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Tags algae , bacteria , microbiology , microscopes , paramecium , protozoan , water bear

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Old 29th April 2009, 05:01 AM   #81
jasonpatterson
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Abooga, unfortunately it's almost surely not as good as you'd hope. It's an unfortunate reality that quality optical systems (even fair quality) are expensive. While it's possible that this is a good scope for an insanely low price, it's not very likely.

One hint about whether something is going to be a good scope or not is if the primary selling point is its magnification power. It's fairly simple to come up with microscopes that have theoretical magnifications of 1000x or so, but the quality of their images are so poor that they are essentially worthless. They are basically toy microscopes with adult looking packages.

A decent new student microscope will likely cost at least 300 euros, and a good one will be 600 or more, most likely. The good thing is that if you do a bit of research into reputable manufacturers (I don't know which would be most easily available in your area of the world,) you can actually find some very good deals on eBay by buying a used scope. (Try to avoid buying microscopes surplussed by schools as these have usually been treated roughly.)

Again, buying a cheaper new microscope gives you a lot more headaches than you'd think (literally) and winds up resulting in giving up the hobby, more often than not.
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Old 29th April 2009, 06:37 AM   #82
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Dammit, I knew it was too good to be true...

Ebay doesn´t have anything interesting, so I think I might go for a new one with digital camera... for 350 (+/-) Euros I should get a decent one I hope.

Thanks Jason! Ah, this thread is exactly what I needed, to learn about microscopes!
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Old 2nd May 2009, 05:18 AM   #83
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Originally Posted by Bob Blaylock View Post
I'm going to see if I can culture these [spirochaetes] in a petri dish in hope of getting a sample with a dense enough concentration of these things that perhaps I can get some better pictures of them.

Alas, my attempt to culture these spirochaetes did not produce useful results. I definitely had a lot of bacteria of some sort, but on examining a sample, no spirochaetes. I was hoping that I'd get a dense enough sample that I could just put it under my microscope, and keep taking pictures, and there's always be several in my field of view at any given time. No such luck. I guess these spirochaetes just don't like Wild Goose Science's Easygel nutrient.


I did look at a sample taken from a mud puddle as I was arriving home from work. Not much new, but I did see a few instances of this sort of organism:

20090502_043806.jpg 20090502_043859.jpg

This is the same thing, photographed with the usual illumination from below, and then also photographed with illumination from above. I was using the 10X objective and the 15X eyepiece, so each numbered tick is 122 micrometers.

What is it? I don't really know. I'm sure it's a living organism, probably some sort of plant or fungus.
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Old 2nd May 2009, 01:45 PM   #84
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Originally Posted by Bob Blaylock View Post
When the Kodak began to become unreliable, I suspected that perhaps the CompactFlash card was the cause. I sent my wife off to look for a replacement; she returned with the report that at the one place she checked, the cheapest CompactFlash card that they had in stock was $60, but that they also had a camera, which she though was very likely better than the Kodak, for $40. Later, we went off to Wal*Mart, to look at what they had to offer, both by way of CompactFlash cards, and new cameras in roughly the same price range. We ended up getting this Sakar for $60.
I actually checked at least 3 places: Office Max (17th & J), Long's (17th & K), and RiteAid (23rd & F). I also did some online hunting on the card.
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Old 2nd May 2009, 09:47 PM   #85
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Bob, I'd love to see one of those funky fellas you show in post 83 (I think it was 83, your post right before this one anyway) lit obliquely. If you have a disk diaphragm on your microscope, you just turn it a bit farther than you need to and the contrast really comes out. If it's an iris diaphragm, you can slip a piece of paper over half of the diaphragm's opening and get the same effect.

Also, if you haven't seen it, there is a program called CombineZ that can take several images at various focus depths and turn them into a single image with a wonderful depth of view. A Microscopy UK article with a couple of pictures showing CombineZ's ability. Another trick is to take two images of the same slide from very slightly different positions. If you cross your eyes and look at them (just like you do with Magic Eye images) then it appears 3D. Just some ideas for stuff to try if you're feeling like something different.
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Old 2nd May 2009, 11:52 PM   #86
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Another of Leftysergeant's much-hated Walton larvae, photographed using the 5X objective and the 15X eyepiece. Each numbered tick is 230 micrometers, and this bourgeois maggot is about 1500 micrometers, or 1½ millimeters in length. I photographed it both using normally transmission illumination from below, and with reflected illumination from above.




I observed this larva oppressing this poor working-class telotroch [seen near the right edge of the picture below, just under the 6.5 tick], who was just trying to organize his fellow protistan workers into a union. This picture was taken using the 10X objective, so each numbered tick is 122 micrometers.



By the time I cleaned off this slide, things were getting ugly. A group from Local 147 of the International Brotherhood of Vorticellas, Paramecia, and Coleps had tried to picket this slide, but this maggot hired a bunch of rotiferian thugs to drive them off.



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Old 3rd May 2009, 01:28 AM   #87
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A couple of protists from some gutter water; both taken with the 10X objective and the 15X eyepiece. The scale is not visible in that first picture, and these pictures are not to the same scale. The round protist in the first picture is approximately 60 micrometers in diameter. In the second picture, each numbered tick on the scale is 122 micrometers, and the teardrop-shaped protist is about 65 micrometers in length.

20090503_001016_Protist.jpg 20090503_001918_TeardropProtist.jpg



And now, for something completely different…

Here's a smear of my blood, showing red blood cells:



This was taken using the 60X objective and the 15X eyepiece. Each numbered tick is 20 micrometers. My red blood cells appear to be about 10 micrometers in diameter. The Wikipedia article claims that human red blood cells are typically 6 to 8 micrometers in diameter. Either mine are unusually large, or else my scale calibration is off. Or perhaps this is some effect of being dried, and possibly flattened out, in the process of smearing them on to a slide.




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Old 3rd May 2009, 09:36 AM   #88
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Originally Posted by jasonpatterson View Post
Abooga, unfortunately it's almost surely not as good as you'd hope. It's an unfortunate reality that quality optical systems (even fair quality) are expensive. While it's possible that this is a good scope for an insanely low price, it's not very likely.

One hint about whether something is going to be a good scope or not is if the primary selling point is its magnification power. It's fairly simple to come up with microscopes that have theoretical magnifications of 1000x or so, but the quality of their images are so poor that they are essentially worthless. They are basically toy microscopes with adult looking packages.

A decent new student microscope will likely cost at least 300 euros, and a good one will be 600 or more, most likely. The good thing is that if you do a bit of research into reputable manufacturers (I don't know which would be most easily available in your area of the world,) you can actually find some very good deals on eBay by buying a used scope. (Try to avoid buying microscopes surplussed by schools as these have usually been treated roughly.)

Again, buying a cheaper new microscope gives you a lot more headaches than you'd think (literally) and winds up resulting in giving up the hobby, more often than not.
I would respectfully disagree - and I would say that you are applying some things said about buying one's first telescope onto buying microscopes, and they don't really apply. Microscopes generally are not sold on the basis of magnification, at least above the plastic models in a clear printed box. Almost all compound microscopes will have a 10x eyepiece and 4x,10x, and 40x objectives. The question then becomes: are the optics decent and what are the features.

The model Abooga linked to would be on the low-end side because the objectives look rather small and thin. That's a sign that they are almost 'pinhole' objectives, which means they skimped on lens size and mechanics. But a few steps above that and you'd have a model that would work just fine more most people's needs.

One way that helps is to get a microscope with DIN objectives. These are usually (but not automatically) better than non-DIN objectifves. Even better is that you can replace them with other DIN eyepieces.


For what's its worth, I wrote a Microscope Buyer's Guide a little while back that some might find useful.
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Old 3rd May 2009, 07:12 PM   #89
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Today I went for a walk, and collected six vials of water from various puddles. So far, I've just examined one of them, and the pictures in this posting are from that one.

First, we have two good-sized protists, both taken with the 10X objective and the 15X eyepiece. Each numbered tick is 122 micrometers, and each of these is about twice that in length.

20090503_165410_Protist.jpg 20090503_165547_Protist.jpg

The second of these was not moving (though I could see some small movement of the structures inside of it). As I was looking at it, some other tiny, fast movements caught my eyes. Spirochaetes!. They appeared to be attacking this protist. This picture, taken with the 60X objective (each numbered tick is 20 micrometers), shows a couple of them:

20090503_170302_ProtistAttackedBySpirochaetes.jpg

See that “V” shape between the numerals “4” and “5”? That's two spirochaetes. The motions of these and others that I observed seemed to suggest that they were trying to “drill” their way into this protist.


I suspect that what this next pictures shows, is two instances of similar protists that have been successfully attached and destroyed by these bacteria. This was taken with the 10X objective, so each numbered tick is 122 micrometers.



And here's a bunch of spirochaetes, photographed through the 6oX objective (each numbered tick is 20 micrometers):



For some reason, in this particular area of the drop, the spirochaetes seemed to relax and rest. They would straighten out and remain still for a while. Occasionally, as I watched, one would curl back into the normal corkscrew shape, and go zooming off.

I wish I could get better pictures of these. Somehow, when I am looking directly at these things, they are more impressive to see, and more interesting, than what I am able to capture with my camera. However, even with direct observation, I find myself wishing very much that I could see them better. I guess, at this scale, I'm really operating very close to the limits of what this microscope can usefully resolve. This is the best picture I've yet been able to produce of spirochaetes, and it's probably the best that I am ever going to get with this microscope.



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File Type: jpg 20090503_171604_DestroyedProtists.jpg (49.2 KB, 163 views)
File Type: jpg 20090503_171952_Spirochaetes.jpg (45.8 KB, 162 views)
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Old 3rd May 2009, 08:02 PM   #90
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Originally Posted by kookbreaker View Post
I would respectfully disagree - and I would say that you are applying some things said about buying one's first telescope onto buying microscopes, and they don't really apply. Microscopes generally are not sold on the basis of magnification, at least above the plastic models in a clear printed box. Almost all compound microscopes will have a 10x eyepiece and 4x,10x, and 40x objectives. The question then becomes: are the optics decent and what are the features.
I understand that microscopes generally aren't sold based on their magnification power. That was why I said to avoid any that were... There wasn't any transfer of telescope to microscope ideas, it's just true for both. The optics are the key, of course, but how does a person who doesn't know what they are looking for evaluate the quality of a microscope's optics from a picture and manufacturer's information?

(Also, though I don't speak Spanish, if you browse out to the linked company's microscope selection page, it contains 3 items. The 80 euro version, a 320 euro version which, judging by appearance alone, looks ok, and a 700 euro trinocular version that also looks ok. Not trying to be a jerk, but that's pretty close to what I suggested...)

Anyway, lots more helpful information about buying and using a microscope can be found at Microscopy UK. The site itself is a bit cumbersome to navigate (would it kill them to include a Search feature on the front page???) but just about anything you search for regarding microscopy on google will return a Mic UK hit.
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Old 3rd May 2009, 09:58 PM   #91
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Here's a Vorticella

20090503_205103_Vorticella.jpg

And here's a group of three of them:



A vorticella anchors itself to some object with a long, thin stalk. When a vorticella is disturbed, it can very rapidly retract that stalk into a short helix, as the middle one has done in the picture below:





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File Type: jpg 20090503_205750_Vorticellas.jpg (48.7 KB, 165 views)
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Old 4th May 2009, 01:22 AM   #92
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Originally Posted by kookbreaker View Post
I would respectfully disagree - and I would say that you are applying some things said about buying one's first telescope onto buying microscopes, and they don't really apply. Microscopes generally are not sold on the basis of magnification, at least above the plastic models in a clear printed box. Almost all compound microscopes will have a 10x eyepiece and 4x,10x, and 40x objectives. The question then becomes: are the optics decent and what are the features.

The model Abooga linked to would be on the low-end side because the objectives look rather small and thin. That's a sign that they are almost 'pinhole' objectives, which means they skimped on lens size and mechanics. But a few steps above that and you'd have a model that would work just fine more most people's needs.

One way that helps is to get a microscope with DIN objectives. These are usually (but not automatically) better than non-DIN objectifves. Even better is that you can replace them with other DIN eyepieces.


For what's its worth, I wrote a Microscope Buyer's Guide a little while back that some might find useful.
Yeah, this one looks much better:

http://www.optical-systems.com/bress...io-p-5123.html

DIN objectivs, and they look pretty fat, don´t they?
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Old 4th May 2009, 10:20 AM   #93
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The DIN description refers to how the optical elements are threaded and the distances over which they are focused. Its primary intent is to allow you to swap out eyepieces.
Good things about this microscope:
price, iris diaphragm, adjustable intensity light, mechanical stage, microscope brand is sold by more than one company, customer reviews seem generally favorable, doesn't look like junk
(It's rare to find a good microscope that does look like trash, but there are some poor microscopes that look good, so it's important to avoid appearance as a major factor.)

Potential Negatives:
There is very little, even from the manufacturer, about the specifics of the optics. You can purchase achromatic objectives from them, but it doesn't say whether the objectives on this microscope are achromatic or not. Additionally, the images of this microscope are either too small or the text on the objectives are 'conveniently' oriented away from the camera so that you can't read the specifics of them. From the price of the microscope and the price of their individual achromatic objectives, I'd guess that they are not, but you never know, it might just be a quality difference between the two versions. Achromatic means that they've corrected the lenses for two different colors since different wavelengths of light refract to different extents. This phenomenon, called chromatic aberration, can be a big issue with poorly made optics. This isn't the end-all be-all of microscopy, but it's nice.

It seems like you've got a good chance at a reasonably priced microscope that should perform fairly well. If you have ANY way of actually going and looking through one before you purchase it, I'd strongly advise that you do so. Unfortunately, unless you live near a proper microscopy or optical store, this is probably not going to happen.

If you buy this (or any other microscope,) you'll also need to purchase slides (flat and/or depression, depending on what you want to look at), cover glasses, and, if you want to use the 100x objective, immersion oil. I'd wait until I got the microscope to make sure that you purchase the correct thickness of slide, glass, and the right type of oil for whatever you buy (unless you can find the manual online, of course.) Other little things, like a medicine dropper and bottles to put specimens in, will be handy as well. Figure on spending another 30 euros on accessories, whatever you buy. You could probably do it for substantially less, if you shop around and use what's already likely lying around your house.
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Old 4th May 2009, 12:06 PM   #94
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Originally Posted by Abooga View Post
Yeah, this one looks much better:

http://www.optical-systems.com/bress...io-p-5123.html

DIN objectivs, and they look pretty fat, don´t they?
That actually seems mighty low-priced for a 4 objective system. What is the Euro worth these days?
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Old 4th May 2009, 12:13 PM   #95
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Originally Posted by jasonpatterson View Post
Potential Negatives:
There is very little, even from the manufacturer, about the specifics of the optics. You can purchase achromatic objectives from them, but it doesn't say whether the objectives on this microscope are achromatic or not.
Achromatic objectives is almost default these days, at least for non-plastic models.

I can say from the body shape that this come from the same factory my supplier gets theirs from. Observe:

http://www.spectrum-scientifics.com/...action&key=250

http://www.spectrum-scientifics.com/...action&key=249

Note the stock body, etc.

And I can say the models I have all have achromatic objectives


Quote:
Additionally, the images of this microscope are either too small or the text on the objectives are 'conveniently' oriented away from the camera so that you can't read the specifics of them. From the price of the microscope and the price of their individual achromatic objectives, I'd guess that they are not, but you never know, it might just be a quality difference between the two versions. Achromatic means that they've corrected the lenses for two different colors since different wavelengths of light refract to different extents. This phenomenon, called chromatic aberration, can be a big issue with poorly made optics. This isn't the end-all be-all of microscopy, but it's nice.
Unless the retailer went well out of their way to get non-objective (why!) this manufacturer is using achromats.
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Old 5th May 2009, 02:29 AM   #96
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Hey thanks a lot for your feedback Jason and Kook!

And yes Kook, your supplier´s microscope looks remarkably similar to that cheap Bresser one I found. 0,75 Euros to a dollar, it would cost 143$ (I think...) It looks like a good deal.

Sorry Bob for derailing your nice thread. Oh, and have you tried to look at these weird little creatures yet? http://www.worsleyschool.net/science...creatures.html I thought it was a hoax when I first heard about them...
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Old 5th May 2009, 06:06 AM   #97
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Ah! the internet is a small place isn´t it? Googleing for "Bresser" I found an article in BAD SCIENCE (one of my fav sites... after jref, of course), http://www.badscience.net/2006/12/ma...istmas-filler/ in which one of Ben´s commentators was telling how he bought a cheap (40 quid) Bresser microscope, and was surprised with the good result! There are some examples of the pics he took. Well, if it´s on BAD SCIENCE I´m inclined to believe it. So I reckon the 190 Euro Bresser Erudit has got to be pretty good!
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Old 5th May 2009, 06:12 AM   #98
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Originally Posted by Abooga View Post
0,75 Euros to a dollar, it would cost 143$ (I think...) It
Oops! I did it the wrong way round. It´s 255 US Dollars
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Old 6th May 2009, 01:32 AM   #99
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Some algae:



Some sort of worm:



I think this is a bdelloid rotifer:




All of tonight's pictures were taken with the 10X objective and the 15X eyepiece. Each numbered tick is 122 micrometers. I've scaled all three of these so that each pixel is 1 micrometer.



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File Type: jpg 20090506_002802_Algae.jpg (51.3 KB, 146 views)
File Type: jpg 20090506_002941_Worm.jpg (55.1 KB, 146 views)
File Type: jpg 20090506_004409_Rotifer.jpg (33.5 KB, 145 views)
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Old 11th May 2009, 02:31 PM   #100
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I've been away on an unexpected out-of-state trip, from which I just returned late last night. I felt compelled to find anything to post in this thread today. A sample of water from a nearby gutter didn't yield very much new, but I did find this spirochaeteWP. 60X objective, 15X eyepiece, the ticks at each side of the image are 20 micrometers apart.

20090511_140440_Spirochaete.jpg
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Old 11th May 2009, 07:23 PM   #101
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Keep it up! You've got me bringing my microscope out of storage and peering into mucky water after a long winter of inactivity, and I appreciate it greatly. I found a whole bunch of the critters you've identified as bdelloid rotifers in a sample from a ditch. They were everywhere. One of my favorite images is of the compound eye of a daphnia.

Daphnia Eye.jpg

This is a 40x objective and a 10x eyepiece as I recall, and the image was taken with a webcam that I mounted in a PVC coupler to fit over my eyepieces. Unfortunately the resolution isn't very good, but I can't manage to convince my digital camera to take nice pictures through the eyepiece as you've done. Any hints?

Oh yeah, here is an example of the use of the CombineZ program I mentioned. I took a series of about a dozen images at various focal depths in the hind graspers of a critter (I was too busy playing with the program to identify it) and used the program to sew them together into a single in focus image. This first picture is the best of the 12 single images.

graspers.jpg

And this is the combination of all of the images.

graspersCZ.jpg

It's still not perfect, by any stretch of the imagination, but it does give you a good idea of the program's power. It is also quite useful for objects under a dissection scope, or for cleaning up telescope images (you take a webcam movie through the eyepiece and the program pulls each frame individually and selects the sharpest pieces of each, resulting in a picture that is relatively free of atmospheric distortion.

ETA: The critter did move a bit during the series of pictures, that's why the edges in the upper portion of its body are strangely doubled in a couple of places.
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Old 12th May 2009, 05:26 PM   #102
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Originally Posted by jasonpatterson View Post
This is a 40x objective and a 10x eyepiece as I recall, and the image was taken with a webcam that I mounted in a PVC coupler to fit over my eyepieces. Unfortunately the resolution isn't very good, but I can't manage to convince my digital camera to take nice pictures through the eyepiece as you've done. Any hints?

Your pictures look pretty good to me. It looks like you have an advantage at higher magnifications that I do not have. I have a 5X and a 10X objective, and then I have a 60X objective. I can get nice, sharp pictures through those first two (giving me 75X and 150X magnifications respectively if I use the 15X eyepiece; With the 60X objective, I jump to 900X magnification, but with a very significant loss of image quality and general ease of use, compared to the lower-power objectives. I read somewhere an article that claimed that 400X was the practical upper limit for an optical microscope with a dry objective, and here I am pushing 900X. I wonder if I'd be happier if I were to get a 40X objective to install in place of the 60X. If I could get the kind of sharpness that you are apparently getting with such an objective, then I think it might easily be worth giving up that much absolute magnification for the increased image quality.



Originally Posted by jasonpatterson View Post
Oh yeah, here is an example of the use of the CombineZ program I mentioned. I took a series of about a dozen images at various focal depths in the hind graspers of a critter (I was too busy playing with the program to identify it) and used the program to sew them together into a single in focus image. This first picture is the best of the 12 single images.

I wonder if there is, somewhere out there, a Macintosh program that offers similar capabilities. In any event, I'd have to come up with some sort of mount for my camera. As it is, I am just holding it in my hand, pointing it down my eyepiece. This is fine for single pictures, but I wouldn't be able to take multiple pictures across focus changes, while keeping the positioning as consistent as it seems a program like CombineZ would require.
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Old 12th May 2009, 07:28 PM   #103
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Oil immersion is pretty much a necessity for good images at that strength of magnification. (I'm sure someone somewhere has made a microscope that can do it in air, but I don't know who or where that person is.) It's actually a 45x objective, now that I check, but still, it produces reasonably sharp images. I got a decent one of a paramecium the other night. (I think I may have popped it, which is why I was able to take a decent picture without it getting away.

paramecium.jpg

I pretty much work with 3 magnifications, a dissecting scope with about 25x magnification total (my daughters love looking at bugs and such in it), and a compound scope with a 10x objective and 10x eyepiece and a 45x objective and 10x eyepiece. I ran out of immersion oil and have been too lazy to buy more, but I might get around to that sometime soon and break out the 100x objective. I definitely do like the higher power though, it's nice to be able to peek at critters' individual cells clearly.

Oh yeah, there is a program called Helicon Focus that does the same thing as CombineZ for the mac. It's shareware though, so after 30 days it'll start putting ad banners on your images.
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Old 12th May 2009, 08:00 PM   #104
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All these are from today's visit to the Duck pond at McKinley Park. All taken with the 15X eyepiece. This posting is of some things that were actually found in a mud puddle adjacent to this pond.

First some sort of insect. It appeared to be dead, probably drowned. This was taken with the 5X objective (each numbered tick = 230 micrometers), in two pieces, spliced together with Photoshop.

20090512_175248_Insect.jpg

All the remaining pictures were taken with the 10X objective (each numbered tick = 122 micrometers).


Here's a bunch of Scenedesmus. I'd occasionally seen a bit of this before, but never this much at once.

20090512_180657_Scenedesmus.jpg


Next, some sort of spiral structure, either algae or cyanobacteria.


20090512_174431_SpiralAlgae.jpg

I think these are both rotifers, of some type that I haven't seen before. Perhaps they are a male and a female of the same species, or perhaps they're two different species entirely.

20090512_175652_Rotifers.jpg

And a Daphnia. I didn't recognize it at first, because I previously only knew what they looked like from the side, and this one I was seeing from either the top or bottom. It did occasionally turn on its side briefly, allowing me to recognize what it was.

20090512_175045_Daphnia.jpg

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Old 12th May 2009, 09:20 PM   #105
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And these are from the duck pond itself. When I visited this same pond a couple months ago, I found mostly a form of motile unicellular algae; that was, by far, the most dominant form of life in that pond. I didn't see any of it this time.

Here's a sample of some of the algae that was common this time. Mostly Scenedesmus, with a few of those spiral structures. This was with the 10X objective and the 15X eyepiece. Each numbered tick is 122 micrometers.

_20090512_202641_Algae.jpg


I also found a few of these things, apparently some colonial algae. This was with the 60X objective and the 15X eyepiece. Each numbered tick is 20 micrometers.

20090512_200907_Algae.jpg


I'm not sure what this is, but I think it may be a bdelloid rotifer, closed up into some sort of defensive state. It was not moving externally, but I could see some movement of its internal organs. 10X objective, 15X eyepiece. The numbers on the scale are cropped out here, but I think it should be obvious that the longest ticks are the numbered ones; they are 122 micrometers apart.

20090512_202820_Rotifer.jpg
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Old 12th May 2009, 10:42 PM   #106
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I never did figure out what this was. The previous instance of this that I saw was from the same duck pond as this sample. I found, here, an example that appeared to have something growing on the outside of it. Here it is through the 10X objective and 15X eyepiece (each numbered tick is 122 micrometers) in both transmitted and reflected light:

20090512_212703.jpg 20090512_212751.jpg


And here, using the 60X objective (each numbered tick = 20 micrometers) is a closer view of some of the growth on it:

]

The growth looks rather like plant life, with leaves and stems and such, but on this size scale, it must really be something unicellular.



And here is something else. I don't know if this is a bit of plant life, or perhaps a bit of a feather. 10X objective, 15X eyepiece; each numbered tick is 122 micrometers.


20090512_213449.jpg



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File Type: jpg 20090512_213055.jpg (53.4 KB, 175 views)
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Old 12th May 2009, 10:49 PM   #107
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I've found masses of exoskeleton parts in the sediment I have been checking recently. I wonder if that plant/feather thing might not be a major component of some bug's skleton. The pieces I've found look fairly similar, at least in general.
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Old 13th May 2009, 12:07 AM   #108
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Originally Posted by jasonpatterson View Post
Oil immersion is pretty much a necessity for good images at that strength of magnification. (I'm sure someone somewhere has made a microscope that can do it in air, but I don't know who or where that person is.)

I'm fairly sure that my 60X objective is not meant to be used in oil. Is there any way to tell for sure, other than trying it? I fear that if it's not meant to be used that way, and I tried it, that oil might leak into it and mess it up.


Originally Posted by jasonpatterson View Post
Oh yeah, there is a program called Helicon Focus that does the same thing as CombineZ for the mac. It's shareware though, so after 30 days it'll start putting ad banners on your images.

Hmmm… Just for the “Lite” version, they want $30 for a one-year license, or $115 for a permanent license. There is something that sits very badly with me about the idea of “buying” software only to be able to use it for a limited time. $115 to actually *buy* this software is just too much, as is $30 to *rent* it for a year. If the $30 actually bought a permanent right to use the software, as is the case with nearly every other software source, then I might consider it.

In any event, it's moot unless I am sufficiently motivated to come up with a steady way to mount this camera on my microscope.


Originally Posted by jasonpatterson View Post
I've found masses of exoskeleton parts in the sediment I have been checking recently. I wonder if that plant/feather thing might not be a major component of some bug's skleton. The pieces I've found look fairly similar, at least in general.

I suppose it could be an antenna; I know that some insects have antennae that branch like that.
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Old 13th May 2009, 12:40 AM   #109
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Originally Posted by Bob Blaylock View Post


I also found a few of these things, apparently some colonial algae. This was with the 60X objective and the 15X eyepiece. Each numbered tick is 20 micrometers.

Attachment 13899

I think this is Pediastrum ? I remember seeing a few of these last time I did some freshwater pond dips.
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Old 13th May 2009, 01:08 AM   #110
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Originally Posted by twistor59 View Post
I think this is Pediastrum ? I remember seeing a few of these last time I did some freshwater pond dips.

You would appear to be correct. Thanks.
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Old 13th May 2009, 10:12 AM   #111
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Originally Posted by Bob Blaylock View Post
I'm fairly sure that my 60X objective is not meant to be used in oil. Is there any way to tell for sure, other than trying it? I fear that if it's not meant to be used that way, and I tried it, that oil might leak into it and mess it up.
It should say on the barrel of the objective. It might say Oil or HI or something else entirely. If there is a serial number on the objective you can probably look it up. Odds are good it's not intended for oil though.
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Old 13th May 2009, 10:42 AM   #112
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I'm loving this thread. I had no idea algea would look so geometric up close. That 1st picture in post #99 looks downright, dare I say it, designed! haha
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Old 13th May 2009, 03:42 PM   #113
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Originally Posted by jasonpatterson View Post
Originally Posted by bob blaylock View Post
i'm fairly sure that my 60x objective is not meant to be used in oil. Is there any way to tell for sure, other than trying it? I fear that if it's not meant to be used that way, and i tried it, that oil might leak into it and mess it up.

it should say on the barrel of the objective. It might say oil or hi or something else entirely. If there is a serial number on the objective you can probably look it up. Odds are good it's not intended for oil though.
Well, here are the only markings on my 60X objective. Nothing that hints at anything to do with oil immersion. I bet the “0.85” is probably the focal length, probably in millimeters. What's the relation between focal length and magnification? I bet it's fairly simple. I think I remember that the magnification of a telescope is the focal length of the objective divided by that of the eyepiece. I bet it's similar with a microscope.

20090513_151512_60X.jpg 20090513_151521_60X.jpg

In removing this objective, to take these pictures, I discovered a crude paper washer, which my father must have placed there in an effort to bring this objective closer to being parfocal with the 10X. It's not quite so, but perhaps it was many years ago, with the washer having had less time to become compressed from the force being exerted on it. Perhaps some time, I'll experiment with trying a similar technique using a more sturdy material, such as sheet brass.



Here are the markings on the front of the microscope itself.

20090513_151627_Microscope.jpg
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Old 13th May 2009, 10:24 PM   #114
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The 0.85 is the numerical aperture of the objective. It basically describes the shape of the cone of light that an objective can view clearly, and can be used to determine the absolute maximum resolution of which the objective is capable. The resolution is inversely proportional to the numerical aperture. For air, the maximum (theoretical) value would be 1.00. In oil, the value could theoretically be as high as 1.5_ (the _ depends on the refractive index of the immersion oil being used.)

You're probably right about the washer. Nice find, I always like bumping into little things like that.

As far as the focal length goes, in general microscopes are set up as either having a finite length (usually, but not always, 160 mm) or are infinity corrected. In the case of your microscope, I can't find much information about it, but I would guess that it is probably 160mm (or thereabouts.) Thus your 60x objective has a focal length of about 2.7mm. (There are microscopes with substantially longer tube lengths, I'm just guessing it's 160 because that is the standard length.) It's also not an oil immersion lens, the shape is wrong for that, if nothing else.
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Old 14th May 2009, 04:03 AM   #115
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Originally Posted by jasonpatterson View Post
As far as the focal length goes, in general microscopes are set up as either having a finite length (usually, but not always, 160 mm) or are infinity corrected. In the case of your microscope, I can't find much information about it, but I would guess that it is probably 160mm (or thereabouts.) Thus your 60x objective has a focal length of about 2.7mm. (There are microscopes with substantially longer tube lengths, I'm just guessing it's 160 because that is the standard length.)

Making some rough measurements with a ruler, it looks like the distance from the top of the tube (where the eyepiece would rest) down through the turret, to the surface against which the objectives mount, is about 170 millimeters, or 6¾ inches.

I'm 46 years old, and I am fairly sure that my father had this microscope before I was born, so it's pretty old. It's probably not safe to assume that it conforms to any current standards. For that reason, with respect to my previous musings about whether I might be happier if I replaced the 60X objective with something more in the 40X range, I probably cannot even assume that it's possible to get an objective that will fit this microscope.


Originally Posted by jasonpatterson View Post
It's also not an oil immersion lens, the shape is wrong for that, if nothing else.

The pictures that I previously posted do not really show the shape of the relevant part of the objective. Not that I think it will change your answer, but here are a few pictures that will hopefully give a better idea of the shape:

20090514_033318.jpg 20090514_032919.jpg 20090514_032903.jpg
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Old 14th May 2009, 12:49 PM   #116
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160mm and 170mm have been common lengths for some time. It's entirely possible that you have a 170mm scope (or even 180 or a totally different length altogether.) In any case, most finite length objectives ought to work for you, the problem is that they won't wind up being parfocal and depending on the manufacturer, various optical effects have been corrected at various positions in any given microscope. You'll get some sort of image, there's just no telling what kind of image it is without more information about the microscope you've got or simply trying it.

I still seriously doubt that it's an oil immersion objective. Odds are good that it's either damaged or was not the best objective to start with. There definitely are 60x objectives for use in air that produce good images. Do you have another, weaker eyepiece? You might try that in combination with your 60x objective and see if the results are any better. It's kind of like enlarging a digital picture. It works well for a while as long as the resolution of the original is high, but if you keep going you eventually wind up pixelating the image.
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Old 15th May 2009, 02:13 AM   #117
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This is from the drainage structure at North 28°30'54.54" West 121°28'20.43", on the grounds of the factory where I work. I think it's a Chlamydomonas, possibly in the process of dividing. It's about 36 micrometers in diameter.

I photographed it with both my 10X and my 60X objectives, using the 15X eyepiece both times, and then in Photoshop, I scaled the two images so that they are on the same scale, pixel-wise. (Each pixel = 0.1333… micrometers). This gives an interesting comparison of the detail that I can resolve with each of these objectives, when viewing objects at this scale.

10X objective60X objective
20090515_010229_ChlamydomonaDividing_10X.jpg20090515_010157_ChlamydomonaDividing_60X.jpg

The two dark lines at the top of the second image are the numbered ticks in the eyepiece, and are 20 micrometers apart.
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Old 15th May 2009, 10:07 AM   #118
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Good idea! I guess part of what we see in an image like this is what we think we ought to be seeing. I tried using my 100x oil objective in air last night and I get images that are much like what you're showing here.
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Old 16th May 2009, 01:03 AM   #119
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Originally Posted by jasonpatterson View Post
…and the image was taken with a webcam that I mounted in a PVC coupler to fit over my eyepieces. Unfortunately the resolution isn't very good, but I can't manage to convince my digital camera to take nice pictures through the eyepiece as you've done. Any hints?

I just now understood this differently than I did before. You're talking about two different cameras, aren't you? A “webcam” that works fine through your microscope, but has very limited resolution, and some other camera, capable of much better resolution, that you cannot “convince…to take nice pictures through the eyepiece…”.

What sort of camera is the latter?

As I said earlier in this thread, I think a “cheap” camera, with a small, fixed-focus lens, has a much better chance of working well for this purpose than a more sophisticated camera. Your “webcam” surely has exactly the sort of small, fixed-focus lens that I think would work well, and my guess is that your other digital camera does not. If you're willing to spend the money, my suggestion is that you go to Wal*Mart and look for the Sakar 7.1-megapixel camera that they sell for about $60. That's what I am using, and it works quite well. It's got the small, fixed-focus lens like a “cheap” camera, but a very high-resolution, up to 3072×2304 pixels.

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Old 16th May 2009, 02:57 AM   #120
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Originally Posted by jasonpatterson View Post
I still seriously doubt that it's an oil immersion objective.

I just figured out something that would seem to rather solidly answer the question. As this picture shows…



…the lens is slightly recessed, forming a concavity that, if this objective were immersed in any liquid, would tend to trap a small air bubble. It seems rather obvious to me that any objective that was designed to be immersed in oil would not have this concavity.
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