OT(ish) DIY USB microscope from webcam?

[David.WE.Roberts]

Decided it would be nice to have a USB microscope just to take a picture of some very small text on a bicycle chain link.

Had a quick Google and they seem to come in at around £40 e.g.

So, webcam with a macro lens and LED lighting.

Given that I have a couple of USB web cams already plus some phones with built in cameras I may have the makings of a DIY temporary microscope.

However before I start trying to bodge together a suitable stand to allow positioning of the camera and subject, am I wasting my time?

LED lighting isn't essential as directed light should do.

The question is the 'macro' lens - is a normal web cam or smart phone good enough?

Has anyone tried this?

Cheers

Dave R

[dave]

Yes. And it works very well. The camera I have (Maplin) has a small screw by the lens. Slacken that and you can turn the lens mount. Adjusts down to a very millimetres without problem. Making a fixture for it would take longer (I didn't do that) but the complex stuff works.

[whisky-dave]

Yes I have one of those.

6 6/

they might not focus close enough.

It's worth trying ultimately depends on the quality you need or expect. On larger magnifications keeping the camera or subject still is the problem . When I was taking the picture of the iPad and the coin the lens was only a bout 5mm or so from the subject.

That's OK provided you don't cast shadows.

The lenses probbaly are but you get distotion and focusing problems.

A similar thing was tried with telescopes on the Sky at night and it works.

[meow2222]

Hold a 35mm SLR lens up to a camera and you have something that'll do the j ob. The main shortcoming is with lighting: expect focal distances in the re gion of 5mm.

NT

[newshound]

No need to pay that much

The lighting even in these cheap ones is remarkably good. A couple of months ago I was trying to read the markings on a small IC in some piece of kit. I tried initially with my usual 10x magnifier and separate light, but just could not read it. But it was very clear with the USB microscope. I've also used it to guide multimeter probes and check out PCB tracks when trying do diagnose an earphone socket fault.

I wish I could persuade them to work on an android tablet though. Webcam software will work the camera, but I have not found out how to toggle the lights on.

[whisky-dave]

job. The main shortcoming is with lighting: expect focal distances in the region of 5mm.

I thought the trick there was to reverse the lens.

[David.WE.Roberts]

Thanks - amazingly cheap. Have you bought that product from that supplier?

Whatever, it seems worth a go at that price. [Which is often the trap people fall into where something is "so cheap!"]

Cheers

Dave R

[newshound]

No, that's just an example. I have one which looks very similar, but I have had it for several years. I also have one of the slimmer, roughly pencil-sized ones. I suspect that irrespective of "name", they are made by a small number of manufacturers.

[Roger Mills]

Are you sure that you need the level of magnification (x200, x800, etc.) provided by something calling itself a microscope?

Presumably the text on the chain was intended to be read by humans - maybe with the use of a magnifying glass.

I've got a half-way decent digital camera which can photograph things only 1cm from the lens in super-macro mode. I often use that when I want to read text that's too small for my eyes, and then blow it up on my computer screen. You could probably do almost as well with a tablet or smartphone, as long as it will focus on very close objects and as long as you can hold it steady enough.

[Brian Gaff]

You really need a decent lens. a friend reckons it goes out of focus after 1 foot even in good light, but then not all webcams are created equal I suppose. Brian

[Mike]

there's a Bresser microscope camera (with O ring missing) here:

- Mike