Saturday, August 16, 2014

TEC Testing!

A couple months ago I invested in a like-new TEC 140 telescope.  The 140 in the model refers to the aperture in millimeters (5.5" diameter).  Its beefy nature required me to acquire a similarly beefy mount for it - I ended up making one using locally obtained materials, and a local welding shop.  As a reminder, it is a simple Altitude/Azimuth mount, shown at left.  Travel and summertime monsoons have conspired against me in getting it out under the stars, except when visiting buddy Pat a few hours one evening . The other day I left after getting home from work to check out the performance of the new mount/telescope combo.

My favorite vantage point is a quick trip to "A" Mountain, or Sentinel Peak, which offers an unparalleled view of the downtown Tucson area.  It is an easy drive there for daytime access, and gains a few hundred feet elevation for "testing" telescopes!  At right is a 2-frame mosaic with labels showing the location of the 3 shots referenced below.

First up was the old Pima County Courthouse, its scenic dome nearly hidden behind the taller court and government office buildings surrounding it.  But I know where to look to find it and it is a rewarding sight and target for testing.  The spectacular tile work was easily seen and sharply resolved  for being 1.4 miles from my location.  This view is shown at full-resolution, and was not down-sized for the blog. 

A good test for color errors in a refractor is to include bright lights in the field of view.  I found some at the UA football practice facility 3+ miles away.  If the TEC were not excellently color corrected, blue or purple halos would have likely been seen, but none can be spotted in this view, again, shown at full resolution.  This view shoots past the field into the Sam Hughes neighborhood as well.

Finally, I took a 2-frame mosaic of St Augustine Cathedral, located just south of downtown.  The left view shows this mosaic, and the right one shows part of it at full resolution.  I can't find any fault with the optics at all.  The mount was producing a little vibration in the considerable breeze atop "A" Mountain that afternoon.  I'm thinking that the interface between the mount and Gitzo tripod could be improved, or a more stable telescope tripod might be stiffer.  In any case, these images show the scope/mount combo works great and I can't wait to get it out again...

1 comment:

Alan Strauss said...

Nice report Dean, it was impressive to see your results. I plan to image the 10/23 eclipse through mine using my Canon.