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150mm F8 achromat refr and 80mm F5 guide


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About this observation
Peter Anderson
Time of observation
07/03/2018 - 14:00
150mm F8 achromat refr and 80mm F5 guide
Observing location
Brisbane Australia
standard camera

Deep sky images posted were a test of these instruments which are ordinary achromats. While faint star images are incredibly small and precise, brighter objects show a coloured fringes.  In particular the 150mm will render excess blue flaring around these images. Please examine these images to see the limitations of simple refractors for such imaging. A resolution test on A Cen came out well and both instruments show good diffraction discs.  Using the 150mm there is plenty of colour on bright objects and a purple haze over extra bright extended objects -eg bright Moon, Jupiter.

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