DavidU
28-02-2010, 08:43 PM
An interesting adventure for sure !. My trusty 8 element UWA 6.7mm has for some reason collected a lot of dust internally over the years, so I removed the lower barrel that houses the two element barlow and cleaned it. Then unscrewed the lower ring that holds the remaining 6 elements, spacer rings and field stops. I clean my fingers with White spirit on a Microfiber cloth to remove all traces of oil and blow air on them to remove all dust.
This is where the cold sweats come in.
I turned the eye piece upside down and placed a micro fiber cloth on the end of my pinky and inserted it into the lower barrel then turned the eye pc the right way up allowing the elements to be held up by my pinky, as I lowered the group and removed my finger I was able to have the elements in a stack resting on the now flat microfiber cloth.
Each lens was cleaned with isopropyl alcohol (2-propanol, iso-propanol) and Q tips. Each surface was then cleaned again with a fresh Q tip and a fogging breath to get a pristine surface on the Anti reflection coatings, then air blown and inspected under a 3x loupe for traces of dust.
The element stack is then held in the palm of my hand on the Micro fiber cloth and slid carefully into the barrel. The barrel is now turned upside down so gravity can keep the elements in the correct place.
The cemented doublet that is the last element nearest the eye must now be fitted neatly into the barrels exit apature, this is done by glueing a 7mm round piece of micro fiber to a 6mm bit of tubing (in this case Heatshrink tube). The eye piece is held in the left hand upside down whilest using the 6mm tube to move the last element to neatly seat it and gravety compleats the correct placement with a slight clunk.
The threaded ring is then tightened against the element group until gently shaking the eye pc just stops the lenses rattling and no tighter.
Finally, screw in place the 1.25 chromed barrel that holds the barlow section and you are done.What else do you do when it's cloudy? LOL.
This is where the cold sweats come in.
I turned the eye piece upside down and placed a micro fiber cloth on the end of my pinky and inserted it into the lower barrel then turned the eye pc the right way up allowing the elements to be held up by my pinky, as I lowered the group and removed my finger I was able to have the elements in a stack resting on the now flat microfiber cloth.
Each lens was cleaned with isopropyl alcohol (2-propanol, iso-propanol) and Q tips. Each surface was then cleaned again with a fresh Q tip and a fogging breath to get a pristine surface on the Anti reflection coatings, then air blown and inspected under a 3x loupe for traces of dust.
The element stack is then held in the palm of my hand on the Micro fiber cloth and slid carefully into the barrel. The barrel is now turned upside down so gravity can keep the elements in the correct place.
The cemented doublet that is the last element nearest the eye must now be fitted neatly into the barrels exit apature, this is done by glueing a 7mm round piece of micro fiber to a 6mm bit of tubing (in this case Heatshrink tube). The eye piece is held in the left hand upside down whilest using the 6mm tube to move the last element to neatly seat it and gravety compleats the correct placement with a slight clunk.
The threaded ring is then tightened against the element group until gently shaking the eye pc just stops the lenses rattling and no tighter.
Finally, screw in place the 1.25 chromed barrel that holds the barlow section and you are done.What else do you do when it's cloudy? LOL.