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Having just discovered an interest in the variety of old gramophone needles, I've been buying up a lot of 'tins with contents' online. Before using some of them, I read here about the importance of looking closely to check if they've been previously used or damaged. I was using my microscope to inspect them more closely, and it was a small step to bolt on (well, tape on) a camera and try some needle photo-microscopy!

I hope you'll find the results interesting. Part of the difficulty with extreme magnification is getting enough light to the subject, given the very small working distance between the subject and the front of the objective. The main problem though is that only a tiny "slice" of the subject is in focus at once, so you need to take multiple images at varying focal points then stack them in software.

The close up image of the spear is a composite and focus-stack of around 300 separate images. The one of the tip of the needle is pushing the current set up to the limits, and the quality of the final image is quite poor, but hopefully I'll improve with future efforts.

Iain

Iain, I found your post interesting. The extreme magnification really does reveal the imperfections in man made objects although the pitting may be due partly to corrosion. It reminds me of the famous picture of a bee sting through the eye a needle that compares the fineness of nature to man made.

jamiegramo wrote: Sun Nov 03, 2024 6:14 am Iain, I found your post interesting. The extreme magnification really does reveal the imperfections in man made objects although the pitting may be due partly to corrosion. It reminds me of the famous picture of a bee sting through the eye a needle that compares the fineness of nature to man made.

Many thanks, I found this fascinating too. It reminds me that I'd like to take an in-depth microscopic look at BCN thorn needle points and record grooves at some point.

@IainP1

Thank you for a most interesting post.

How interesting photos!

jamiegramo wrote: Sun Nov 03, 2024 6:14 am Iain, I found your post interesting. The extreme magnification really does reveal the imperfections in man made objects although the pitting may be due partly to corrosion. It reminds me of the famous picture of a bee sting through the eye a needle that compares the fineness of nature to man made.

Thanks. Wow that is some serious magnification there. Yes, I'll try some others soon, to see if they appear pitted too.
Iain

Orchorsol wrote: Sun Nov 03, 2024 8:46 am

jamiegramo wrote: Sun Nov 03, 2024 6:14 am Iain, I found your post interesting. The extreme magnification really does reveal the imperfections in man made objects although the pitting may be due partly to corrosion. It reminds me of the famous picture of a bee sting through the eye a needle that compares the fineness of nature to man made.

Many thanks, I found this fascinating too. It reminds me that I'd like to take an in-depth microscopic look at BCN thorn needle points and record grooves at some point.

Thanks. I'm setting up the equipment tomorrow so will try a BCN at high magnification and share results here
Iain

IainP1 wrote: Sun Nov 03, 2024 4:37 pm

jamiegramo wrote: Sun Nov 03, 2024 6:14 am Iain, I found your post interesting. The extreme magnification really does reveal the imperfections in man made objects although the pitting may be due partly to corrosion. It reminds me of the famous picture of a bee sting through the eye of a needle that compares the fineness of nature to man made.

Thanks. Wow that is some serious magnification there. Yes, I'll try some others soon, to see if they appear pitted too.
Iain

The picture through the eye of a needle was done on a scanning electron micrograph in 1973. You’ve done very well without such equipment but using the focus-stack images.

Nice and interesting photos! The pits on the needle surface are corrosion - I had inspected old needles some years ago - just with a microscope, no camera - and saw the same pits on a set of supposedly NOS steel needles. The pits were not present in other lots. At the time I also inspected thorn needles after playing a record that was not compatible with it, a 20s US dime store label that looked funny after I played with the thorn: the tip was completely burned, like a spent match. Evidently I never utilized such needles on these cheap labels since.

CarlosV wrote: Sun Nov 03, 2024 4:58 pm Nice and interesting photos! The pits on the needle surface are corrosion - I had inspected old needles some years ago - just with a microscope, no camera - and saw the same pits on a set of supposedly NOS steel needles. The pits were not present in other lots. At the time I also inspected thorn needles after playing a record that was not compatible with it, a 20s US dime store label that looked funny after I played with the thorn: the tip was completely burned, like a spent match. Evidently I never utilized such needles on these cheap labels since.

Thanks Carlos! I've bought a lots of old tins with needles recently, so will inspect them careful before putting them near records