Sunday, September 14, 2008
New equipmets and some development work.
New focusing system for the Tokina 300mm lens.System is based on temperature compensating TCF-s focuser and
it's very accurate.
I printed an angular scale and glued it to telescope ring.
The ring is supporting the front end of the heavy lens and same time works
as an indicator to a camera angle.
New flat "box" with EL-sheet.
Last winter I had lots of problems with bad flats.I managed to buy one A2 size sheet of electro luminescent material.
(Here is the link: http://www.posterpoweruk.co.uk/page5.htm )
It works as a perfectly uniform light source and delivers perfect astronomical flats.
I used unexpencive, light weight, plastic frames to protect the light source.
(Not the one with real glas, it's too heavy for the purpose)
As seen in the image, I used two rubber bands with hooks to attach the panel.
In action
Angular scale for the AO-system
This is a simple solution to easy up guidestar selection with SXV-AO active optics sytem.When OAG (Off Axis Guider) is used, the selection of the guidestar is very important.
Now it's relatively easy to put whole imaging system to an angle readed from
star chart.
The scale is printed to a sticker material and can be seen in upper image.
New Lens for astro imaging
Tokina AT-X 300 f2.8 is a big and heavy lens.
Diameter of the main lens is 112mm.
Optical quality is very good. At f2.8 stars are absolute pinpoints to very corner of the
imaging area of my APS size camera.
STAR TEST IMAGES, LENS FULL OPEN @ f2.8:
Here is five images from cornes and the center of the image.
Image is just stacked (5 x 900s) and stretched, no other image processing methods are used.
As seen in the images, there is no visible optical flaws!Some brighter stars may have some distortion, but it's cauced by guiding and polar alignment errors.
-
-
This is a single 900s H-alpha filtered, flat and bias calibrated frame.Red pixels only, hence 1/4 size from original frame.
Mildly stretched under CCDStack software due the 8bit format, no other prcessing.
Subscribe to:
Posts (Atom)
