ANNOUNCEMENT: ATM Foucault Mirror Surface Profiler Software

Greetings ATM's,

After a month long obsession with getting reliable measurements of a
mirror's surface profile (heights, not just slopes), I am releasing
ATM FOUCAULT TEST - MIRROR SURFACE PROFILER UTILITY v.0.5.

- It's FREEWARE (for version 0.5)
- Windows (95-XP) Based
- Uses N-degree polynomial curve fitting, instead of piece-wise numeric
integration
- Compensates for Zone Mask Parallax (to some extent)

So far, the results appear to be very accurate. Based on preliminary tests
of a 10" f/3 mirror test data, both as a sphere and as a paraboloid,
the calculated deviation from ideal is less than 1/1,000th of a wave
for the SURFACE, not wavefront.

Other Features and Limitations:
- 5 Test Zones, plus center (Zone 0)
- Zones may (should) be set by user
- Maximum of 5 test sets per calculation
- Wave rating is for surface only, not wavefront
- No attempt to quantify final image quality
(P-V, RMS, Strehl, encircled energy, etc. - subject to too much debate)
- No Monte Carlo assessment of probable errors in user supplied data
- Results can be saved in a text file, for import to a spreadsheet.
- Previous data is NOT read back in as a start up configuration.
- Filesize is about half a megabyte (uncompressed for download)
- No Zip tool needed.
- Sketchy instructions on web-page. No other help file.
- Assumes the mirror's curve is reasonably free of abrupt zonal
irregularities.
- Relies on MOVING SOURCE or SLITLESS Foucault Testers. For fixed
source, the off-axis nature, and the discrepancies of measurement
angle may kill accuracy on fast mirrors ( f/5 !)

For those who download and use the utility, I will be interested to
see how the results stack up against other Foucault Data Reduction
programs such as Tex or SixTests. For long focus mirrors, I doubt
there will be much difference. For larger, faster mirrors, the
results may be more interesting.

The Download and Instructions page is at:

http://www.vvm.com/~piscescs/foucault/foucault_sw.html

Screenshot is included.

Larry G wrote:
Greetings ATM's,


For those who download and use the utility, I will be interested to
see how the results stack up against other Foucault Data Reduction
programs such as Tex or SixTests. For long focus mirrors, I doubt
there will be much difference. For larger, faster mirrors, the
results may be more interesting.

The Download and Instructions page is at:

http://www.vvm.com/~piscescs/foucault/foucault_sw.html

Screenshot is included.


From your discussion here, I see you have primarily worked against
the "paraboloid" as a goal. However, have you considered other
goals, e.g.: those mentioned in:

http://users.rcn.com/rflrs/sectest.htm


especially as it is a problem more in line with your stated
initial goal (handling fast surfaces).

On Wed, 26 Jan 2005 10:37:06 +0000, Richard F.L.R. Snashall
wrote:

Larry G wrote:
Greetings ATM's,


For those who download and use the utility, I will be interested to
see how the results stack up against other Foucault Data Reduction
programs such as Tex or SixTests. For long focus mirrors, I doubt
there will be much difference. For larger, faster mirrors, the
results may be more interesting.

The Download and Instructions page is at:

http://www.vvm.com/~piscescs/foucault/foucault_sw.html

Screenshot is included.


From your discussion here, I see you have primarily worked against
the "paraboloid" as a goal. However, have you considered other
goals, e.g.: those mentioned in:

http://users.rcn.com/rflrs/sectest.htm


especially as it is a problem more in line with your stated
initial goal (handling fast surfaces).

For the moment, my major concern is for accurate measurement of
concave surfaces commonly employed in amateur telescopes - the
paraboloid and the sphere. At some time in the future, the utility
may be expanded to encompass ellipsoids and hyperboloids, though
there are less commonly sought by ATM's.

One of the reasons the results can be saved as a text file, is
so the numbers can be directly imported into a spreadsheet, for
those telescope makers who want to compare the results with curves
of their own description, including fourth degree curves (as long as
it is concave at all points. (Sorry, no direct measurement for
Schmidt correctors!)

Thanks for the interest.

Cheers,
Larry G.

Larry G wrote:
For those who download and use the utility, I will be interested
to
see how the results stack up against other Foucault Data Reduction
programs such as Tex or SixTests.

Nice utility, Larry.

I am interested in buying a low-end Foucault slitless tester rather
than fabricating one. Would anyone in this usenet group have any
suggestions for a source? - Canopus56

On 26 Jan 2005 18:12:08 -0800, canopus56 wrote:

Larry G wrote:
For those who download and use the utility, I will be interested
to
see how the results stack up against other Foucault Data Reduction
programs such as Tex or SixTests.

Nice utility, Larry.

I am interested in buying a low-end Foucault slitless tester rather
than fabricating one. Would anyone in this usenet group have any
suggestions for a source? - Canopus56



Thanks for the feedback. I'm glad you like it. Hopefully it can
be expanded to be even more useful in the future.

For what it is worth, I have played with the idea of producing
Slitless Foucault Testers as a commercial product. However,
it is very difficult to determine the market for such things.
ATM's seem to prefer making things themselves, though building
a good one, from scratch, can take nearly as long as producing
a modest mirror.

Out of curiosity, (marketing research) how much would you (and other
interested ATM's) be willing to pay for a unit? What options and features
would you expect at that price?

TIA,
Larry G.

Thanks. $90-$110. I am not experienced enough in mirror figuring to
offer a useful opinion. I would expect to be able to use it in
beginner mirror grinding and figuring. - Canopus56