Microscope photos: Proof sovereign comparison

[Charliemouse]

1984

1986

2015

 

[9x883]

They need you for quality control at the mint🧐

[Organics]

WOW! What is it they say “they don’t make em like they used to” 😞

[ZRPMs]

And that's progress right there for you. I think the detail gets better the further back you go.

[dicker]

Very nice images!

[Charliemouse]

1 hour ago, ZRPMs said:

And that's progress right there for you. I think the detail gets better the further back you go.

Agreed.  The frosting gets more 'frosty' as time moves forward (and more holes), but the definition of the face and detail gets worse.

What is especially noticeable is that, with the 1984, I could not keep the whole face in focus because the relief was so much higher.  The later coins, especially the 2015, are flatter and easily focused.

[ZRPMs]

It makes you wonder if the dies are being produced with less quality as part of an overall cost cutting exercise or are we loosing a craft to mechanism. You'd think with todays tech you could almost increase the quality of the detail. Look at the Great Engravers series. The originals were made with far better detail. 

[Charliemouse]

2 minutes ago, ZRPMs said:

It makes you wonder if the dies are being produced with less quality as part of an overall cost cutting exercise or are we loosing a craft to mechanism. You'd think with todays tech you could almost increase the quality of the detail. Look at the Great Engravers series. The originals were made with far better detail. 

It's a valid point.  I do not have any old proof sovereigns, so I cannot go further back.

But I can compare modern proof coins from other mints, even if it isn't like-for-like.

[Charliemouse]

1999 Perth Mint Bi-Metallic Sovereign

2018 RCM $200 110th Anniversary .99999

This is just weird.  Appears to be made with an entirely difference process.

[DdraigAur]

Very interesting topic. Would those neat striations on the Canadian coin indicate the die was somehow CNC/machine finished?

[Charliemouse]

1 hour ago, DdraigAur said:

Very interesting topic. Would those neat striations on the Canadian coin indicate the die was somehow CNC/machine finished?

I have no idea.  Hopefully someone with more coin minting knowledge can answer.

In the meantime, here are some more pics.  Including some missing 'frosting'.

For scale, those digits are approximately 1.5mm tall.  That makes the 'striations' about 50 microns wide.

[James32]

29 minutes ago, Charliemouse said:

I have no idea.  Hopefully someone with more coin minting knowledge can answer.

In the meantime, here are some more pics.  Including some missing 'frosting'.

For scale, those digits are approximately 1.5mm tall.  That makes the 'striations' about 50 microns wide.

Die has been laser etched? Or a dwarf with a teeny weeny hammer did it.

[Charliemouse]

2 minutes ago, James32 said:

Die has been laser etched? Or a dwarf with a teeny weeny hammer did it.

It's always the leprechauns.  🤣

[NGMD]

47 minutes ago, Charliemouse said:

I have no idea.  Hopefully someone with more coin minting knowledge can answer.

In the meantime, here are some more pics.  Including some missing 'frosting'.

For scale, those digits are approximately 1.5mm tall.  That makes the 'striations' about 50 microns wide.

Not CNC. Could be finished with a laser finished with a small aperture. The same as the assay office use.

[Booky586]

Fantastic photos, keep on posting them!

I'm with James and NGMD, I wouldn't be surprised if the dies are finished by laser.

Have a look at the scan I've attached from an 1986 Royal Mint Coin Club Bulletin. It describes how the frosting used to be applied to the dies, historically by Nitric acid etching and then by glass bead shot blasting.

1986-21 Die Polishing.pdf

Edited February 27 by Booky586

[9x883]

23 hours ago, Charliemouse said:

1984

1986

2015

 

The 80's really were the best times. Keep these photos comming, fascinating indeed💖👌

[NGMD]

1 hour ago, Booky586 said:

Fantastic photos, keep on posting them!

I'm with James and NGMD, I wouldn't be surprised if the dies are finished by laser.

Have a look at the scan I've attached from an 1986 Royal Mint Coin Club Bulletin. It describes how the frosting used to be applied to the dies, historically by Nitric acid etching and then by glass bead shot blasting.

1986-21 Die Polishing.pdf 493.95 kB · 1 download

The blasting media is usually done with ceramic now for consistency as glass breaks down to powder easily and has too much colour fluctuations and can hide surface imperfections. 
Oh hang on, it’s the Royal mint- grit and tarmac sandpaper.

 

[NGMD]

22 hours ago, Charliemouse said:

Agreed.  The frosting gets more 'frosty' as time moves forward (and more holes), but the definition of the face and detail gets worse.

What is especially noticeable is that, with the 1984, I could not keep the whole face in focus because the relief was so much higher.  The later coins, especially the 2015, are flatter and easily focused.

Do you have any close up shots of alternatives mints? Be good to see their process on magnified details.

[Spyder]

Any chance of doing a Gillick and some earlier Victoria through to George V to see how things have gone down hill 

Edited February 27 by Spyder

[iacabu]

I do love seeing these extreme close ups, great thread.

What magnification are these taken at? 

[Charliemouse]

35 minutes ago, NGMD said:

Do you have any close up shots of alternatives mints? Be good to see their process on magnified details.

Which do you mean?  The previous two were Perth and Canada.  They are the only proof coins I have with the Pistrucci design, to compare George's head like with like.

I am happy to photograph anything I've got with the microscope, but I don't have proofs going further back than the 1980's.

[NGMD]

Just now, Charliemouse said:

Which do you mean?  The previous two were Perth and Canada.  They are the only proof coins I have with the Pistrucci design, to compare George's head like with like.

I am happy to photograph anything I've got with the microscope, but I don't have proofs going further back than the 1980's.

Love to see like modern Germania/Perth proofs or anything you have under the mattress to see alternative modern processes under high magnification.

[Charliemouse]

49 minutes ago, Spyder said:

Any chance of doing a Gillick and some earlier Victoria though George V to see how things have gone down hill 

Here's a couple of Gillicks.  First year and last year.  Sadly, only bullion.

1958 Bullion Full Sovereign

1968 Bullion Full Sovereign

Amazingly, I think there is more definition in these faces than in the 2015 proof above.  Of course the finish is not as good with bullion, but it makes you wonder.

Edited February 27 by Charliemouse

[Charliemouse]

33 minutes ago, iacabu said:

I do love seeing these extreme close ups, great thread.

What magnification are these taken at? 

Difficult to be precise.  The closest this lens focuses is about 12mm, which gives a stated magnification of 700x.  I take these figures with a bit of a pinch of salt though, and it obviously depends what monitor you view it on.

A more useful measure is what distance the image covers on the subject.  The image of George's head is about 1.5mm x 1mm.

[Charliemouse]

12 minutes ago, NGMD said:

Love to see like modern Germania/Perth proofs or anything you have under the mattress to see alternative modern processes under high magnification.

Here's a couple:

2014 1oz Reverse Proof Maple

2014 1/4oz Proof Kangaroo