I'd like to share a technique I use to build 3D models of ancient coins that can be studied from any angle. They're fun to look at, and sometimes you notice things you haven't seen before. The technique uses "focus stacking", a way to create sharp composite pictures of high relief coins from many individual shots. The first step is to shoot a coin using many small focus increments that capture both the high points and the low points (such as the rim). From that, a depth map is generated that is to be used to create a 3D simulation. The software used is Helicon Focus. If you look closely, you can see the steps on the depth map, representing focus increments. The resulting model can be rotated at any angle to show details of the relief: Perhaps the most interesting use of the depth map is creating a 3D animation of the coin: Finally, the focus-stacked obverse and reverse:
Thanks! That would take some more sophisticated 3D modeling software. It's beyond the capabilities of Helicon Focus' 3D Viewer.
This is great! And just what coin photography has been in need of for improving digital image sharing. Some questions... How long does it take to generate these 3d models with this software and what does the software cost. Also, is this software better or gaining on 3D video camcorders, or can the software process 3D video?
I should clarify...all the software can do is focus-stack, build a depth map, and create the simulation as stills and video. It cannot process any videos. From start to finish, it's a little bit involved. First thing is setting up the shot--lighting, etc. Then you need to calculate the focus step increments; the tethering software I use makes this easy. Then, you might want do some adjustments to the photos, which I do using a batch processor in photoshop. The final step is importing the pictures into Helicon Focus, creating the final image and depth map, then exporting as a 3D video. The work done in Helicon Focus is pretty quick--about 5-10 minutes, depending on how much you work on the 3D display parameters. As for price--I would check out their site for licensing prices. I think they have a sale now.
Nice work Kurt! Ancients are an excellent application for the 3D/perspective, focus stacking/depth map technique. Most of my 3D/perspective shots are of varieties at higher magnification. Interested folks can see them in my image gallery at http://www.macrocoins.com/image-gallery.html
That is so super cool.....and probably more than a little over my head and beyond my poor camera's specs---but something I would love to attempt one day.. I have 'bookmarked' your link, 'rmp' for future reference...
we use focus stacking to take close up photos of objects that occupied larger depth of field (larger miniatures), where we just shoot stationary objects with different focal throws, and it's considered annoying work that no one ever volunteer for it. can only imagine how much work this would be, having to angle for each shot. Perhaps a tilt-shift lens would make this more pleasant?
The shots are not taken at an angle, just straight-on at different focal planes. The software creates a depth map and then uses the depth information to render the angled perspective view. The angled view is purely calculated, based on the XYZ information from the original stack of images.
