View Single Post
  #3  
Old August 28th 04, 02:04 AM
S&B
external usenet poster
 
Posts: n/a
Default

There are higher quality versions of this test target on the Web.
Google the search terms USAF resolution download, etc. You might want
to also download a postscript (PS) version or PDF. Print out on a
decent laser printer.

I've done a fair bit of resolution testing for camera lenses and none
for scopes. I imagine that you may run into problems if you conduct
your tests on bright sunny days which heats up the pavement and causes
"seeing" problems.

Many Leica lens users will say that resolution tests don't really tell
you much about a camera lens' performance on actual subjects.
Qualities such contrast, colour accuracy, distortion, saturation and
bokeh are not something that can be measured or defy quantification in
a USAF test, at least for folks who lack lab grade test bench
equipment. Mixed all that up with telescope eyepiece performance and
visual versus photographic resolution and what does it all mean? As
such, I'm not sure if resolution testing would tell me much about my
scope's performance for stellar objects (assuming this is what we're
mostly using the scope for).

Being new to star gazing, I thought the best way to test one's scope
is to split doubles or bring it to a star party and compare. My $.02

S&B




(Pieter Tieghem) wrote in message . com...
Hi ppl

I was just wandering if it is possible to do a ground-based test of
the resolving power of a telescope. With ground-based I mean you look
at a target on earth, to exclude seeiing. I tought on something like
http://www.efg2.com/Lab/ImageProcess...s/Image133.gif
placed some 20-30 meters away or so.
Would this work for a telescope test?

Thanks for your help!
Pieter