Are there any drawbacks to an Inverted microscope? I mean it seems like all brightfield microscopes should be inverted for each access to the specimen while viewing.
Is there some reason why I would not want an inverted microscope? Are they bad at something that a normal microscope is good at?
Drawbacks to an inverted microscope?
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Charles Krebs
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Welcome to the group.
My experience is 99% upright. I do have an old Olympus CK inverted which has let me dabble with rudimentary inverted usage. (And it's caused me to come very close on a couple of occasions to jumping in more seriously!) They have some obvious advantages with certain subjects.
You asked about disadvantages. Just about anything that might be considered a "disadvantage" can be overcome with some of the newer inverted scopes. But these can cost a fortune, so I'll give a few considerations that do crop up with some of the older used ones. (Hopefully a more well versed inverted user will jump in with other thoughts.)
Condensers are very often a long working distance designs. This means that many are limited to a NA of 0.30 to 0.50. With these condensers, objectives with higher NA's can not produce the resolution they are capable of. And this is why it's not unusual to see a 40X as the highest power objective on these scopes. (And frankly, if it is a 0.30 NA condenser it can't do a decent 40X justice).
In order to be able to focus through the bottom of a slide, dish, or container, the objectives used are also often LWD designs. There will be fewer of this type to choose from, and they sometimes have lower NA's than their upright counterparts. If you want to use some of the really nice objectives that were designed to be used with 0.17mm cover slips, wet mounts will sometimes require "custom" containers and some inventiveness.
These are the two main things that I think about. If you anticipate that a 40X objective is the most powerful you will need, and can get a condenser with a useful NA then most of these concerns disappear. If you really want to use more powerful objectives, or ones where the NA greatly exceeds the available condensers then you need to think and look things over more carefully.
My experience is 99% upright. I do have an old Olympus CK inverted which has let me dabble with rudimentary inverted usage. (And it's caused me to come very close on a couple of occasions to jumping in more seriously!) They have some obvious advantages with certain subjects.
You asked about disadvantages. Just about anything that might be considered a "disadvantage" can be overcome with some of the newer inverted scopes. But these can cost a fortune, so I'll give a few considerations that do crop up with some of the older used ones. (Hopefully a more well versed inverted user will jump in with other thoughts.)
Condensers are very often a long working distance designs. This means that many are limited to a NA of 0.30 to 0.50. With these condensers, objectives with higher NA's can not produce the resolution they are capable of. And this is why it's not unusual to see a 40X as the highest power objective on these scopes. (And frankly, if it is a 0.30 NA condenser it can't do a decent 40X justice).
In order to be able to focus through the bottom of a slide, dish, or container, the objectives used are also often LWD designs. There will be fewer of this type to choose from, and they sometimes have lower NA's than their upright counterparts. If you want to use some of the really nice objectives that were designed to be used with 0.17mm cover slips, wet mounts will sometimes require "custom" containers and some inventiveness.
These are the two main things that I think about. If you anticipate that a 40X objective is the most powerful you will need, and can get a condenser with a useful NA then most of these concerns disappear. If you really want to use more powerful objectives, or ones where the NA greatly exceeds the available condensers then you need to think and look things over more carefully.
Inverted microscopes fall into two main categories.
One and probably the oldest is the inverted metallurgical scope.
This was cooked up in order to take advantage of the greater size capability
of the inverted layout. These scopes are intended for looking at opaque specimens and have vertical illuminators. So they may not have some of the limitations that Charles correctly observes in the above post.
The second type is the biological or tissue culture type of inverted scope.
These have transmitted light illumination and are designed to function through Petri dishes or tissue culture flasks. And typical examples of them do have the constraints mentioned above. They are intended to look at live layers of cells (usually) and trade the ability to do so for some of the ultimate "PlanApo" observation and photodocumentation ability that makes us eagerly await Charles latest posts.
They also have a more complex light path with more prisms(hopefully) or mirrors to manipulate the image line and flip it around. This means more surfaces to collect dust , grow fungus , scatter light , decrease contrast etc. Especially if the scope is not new.
One and probably the oldest is the inverted metallurgical scope.
This was cooked up in order to take advantage of the greater size capability
of the inverted layout. These scopes are intended for looking at opaque specimens and have vertical illuminators. So they may not have some of the limitations that Charles correctly observes in the above post.
The second type is the biological or tissue culture type of inverted scope.
These have transmitted light illumination and are designed to function through Petri dishes or tissue culture flasks. And typical examples of them do have the constraints mentioned above. They are intended to look at live layers of cells (usually) and trade the ability to do so for some of the ultimate "PlanApo" observation and photodocumentation ability that makes us eagerly await Charles latest posts.
They also have a more complex light path with more prisms(hopefully) or mirrors to manipulate the image line and flip it around. This means more surfaces to collect dust , grow fungus , scatter light , decrease contrast etc. Especially if the scope is not new.
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gpmatthews
- Posts: 1040
- Joined: Thu Aug 03, 2006 10:54 am
- Location: Horsham, W. Sussex, UK
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You may be interested in my posting:
http://www.photomacrography.net/forum/v ... php?t=9159
showing a Leitz Diavert with modifications - it is quite possible to fit a higher NA condenser, but you need to consider thickness of the slide/vessel and objective working distance etc.
The Diavert is a nice microscope to work with.
http://www.photomacrography.net/forum/v ... php?t=9159
showing a Leitz Diavert with modifications - it is quite possible to fit a higher NA condenser, but you need to consider thickness of the slide/vessel and objective working distance etc.
The Diavert is a nice microscope to work with.
Graham
Though we lean upon the same balustrade, the colours of the mountain are different.
Though we lean upon the same balustrade, the colours of the mountain are different.
Re: Drawbacks to an inverted microscope?
They're bad at simplicity. Inverteds are the current battle ground in live cell imaging techniques among the big 4 manufacturers. Confocal, fluroescence, in vitro , etc. Anything involving incubation, etc. Does an amateur need one? No. Not untill you can buy a near current one for cheap. Also, high NA brightfield with inverteds are a pain, if you can even locate the proper condenser.kenw232 wrote:Are there any drawbacks to an Inverted microscope? I mean it seems like all brightfield microscopes should be inverted for each access to the specimen while viewing.
Is there some reason why I would not want an inverted microscope? Are they bad at something that a normal microscope is good at?
A simple, low power inverted is nice for pond water, but the higher up you go, the logistics get complicated.
I am not young enough to know everything.