What scanner to use

I just scanned these silver bars using my Epson V330,
the Copper round I used my point ans shoot canon

 

Log in or Sign up to hide this ad.

It should be noted that this stuff comes with a fairly steep learning curve; you've no choice but to learn the business of photography (it's not an "art" in our specialty, it's a skill which can be taught) in order to employ it properly because "automatic" ain't happening.

From an ease of use standpoint it's far simpler to attach a $500 bespoke 100mm Macro lens to the camera, but we don't all have that kind of cash to throw at a single lens.

 

What purpose do the "bellows" serve Dave?

What type of lights are those?

 

I borrowed your image from your post to illustrate a question I have. Hope you don't mind.

Scanners do not scan perfect. The scanner head never comes from the factory set perfectly square to the scanner bed. They all scan at a angled perspective. Refer to the crude arrows black and yellow I drew on the image above to illustrate this point.

What a flatbed scanner will do is scan imperfect - perfectly each time. If this makes any sense. Always at the same focal length, distance and angle to the scanner bed.

If you put your coin in a 2 x 2 cardboard flip, which are cut almost perfectly square, square the flip edge against the alignment bar on the scanner and make 4 different scan rotating the coin 90 degrees each time as illustrated in the image above. You capture 4 different perspectives of the coin at the same distance, focal and angle.

Import the 4 scans into your image editor rotate right side up and stack and render them into a 3-D image.

Do you think this would work?

 

A bellows sets the magnification level of the lens, allowing you to use the same lens at varying magnifications (akin to a "zoom"). With the goal being to get a full-face coin image to fill the sensor (1:1 magnification), you can fine-tune magnification to that end. It can also be done with adapters and spacers, but that creates a fixed distance from lens to sensor and therefore fixed magnification. You don't want the same magnification for a Merc as you would a Morgan, all other things being equal.

This is all necessary because the system uses film duplicating lenses, which are not only very cheap but also very good at what they do, and what they do (flat field, color-accurate, sharp) is exactly what we need in coin imaging.

The lights are the Ikea-bought Jansjo LED's I've mentioned elsewhere. They're a loss leader for Ikea, distributed around the stores in stackouts, and cost $10.

It would work, but I don't see what it would improve that a scanner isn't good at. Won't improve color or luster reproduction.

 

Luster and color are not significant issues for me, I use coin images primarily for attributing varieties and errors.

 

OK. With that in mind, a single pass on a decent scanner should provide all the detail you require. It's what they're good at. Your proposed technique stands a good chance of eliminating any shadowing, which is cool, but it might also multiply the hotspots. Gonna try it, I hope? It's an interesting idea.

 

I was thinking since the 4 different scans would actually be from 4 different angular perspectives - that a 3-D image could be rendered from the stack with 3-D rendering software.

 

I use a Sigma 150mm macro but I'm thinking a bellows system would be really cool. I now wish I had gone that direction.

 

Well, for you a $100 bill would suffice to get started, if you want to dabble. You can do this on a tripod - with a little rigging - and not need to come up with a copystand for the moment. The tradeoff is having to square the rig every time you shoot.