[Leica] I got published in Sky & Telescope magazine, but...

[mark at rabinergroup.com (Mark Rabiner)]

Thanks for the info Howard sorry if I was hard on you.
I shot it too that night and a few years later and it was not f16 rule for
sure but very dark red. I was at iso 6400 and my shutter speeds less than
recommended. As no film I don't think was iso 6400 I could say I got the
shot but could not have in the days of film. At least that's how I felt at
the time.


On 3/17/15 4:39 PM, "Howard Ritter" <hlritter at bex.net> wrote:

> Mark?
> 
> Actually, blur due to the Earth?s rotation is not really evident in this
> image. In 2 seconds, an object on or near the celestial equator (like the
> Moon) will move through 30 seconds of arc, which is 1/60 of the Moon?s 
> angular
> diameter. In the small image, this is a fraction of a millimeter.  I cannot
> detect this in my image even when viewed large. The image of the Moon is
> rather poor, since it was taken with a relatively short FL (for an
> astronomical object) of 400 mm, and focus was questionable, since modern
> lenses seem not to need infinity stops any longer (except when they do). If
> you look at the stars in the field, you?ll see that there is no ?trailing? 
> due
> to the Earth?s rotation, which would affect them the same as the Moon. The
> stars do not quite appear as points, probably again due to imperfect focus,
> but they are round, indicating that the exposure was short enough that the
> tiny amount of trailing was small compared to image imperfections. And in 
> any
> case, I was not going for a high-definition image of the Moon?s face, but 
> of
> the eclipsed Moon in a starry sky. You?re certainly correct that a good 
> image
> of the Moon itself, filling the frame or even bigger, would have to be made
> with a shorter exposure. Such images are usually made with telescopes on
> motor-driven mounts that track celestial objects. But since the Moon is a
> landscape in full sunlight when it?s not eclipsed, the f/16 @ 1/ISO rule of
> thumb works. A camera @ ISO 400 on an f/8 telescope would need a shutter 
> speed
> of about 1/800 sec for the un-eclipsed Moon, and the blur due to the 
> Earth?s
> rotation without the motor mount would be then about 1/50 of a second of 
> arc,
> equivalent to about 100 feet of distance on the surface of the Moon and
> therefore totally invisible when viewed at any scale.
> 
> I needed 2 sec @ f/8 and ISO 6400 because the darkest part of the fully
> eclipsed Moon is dramatically darker than the un-eclipsed Moon, on the 
> order
> of 1/10,000th as bright, a fact that is not obvious to the visual observer.
> 
> As for the orbital motion of the Moon, it?s in the opposite direction to 
> the
> Moon?s apparent motion in the sky due to the Earth?s rotation, but it's
> negligible in any case.
> 
> ?howard
> 
> 
>> On Mar 17, 2015, at 10:36 AM, Mark Rabiner <mark at rabinergroup.com> 
>> wrote:
>> 
>> 2 seconds an amazingly long exposure for the fast moving moon.
>> The blur is  plainly evident in the image even quite small.
>> 
>> http://forums.popphoto.com/showthread.php?338537-Moon-minimum-shutter-speed
>> 
>> 
>> On 3/16/15 5:13 AM, "Peter Dzwig" <pdzwig at summaventures.com> wrote:
> 
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-- 
Mark William Rabiner
Photographer
http://gallery.leica-users.org/v/lugalrabs/