[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

Re: [ATM] Attempted Parametrization of a Petzval Design





Monday, January 9, 2006, 12:00:26 PM, you wrote:

RFLRS> Attila Schné wrote:

>>
>>Dou you use Zemax to design these lenses? Can you give me suggestion
>>how can I use the optimisation function in Zemax?
>>
>>I have not to much knowledge about it.
>>
RFLRS> Actually, I used the GSUM tool to design the doublet.  Then I used
RFLRS> ZEMAX to test the Petzval design.

RFLRS> I want to preface the rest with the note that I don't think I've
RFLRS> found two people who agree on merit functions.  Many will
RFLRS> totally disagree with mine.  Also, you should really read the
RFLRS> optimization chapter in the User's Guide.  You may also have to
RFLRS> go back to previous chapters to get the background for the
RFLRS> optimization discussions.

RFLRS> In April 2000, George Anderson sent us Roland Christen's 11 inch
RFLRS> Petzval Design.  That design consists of two air-spaced N-K5/F2
RFLRS> doublets.  Each doublet has isoconvex crown element and mating
RFLRS> inner radii.  Attempting to parametrize that design in ZEMAX:

RFLRS> First, the desired effective focal length had to provide a
RFLRS> given f/#:

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>    2 CONS                    7.50000E+000           0
RFLRS>    3 EPDI                    0.00000E+000           0
RFLRS>    4 PROD    3    2          0.00000E+000           0
RFLRS>    5 EFFL         6          0.00000E+000           0
RFLRS>    6 DIFF    5    4          0.00000E+000           0
RFLRS>    7 CONS                    1.00000E+000           0
RFLRS>    8 PROD    7    6          0.00000E+000           1

RFLRS> Second, the desired doublet to doublet separation had to be a
RFLRS> given fraction of the focal length:

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   10 CONS                    8.77745E-001           0
RFLRS>   11 PROD   10    5          0.00000E+000           0
RFLRS>   12 TTHI    5    5          0.00000E+000           0
RFLRS>   13 ETVA    5    0          0.00000E+000           0
RFLRS>   14 MINN   12   13          0.00000E+000           0
RFLRS>   15 DIFF   14   11          0.00000E+000           0
RFLRS>   16 CONS                    1.00000E-001           0
RFLRS>   17 PROD   16   15          0.00000E+000           1

RFLRS> I need to calculate semi-diameters (ZEMAX supplies diameters):

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   19 CONS                    5.00000E-001           0

RFLRS> ZEMAX does not allow specification of isoconvexity and
RFLRS> fixed edge thickness.  Consistent with the design of the
RFLRS> GSUM tool, I specify the minimum thickness as a fraction
RFLRS> of the semi-diameter, but with different values for convex
RFLRS> and concave lenses; I know this gives a discontinuity at
RFLRS> the boundary, but ...

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   21 CONS                    1.25000E-001           0
RFLRS>   22 CONS                    1.50000E-001           0

RFLRS> Semi-diameter of the first doublet:

RFLRS>   Num Type Int1 Int2          Target            Weight

RFLRS>   24 DMVA    2               0.00000E+000           0
RFLRS>   25 PROD   24   19          0.00000E+000           0

RFLRS> Edge thickness of the convex lens in the first doublet.

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   27 ETVA    2    0          0.00000E+000           0
RFLRS>   28 DIVI   27   25          0.00000E+000           0
RFLRS>   29 DIFF   28   21          0.00000E+000           0
RFLRS>   30 CONS                    5.00000E+000           0
RFLRS>   31 PROD   30   29          0.00000E+000           1

RFLRS> Central thickness of the concave lens in the first doublet.

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   33 TTHI    4    4          0.00000E+000           0
RFLRS>   34 DIVI   33   25          0.00000E+000           0
RFLRS>   35 DIFF   34   22          0.00000E+000           0
RFLRS>   36 CONS                    5.00000E+000           0
RFLRS>   37 PROD   36   35          0.00000E+000           1

RFLRS> Semi-diameter of the second doublet:

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   39 DMVA    6               0.00000E+000           0
RFLRS>   40 PROD   39   19          0.00000E+000           0

RFLRS> Edge thickness of the convex lens in the second doublet:

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   42 ETVA    6    0          0.00000E+000           0
RFLRS>   43 DIVI   42   40          0.00000E+000           0
RFLRS>   44 DIFF   43   21          0.00000E+000           0
RFLRS>   45 CONS                    5.00000E+000           0
RFLRS>   46 PROD   45   44          0.00000E+000           1

RFLRS> Central thickness of the concave lens in the second doublet:

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   48 TTHI    8    8          0.00000E+000           0
RFLRS>   49 DIVI   48   40          0.00000E+000           0
RFLRS>   50 DIFF   49   22          0.00000E+000           0
RFLRS>   51 CONS                    5.00000E+000           0
RFLRS>   52 PROD   51   50          0.00000E+000           1

RFLRS> A small air-space in the first doublet may yield ghosts.
RFLRS> This will have to be checked later.  Absolute thickness
RFLRS> constraint on the air-space in the first doublet:

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   54 CONS                    0.00000E+000           0
RFLRS>   55 TTHI    3    3          0.00000E+000           0
RFLRS>   56 ETVA    3    0          0.00000E+000           0
RFLRS>   57 MINN   55   56          0.00000E+000           0
RFLRS>   58 DIFF   57   54          0.00000E+000           0
RFLRS>   59 OPGT   58               0.00000E+000           0
RFLRS>   60 CONS                    1.00000E-001           0
RFLRS>   61 PROD   60   59          0.00000E+000           1

RFLRS> Absolute thickness constraint on the air-space in the
RFLRS> second doublet:

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   63 CONS                    0.00000E+000           0
RFLRS>   64 TTHI    7    7          0.00000E+000           0
RFLRS>   65 ETVA    7    0          0.00000E+000           0
RFLRS>   66 MINN   64   65          0.00000E+000           0
RFLRS>   67 DIFF   66   63          0.00000E+000           0
RFLRS>   68 OPGT   67               0.00000E+000           0
RFLRS>   69 CONS                    1.00000E-001           0
RFLRS>   70 PROD   69   68          0.00000E+000           1

RFLRS> Optical performance:

RFLRS> Num Type Int1 Int2          Target            Weight

RFLRS>   72 DMFS

RFLRS> I selected the lens diameters, f/#, separation ratio,
RFLRS> wavelengths and field.  After freezing the thicknesses and
RFLRS> radii (manual intervention):

RFLRS> Surf     Radius      Thickness      Glass      Diameter

RFLRS> STO   Infinity      -6.652961                      290
RFLRS>    2    1583.45             33       N-K5           300
RFLRS>    3   -1583.45           5.55                      300
RFLRS>    4   -1583.45           22.5         F2           300
RFLRS>    5    49432.3         1909.1                      300
RFLRS>    6    1017.51           22.4       N-K5           200
RFLRS>    7   -1017.51              0                      200
RFLRS>    8   -1017.51             15         F2           200
RFLRS>    9    61956.2       1046.915                      200
RFLRS> IMA  -3055.721                                42.27809

RFLRS> The only bad ghost detected by ZEMAX is the reflection
RFLRS> between the lenses of the second doublet;-)



RFLRS> _______________________________________________
RFLRS> ATM mailing list http://www.atmlist.net/

Hello Richard,

Thank's for the lot of information!
I need time to interpret them. Maybe I will find some solution for my
difficulties.


   Clear skies!
-- 
Üdv:
Attila Schné
                          mailto:yolo@chello.hu

_______________________________________________
ATM mailing list http://www.atmlist.net/