OPTARC x40 User manual

OptArc x40 dry and x100 oil
Objectives
User Guide
Document created: 18.09.2022, Last edited: 18.09.2022
Manual prepared by OptArc − Designers
and manu acturers o custom optical and
optoelectronic systems using 3D printing
rapid prototyping and based in the UK.
See optarc.co.uk or details.

Sa ety In ormation
Identi ication o risk
Throughout this manual please take heed of warnings given in bold text and
highlighted yellow to avoid possi le damage to equipment and/or harm to people.
Risk to vulnerable groups
OptArc la supplies and equipment are not toys. They contain small parts which may
come loose, glass components that may splinter or reak or otherwise present a
choking or sharp o ject hazard or chemical hazard. Please do not let babies or
young children play with or gain access to any aspect o this product. Older
children should only access this product with close appropriate adult
supervision. Likewise keep this product away rom pets.
OptArc x40 and x100 oil Objectives Page 2 of 16 User Guide v1.0

Contents
Safety Information.............................................................................................................2
Identification of risk.......................................................................................................2
Risk to vulnera le groups.............................................................................................2
Download link for PDF version of this Manual..................................................................4
Legal Information..............................................................................................................5
Copyright.......................................................................................................................5
Trade Marks..................................................................................................................5
Limitations of Use.........................................................................................................5
Disclaimer.....................................................................................................................5
Introduction........................................................................................................................6
Need for a condenser lens................................................................................................7
...........................................................................................................................................8
...........................................................................................................................................8
How to insert and remove a specimen for use with the x40 (dry) o jective.....................9
How to insert and remove a specimen for use with the x100 (oil immersion) o jective.12
Maintenance....................................................................................................................14
Immersion medium.....................................................................................................14
Cleaning......................................................................................................................14
OptArc x40 and x100 oil Objectives Page of 16 User Guide v1.0

Download link or PDF version o this Manual
OptArc x40 and x100 oil Objectives Page 4 of 16 User Guide v1.0
You can download the latest version of this User’s Manual
as a PDF file from the Support section of the OptArc
we site via this link:
https://www.optarc.co.uk/support/

Legal In ormation
Copyright
This user’s manual is copyright © 2022 y Dr Paul J. Tadrous. All rights reserved.
Trade Marks
OptArc and the OptArc logo are Registered Trade Marks of Dr Paul J. Tadrous
(registered with the UK Intellectual Property Office).
Limitations o Use
These products are released to e used for research and educational purposes only.
Disclaimer
Only competent people trained in the use of microscopy and the handling of la oratory
equipment should use this product.
Dr Paul J. Tadrous, TadPath and OptArc cannot accept any lia ility for any loss or
damages that may occur from the misuse or mis-handling of this product.
OptArc x40 and x100 oil Objectives Page 5 of 16 User Guide v1.0

Introduction
The OptArc high magnification o jectives (x40 and x100 oil) allow fine morphological
features to e seen at magnifications of x400 and x1000 when used with a x10
eyepiece.
Unlike the lower magnification o jectives, these lenses have a long casing that
restricts the clearance o the specimen rom the lens. This means that it is
relatively easy or the specimen or slide to come into physical contact with the
objective lens and this may cause damage to the specimen and/or the objective
lens i not handled correctly.
The purpose of this manual is to provide the necessary guidance to minimise the risk of
adverse consequences to the sample and o jectives y descri ing safe methods of
use.
These issues are also relevant regardless of the supplier of the o jective lens – even if
you are using lenses that are not supplied y OptArc. Also, even if you are an
experienced microscopist with traditional ench top la oratory microscopes, the unique
design of the PUMA microscope poses its own challenges. So please read this manual
fully efore first fitting or using any high magnification o jective lens with a PUMA
microscope
OptArc x40 and x100 oil Objectives Page 6 of 16 User Guide v1.0

Need or a condenser lens
The x40 o jective has a numerical aperture (NA) of 0.65 and the x100 oil has a
maximum NA of 1.25. These o jectives will, therefore, only give good quality images if
they are used with a wide angled eam illumination system. Without such illumination
the images will appear ‘tinny’, hypercontrasted, dark, overly refractile and lacking in
resolution.
Such an illumination system is conventionally
achieved y means of a condenser lens.
For transillumination the PUMA A e condenser
is recommended (figure 1).
For co-axial epi-illumination the o jective lens
itself will act as a well-matched condenser
system.
The full Köhler illuminator is not a pre-requisite
ut it will provide good quality full-field flat trans-
illumination when used in conjunction with the
A e condenser
For more detail a out condenser lens systems
see the following videos on the PUMA
microscope YouTu e channel:
A e condenser video
https://youtu. e/2wpsvA2cQgQ
OptArc x40 and x100 oil Objectives Page 7 of 16 User Guide v1.0
Figure 1. The optional PUMA A e
condenser upgrade is recommended
for use with high magnification
o jectives.

Epi-illumination video
https://youtu. e/cAEB10K8PqI
Köhler illumination video
https://youtu. e/XEE-el7vC5k
OptArc x40 and x100 oil Objectives Page 8 of 16 User Guide v1.0

How to insert and remove a specimen or use with
the x40 (dry) objective
Because the PUMA microscope does not have a swing out o jective turret and space
on the stage is very limited (compared to a conventional ench-top microscope), there
is a danger that inserting a slide onto the stage with the objective in place could
result in an edge or corner o the glass slide coming into contact with the ront
lens o the objective and scratching it. This will permanently damage the o jective
and cause loss of image clarity. A non-coverslipped slide or specimen has an even
greater risk of the specimen contaminating or scratching the lens if it comes into
contact.
For that reason the recommended procedure for inserting and removing a cover-
slipped glass slide when using a high magnification o jective is as follows:
1. With a low power lens in place (like the x4 lens that comes with a Foundation scope
kit), insert your slide onto the stage and focus the microscope.
2. Move the slide till the the area of interest is in the centre of the low power field of
view.
3. Raise the focus platform y two full rotations of the fine focus gear (ensure you are
raising it – to increase the distance etween the slide on the stage and the o jective
fixed to the focus platform – not lowering it – see figure 2).
OptArc x40 and x100 oil Objectives Page 9 of 16 User Guide v1.0
Figure 2. Turn the fine (or coarse) gear in the anti-clockwise direction to raise the
focus plate and lift the o jective away from the specimen on the stage.

4. Remove the optical tu e from the microscope and change the o jective to your high
power o jective. Ensure it is screwed in fully to the RMS thread.
5. Re-insert the optical tu e. When fully inserted look closely from the side to ensure
there is still a gap etween the front lens of the o jective and the slide on the stage. If
there is no gap then you should raise the focus plate till you see at least a 1 mm gap
(see figure 3)
You can now focus the microscope with the fine focus wheel while looking down an
ocular lens till the specimen is in focus. If you find you are making excessive turns of
the fine focus gear (more than two full turns) then look again at the gap etween the
o jective and the slide to ensure you have not gone too far down and made contact
with the slide. If you have made contact then raise the focus platform with the focus
gear until you get at least (a out) 2 mm clearance etween the o jective and the
specimen and try again. Ensuring that some contrasting feature is present in the field of
view will assist the focussing endeavour. Another potential pitfall is that the focus
platform gets stuck so does not lower when you turn the focus gear. See the video on
trou leshooting the Z stage for more information a out that and how to fix it:
https://youtu. e/ffLx28N85u
OptArc x40 and x100 oil Objectives Page 10 of 16 User Guide v1.0
Figure 3. Looking at the x40 o jective from the side, the slide will e in focus when
the working distance (the gap etween the lower lens of the o jective and the top
surface of the coverslip) is a out 1 mm, as shown. This is also a out the same
distance as the pitch of the thread in the focus post olt (seen on the left).

While the coverslipped specimen is in focus you can carefully slide the specimen
around the stage ut e very careful not to raise it, especially when the edge of the
sample of a coverslip is near the o jective lens, to avoid scratching the lens.
I your sample is not cover-slipped specimen then even more caution is required to
avoid contact etween the specimen and the o jective lens. In this cases I recommend
several (more than 4) full rotations of the fine gear to raise the focus platform in step 3
a ove and careful direct vision from the side when re-inserting the optical tu e in step
5 (stop and remove the tu e if it appears that the o jective may e coming close to
making contact with the sample). Also i moving a non-coverslipped specimen
around on the stage take care than any elevated parts do not crash into the lens
(like components on a printed circuit oard) – careful frequent o servation from the side
while moving the sample around is required.
The x40 o jective is a dry o jective. You must not get any immersion oil or water or
other substance onto the lens sur ace o this objective. If you are going to o serve
a specimen with this o jective that has just een o served with a x100 oil o jective, e
sure to first wipe and clean off any oil that remains on the surface of the specimen from
your previous o servations efore putting the x40 lens in place. See the ‘Maintenance’
chapter for more a out how to look after your o jective.
To remove a specimen after completing o servations with the x40 lens use the
following procedure:
1. First ensure there is good clearance etween the o jective and the specimen ( y
looking from the side). This should already e the case if you were making
o servations in focus for coverslipped slides ut if you have een o serving non-
coverslipped specimens like a PCB then elevating the focus platform to provide extra
clearance from surrounding o jects may e a wise precautionary measure at this stage.
2. Remove the optical tu e from the scope
3. Remove the specimen from the stage.
OptArc x40 and x100 oil Objectives Page 11 of 16 User Guide v1.0

How to insert and remove a specimen or use with
the x100 (oil immersion) objective
Because the PUMA microscope does not have a swing out o jective turret and space
on the stage is very limited (compared to a conventional ench-top microscope), there
is a danger that inserting a slide onto the stage with the objective in place could
result in an edge or corner o the glass slide coming into contact with the ront
lens o the objective and scratching it. This will permanently damage the o jective
and cause loss of image clarity. A non-coverslipped slide or specimen has an even
greater risk of the specimen contaminating or scratching the lens if it comes into
contact. For oil immersion o jectives this risk is even greater than with dry o jectives
(like the x40) so we recommend that you only use oil immersion (or specialist
water immersion) objectives with coverslipped specimens.
The recommended procedure for inserting and removing a cover-slipped glass slide
when using a x100 oil immersion o jective is as follows:
1. With a low power lens in place (like the x4 lens that comes with a Foundation scope
kit), insert your slide onto the stage and focus the microscope. If you are going to oil the
PUMA A e condenser for maximum enefit, first put one or two drops of immersion oil
on the top lens of the condenser then insert your slide onto it to get a layer of
immersion oil spreading etween the undersurface of your slide and the top lens of the
condenser. Do not put any oil onto the coverslip at this stage. Please note, not all
condensers are suita le for oiling in this way. The PUMA A e condenser is suita le y
design. If you are using any other condenser please check with its specifications as to
whether it may e oiled. Do not oil a condenser that is not designed for oiling or oil may
get inside the lens system and damage it. For the PUMA A e condenser use only one
or two drops of oil and e sure to wipe excess oil off the condenser after the slide has
een removed at the end of your imaging session.
2. Move the slide till the the area of interest is in the centre of the low power field of
view.
3. Raise the focus platform y two full rotations of the fine focus gear (ensure you are
raising it – to increase the distance etween the slide on the stage and the o jective
fixed to the focus platform – not lowering it – see figure 2).
4. Remove the optical tu e from the microscope and change the o jective to your high
power o jective. Ensure it is screwed in fully to the RMS thread. I recommend that you
first focus the scope with a dry high power o jective if you have one (such as the x40
o jective) following the procedure for inserting and focussing the x40 dry o jective from
step 4 onwards as descri ed in the section on ‘How to insert and remove a specimen
for use with the x40 (dry) o jective’ a ove. This helps you centre in on whatever high
power field of view you want to examine y oil ecause it will e unlikely that you will e
a le to see such detail with a low power x4 o jective). This also gets the scope into a
etter par-focal situation so you will not e far out of focus if you first focus with a x40
dry o jective efore switching to the x100 oil. Once you have located you field of
interest with the dry x40 o jective, raise the focus platform y two full rotations and
remove the optical tu e. Replace the dry x40 lens with your oil immersion x100 lens.
OptArc x40 and x100 oil Objectives Page 12 of 16 User Guide v1.0

5. With the optical tu e removed, place a drop of synthetic microscope immersion oil
onto the coverslip in the centre of the field of view. Do NOT put oil directly onto the
objective lens (the lens will eventually ‘dip in’ to the oil on the coverslip as descri ed
elow ut you do not apply the oil directly to the lens). Do not use excessive amounts
of oil. Literally one or two drops is all that is required.
6. Re-insert the optical tu e containing your x100 oil lens. When fully inserted look
closely from the side to ensure the front of the lens makes contact with the oil on the
slide coverslip. If it has not made contact even after ensuring the optical tu e is fully
inserted, this is OK, it just means you will need to first lower the focus platform with the
fine focus gear till contact with the oil is made. You should also ensure that the
o jective spring-loaded mechanism has not een activated – if it has then the o jective
is too close to the specimen and your first focussing action must ee to raise the focus
platform till the o jective is lifted slightly off the coverslip.
You can now focus the microscope while looking down an ocular lens till the specimen
is in focus. If you find you are making excessive turns of the fine focus gear (more than
two full turns) without achieving focus then look again from the side at the gap etween
the o jective and the slide to ensure you have not gone too far down and activated the
spring retraction mechanism, or too far up and separated the o jective lens from the oil
layer. Ensuring that some contrasting feature is present in the field of view will assist
the focussing endeavour.
While the specimen is in focus you can carefully slide the specimen around the stage
ut e very careful to to raise it, especially when the edge of the sample of a coverslip
is near the o jective lens, to avoid scratching the lens.
To remove a specimen after completing o servations with the x100 oil lens use the
following procedure:
1. First ensure there is good clearance etween the o jective and the specimen ( y
looking from the side). You should elevate the focus platform y a few turns to provide
extra clearance from surrounding o jects.
2. Remove the optical tu e from the scope ut take great care to keep the objective
lens in its working upright position at all times. Do not let it lay on its side or turn
it upside down or immersion oil may drip and ooze into its protective spring
mechanism and casing. At this stage, there ore, you should have a clean lens
tissue handy to wipe away excess immersion oil rom the ront lens and
surrounding metal be ore putting the optical tube down.
3. Remove the specimen from the stage.
Remove the o jective from the optical tu e and continue to wipe clean the front surface
of the o jective with a lens tissue efore keeping it safe in its supplied case prior to next
use.
See the ‘Maintenance’ chapter for more information.
OptArc x40 and x100 oil Objectives Page 1 of 16 User Guide v1.0

Maintenance
Immersion medium
The x40 o jective must e used dry without an immersion medium of any kind. If any
immersion medium gets onto the lens you should clean it off efore further use. See
‘Cleaning’ elow.
The x100 oil immersion o jective is designed to e used with only synthetic microscope
immersion oil. Natural immersion oils like Cedarwood oil must be avoided
because they dry to a crust on the sur ace o the lenses that can damage the lens
sur ace when cleaning off. A synthetic immersion oil with the DIN/ISO standard
refractive index of 1.518 is generally recommended. Alternative immersion media such
as water or glycerol may e used ut if using such media it is important that any trace
of a previously used medium e cleaned off the lens (and specimen coverslip) first. In
general if you choose to change over to a different immersion medium any trace of the
previously used used medium must e cleaned off the lens (and sample) efore
switching.
Cleaning
The o jectives should not require routine cleaning other than removing oil or other
immersion medium from the front lens of the x100 oil o jective. However if the exposed
lenses ecome soiled then the following guidance may e helpful.
If lenses are soiled y simple falling solid de ris like dry dust, pollen etc. then an air
duster may e used to low these fragments off the surface of the lens. If this does not
work then consult a specialist microscope technician for advice. Wiping a lens that
has dry debris on it (even with a special lens paper wipe) runs the risk o
scratching the lens or its coating, so this type o ‘wipe-cleaning’ must be avoided
in such circumstances. A small amount of residual dry dust contamination will not
usually need cleaning ecause it is unlikely to cause significant deterioration of the
image. Over-cleaning or overly aggressive cleaning may do more harm in the long run.
If the front lens gets contaminated y immersion oil or grease (e.g. from a finger print)
or other pure fluid then the lens may e cleaned using special lens paper with or
without simple reath condensation or pure isopropyl alcohol. Do not use domestic
tissues or other cloths (because these may cause scratches to the lens or its
coating and/or leave dust and debris behind). Do not use more aggressive
solvents like acetone or xylene because these may damage the cements used to
keep the lenses in place.
For removing such fluid contamination first wipe off excess fluid with a dry lens paper.
Then make a few more passes with a clean lens paper using either your reath
condensation as applied moisture to the surface of the lens or put a drop of pure
(99.9%) isopropyl alcohol onto the lens paper (not the surface of the lens) prior to
wiping.
OptArc x40 and x100 oil Objectives Page 14 of 16 User Guide v1.0

Always clean the oil (or other immersion medium) off the surface of the x100 oil lens
after each imaging session and do not leave oil on the lens overnight when not in use.
When not in use, keep your o jectives in their protective cases.
These lenses do not have any user-servicea le parts inside. Do not dismantle them.
As descri ed in a previous section, if you are using an oiled condenser ensure that all
excess oil is wiped off the top surface lens of the condenser after removing the slide at
the end of your imaging session and remove oil from the surfaces of the slide as well.
An ordinary household paper towel or tissue may e used for that purpose.
A tip to prevent any plastic dust of other de ris from falling into the ack of any
o jective lens is to use a clean plain round glass coverslip (17 to 18 mm diameter) in a
filter slider in the lowest filter slot in the filter lock (see figure 4). This ‘plain glass filter’
will act as a physical arrier preventing any plastic dust or de ris from falling into the
ack of the o jective as you manipulate the scope and insert and remove various
ocular attachments and higher filters. From time to time you can remove this lower plain
glass filter and clean it from any fallen de ris. This is much prefera le to cleaning the
o jective lens and in most cases it will not e significantly detrimental to image quality.
OptArc x40 and x100 oil Objectives Page 15 of 16 User Guide v1.0
Figure 4. Protect your o jectives from falling de ris inside the optical tu e y making
a plain glass filter with a plain 18 mm diameter coverslip in a PUMA filter slider-holder
as shown (inset) and keep this ‘filter’ in the lowest filter slot of your microscope.

[End of Document]
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