About Seeing Limitations and Resolution:
Solar observing seeing conditions vary greatly from nighttime conditions.
During th e daytime, ra diant he ating from th e sun affect s seeing
significantly. Characterized by turbulence or shimmering as seen over a
hot street, seeing can cause significant impa ct on quality o f solar
observations.
- Bad seei ng is cau sed b y air of diffe rent tempe ratures mixing. This
typically hap pens within t he lowest 10 f eet of air. It occu rs mo st often
over pavem ent, dark obje
cts, roo ftops and
sometimes trees.
- High cirrus clouds or “scuzz” will cause scattering of sunlight in the high
atmosphere which often makes for b ad viewing conditions. A classi c
sign of high cirrus clouds is the inability to achieve fo cus, or the need to
“chase focus”, or a lack of contrast.
- A jet-stream moving overhead can also hurt seeing conditions even on
a clear day.
DayStar Filters are high power viewing platforms and this high resolution
can b e su sceptible to seei ng issu es. Solar Ob servers usi ng high
powered, hig h resolution telescopes a nd DayStar f ilters should hee d
daytime seeing. While many of these conditions are beyond our control,
observing in an are a wit h ideal c onditions, witho ut pavement in the
direction of viewing, and on days with no high cirrus will offer best
results. Grass is the best environment for daytime seeing stability.
Each observing location offers different behavior for daytime seeing cells
at different times of the d ay, as the air through which one views changes
with movement of the sun. Some lo cations benefit from best seeing in
the morni ng, while ma ny have best see ing in the afterno on. Because
most heat va riation between air and g round surfaces occurs within the
first 10 feet above the gro und, often a high observing platform wil l offer
superior seeing. This might include a second story deck which overlooks
grass.
