Sciencemadness Discussion Board

Magnifying loop for mounting on glasses or your head

yobbo II - 27-11-2019 at 12:05

Hi,
Does anyone have any experience with these types of mag devices. Used by surgeons and dentists and other too!

The important thing is that they must have a foot or so 'stand off' distance. That is to say the distance between your head and the thing you are looking at must be around a foot or so. You can get very cheap binocular glassed but you must be very close to the object you are looking at.
Anyone any thoughts on where you could be a high quality perhaps second hand pair for cheap. I would like about 5 or 10x. Variable x would be great but I don't think that exists.
What is the proper name for these devices.

eg.
https://www.ebay.co.uk/itm/8X-420mm-Dental-Medical-Loupe-Den...

Thanks,
Yob

s-l1600.jpg - 55kB

Twospoons - 27-11-2019 at 13:32

I have some 3.5x ones with a working distance of 340mm that I use for surface mount electronics work. They were going free when a company I worked for closed down, so I have no idea how much they cost or where they came from.

They take a little getting used to - you do need to spend some time setting them up for your eye spacing. They're quite heavy, so you need solid glasses to mount them on. I actually have one set mounted on the arm from an equipoise lamp - some things are easier to work on that way.

I dont know what your application is, but for me, working on small electronics, 3.5x is plenty of magnification. The only time I want more is for inspecting individual solder joints, for which I prefer a microscope.

yobbo II - 4-12-2019 at 11:19


Thanks for reply. I seem some good examples by searching for 2used dental binocular2 on ebay. They seem to be pretty expensive. I have an arm mounted microscope that perhaps will do my job. I have to set it up properly. I am trying to change the platters in a hard drive to recover data. I keep messing up the drive heads as they are so small. The 4+ dioptre glasses (cheap ones from the hardware store but pretty ok) are just not magnifying enough.



RELATED
What Is Magnification Power?
Updated April 24, 2017
By Keith Allen
Magnification and diopters are actually two different measurements. Magnification is a measurement of the change in the size of the object viewed through the lens. Diopter is the measurement of the lenses ability to bend light. Because the lens’ function of bending light accomplishes the magnification, the two measurements are related and if the magnification is known the diopters can be calculated.





Note the magnification power of the lens or lens system. A magnification power of 1x indicates a 100 percent or doubling of the perceived size of the object viewed through the lens when compared to the same object viewed with the naked eye. A 2.5x power lens would increase the size of the object by 250 percent. A 3-inch object would appear as 10 1/2 inches through the lens. The increase in the size of the object is 7 1/2 inches (3 inches times 2.5) plus the original size of the object.


Some googling:
Calculate the diopters of the lens by multiplying the magnification by four. The amount the light is bent by one diopter amounts to an increase of 25 percent in the size of the viewed object. A lens with a light bending capacity of four diopters, stated as 4d, would double the size of the object and have a magnification of 1x
My o
YOB

[Edited on 4-12-2019 by yobbo II]

Twospoons - 4-12-2019 at 13:25

Interesting project - I wish you luck.

Yes they are expensive, and as usual you get what you pay for. I know there are cheaper Chinese made versions, but they are likely using plastic lenses of poorer quality, which leads to poor contrast, distortion and uneven focus.

Cheap tools are a false economy - I have never regretted spending more for a quality tool.

yobbo II - 9-12-2020 at 16:40



I am trying to acertain what magnification of 'dental loupes' to purchase. I cannot get a pair to try on, so as to see how large/clear an object is when looked at. I am not in the dental business just want for doing fiddly jobs.

Dental loupes are descibed as 2.5x 3.5x etc.
Cheap reading glasses are also described as 2.5x, 3.5x etc.
Are these desciptions comparable?
I am not talking about the quality of the loupes or spectacles here. Lets assume both things have similar quality optics.
I am aware that the loupes give you a greater 'stand off' distance. You can stay back perhaps 30 or 40 centimeters from the viewed object and see it in focus. A pair of 3x spectacles would require (me anyways) to be much closer to the viewed object.
There are also dept of field and field of view stuff but I am just interested in finding out how 'big' the magnification is.
Assume lighting conditions are equal.

'Proper' spectacles (for reading etc) are very often described in diopters. Lets ignore that too.

What I am trying to ask is:
If I can see (say) a max. of 500 lines per inch with a pair of 3.5x spectacles, will I be able to see a max. of 500 lines per inch with the 3.5x loupes? Or will I see more?
Dental oupes (EBAY) range in price from about 50 bucks to 3000 bucks. At least my dentist said his cost 3 grand as he increased the speed and pressure on the drill..............
The dentist said you can see 'far more' with the 2.5x loupes than with 2.5x specks but I do not think he realized exactly what I was asking. If wearing 2.5x specks he would need to be far too close to my gob to do anything useful and see what he was doing at the same time.

Also with loupes you can have a very focued light but thats a seperate issue.

TFYT.

yobbo II - 25-3-2021 at 12:17



Original question was:

Dental loupes are descibed as 2.5x 3.5x etc.
Cheap reading glasses are also described as 2.5x, 3.5x etc.
Are these desciptions comparable?

The answer is yes. You get a similar magnification. The standoff distance is (of course) greater.

The dental loupes vary in price from 3 grand to twenty quid. You get what you pay for but the magnification is comparable.
What I am saying if you do not have a clue what mag. you actually need, put on reading glassess (though you can only get them up to 4x) and that will give you an idea of what you need/want.

Yob