Description

Vintage Cooke Troughton & Simms M3000 Research Model Microscope with incident & brightfield illumination c1950s, Cased

Offered for sale is a very capable and well-equipped example of an M3110 binocular research-grade microscope by well-known British optical manufacturers Cooke Troughton & Simms (CTS) of York.  This example will date to around the 1950s and it bears serial number M30393.  It’s in modified condition with sub-stage fittings added to also give brightfield capabilities in addition to its factory incident illumination set-up, making a rather good microscopy proposition, so probably one for the collector or serious amateur.  According to my CTS booklet it’s most likely to be the M3110 Research Model (shown in final few listing photos) with binocular body, universal epi-illuminator and various other accessories as set out in the listing – probably quite a rare example with this type of comprehensive configuration.

The M3000 model series was first introduced by CTS in the late 1940s, with the final examples produced during the mid-1960s when the CTS brand name was dropped by owners Vickers Instruments.  The condition is generally very good for a working instrument, it’s got virtually no signs of wear and it has recently been through a sensitive clean, check-over and lubrication. 

Turning to the main technical details of this quality vintage binocular microscope, we have a U-shaped foot with twin uprights to pivot, with tension adjustment available via lever.  From the pivot point rises the limb in Lister-style arrangement with coarse and fine focus attached.  There’s a binocular eyepiece unit that’s adjustable for both focus by gently twisting the right-hand eyepiece tube and eyepiece separation by gently pulling on the adjustment tabs.  These binocular units are fixed at +1.5x magnification therefore effectively giving the eyepieces a 50% magnification boost.  The binocular head is in good clean condition for its age and works pretty well.  There’s also a monocular eyepiece unit with side photo-tube on a push-pull slider – all in all a very comprehensive set of eyepiece hardware, suiting both monocular, binocular and image capture applications.

There’s also a good range of magnification provided by the eyepieces as follows:

– 5x magnification pair for binocular use
– 8x magnification pair for binocular use

There’s also single eyepieces for the monocular unit:

– 6x magnification with graticule
– 10x magnification with graticule
– 10x magnification with graticule

The range of magnification provided by the eyepieces taking account of the binocular and monocular heads is therefore 6x up to 12x.

The coarse focus system moves the main microscope optical tube in a vertical plane, with its controls at the top of the limb.  There is a lovely smooth action through the twin-sided thumb-wheels – travel and focus are both good with the tube holding position throughout its working range.  Fine focus adjustment essentially works by moving the nose-piece only, therefore the fine focus mechanism doesn’t carry the full weight of the main focus tube and monocular/binocular head and therefore has an almost frictionless action – a neat CTS patented design feature that works very well.  

With is being an M3000 series model, there’s a number of special features over and above the M2000 model making it especially suited for incident microscopy.  These are:

– Additional adjustment to coarse focus range
– The stage has height adjustment via single-sided thumb-wheel control – this is also used for coarse focus adjustment

There’s a useful mixture of progressive magnification objective lenses for brightfield with a rotating 4-way turret which clicks into place positively as each objective is rotated into its viewing position.  The objective lenses are as follows:

– 5x magnification – CTS
– 10x magnification – C. Baker
– 20x magnification – Beck
– 40x magnification – CTS
– 95x magnification – oil immersion – CTS

(The effective overall magnification available from all the different mono/binocular options and eyepieces therefore ranges from 30x to over 1,000x when using oil immersion with the highest magnification combination)

This version of the CTS M3000 tilts for inclined viewing and holds in position well, it can be tightened further as required via the pivot locking mechanism.  The specimen stage is fully mechanical being a CTS rectangular design.  It also has twin thumb-wheel x-axis and y-axis controls mounted the right-hand side of the stage with a locking mechanism to prevent the y-axis slipping on inclination.  There’s a two-part after-market slide holder mechanism for holding samples in place during viewing sessions, which works well.  The stage mechanisms all run nice and smoothly being perfect for holding and manoeuvering slides/specimens of various sizes. 

Incident Illumination

Illumination for incident microscopy is via the CTS Universal Illuminator as shown fitted, with quick-release system for mounting objectives.  This has two interchangeable tubes one for standard incident illumination, the other for incident darkfield (requires suitable objectives – not supplied).  There are various controls on this epi-illuminator including a slider for switching between different types of illumination, an iris and other controls.  It’s a complex component and I’ve included some information on it from a contemporary CTS product brochure, which I can also provide additional information on should the reader be interested.

Objectives for incident illumination:

– CTS 3x button objective with RMS adapter attachment
– 5x metallurgical
– 10x metallurgical
– 20x metallurgical
– 40x metallurgical
– 4mm MET CTS non-RMS (40x)
(There are 4 quick-release fittings both RMS and non-RMS objectives supplied)

In the listing photos I’ve shown the instrument set up for incident illumination in both binocular and monocular styles, using a lighting source of Watson Dalek lamp and PSU – these are not supplied as part of this listing but could be added for an additional GBP 100 – just ask seller for details.  Once the incident light path is established in this manner, coarse focus adjustment switches to stage height adjustment, so as not to disturb the established light path.  Fine focus can be used in the normal manner.

Transmitted Light Illumination/Brightfield

Below-stage, hardware has been added by a previous custodian to give additional brightfield capabilities, which is a very useful addition.  There’s a condenser in a fixed custom mount with a working iris and a swing-out filter holder for adding coloured, opaque or dark-field filters.  

Sample illumination for brightfield is provided via a standard plano-concave mirror on an swiveling gimbal mount, with silvering that’s in excellent condition to both sides. 

Objectives for brightfield:

– CTS 5x
– C. Baker 10x
– Beck 20x
– CTS 40x
– CTS 95x

(The various objectives have correct period canisters)

The overall condition of this M3000 series technical research-grade microscope is really very good and it’s got the benefit of very little evidence of wear to the paint finish, with only the odd minor chip where one would normally expect to see some signs of use for a vintage piece of technical equipment.  It’s also supplied with a sturdy hardwood research-grade storage case with a little fading to its outer surface and some minor shrinkage cracking to the door, but structurally very sound overall.  It’s got a number of internal storage racks for the lenses, metal carry-handle and door that’s got a working lock and key which is always nice to have.

In summary, this is a really well-equipped vintage technical mono/binocular microscope from quality British optical firm CTS that makes an excellent microscopy set-up as it caters for both incident and transmitted light functionality and has an extra port for image capture.  It may therefore appeal to both specialist collectors of technical equipment and of course those seeking a comprehensively equipped good quality CTS M3000 model to add to their collection.  It’s also got an imposing retro look, which makes it a great display piece in its own right.  It’s supplied with a research-grade wooden case which is in pretty good condition and it’s fitted with a precision mechanical stage which is a must for high-magnification use.  It’s essentially usable out of the box with a bit of time spent getting to know it and setting up its various features and controls for optimum viewing results depending on chosen application.

This microscope equipment is very heavy especially in view of the hardwood case and overall weighs in at over 15kg with packaging.  It will be partially dismantled secured to its case with a transit bolt, very well packaged for transport and will be shipped by insured courier upon receipt of cleared funds.  

Thanks for looking.