[ATM] CCD Slit Test & 24" M-o-M

[Richard]

Hi Bill,

Friday, January 5, 2007, 7:00:45 PM, you wrote:

BT> the CCD Slit Test has moved to:
BT> http://www.yubagold.com/

Interesting test Bill. Like a very simple 1D hartmann.

Couple of things came to mind that may help you or others which you
may want to mention on your site. To measure the Ypix distances in any
graphics image viewer, there's a great little cheap program called
Screen Calipers. It literally puts a pair of calipers on your screen,
which you can zero, calibrate, tilt at any angle, lock, etc. You can
also define your own arbitrary units if you want. I use it for
measuring downloaded drawings which have maybe 2 dimensions and never
of the part you need. You can measure the known part and it tells you
how many pixels it is, go to Calibration and tell it the known
Millimeters or Inches from the known dimension and from thereon the
calipers are calibrated for that image. You don't have to go through
all that if you just want dims in pixels. By rotating the calipers to
the angle that the lines may be at with respect to the image, and then
locking that angle, all you readings are then corrected for camera or
mask tilt.

Screen Calipers at http://www.iconico.com/caliper/

The other thing I had tucked away in my favourites was a link to a
website with the dimension from the lens mount to the film plane of
CCD plane of many cameras. If it isn't listed there, T adapters (M42)
are 55mm.

http://www.a1.nl/phomepag/markerink/mounts.htm

-- 

Best regards,
  Richard in the UK