styxman
02-23-2016, 11:56 PM
Found this Cent a while back and thought it was interesting – wanted to see what the LCF folk think. The coin is a rather rough 1942D cent with an arrow shaped divot (lamination error) in the observed side that encompasses the numeral 9 of the date and about half (medial aspect) of the mint mark. The 9 and the mint mark are almost complete; the mint mark shows minimal loss of metal from the top surface in the area of the divot. The extrusion level of the numeral 9 is about the same level as the other numbers of the date (see figures: 1942D_Divot_Flat_Inferior.jpg and 1942D_Divot_Flat_Superior.jpg.)
To my primitive eye, it seems that the lamination error must have been formed at the time of the strike. If the divot appeared earlier than the strike, I would expect to see deficiencies (possibly resembling a strike through) in the 9 and the mint mark as there would be a shortage in the amount of metal needed to form the 9 and the mint mark. On the other hand, if the divot occurred after the strike, it most likely would have affected the 9 and the mint mark – some or all of the relief would have been sheared away. Because the devices are essentially complete, the metal forming the 9 and the mint mark must have been recessed (protected) within the die when the divot was created. This would place the formation of the lamination error at the time of the strike. I could be completely wrong here – would like to know what others think – Thanks!
Error-Ref.com lists six types of Lamination Errors: Cracks, Loss After Strike, Loss Before Strike, Fold-over Before Strike, in Clad Coins, and Retained. This particular coin does not seem to fit into any of these categories. As such, if my assumptions are reasonable, I would propose a seventh category: Lamination Error: During Strike. OK – a wild *** dream!
I have placed this example within the Coin Photography Sub-Forum as it is contains more photographs using the axial lighting technique. The full coin shots were taken using the axial lighting – this time I use four lights all projecting on the glass. The lights are:
1: GLW 10w 12DCV Warm White LED Flood light
2: Peak to Peak 20w 12DCV Up/Down Wall-Washer Light
3 and 4: Jansjo LED Lights – aimed at a slight angle from either side of the center
The GLW and the Peak to Peak lights are powered using a variable voltage / current meter; the GLW set at 11.9 volts / 0.40 amps and the Peak to Peak set at 13.7 volts / 1.70 amps.
The glass I used is a 2mm thick optical glass sheet which measures 5 inches by 4 inches. It is held in place using a Fisso Arm – usually used for machined measurements. The clamp holding the glass is a Flexbar Microfine which is ideal as it fits the 2mm glass perfectly. The clamps and arms holding the GLW and Peak to Peak lights are Magnetic Base With Flexbar Arm which you can bend into any shape you want. Oher details are as follows:
Camera: Nikon D7000
Camera Lens: Nikon ED AF Micro Nikkor 200mm 1:4 which gives a great working distance between the end of the lens and the coin – plenty of room for glass, blocking screens and lights.
All the shots (except the setup photos) were taken using a StackShot to generate a stacked set. The StackShot is a motorized rail system which moves a platform in precise increments – the increments can be as small as 1 micron (0.001mm), or as large as a centimeter. For these photos, I attached the camera to the StackShot; it works just as well if you move the coin with the camera in a fixed position. (See attached Setup Photos.) The stacked sets were acquired through the tethering software Control My Nikon and rendered in Helicon Focus 6 using the raw .NEF native Nikon format pictures codec (parameters shown below). The full view images were generated from stacks of 30 images taken at 20 micron increments. The close-up of the lamination error (Divot) was generated from a stack of 350 images taken at 10 micron increments. For the close-up photos, the coin was mounted at about 45 degrees from the horizon and shot using a Nikon 4/0.1 160~ P Microscope Objective Lens mounted to the Nikon ED AF Micro Nikkor 200mm 1:4 lens. (See Photo: 1942D_Divot_Setup_Close_Up_02.jpg.) The Nikon 400mm lens focus was set at infinity. Following the rendering of the close-up stack, the results were then sent to the Helicon 3D Viewer. The output from the Helicon 3D Viewer was captured using Snagit to create a video of the coin. As the forum prohibits the up-loading of mp4 files, the video was compressed to a zip file which was up-loaded: (1942D_Divot_Close_Up.zip). To view, you will have to save the file to your computer; un-zip to yield the file: 1942D_Divot_Close_Up.mp4; double click on the file to open your media player (Windows Media Player or Quicktime) to play the video.
While there is some improvement in my photos, they are far from what Ray Parkhurst would produce. My lighting continues to be poor and it is non-uniform due to use of multiple lights. I am unable to find a single light that is bright enough to illuminate a coin to where I am not shooting at a half a second exposure time. The stacking remains difficult for me as I seem to generate bumps and valleys at random locations – not sure if my lenses need alignment or something else I am doing. Nevertheless, this was a fun project to put together with an interesting (but worthless) cent. Sorta the theme of my life! Oh well, enjoy.
Helicon Focus 6 parameters used:
Rendering method: Method B (depth map)
Radius: 8
Smoothing: 4
Downscaling: Full resolution (100%)
Codec: Nikon .NEF Raw File Decoder
Exposure compensation: 0.0
Contrast: 0.0
Gamma: 1.0
Sharpness: 0.0
Saturation: 0.0
Tint: 0.0
Noise reduction 0.0
URLs:
GLW 10w 12DCV Warm White LED Flood light:
http://www.amazon.com/gp/product/B008XZAQDU?psc=1&redirect=true&ref_=oh_aui_detailpage_o08_s00
Peak to Peak 20w 12DCV Up/Down Wall-Washer Light:
http://www.amazon.com/gp/product/B00B43D00E?psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s00
Jansjo LED Lights:
http://www.amazon.com/Ikea-201-696-58-Jansjo-Light-Black/dp/B0055IVM1I/ref=sr_1_1?s=lamps-light&ie=UTF8&qid=1456113430&sr=1-1&keywords=ikea+light
Glass for axial lighting:
http://www.surplusshed.com/
Fisso Arm (Strato 3D Line Gaging Arm):
http://www.amazon.com/gp/product/B001C1B7AI?psc=1&redirect=true&ref_=oh_aui_detailpage_o07_s00
Flexbar Microfine Adjustment Only:
http://www.amazon.com/gp/product/B001C1FBFA?psc=1&redirect=true&ref_=oh_aui_detailpage_o07_s00
Magnetic Base With Flexbar Arm
http://www.amazon.com/gp/product/B001BPD7LC?psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00
StackShot:
https://www.cognisys-inc.com/products/stackshot/stackshot.php
Control My Nikon:
http://www.controlmynikon.com/
Helicon Focus 6:
http://www.heliconsoft.com/heliconsoft-products/helicon-focus/
Nikon native .NEF Codec:
http://downloadcenter.nikonimglib.com/en/products/170/NEF_Codec.html
Snagit:
http://discover.techsmith.com/try-snagit/?gclid=CjwKEAiA3aW2BRCD_cOo5oCFuUMSJADiIMILWtGicDs NOysemrJ1dplRU_TwZWbAa4IaHr4Q0d3nbhoCa6Xw_wcB
To my primitive eye, it seems that the lamination error must have been formed at the time of the strike. If the divot appeared earlier than the strike, I would expect to see deficiencies (possibly resembling a strike through) in the 9 and the mint mark as there would be a shortage in the amount of metal needed to form the 9 and the mint mark. On the other hand, if the divot occurred after the strike, it most likely would have affected the 9 and the mint mark – some or all of the relief would have been sheared away. Because the devices are essentially complete, the metal forming the 9 and the mint mark must have been recessed (protected) within the die when the divot was created. This would place the formation of the lamination error at the time of the strike. I could be completely wrong here – would like to know what others think – Thanks!
Error-Ref.com lists six types of Lamination Errors: Cracks, Loss After Strike, Loss Before Strike, Fold-over Before Strike, in Clad Coins, and Retained. This particular coin does not seem to fit into any of these categories. As such, if my assumptions are reasonable, I would propose a seventh category: Lamination Error: During Strike. OK – a wild *** dream!
I have placed this example within the Coin Photography Sub-Forum as it is contains more photographs using the axial lighting technique. The full coin shots were taken using the axial lighting – this time I use four lights all projecting on the glass. The lights are:
1: GLW 10w 12DCV Warm White LED Flood light
2: Peak to Peak 20w 12DCV Up/Down Wall-Washer Light
3 and 4: Jansjo LED Lights – aimed at a slight angle from either side of the center
The GLW and the Peak to Peak lights are powered using a variable voltage / current meter; the GLW set at 11.9 volts / 0.40 amps and the Peak to Peak set at 13.7 volts / 1.70 amps.
The glass I used is a 2mm thick optical glass sheet which measures 5 inches by 4 inches. It is held in place using a Fisso Arm – usually used for machined measurements. The clamp holding the glass is a Flexbar Microfine which is ideal as it fits the 2mm glass perfectly. The clamps and arms holding the GLW and Peak to Peak lights are Magnetic Base With Flexbar Arm which you can bend into any shape you want. Oher details are as follows:
Camera: Nikon D7000
Camera Lens: Nikon ED AF Micro Nikkor 200mm 1:4 which gives a great working distance between the end of the lens and the coin – plenty of room for glass, blocking screens and lights.
All the shots (except the setup photos) were taken using a StackShot to generate a stacked set. The StackShot is a motorized rail system which moves a platform in precise increments – the increments can be as small as 1 micron (0.001mm), or as large as a centimeter. For these photos, I attached the camera to the StackShot; it works just as well if you move the coin with the camera in a fixed position. (See attached Setup Photos.) The stacked sets were acquired through the tethering software Control My Nikon and rendered in Helicon Focus 6 using the raw .NEF native Nikon format pictures codec (parameters shown below). The full view images were generated from stacks of 30 images taken at 20 micron increments. The close-up of the lamination error (Divot) was generated from a stack of 350 images taken at 10 micron increments. For the close-up photos, the coin was mounted at about 45 degrees from the horizon and shot using a Nikon 4/0.1 160~ P Microscope Objective Lens mounted to the Nikon ED AF Micro Nikkor 200mm 1:4 lens. (See Photo: 1942D_Divot_Setup_Close_Up_02.jpg.) The Nikon 400mm lens focus was set at infinity. Following the rendering of the close-up stack, the results were then sent to the Helicon 3D Viewer. The output from the Helicon 3D Viewer was captured using Snagit to create a video of the coin. As the forum prohibits the up-loading of mp4 files, the video was compressed to a zip file which was up-loaded: (1942D_Divot_Close_Up.zip). To view, you will have to save the file to your computer; un-zip to yield the file: 1942D_Divot_Close_Up.mp4; double click on the file to open your media player (Windows Media Player or Quicktime) to play the video.
While there is some improvement in my photos, they are far from what Ray Parkhurst would produce. My lighting continues to be poor and it is non-uniform due to use of multiple lights. I am unable to find a single light that is bright enough to illuminate a coin to where I am not shooting at a half a second exposure time. The stacking remains difficult for me as I seem to generate bumps and valleys at random locations – not sure if my lenses need alignment or something else I am doing. Nevertheless, this was a fun project to put together with an interesting (but worthless) cent. Sorta the theme of my life! Oh well, enjoy.
Helicon Focus 6 parameters used:
Rendering method: Method B (depth map)
Radius: 8
Smoothing: 4
Downscaling: Full resolution (100%)
Codec: Nikon .NEF Raw File Decoder
Exposure compensation: 0.0
Contrast: 0.0
Gamma: 1.0
Sharpness: 0.0
Saturation: 0.0
Tint: 0.0
Noise reduction 0.0
URLs:
GLW 10w 12DCV Warm White LED Flood light:
http://www.amazon.com/gp/product/B008XZAQDU?psc=1&redirect=true&ref_=oh_aui_detailpage_o08_s00
Peak to Peak 20w 12DCV Up/Down Wall-Washer Light:
http://www.amazon.com/gp/product/B00B43D00E?psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s00
Jansjo LED Lights:
http://www.amazon.com/Ikea-201-696-58-Jansjo-Light-Black/dp/B0055IVM1I/ref=sr_1_1?s=lamps-light&ie=UTF8&qid=1456113430&sr=1-1&keywords=ikea+light
Glass for axial lighting:
http://www.surplusshed.com/
Fisso Arm (Strato 3D Line Gaging Arm):
http://www.amazon.com/gp/product/B001C1B7AI?psc=1&redirect=true&ref_=oh_aui_detailpage_o07_s00
Flexbar Microfine Adjustment Only:
http://www.amazon.com/gp/product/B001C1FBFA?psc=1&redirect=true&ref_=oh_aui_detailpage_o07_s00
Magnetic Base With Flexbar Arm
http://www.amazon.com/gp/product/B001BPD7LC?psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00
StackShot:
https://www.cognisys-inc.com/products/stackshot/stackshot.php
Control My Nikon:
http://www.controlmynikon.com/
Helicon Focus 6:
http://www.heliconsoft.com/heliconsoft-products/helicon-focus/
Nikon native .NEF Codec:
http://downloadcenter.nikonimglib.com/en/products/170/NEF_Codec.html
Snagit:
http://discover.techsmith.com/try-snagit/?gclid=CjwKEAiA3aW2BRCD_cOo5oCFuUMSJADiIMILWtGicDs NOysemrJ1dplRU_TwZWbAa4IaHr4Q0d3nbhoCa6Xw_wcB