On 09/26/2015 07:46 PM, Davoud wrote:
RichA:
Don't forget. Exposure times from unclipsed full moon and fully-eclipsed
moon can vary from (at ISO 200) f/8 at 1/1000th to as much as 8
minutes(!need driven mounting).
You're just as ignorant here as you are in sci.astro.amateur.
You can't make an eight-minute exposure of the Moon; no telescope mount
is designed to track it precisely for that length of time and manual
guiding won't work over that length of time on a non-point source.
Furthermore, the moon is very bright when full, fairly bright in full
eclipse; I can't imagine any circumstance in which such a long exposure
would be required.
I typically photograph the Moon with a Questar Duplex
https://www.flickr.com/photos/primeval/21181354091, 89mm aperture, FL
1400mm @ Ÿ16.
Those who photograph the Moon at high-resolution and long focal lengths
(up to 8 meters, in my case) typically use scientific imaging cameras
such as those from Point Grey http://www.ptgrey.com/ to shoot video,
then they use special software to choose the best frames and align and
combine them.
Sometimes, though, one can get lucky with a single DSLR exposure. See
my 2009 photo at https://www.flickr.com/photos/primeval/21552899880/.
Made with an 1100mm Ÿ7.3 astronomical telescope @ ISO 100 and 1/250
sec.
That 8 minute exposure kind of threw me when I first saw it. I have
photos of a full moon, that I shoot using the "Sunny-16" rule (shutter
speed equals ISO, Full sun= f/16, etc.) at around f/5.6 or f/8.
I was guessing that a "blood moon" would be a couple or three stops down
from the light of a full moon.
I'll be shooting ISO400 ('cuz I've got a pile of that film!), using my
1200mm lenses with Canon FX cameras. Since my 1200mm is f/11, I'll be
adjusting the exposure with the shutter speed and shooting wide open. I
don't think depth of field will be an issue. I figure shutter speeds
from 1/125 to 1/30 should get it. I'll be shooting with two setups side
by side, with one setup a stop wider than the other. All this assumes
the weather holds, and each forecast is looking better.
I figured for metering I'd use a Luna-Pro. That's a joke- lunar eclipse,
"Luna"-Pro- get it?
--
Ken Hart