Animation and Coin Photography

I used just three or four frames to try to capture the colors.

 

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Very pretty coin.

 

I have a couple of toned Wheaties that I want to try this on this weekend. It's impossible to catch their full glory with a single image, so I'm hoping this technique can show it off.

 

This is another attempt to recreate luster.

First, I took five photos of the obverse and five of the reverse. I kept the coin at the same tilt towards the light, but just rotated it in place beneath the camera. The lighting was at the 10:00 and 2:00 positions for each of the shots.

This animation shows the five positions.


I then aligned these sets of images as best I could. I rotated each of the obverse photos so LIBERTY is horizontal, then aligned each reverse image so the bottom of UNITED STATES is horizontal. Then they were joined into five new front+back photos. Finally, I took all five still images and put them together. Usually I specify a full second between each image. This time I only allowed one-quarter second.



Is this good for showing cartwheel luster?
Is it too fast?
Feel free to take apart the 5 images and try different durations, or to try new arrangements like 1-2-3-4-5-4-3-2...repeat. I'm curious to see what you all think.

 

That looks good!

It does feel just a little bit fast, but I think part of that may be that there is a fairly large jump between each image. I think if you had 8 images for the same rotation, it wouldn't feel so jumpy, and would give a smoother animation.

I do really like this technique though.

 

Are your lights fixed such that you can't move them around the coin? Keeping the coin stationary and moving the lights instead would make the alignment step unnecessary.

I think the speed is too slow and the change in lighting from frame to frame is too large. Also, the jump from last frame to first is no good. You need to go forward and backward as you mention above, because that's how you look at the coin. Look at the coin in hand and move it around in the light to see the luster. How long does it take to get the coin back to the starting position. A second or two, probably. Time your animation the same way so that it simulates looking at it in hand. My script that composes these uses 200 msec per frame if I have 6 frames, and 50 msec if I have 15. For the 15-frame composition, I additionally dwell on the first and last frame for 100 msec rather than 50.

 

These are exactly the ideas I was playing with in my mind. I will give them a try soon and see what I can do with 5 frames. When I use two frames, I have been using one second between them.

I feel that is about the right duration from beginning to end, so I will adjust the frame times to fit, as you suggest. And I would like to try a bit of a pause at each extreme - that just feels right. I may be offline for a day or so, but I will definitely give this a serious effort and see what I can achieve. And report the results, of course.

I am amazed at how many uses there are for animations. In this thread alone we have seen many different purposes, from showing luster, toning at different angles, a series of hobo nickels, and more! This encourages me no end.

I still hope that this opens up a new avenue for us to convey what we see and why it interests us.

 

OK, you guys got me interested in trying out a full-coin animation. Here is the reverse of one of my 41-D Lincoln Toners:

It's a big file, ~20MB, so give it time to load...

 

40 frames! Looks nice. The coloring seems to have survived quantization, although I don't have the coin in hand, so only you'll be able to tell us how well it worked. Lustrous, colorfully toned copper will present the biggest potential for problems in this respect.

I had put a request in to the PCGS registry people to allow animated GIF uploads for registry pages. I don't know if they'd go for 40 MB per coin, though.

 

I rebuilt the animation using exactly the same photos as in post #45, above. The sequence is 1-2-3-4-5-5-4-3-2-1, repeated. If we allow one second to go from the first position to the other extreme, this is like using one second to tilt the coin in hand.

To achieve this, each frame is shown for two-tenths of a second. The start and end frames are shown twice to simulate the pause when you tilt the coin back the other way. I also realigned one image that seem to jump a bit.

Because I had the coin at an angle to the lens each image has slightly different foreshortening from rotating the coin. I kind of like that - some change in perspective is what you would see when tipping it in your hand, and makes it feel more natural to me.

So this is essentially just what @messydesk proposed. I find the effect, using the exact same photos, to be vastly improved.

 

Dang, that looks nice! I am planning to try this for some of my toned coins as well.

I made a similar request to the NGC registry, but I haven't heard anything back yet. I initially wanted to the ability to link youtube videos, before we started talking about these gifs.

 

Here is a companion, also using 5 frames. I adjusted my algorithm permanently to account for the number of images. The movement in one direction lasts one second, then the movement back lasts another second.

 

It still isn't as smooth as @rmpsrpms , but it is better than my previous attempts. As messydesk has been saying, moving the lights instead of the coin produces a better product. I think my light movement was still a bit janky, so I still need to practice.... but it is improving.

 

My setup is too crude to move the lights without having the camera body get in the way. Plus the lights would fall off the desk.

In this one there are again five positions. They define a 90 degree arc from -45 to +45 from horizontal. The two lights are spaced 120 degrees apart. That should be sufficient to ensure that each part of the coin will be illuminated in one of the five images. (I was going to draw a diagram...)

Edit: I'm beginning to appreciate that the techniques to show luster may not be the same as showing toning. For luster both halves of the coin can be lit at once, so if the range of motion plus the angle between the lights is at least 180 degrees then the entire coin gets illuminated.

For toning a specific angle may be needed to light it, so more images will be needed to get the full effect.

I also like the small perspective shift shown below since it feels like moving the coin to see luster. To appreciate toning a more stable image is probably preferable.

This example uses a somewhat lustrous silver coin to explore how that looks.

 

This is yet another approach for a specific purpose. The vendor presented this nickel as 1916 BUFFALO NICKEL- UNCIRCULATED !! LUSTER !! Yet these were the vendor's photos (cropped and joined for display here). I sure don't see much sign of any LUSTER!! Maybe the vendor was trying to say the coin was better than the image?



For this animation I was looking for a more clinical analysis, rather than showing luster or toning. I took five photos, as with the examples earlier in the thread. I used a new technique for positioning, though. The coin was tipped to the left, then slightly tipped toward the right in small steps. It was not rotated with respect to the lights or camera, only angled from left to right.

First, it does seem that the seller pushed the color over towards the red. They take a lot of photos, so this does not seem like an accident.

Second, their photo of the obverse is overly dull and lifeless.

Third, I would not call this luster. The reverse strike, in particular, shows lines from the planchet. In other threads people have theorized that a rough planchet interrupts the flow of metal that would give a shimmering cartwheel luster (or did I just make that up?). At any rate I would call this reflective, but not lustrous.

I think the animation helps to show the coin as it is. I also think the vendor could have attracted more bidders with the animation. Although this date is not hard to find in upper grades, this is a nice coin that could be sold without juicing the photo or shouting LUSTER!! in the title.

For comparison, here are two of the still images that went into the animation.

 

This animation has six frames for each side. They are taken by rotating the coin about 10 degrees between each shot, as in post #56, above.

This is about .7 stop underexposed. The coin itself is brilliant. I guess I have to figure out how to show that shine, in addition to the luster.

 

This example uses the same set of 5 images. All of the animations I have shown have put the obverse and reverse side by side. However, for some contexts they may be better stacked vertically. In this forum, for example, a 1600 pixel wide image will be scaled down to fit, even though it can be clicked and expanded back to its full size. An image that is 800 wide by 1600 tall will show in its entirety.

First is the 800 tall by 1600 wide, then the 1600 tall by 800 wide. Everything within the animations is the same - the photos, orientations, color correction, and timing of each of the 5 frames.

1600 x 800 pixels

800 x 1600 pixels

 

I'd try this but I only have a camera phone. I can't imagine it working too well.