Hand Tools Archive

Subject:
top lighting

David Weaver
It won't be news to you, but it may be helpful for other people - metallurgical scopes usually have a shallow depth of field and are top lit with a separate light control as well as a shutter. Even my relatively cheap scope (about $500 now? guessing, it was $425 several years ago) has a separate halogen light source, and then ability to choose between camera or eyepiece for light priority and the shutter can vary the light effect (on top of the dimmable control on the light source itself).

What would really make the whole thing work would be software and electrical control to take pictures in layers and then put together a 3d image. I'm sure that exists, but at what cost, I have no clue.

For the cheaper hobby scopes and hand held scopes, top lighting is available (the hand scopes are top light just because there's nowhere else to put the lights on them other than to arrange LEDs around the lens), so they end up being a good option to view things without any other light - the software for them is real time so you can view what you're looking at on your screen without needing a third hand to snap a picture (one hand holding the item firm, the other holding the hand scope).

Take pictures complicates a lot more. I got my hand scope working again yesterday, but it's older - it claimed to be 600x, but it's probably 50-60 and the resolution is 640x480 - it's plenty good to identify sharpening problems. zooming in to even something like 150x makes the pictures worthless, though.

Not sure about bio scopes other than dissection scopes (those are usually something like 10-25x, good depth of field compared to metallurgical scopes and lighting is less concentrated). but a phone or eyepiece camera would have to have supplemental magnification to see the very edge - they are good as is to find out which stones actually provide a true polish. A simple dissection scope exposed my $400 japanese stone from hida tool as not being that fine compared to the folklore on the internet at the time that all japanese finishers were much finer than synthetics. It was more like a 6-8k synthetic equivalent.

My point that I'm slowly getting to is the light has to be OK for viewing, you can move objects around, object holding around and see what you need to see. To hold it in place, not bump it and get a picture that looks good at high resolution is a much taller order.

© 1998 - 2017 by Ellis Walentine. All rights reserved.
No parts of this web site may be reproduced in any form or by
any means without the written permission of the publisher.

WOODCENTRAL, P.O. BOX 493, SPRINGTOWN, PA 18081