How to show Shiny & Sharp?

Capturing
#1

One of my interests is making things polished and sharp,
down to sub-micron levels. It is not difficult to show a good polished
surface; just watch out for blown highlights.

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This is a watch caseback opener. It is not supposed to have a sharp
edge. The bevel has a mirror-polish, but the large flat area above it
is mottled, thus it cannot take a good shine.

So far, the task was relatively easy.
But how on earth does one visualize sharpness?
It is easy to show a strand of hair, split length-wise.
But that does not document the edge itselfā€¦

Have fun!
Claes in Lund, Sweden

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#2

:razor::drop_of_blood::vampire:
The effect of sharpness.

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#3

One of my hobbies is woodworking with hand tools. Sharp tools like chisels, saws and plane irons are essential to achieve good results.
With a well set up plane for a fine cut and a really sharp plane iron it is possible to take off such thin shavings that you can read eg. the dial of a watch through that shaving - that shows sharpness indirectly.

E.

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#4

For shiny, I think sometimes strong highlights (like blown) can show it. Sort of Specular highlight - Wikipedia So i guess local contrast can help too?

#5

Could you create an HEIF with either an HLG or PQ still image?

#6

Joking aside, I started on the wrong foot: I believe this is a capturing challenge, not a thread solely for remarks and quips. :wink:

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#7

Testing my kitchen knife (because :fr:) and my color light source:

Sharpness
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#8

Sharp for sure :sunglasses:.

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[Edit: wb]

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#9

Or not so sharpā€¦ or shiny? Anyone guess what this is? Hint: it is meant for cutting - otherwise I wouldnā€™t have posted in this thread.
I canā€™t remember what lens I usedā€¦ it was reverse mounted on a set of Pentax bellowsā€¦ I think it was a 28mm K-mount Tokina. @Claes , hope you donā€™t mind me posting in hereā€¦

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#10

Impromptu guesses: Bottle opener? Pipe cutter?

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#11

Itā€™s part of a chainsaw - the cutting teeth, I guess they could be called.

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#12

Claes , hope you donā€™t mind me posting in hereā€¦

Not at all!
However I wonder whether someone will be able to
find the proper reply to the original question:

But how on earth does one visualize sharpness?

How to document in an image that an edge is sharp,
as opposed to bluntā€¦

#13

I think the best way would be to show it in action, cutting through somethingā€¦ not quite sure how though. Iā€™ll try to try!

@afre and @MetalMick99 thanks for the guesses, Michael youā€™re absolutely right. :+1: A chainsaw cutting tooth. The field of view is about 10mm for a guess. Thanks!

#14

Does poking through something count?

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#15

HELP! :running_man:

#16

No. That is not considered a cut,
and does not need a sharp edge.

A hint: there is a way to show a sharp edgeā€¦

#17

Oho! I think you know already :slightly_smiling_face:ā€¦ not that it helps. Iā€™ve no new ideas!

#18

I knew I should have put a sarcasm tag on my post.

I should also have used sabre rather than ƩpƩe, since this is a cutting weapon. The difficulty is that at top level competitions, the background is black, which makes the blade difficult to see. At lower levels, you often lose the blade in a messy background.

#19

Is it not possible to use a speedlight at a low setting? Could create some really cool reflections with the dark background and the athletes in the foreground :thinking:

#20

At a competition, no. I have used flash and other light sources in a club situation.

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