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Does anyone have recommendations for 3D magnifiers for PCB work?

11/14/2021 7:39 AM

I already posted this question, but it does not appear in the list of Latest Forum Threads.

Fortunately I cross referenced it in another thread, and Solar Eagle was kind enough to PM me to say that the thread will not allow replies. (Without that I probably would not have noticed that it does not appear in the Latest Forum Threads, and would just wondered why I had had no replies)

Anyway maybe I broke some CR4 rules regarding advertisements (although the post has not been deleted) so I will just précis it here.

I am thinking of buying some dental loupes they are used by dentists to give 3.5 x magnification at 420mm with a good depth of vision. I suspect that because they are designed for a focal distance of 420mm, then if I used them on top of cheap reading glasses I could get much more magnification at a much shorter focal distance.

Alternatively, there are magnifiers with interchangeable lenses (called EEEKit) that give from 1 to 14 times magnification, but I'm not sure that they will have the same 3D depth of field.

Solar was also kind enough to point me to some digital microscopes with a small LCD display: I've got one of those, they're great for some jobs but they do not have any depth of field.

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#1

Re: Does anyone have recommendations for 3D magnifiers for PCB work.

11/14/2021 10:02 AM

I suspect that because they are designed for a focal distance of 420mm, then if I used them on top of cheap reading glasses I could get much more magnification at a much shorter focal distance.

The focal length of a lens, f, is the distance at which it will focus parallel rays, for example, sunlight.

Given the focal length and distance from the object, O, you can calculate the magnification, M = image size / object size, of the object as shown in the diagram below.

1 / image_distance = 1 / focal_length - 1 / object_distance

Magnification = image_size / object_size = image_distance / object_distance

https://byjus.com/physics/lens-formula/

If you add a second magnifying lens, the combined focal length will be shorter and magnification greater. The focal length of the combination can be calculated by the following formula:

1 / f = 1 / f1 + 1 / f2 - d / (f1 x f2),

where f is the focal length of the combination. The focal lengths of the 2 lenses are f1 and f2, and the distance of separation is d.

https://physics.stackexchange.com/questions/247617/how-is-focal-length-defined-for-a-two-lens-system-separated-by-a-distance-d

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#11
In reply to #1

Re: Does anyone have recommendations for 3D magnifiers for PCB work.

11/15/2021 8:28 AM

So simplistically using x3.5 reading glasses should bring the focal distance down to about 6", which would be OK.

I'm not sure if that holds when the dental loupes are already a two lens system.

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#2

Re: Does anyone have recommendations for 3D magnifiers for PCB work.

11/14/2021 10:16 AM

I think a lot of the 3-D effect is resolution, and getting a good viewing angle...what if I may ask is the resolution of your viewer?

I know to get to blueray resolution on my computer screen I had to change the video card in my computer, go to HDMI connections, and buy a new hd monitor....even though I thought I had HD to begin with...and change the DVD drive to a blueray capable reader...So getting digital resolution to a 3D like experience is not so easily done...and to get the best experience you need not only high quality optic magnification, but you need high resolution viewing as well...

https://projectorslab.com/everythings-about-resolutions/

The ultimate setup is an engraver type binocular....but can get very pricey

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#3
In reply to #2

Re: Does anyone have recommendations for 3D magnifiers for PCB work.

11/14/2021 10:33 AM

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#10
In reply to #2

Re: Does anyone have recommendations for 3D magnifiers for PCB work.

11/15/2021 6:44 AM

The digital microscope I have is 1080p, but to get this picture