Author Topic: Some tips for friends who plan to upload picture and want to know coin authentic  (Read 1876 times)

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Offline pitcoinchaser

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Hello,

This is my first topic so I want to briefly introduce myself here. I am a super coin fan and collect coins for many years. I am now living in east coast of US. Before coming to US, I live in  China and learn coin knowledge especially judging authentic with a very prestigious coin dealer there.

I am very pleased to help you judge coin authentic here. I believe this is a efficient to improve and learn new things. Here are some tips for friends who plan to upload picture and want to know coin authentic

I want to concentrate although image can help us to sift many low quality reproductions, but it cannot 100% judge authentic. That's why many professional dealer or collector like to spend several days flight to the auction to pre-view the lots rather than stay behind the computer and see high resolution pictures. Many dealer always say:we must actually put the coin in hand then I can tell you whether its genuine. So, it is VERY IMPORTANT to actually touch, feel and even smell the coin. Trust me, many artificial toning has strange odor due to the usage of chemical liquid or other reasons.

Because using image to judging authentic has its own limitation, we need very careful to take pictures and try our best to make the coin as it is in the picture. Some tipes are as follows:

1. Please do not upload overexpose, low illumination or out of focus image. Since those images will provide few details.
2. Please do not upload scan image. I know scan image are some times used in some auctions, it will provide fine details of the coin. But, we cannot judge luster from the picture, so we cannot correctly judge coin condition. For some high quality reproductions in AU to UNC condition, luster can also provide clues for its authentic.
3. Please, please include rim image. THAT IS VERY IMPORTANT since rim itself is a kind of anti-forgery technology. Nowadays, although forgers can perfectly reproduce surface of the coin, but they still cannot 100% make rim pattern exactly correct. So, I hope you can also include rim image in future.
4. If possible, please take more pictures to reflect some details rather than just take both side pictures.

Any other suggestions are welcome.

Joe N39 N40
  

Offline SANDAC

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pitcoinchaser,

I'm intrigued by your pictures and comments about 字口是否好.  ( http://china-mint.info/forum/index.php?topic=11935.msg70669#msg70669 ) It is certainly a great reason for taking high resolution pictures of coins in question.  We had several threads about coin photography:
http://china-mint.info/forum/index.php?topic=11855.0
http://china-mint.info/forum/index.php?topic=834.0

The camera technology is evolving rapidly.  It is my hope that with a good camera and good shooting techniques, we can detect fakes reliably and educate collectors in the process.  A couple follow ups to your comments:
1.  Are there particular areas in a coin that closeup and high resolution are particularly helpful, such as corners of characters?
2.  How should the light be position?  Is it useful to take several pictures with different light positioning?
3.  Lastly, can you comment on this coin: http://china-mint.info/forum/index.php?topic=7732.0  

Welcome to CCF, and thank you for your contributions.

Offline Rainbird

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pitcoinchaser,

I'm intrigued by your pictures and comments about 字口是否好.  ( http://china-mint.info/forum/index.php?topic=11935.msg70669#msg70669 ) It is certainly a great reason for taking high resolution pictures of coins in question.  We had several threads about coin photography:
http://china-mint.info/forum/index.php?topic=11855.0
http://china-mint.info/forum/index.php?topic=834.0

The camera technology is evolving rapidly.  It is my hope that with a good camera and good shooting techniques, we can detect fakes reliably and educate collectors in the process.  A couple follow ups to your comments:
1.  Are there particular areas in a coin that closeup and high resolution are particularly helpful, such as corners of characters?
2.  How should the light be position?  Is it useful to take several pictures with different light positioning?
3.  Lastly, can you comment on this coin: http://china-mint.info/forum/index.php?topic=7732.0 

Welcome to CCF, and thank you for your contributions.

good photography is not enough. you might also need to feel the weight as well as how is the light reflected from the surface. i collection porcelains too, it will often lead to mistakes if judging by photos only. same for coins, but it seems to be easier.

Offline pitcoinchaser

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1.  Are there particular areas in a coin that closeup and high resolution are particularly helpful, such as corners of characters?
Yes, closeup or high resolution on the rim, edge of the characters and any pattern that has fine textures (such as badge, button on the cloths of warlord on some silver medals. These details need high pressure punching machine to be demonstrated. Most of counterfeiter cannot use such high pressure punching machine to make reproductions, so these details may be blurred and not very clear)

2.  How should the light be position?  Is it useful to take several pictures with different light positioning?
That's a very good question and I think this is a open question. Every people have their own flavor of lighting position, for me, I like to use two light sources on left and right upper position. But it varies with people. Overall speaking, as long as the lighting can preserve details and not very off with the original color of the coin, it will be accepted.  

3.  Lastly, can you comment on this coin: http://china-mint.info/forum/index.php?topic=7732.0  
I have commented already. Coin is counterfeit with transfer die damage. Thanks!

pitcoinchaser,

I'm intrigued by your pictures and comments about 字口是否好.  ( http://china-mint.info/forum/index.php?topic=11935.msg70669#msg70669 ) It is certainly a great reason for taking high resolution pictures of coins in question.  We had several threads about coin photography:
http://china-mint.info/forum/index.php?topic=11855.0
http://china-mint.info/forum/index.php?topic=834.0

The camera technology is evolving rapidly.  It is my hope that with a good camera and good shooting techniques, we can detect fakes reliably and educate collectors in the process.  A couple follow ups to your comments:
1.  Are there particular areas in a coin that closeup and high resolution are particularly helpful, such as corners of characters?
2.  How should the light be position?  Is it useful to take several pictures with different light positioning?
3.  Lastly, can you comment on this coin: http://china-mint.info/forum/index.php?topic=7732.0  

Welcome to CCF, and thank you for your contributions.