Cut Crystal Tests
Ono, 3 way comparison of SF10 glass.
Original:
2nd method:
2nd method using principal dispersion wavelengths:
2nd way has the centre spectrum issues I mentioned. This does seem to be drawing a line 'through' the measured data.
3rd way fits the curve best for the majority of the visible spectrum. Fits better than original method but still drops of through violet.
Original:
2nd method:
2nd method using principal dispersion wavelengths:
2nd way has the centre spectrum issues I mentioned. This does seem to be drawing a line 'through' the measured data.
3rd way fits the curve best for the majority of the visible spectrum. Fits better than original method but still drops of through violet.
"A foolish consistency is the hobgoblin of little minds..." - Emerson 1841
what's the actual difference in the three methods?
I'd say, a mix of 2nd and 3rd would give the best match, if there is any way to do that...
'cause 2nd is *quite* correct in the violet spectrum, but then, it starts being more incorrect than the 3rd.
1st is least accurate...
Can you think of any way, to mix 2nd and 3rd mode? For example, you could (maybe) blend them from 2nd to 3rd
(a quite quick blend, should already be in the middle of the two, at 442.5 nm or something )
I'd say, a mix of 2nd and 3rd would give the best match, if there is any way to do that...
'cause 2nd is *quite* correct in the violet spectrum, but then, it starts being more incorrect than the 3rd.
1st is least accurate...
Can you think of any way, to mix 2nd and 3rd mode? For example, you could (maybe) blend them from 2nd to 3rd
(a quite quick blend, should already be in the middle of the two, at 442.5 nm or something )
Here are the details:
The first method uses the gradient of a line drawn between nF and nC (the principal dispersion), using um^2 for the wavelength measurements (x), to get B and a rearranged cauchy equation to solve for A
The second method uses the gradient of a straight line between 400nm and 700nm, using um^-2 for the wavelength measurements, to get B and using B finds the y intercept (x = 0) to get A.
The third method uses the same equations as the second method but uses the principal dispersion wavelengths (nF and nC) instead of 400nm and 700nm.
The first method uses the gradient of a line drawn between nF and nC (the principal dispersion), using um^2 for the wavelength measurements (x), to get B and a rearranged cauchy equation to solve for A
The second method uses the gradient of a straight line between 400nm and 700nm, using um^-2 for the wavelength measurements, to get B and using B finds the y intercept (x = 0) to get A.
The third method uses the same equations as the second method but uses the principal dispersion wavelengths (nF and nC) instead of 400nm and 700nm.
"A foolish consistency is the hobgoblin of little minds..." - Emerson 1841
Ono seems to ahve fallen asleep in IRC so I have yet to get his opinion on this. I personally think that this is why Sellmeier revised Cauchy; Cauchy simply isn't accurate enough across the spectrum for all mediums whereas Sellmeier is.
"A foolish consistency is the hobgoblin of little minds..." - Emerson 1841
Version 14 of Schott Glass Catalog spreadsheet available
EDIT: Link removed - See thread entitled Tabulated Schott Glass Catalog.
@Ono: A and B calcs used in this are those based on um^-2 please take a look and see what I mean about the odd results. These calcs seem to result in either a near perfect fit or a really bad fit from glass to glass.
EDIT: Link removed - See thread entitled Tabulated Schott Glass Catalog.
@Ono: A and B calcs used in this are those based on um^-2 please take a look and see what I mean about the odd results. These calcs seem to result in either a near perfect fit or a really bad fit from glass to glass.
"A foolish consistency is the hobgoblin of little minds..." - Emerson 1841
this does it if you don't have the programs - Like meWytRaven wrote:It's jsut a standard Office 97-2003 Excel spreadsheet. If you aren't on windows and/or don't have MS Office then I guess something like Open Office would be a good start?CoolColJ wrote:not the archive itself, I can unpack it with Winrar just fine, but read the file itself
http://www.microsoft.com/downloads/deta ... laylang=EN
I realise now all the maths I learnt at school come is actually useful....
along with a scientific calculator
http://www.calculator.com/calcs/calc_sci.html
along with a scientific calculator
http://www.calculator.com/calcs/calc_sci.html
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