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Re: (meteorobs) Re: LM's and the Milky Way
In a message dated 98-08-30 09:46:09 EDT, you write:
marco<<
The apparent upper limit to the Lm a person can estimate as pointed out
by George for his case (6.0 in his case) is interresting, since I have
noted a similar phenomenon myself, albeit (and there we go again: this is
in line with what Bob explains and I already alluded to!) in my case the
upper limit seems to be 7.0-7.1. I reach up to 6.8-6.9 and occasionally
(very rare) 7.0 from Biddinghuizen. In Southern France and Spain I
reached 7.0. But even under the best of conditions, I have never come
higher, similar to George's 'upper limit' which in his case is at 6.0. For
example, I observed
from 2100m Calar Alto observatory in the Spanish Sierra during the alfa
Monocerotids of 1995. The sky there was much darker than in Alcudia
(lower Guadix-Baza basin in southern Spain) the previous nights, with
gegenschein and even the faint 'light bridge' really blazing from the sky.
But my Lm was almost similar (6.8-7.0 from Alcudia: 7.0-7.1 from Calar Alto)!
Perhaps, due to some reason, there is a upper limit to your perception.
Most likely, where that limit lies is personal. I.e., even from the
mentioned Calar Alto I never obtained the 7.3 Lm's of for example Norman,
nothwithstanding extremely good sky conditions.
>>
I wonder if the response in our eyes is something similiar to film? On film,
the grain emulsion size and number is varied with it's film speed. For
example, the grains on very fast films are large and not as many per area. For
slow film the grains are very small and numerous. I wonder if the number of
cone and rod cells vary appreciably in individuals as well? Maybe for someone
like me with low perception has a lesser/or greater number of light sensitive
cells and someone like bob and marco have the opposite of whatever would allow
their eyes to be more sensitive? Just a thought.
GeoZay