Magnifying Glass

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SunshineLW
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Magnifying Glass

#1 Post by SunshineLW » Thu Mar 21, 2019 9:32 pm

An acquaintance of mine has a micro habitat with pond sludge, and wants a closer look at some of the organisms using a magnifying glass (not a microscope). Does anyone have any experience with magnifying glasses? Any recommendations for an affordable magnifying glass?

desertrat
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Re: Magnifying Glass

#2 Post by desertrat » Thu Mar 21, 2019 10:22 pm

Years ago I bought a 5 piece plastic bodied loupe set from Harbor Freight tools at a low price. They were surprisingly good considering the low price, and a couple of them were high enough in magnification for small but not microscopic pond organisms.

Harbor freight still sells these, and I notice they have several stores in Texas.

https://www.harborfreight.com/5-piece-l ... 98722.html
Rick

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billbillt
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Re: Magnifying Glass

#3 Post by billbillt » Thu Mar 21, 2019 10:24 pm

Hello Sunshine,

I have used one of these for years, and like it..

https://www.ebay.com/itm/Bausch-Lomb-Fo ... xyvSVRFXva

BillT

apochronaut
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Re: Magnifying Glass

#4 Post by apochronaut » Thu Mar 21, 2019 10:28 pm

A magnifying glass or loupe of sufficient quality can work.
A magnifying glass is just a simple microscope but as the magnification goes up so do optical distortions and vibration. Microscopes can increase the magnification and keep distortions to a minimum. A magnifying glass is hard pressed to reach 5X without severe distortion but better designs with more complex optics can improve the quality of the image. Hastings magnifiers are one such design.

There are a lot of simple microscopes that are glorified magnifying glasses, with higher magnifications yet clearer wider fields. Several of the forum members use some of these to observe their aquariums. Some microscope companies made straight tube inspection microscopes of over 10X to observe things manually but as the magnification goes up, so does the vibration so holding optics of high magnification manually can become almost impossible, hence, even low power microscopes need to be in a fairly rigid mount.

Previously, aquarium watching was a popular parlour pastime. Some older stereo microscopes could be rotated 90 degrees to a horizontal position and with fairly low power objectives be used against the aquarium glass. They even made water immersion low power stereo objective pairs, which could be dipped into the aquarium from above, theoretically....or used with an extracted sample in a bowl or petri dish.

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zzffnn
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Re: Magnifying Glass

#5 Post by zzffnn » Thu Mar 21, 2019 10:53 pm

I bought this for a lower price that listing and like it:

https://www.amazon.com/TS1983-Focus-Sca ... 5078&psc=1

Pond organisms may need at least an self- illumniated 15x though, I am guessing. You need some good working distance, which is difficult from a hand loupe at 15x and up.

MicroBob
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Re: Magnifying Glass

#6 Post by MicroBob » Fri Mar 22, 2019 9:42 am

This is a great loupe, I have one for several years and like it a lot:
https://www.ebay.de/itm/321384722424

It is a real triplet and gives a nice view over the whole field of view. The LED-light works very well. I have just replaced the first set of batteries.

Warning: The title "Triplet" is widely used as a sign of quality. In most cases you only get one bubbly lens of cheap glass with severe chromatic errors - so beware. The is more junk than usable quality on the market. The given magnifications are also often not true.

Such a loupe is used close to the eye, than you move your head towars the object. Until you are in focus your nose might already have dipped in! :lol:

For extended observation a stereo microscope with an articulating arm or boom stand is much better, if funds allow.

Bob

ChrisR
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Re: Magnifying Glass

#7 Post by ChrisR » Fri Mar 22, 2019 10:25 am

For school we use a number of the Chinese cheap magnifiers, many with LEDs built in, for a couple of bucks. Most of them are absolutely fine. Some are glass doublet or triplet.

Be aware that "magnification" has a variable meaning, as far as vendors are concerned. Some work on area, so what you thought would be a really strong 50x turns out to be only 7x!

I like to use a long working distance microscope objective as a loupe. "Faulty" ones will often work perfectly well enough. There's nothing cheap off-the-shelf as far as I know, though.. If you see a 10x LWD say, it's worth a try if affordable.
My faves are Measuring Microscope objectives. A true 5x has wd 64mm, and a true 10x, 49.5mm. You stay clear of the messy stuff!

Ebay is also awash with stereo, spectacle-fitting magnifiers of the type microsurgeons use, which have varying working distance. I have used some expensive ones which are wonderful - I've heard the cheaper copies are good too.

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