes which I find annoying to use. Find a set of widefield ones if you can.

Something like these

http://www.ebay.co.uk/itm/Pair-of-Super-Widefield-10X-Microscope-Eyepieces-30mm-/190814081296?pt=LH_DefaultDomain_0&hash=item2c6d67d110

[muvideo]

Those eyepieces have very small viewing holes which I find annoying to use. Find a set of widefield ones if you can.

Something like these

http://www.ebay.co.uk/itm/Pair-of-Super-Widefield-10X-Microscope-Eyepieces-30mm-/190814081296?pt=LH_DefaultDomain_0&hash=item2c6d67d110

Thank you for the advice, the diameter of SZ7 eyepieces is 23.2mm not 24.5mm like i said before,
I had im my head old telescope eyepieces diameters. Do you think I have to search for B&L eyepieces
or also the ebay ones are good enough?

[KJDS]

Those eyepieces have very small viewing holes which I find annoying to use. Find a set of widefield ones if you can.

Something like these

http://www.ebay.co.uk/itm/Pair-of-Super-Widefield-10X-Microscope-Eyepieces-30mm-/190814081296?pt=LH_DefaultDomain_0&hash=item2c6d67d110

Thank you for the advice, the diameter of SZ7 eyepieces is 23.2mm not 24.5mm like i said before,
I had im my head old telescope eyepieces diameters. Do you think I have to search for B&L eyepieces
or also the ebay ones are good enough?

If you can find some genuine B&L ones then get them, they'll give a clearer view, however I suspect that you'll be a long time trying to find them and some cheap ones will be ok for now. If you wear glasses then find some with a spectacle symbol on them.

[cippal]

Hello,
I need some help to repair my stereo zoom 7. I'm not able to remove the white top. Could someone help me to do that? Any suggestion?

Thanks a lot for your attention.

Ragards
Sebastiano

[Lunasix]

I think you just need to remove the two black tubes, they are screwed. It was the same method for a Leica GZ3.