Microscopy

[parkranger]

I imagine that a few members are involved to some extent in microscopy. Can anyone recommend a digital microscope suitable for a Mac?

 

[Baggyone]

How detailed do you want? Just a passing interest or really go for it cos you can get the Lidl special for 40 quid which I have. Great for pollen analysis but havn't done any disection with it. You can pay pretty much what you want for one.

baggy

 

[Black Comb]

Brunel microscopes have a good range and give good service. Recommended by many on here.

 

[susbees]

Brunel microscopes have a good range and give good service. Recommended by many on here.

 

[masterBK]

Has everyone noticed that entries for the BBKA microscopy assessment don't have to be in until 31 August 2013 (in previous years there was a February deadline) with the assessment taking place a few weeks later in the autumn. Too many people entered last year in Feb but didn't manage to get all their slides done in time and so backed out just before of the exam. This new later deadline means that candidates won't be tempted to enter before they have all their pollen and anatomy slides already prepared.

 

[Black Comb]

On the BBKA site it still says 28 Feb. (closing date on the assessment fees list)

 

[masterBK]

Looks like the "assessment fees list" needs updating but if you look on the page "Examinations and assessments" you get the latest info
---------------------------------------------------------------------------------------------------
Examination Dates 2013
Module 1,2,3,6,8 Examinations, March– 23rd March 2013
(Applications in by 10th February 2013)

Module 1,2,3,5,7 Examinations, November– 9th November 2013
(Applications in by 30th September 2013)

Basic and Junior Certificate date by arrangement with the County Examinations Secretary
(Applications 1 month before assessment)

Advanced Certificate in Beekeeping Husbandry – 15th/16th June 2013 and 29/30th June 2013 depending on numbers (Applications in by 28th February 2013)

General Certificate in Beekeeping Husbandry date by arrangement with the Examinations Board Secretary (Applications in by 28th February 2013)

Microscopy date by arrangement with the Examinations Board Secretary (Applications in by 31st August 2013, Microscopy Assessment takes place in Autumn 2013)

 

[Ruary]

How detailed do you want? Just a passing interest or really go for it cos you can get the Lidl special for 40 quid which I have. Great for pollen analysis but havn't done any disection with it. You can pay pretty much what you want for one.

baggy

I don't think you would get very far dissecting with that microscope as it is compound not stereo. I am afraid that your reply shows a basic lack of knowlege of microscopy.

 

[MuswellMetro]

Looks like the "assessment fees list" needs updating but if you look on the page "Examinations and assessments" you get the latest info
---------------------------------------------------------------------------------------------------


Microscopy date by arrangement with the Examinations Board Secretary (Applications in by 31st August 2013, Microscopy Assessment takes place in Autumn 2013)

this pdf is all i get searching, which says Febuary, i can not find your link


ooophs, it on the front page isn't it, various pages need changing though

 

[luckyclover]

What makes a digital microscope a compound microscope? It could have one lens and the image projected onto a CCD, this isn't a compound microscope.
The reason why the digital microscope might not be suitable for dissection is that the magnification is typically too high compared to a stereomicroscope.

Constructive replies might be more helpful..

 

[oliver90owner]

that microscope as it is compound not stereo.

and

the magnification is typically too high compared to a stereomicroscope.

Compound microscopes have been around a long time and an awful lot of dissection was carried out long before stereo microscopes were invented. Magnification is a red herring if ever I saw one.

'Horses for courses', as usual.

 

[luckyclover]

The fact remains that you can't use high magnification to view dissection, so its not a red herring..

Horses for courses I agree with

 

[masterBK]

A dissecting microscope certainly needs a lower range of magnification plus a good depth of field and a decent working distance between lens and specimen to allow you to dissect under it Also needs a stereo head with erecting prisms or similar so that if the specimen is moved in a particular direction the image goes in the same direction. Are there any digital microscopes at a comparable price that can match the optical qualities of a stereo dissecting microscope?

 

[DanBee]

Dissecting microscopes are stereo microscopes. Key characteristics is that they give a stereo view* and have sufficient space between the objective (bottom lens) and the subject when focussed to allow you to get your hands in and manipulate. Manipulation of the subject generally takes place under the microscope, e.g. dissection, and the stereo view gives necessary depth perception. Useful magnifications of x10 - x30 for beekeepers.

Compound microscopes may have 1,2,3 or indeed 4 eyepieces, but still have one set of optics, so cannot give a stereo view. Objective lenses are usually on a turret - used to rotate different magnification objectives into usage. Very short distance (~ 1mm) between the objective lens and the subject, which precludes any manipulation with tools. Subjects are generally manipulated elsewhere, mounted on a glass slide, then look at under the compound microscope. Useful magnifications of x40 - x400 for beekeepers, x1000 if you want to look at foul brood specimens.

Bob Maurer's new book Practical Microscopy for Beekeepers - launched at the National Honey Show - is excellent. It will take you from the above descriptions being gobbledeygook to being able to make up pollen slides, perform dissections, do nosema diagnosis, etc. Money well spent at £15.

Remember also the "buy cheap, buy twice" mantra when looking at the £50 - £100 microscopes. Do not believe the claims for magnification, because whilst they can make blobs look big they cannot make big blobs look detailed at that price. Detail is what you need and is what people pay for in optics £150 - £300 buys some damn good microscopes these days.

ETA: you can get various eyepiece mounts for digital cameras to allow you to take photos down either type of microscope with your existing camera (generally). Then there are dedicated cameras available and again price is open-ended.

*Two eyepieces does not mean stereo view. Stereo comes from the microscope being designed with a set of lenses for each eyepiece. The image inversion is corrected using prisms so that you see the subject the right way up. Both these features are present in stereo microscopes and absent in compound microscopes.

 

[Ruary]

Constructive replies might be more helpful..

Baggyone was implying that the Lidl microscope would be suitable for pollen analysis (I doubt that the resolution at X400 would be satisfactory) AND ALSO FOR DISSECTION which it obviously would not be. for reasons explained eloquently by DanBee.
I was pointing out that this lack of knowlege wcould be seriously misleading to intending purchasers.
Ruary

 

[luckyclover]

The stereo effect comes from not only twin lenses but the way the images are inclined by a few degrees.
I would also point out, perhaps wrongly, that Baggyone did not say it was suitable for dissection. Maybe a picture or two of pollens from one of these Lidl things might be useful here?

 

[itma]

Baggyone was implying that the Lidl microscope would be suitable for pollen analysis (I doubt that the resolution at X400 would be satisfactory) AND ALSO FOR DISSECTION which it obviously would not be. ...
Ruary

Part of the confusion may be due to the fact that there is no such thing as "the Lidl microscope".

They have sold several rather different Bresser products over the years.
One I recall having no eyepiece, just an LCD screen.
The current (Dec 2012) offering has a max magnification of 1280x using an oil-immersion objective - which should surely be sufficient for pollen examination.
As well as conventional eyepieces, it also has a "pc output" option via a usb camera in place of an eyepiece - but I believe that only has a 640x480 digital resolution.

 

[alanf]

I would also add that with top quality optics you are paying for a larger field of view. Early microscopes, and for that matter cheap microscopes now, can get high magnification of a very limited field. It's only with sophisticated optics that you get not only the resolution but a wider field without distortion or colour problems around the edges.

One of the factors that I thought added to Brunel's reputation was that at a show they were freely pointing out that their cheapest stereo microscope had a field of view smaller than a bee.

 

[luckyclover]

Just to add the equation:
field size = field number on lens / magnification - as alanf pointed out this should be checked when you go looking for a stereomicroscope.

(This is of course different from depth of field which typically decreases with higher magnification as well).