Sorting Out Step Cut Specs (say that 5x fast)

[Karl_K]

Hi Karl,

Sorry for the slow reply on this - I was hoping it was going to sink into my subconscious and make sense, but it still hasn't done so lol

I guess I am just confused because in the image, the red arrow and the green arrows appear to be showing exactly the same facet on opposite sides of the stone, so how can one be a large virtual facet and the other be a medium??!?

Magic or physics.
Think about a flash of light that shape coming off the diamond.
it will be narrow but long.
Moved one way it will quickly pass your eye. the other way it will be on your eye a long time.
Cut out a narrow long strip of paper hold it up in front of you and rotate it both ways and it will quickly be obvious.

 

[OoohShiny]

Magic or physics.
Think about a flash of light that shape coming off the diamond.
it will be narrow but long.
Moved one way it will quickly pass your eye. the other way it will be on your eye a long time.
Cut out a narrow long strip of paper hold it up in front of you and rotate it both ways and it will quickly be obvious.

Ohhhhhh, I see now!

So the 'large' virtual facet isn't technically bigger than the 'medium' virtual facet in terms of physical size, but it is 'bigger' because it is longer in duration due to the direction it moves?

Would the bigger/longer flashes off the large(r) virtual facet also be more likely to produce a range of different fire colours (rather than perhaps just the one that the medium virtual facet would), on the basis that the movement of the stone is likely to change angle/distance from the viewer's pupil ever so slightly, and therefore the dispersion fans will scan from end to end across the pupil? (Whereas the medium virtual facet is likely to be a quick flash of a single colour?)

 

[Karl_K]

Ohhhhhh, I see now!

So the 'large' virtual facet isn't technically bigger than the 'medium' virtual facet in terms of physical size, but it is 'bigger' because it is longer in duration due to the direction it moves?

It acts larger depending on how you move it because it is bigger one way vs the other.
Im doing a horrible job explaining this!

 

[Karl_K]

Would the bigger/longer flashes off the large(r) virtual facet also be more likely to produce a range of different fire colours (rather than perhaps just the one that the medium virtual facet would), on the basis that the movement of the stone is likely to change angle/distance from the viewer's pupil ever so slightly, and therefore the dispersion fans will scan from end to end across the pupil? (Whereas the medium virtual facet is likely to be a quick flash of a single colour?)

Depends on the lighting, in some vendors videos where they rotate over the long side remember they are white the entire way and hardly flash at all.
Medium virtual facets are actually more efficient at producing fire than very large ones.
But when both are producing fire your correct the long large virtual facet has a longer fan and the medium facet is a quicker flash.

 

[OoohShiny]

Thanks Karl!

Medium virtual facets are actually more efficient at producing fire than very large ones.

I note that this seems to be the opposite of OECs??

 

[Karl_K]

Thanks Karl!


I note that this seems to be the opposite of OECs??

oec virtual facets are large relative to the size of the stone and the reflectors face a different direction than a step cut which changes the tilt action interaction.
But the one the green arrow points to acts differently than the red arrow one even in an oec or RB when rotated side to side.
Orientation counts.

 

[OoohShiny]

Thank you for the explanation and diagrams!

That is a new thing I have learnt this week

(Now I just have to not forget it... lol)