FOV in Zemax

[Andrea]

Hi,

can anybody here suggest a convenient way to calculate the entrance
and exit windows for a lens system in Zemax-EE?
In my lens file I have a CCD on the image plane and I wish to know
ther FOV!

Any suggestion will be highly appreciated

Regards

Andrea

[Dave Schaack]

Post by Andrea
Hi,
can anybody here suggest a convenient way to calculate the entrance
and exit windows for a lens system in Zemax-EE?
In my lens file I have a CCD on the image plane and I wish to know
ther FOV!

Andrea, to get anywhere in ZEMAX, one must set up certain aspects of the
system, including its aperture and its field of view. The field of view is
set in the field dialog, where there is a convenient pushbutton that selects
how the field of view is defined. Two options on this pushbutton are of
interest here: "paraxial image height" and "real image height" (if my
memory serves correctly). So, you select the one of these that you prefer,
and then below, in the field angle list, enter the actual height (i.e., half
of its full dimension) of your CCD as one of the field values.

Just now, I have forgotten where you can read the resulting field of view in
degrees, but it should be on one of the lens specification listings, if
nowhere else.

[Andrea]

Post by Dave Schaack

Post by Andrea
Hi,
can anybody here suggest a convenient way to calculate the entrance
and exit windows for a lens system in Zemax-EE?
In my lens file I have a CCD on the image plane and I wish to know
ther FOV!

Andrea, to get anywhere in ZEMAX, one must set up certain aspects of the
system, including its aperture and its field of view. The field of view is
set in the field dialog, where there is a convenient pushbutton that selects
how the field of view is defined. Two options on this pushbutton are of
interest here: "paraxial image height" and "real image height" (if my
memory serves correctly). So, you select the one of these that you prefer,
and then below, in the field angle list, enter the actual height (i.e., half
of its full dimension) of your CCD as one of the field values.
Just now, I have forgotten where you can read the resulting field of view in
degrees, but it should be on one of the lens specification listings, if
nowhere else.

Thanks a lot Dave,

gonna try soon! I'll let you know!

Regards

Andrea

[Richard F.L.R.Snashall]

Post by Dave Schaack
Just now, I have forgotten where you can read the resulting field of view in
degrees, but it should be on one of the lens specification listings, if
nowhere else.

Unfortunately, it may not be presented that way -- only if the original
setup was in degrees; accessible via < {Reports} >< System Data > or
< {Reports} >< Prescription Data >< Settings >< General Data >. When
I set up the field as, say, paraxial image height in mm, it will come
out that way in the reports; I then must calculate atan( field / EFL )
to get the value -- chagrin!;-).

[Dave Schaack]

When I set up the field as, say, paraxial image height in mm, it will come
out that way in the reports; I then must calculate atan( field / EFL )
to get the value -- chagrin!;-).

Thanks. That's why I couldn't remember -- I've probably never actually done
it!
One of the many irritating quirks that go along with using software.

[w***@provide.net]

Post by Dave Schaack

When I set up the field as, say, paraxial image height in mm, it will come
out that way in the reports; I then must calculate atan( field / EFL )
to get the value -- chagrin!;-).

Thanks. That's why I couldn't remember -- I've probably never actually done
it!
One of the many irritating quirks that go along with using software.

Zemax is very powerful, and in addition to being used every day in my
work, it is also my favorite toy. However, it does have some
unpleasant features. It is full of obscurely-located "switches", all
of which have to be set correctly to get correct results. It is not
always consistent in its use of units, although ZDC is getting better
at this. The lens layout windows work in a way that indicates the
coders never looked at a real CAD program. And it doesn't always play
nice with other applications. Having said that, though, I'd be hard-
pressed to choose, if I had to give up either Zemax or my library
card.

Wade Kelman

[Dave Schaack]

Post by w***@provide.net
Zemax is very powerful, and in addition to being used every day in my
work, it is also my favorite toy. However, it does have some
unpleasant features. It is full of obscurely-located "switches", all
of which have to be set correctly to get correct results. It is not
always consistent in its use of units, although ZDC is getting better
at this. The lens layout windows work in a way that indicates the
coders never looked at a real CAD program. And it doesn't always play
nice with other applications. Having said that, though, I'd be hard-
pressed to choose, if I had to give up either Zemax or my library
card.

I agree that it is powerful. This business of not showing the chief ray
angle anywhere if you haven't set up things in angle space to begin with is
one of a number of places where ZEMAX makes it painfully obvious that it was
not written or maintained by a working optical designer.

[Jim Klein]

Hi,

Post by Dave Schaack
I agree that it is powerful. This business of not showing the chief ray
angle anywhere if you haven't set up things in angle space to begin with is
one of a number of places where ZEMAX makes it painfully obvious that it was
not written or maintained by a working optical designer.

He was experienced but not a "years and years in the trenches"
designer like Dillworth, Kidger or Sinclair.

I had 10 years in when I started mine in 87 and did not have a
releasable code till 95. I wrote to copy ACCOS-V and Hexagon and
started adding a GUI after 2000.

Jim Klein



James E. Klein
***@earthlink.net

Engineering Calculations
http://www.ecalculations.com
***@ecalculations.com
Engineering Calculations is the home of
the KDP-2 Optical Design Program
for Windows.
1-818-507-5706 (Voice and Fax)
1-818-823-4121

"KDP2, not quite easy enough for a Caveman to use" :-)

[Dave Schaack]

Post by Jim Klein
He was experienced but not a "years and years in the trenches"
designer like Dillworth, Kidger or Sinclair.

It shows. That is why ZEMAX is not my first choice of tool for most
projects.

Post by Jim Klein
I had 10 years in when I started mine in 87 and did not have a
releasable code till 95. I wrote to copy ACCOS-V and Hexagon and
started adding a GUI after 2000.

Because it has become so popular, ZEMAX became and must remain my second
choice; and I imagine that this is true for many designers. The network
effect again.

[Dave Schaack]

And it [ZEMAX] doesn't always play nice with other applications.

What exactly are you referring to here?

[w***@provide.net]

Post by Dave Schaack

And it [ZEMAX] doesn't always play nice with other applications.

What exactly are you referring to here?

Hi Dave,
My saying "it doesn't play nice with other applications" was an
extremely poor choice of words, and I apologize to the Zemax coders
for saying that. I should have said that it doesn't seem to
seamlessly conform to Windows standards, which is a surprising thing
in a company that early adopted the exclusive use of Microsoft
Windows. File windows don't open with the defaults they have in my
other programs, layouts take longer to print than in any other
application, and I'm not always able to export the parts of the file
that I want to my CAD programs. These are minor annoyances and don't
actually harm other programs. They probably result from the fact that
ZDC has limited resources, and is putting those resources into things
that provide the most bang for the buck.
Back in 1974, long before I knew what I was good at, I wrote a ray
trace program in FORTRAN to trace rays through optical systems. It
used punch cards, ran on an IBM 360 mainframe, gave accurate results,
and was not very productive by today's standards. When I found that I
could just buy (for $500) a program called Max v1.46, I jumped at the
chance and have never looked back.

Wade Kelman

[Dave Schaack]

Post by w***@provide.net

Post by Dave Schaack

And it [ZEMAX] doesn't always play nice with other applications.

What exactly are you referring to here?

Hi Dave,
My saying "it doesn't play nice with other applications" was an
extremely poor choice of words, and I apologize to the Zemax coders
for saying that. I should have said that it doesn't seem to
seamlessly conform to Windows standards, which is a surprising thing
in a company that early adopted the exclusive use of Microsoft
Windows.

OK, thanks. I was worried that you were going to say that there were
problems when one tries to generate extensions to ZEMAX, which I believe
that I will be attempting soon.

[m***@oscintl.com]

Post by Andrea
Hi,
can anybody here suggest a convenient way to calculate the entrance
and exit windows for a lens system in Zemax-EE?
In my lens file I have a CCD on the image plane and I wish to know
ther FOV!
Any suggestion will be highly appreciated
Regards
Andrea

To find the physical size of your entrance and exit windows, take a
look at the illumination footprints.

To find the FOV of that the sensor can see through the lens, this
should be your field of view coordinates if you are tracing from
object to image, if you are tracing backwards, you can do some trig on
the angles from the image height and image distance, or look at some
real ray angles.

Dont forget to look at the corners of the CCD for the largest field
angle, not just the X and Y axis.

Michael
www.oscintl.com