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 Replies: 27 / Views: 3,932 |
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Pillar of the Community
  United States
4038 Posts |
Quote:
You got a StackShot, didn't you? Almost...I actually traded a lens for a custom-made vertical stacking setup. A guy wanted a Printing-Nikkor and had electromechanical skills to offer, so we traded. I was not happy with the accuracy and step size limitations of the StackShot (reading about it, not testing) and this guy recommended a Trinamic stepper and a fine-pitch linear stage with nominally 5x the resolution. I was thinking about doing higher magnification stacking (50x) but never did get going with it. Turns out the small step size is required for high accuracy 3D rendering at lower mags, so here's the result. And as you can imagine the optics are special as well, not just your run of the mill high res objectives... edited to add...this is done with 5 microstep spacing per image, so in theory I could get 180 images in the stack if needed...but my objective isn't THAT good... Edited by rmpsrpms
10/25/2013 09:59 am
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Pillar of the Community
United States
627 Posts |
Phenomenal!! I have nothing further of import to add.  |
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Moderator
United States
23522 Posts |
"A StackShot didn't have enough resolution." The geek in me is giggling uncontrollably at this. |
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Pillar of the Community
United States
4038 Posts |
1951-D/S OMM#1   Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Moderator
United States
23522 Posts |
I have nothing, Ray. You're in a league of your own.
The OMM is almost irrelevant - I'm studying metal flow from your incomprehensible images. Note the curvature towards the devices by comparison to the straight flow in the open fields; one can actually imagine the metal behaving as a fluid under the intense pressure of the strike. I find it illuminating that the MM shows no flow lines but appears to have been cast instead; it must have formed in an instant, even on the scale of 150 strikes per minute. Otherwise, flow would show on the deepest parts of the MM.
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Pillar of the Community
United States
4038 Posts |
You start to see flow lines near the "base" of the MM where it lifts out of the field, but not near the top. From my understanding, the "look" of the metal flow lines is actually created by wear to the die. As many coins are struck, and coin metal flows across the die surface due to displacement, and this gradually wears the die. So what we see on the coin is actually the metal flow lines present in the die. There are no flow lines on the tops of the devices because there is very little wear happening on the die in those areas. This assertion is backed up by observation that early die state examples have far less luster than later die states, luster being enhanced by the presence of flow lines.
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Pillar of the Community
United States
4038 Posts |
Here's a 1949-S Lincoln Cent DDO#3 presented with a couple of techniques. Unprocessed image using 5x magnification, 25-stack of images:  Unprocessed image using 10x magnification, 36-stack of images:  3D processed 10x image but looking straight on to compare with unprocessed:  3D processed 10x image looking at 45-deg from 9:00:  3D processed 10x image looking at 45-deg from 2:00  I think this technique is useful to help visualize these kind of variety details in a similar way to viewing then with a microscope, at least the way I view them. I'm not so sure the 3D versions of these is all that useful, but some may like them. I find them kind of gimmicky, and while they can be sort of cool they don't offer any more information than the 2-D perspective views above. If you disagree, let me know. It's not too hard to include 3D versions of these. Ray |
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Moderator
United States
23522 Posts |
Well, they could be a definitive telltale between a genuine RPD and a lucky postmint hit, for instance. Illustrating the actual depth of the two different punches can be very useful. Gimmicky, maybe, but things like this are visually stunning, and capable of drawing non-numismatist eyes. That's a good thing for the hobby. So what are the optics and software involved? I can think of more than a few Morgan VAMs which would greatly benefit from this kind of treatment. I have two kidneys; I can spare one. |
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Pillar of the Community
United States
4038 Posts |
I'm going to keep the lens secret for a while, but the software is Helicon Focus...
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Moderator
United States
23522 Posts |
Fair enough. I *do* see practical real-world applications for 3D renderings, though, as definitive descriptions of doubling errors and field displacement (an area of interest with certain Morgans).
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Pillar of the Community
United States
4038 Posts |
If you'd like to see what it would look like, you could send me a coin to image...
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Pillar of the Community
United States
4038 Posts |
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Pillar of the Community
United States
4038 Posts |
Here's a 3D version. I cropped it to make it easier to visualize, ie you don't have to cross your eyes as much...  |
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Pillar of the Community
United States
3486 Posts |
I don't think that it is gimmicky at all.
The trick is to relax your eyes and focus on the central image.
I have no trouble doing this but many people do.
Thanks for the experiment, rmps.... Doesn't hurt to try new things.
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Pillar of the Community
United States
784 Posts |
These are simply unbelievable! So when do we get the 3D flyover video view? :)
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Replies: 27 / Views: 3,932 |
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First Page
Posted 10/25/2013 10:00 am
