gernoff
Hot Rolled
- Joined
- Mar 19, 2011
- Location
- Great Falls, Montana
Here is a quick rundown of how I use a D600 autocollimator.
Standing at the eyepiece, autocollimator adjustment knob upright and looking towards your reference mirror, the right hand half of the field of view is where measurements are taken. The LH half of the FOV is what 'looks at' the reference mirror. To get your reference mirrors initially aligned, remove the eyepiece and sight thru the scope to your mirror. While moving the mirror and or scope look for the green light of the illuminator in the reflection of the mirror, this is a touchy adjustment. Once you are close, you can re install the eyepiece and then gently moving the scope look for the reticule image in the FOV.
From this point, you need two mirrors to do any real measurement with the D600. The reference mirror sit stationary in the LH half of the FOV and the measurement mirror fills the RH half. Changes in the tilt of the measurement mirror vertical axis can be determines by adjusting the knob (1/10 second per division) until the reticule lines are interspersed. The two reflected reticule images are each a pair of parallel lines. To take a measurement, turn the adjustment knob CCW until the pairs are separated, now turn the knob CW and adjust until the lines are superimposed and then continue until the trailing line of the movable pair equally splits the fixed pair of lines. The angular difference between the reference and measurement mirrors is read directly from the adjustment know. It is graduated to tenths of an arcsecond. I'd say you can consistantly repeat to a 1/2 second, and with good conditions and practice can probably get down to 1/4 arcsecond.
The better your mirror surface quality, the sharper these lines are.
Standing at the eyepiece, autocollimator adjustment knob upright and looking towards your reference mirror, the right hand half of the field of view is where measurements are taken. The LH half of the FOV is what 'looks at' the reference mirror. To get your reference mirrors initially aligned, remove the eyepiece and sight thru the scope to your mirror. While moving the mirror and or scope look for the green light of the illuminator in the reflection of the mirror, this is a touchy adjustment. Once you are close, you can re install the eyepiece and then gently moving the scope look for the reticule image in the FOV.
From this point, you need two mirrors to do any real measurement with the D600. The reference mirror sit stationary in the LH half of the FOV and the measurement mirror fills the RH half. Changes in the tilt of the measurement mirror vertical axis can be determines by adjusting the knob (1/10 second per division) until the reticule lines are interspersed. The two reflected reticule images are each a pair of parallel lines. To take a measurement, turn the adjustment knob CCW until the pairs are separated, now turn the knob CW and adjust until the lines are superimposed and then continue until the trailing line of the movable pair equally splits the fixed pair of lines. The angular difference between the reference and measurement mirrors is read directly from the adjustment know. It is graduated to tenths of an arcsecond. I'd say you can consistantly repeat to a 1/2 second, and with good conditions and practice can probably get down to 1/4 arcsecond.
The better your mirror surface quality, the sharper these lines are.
