Archived posting to the Leica Users Group, 2019/01/20
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Howard R, Thanks for the advice. No eclipse as seen from here, so it will have to wait a couple of years Cheers Jayanand On Sun, Jan 20, 2019 at 9:18 PM Howard Ritter <hlritter at bex.net> wrote: > Jayanand, Howard, and Douglas, > > That is correct for a Moon illuminated by the full Sun, as it was when > Howard shot it. At ISO 400 and f/8, the (1/ISO @ f/16) rule of thumb would > call for an exposure of 1/800 or so, just as Howard shot it. Things change > radically as the eclipse progresses. > > Before the Moon enters totality, while it?s moving through the penumbra, > illuminated by the partially eclipsed Sun, the correct exposure will > decrease fairly rapidly, as any given point on the Moon will go from > illuminated by the full Sun to entering the umbra in the space of just an > hour. In fact, since the Moon?s diameter is almost exactly the same as the > width of the penumbra, there wil be a moment, as the eastern limb of the > Moon enters the umbra, when the illumination level varies across the Moon > from full shadow to full sunlight. > > At the middle of full eclipse, the level of illumination is quite low, > coming from ?all the sunsets in the world? as someone noted ? the sunlight > from the hidden Sun scattered by the Earth?s atmosphere. This is a tiny > fraction of direct sunlight, so a reasonable starting point for f/8 would > be 1 sec at ISO 6400. The position of the Moon within the umbra at > mid-eclipse, as well as the degree to which the Earth?s atmosphere scatters > sunlight can cause the brightness of the Moon at mid-eclipse to vary from > eclipse to eclipse, from nearly invisible to rather prominent. So the above > settings are just a starting point. The deep shadow is why you can?t > hand-hold at mid-eclipse. It?s also why it?s difficult to capture both the > sunlight and the shadow portions of the partially eclipsed Moon. Aggressive > HDR or Photoshopping is necessary. The best results come from stacking a > number of images spanning the full exposure range. > > Nathan?s point about foreground elements adding interest is well taken. > Here are several images I made of the ?Blood Moon? eclipse four years ago. > Mid-eclipse occurred when the Moon was quite low in the sky as seen from > the eastern U.S., so these images capture foreground trees. In fact, they > depict the whole range of distances from trees just tens of meters away, to > the blue sky at tens of km, to the Moon at hundreds of thousands of km, to > the planet Uranus (the blue-green dot to the left of the Moon) at hundreds > of millions of km, to the stars at trillions of km. > > Please view large! > > > http://gallery.leica-users.org/v/hlritter/Blood+Moon/Mideclipse+in+Pisces+small.jpg.html > < > http://gallery.leica-users.org/v/hlritter/Blood+Moon/Mideclipse+in+Pisces+small.jpg.html > > > > > http://gallery.leica-users.org/v/hlritter/Blood+Moon/Blood+Moon+Eclipse.jpg.html > < > http://gallery.leica-users.org/v/hlritter/Blood+Moon/Blood+Moon+Eclipse.jpg.html > > > > http://gallery.leica-users.org/v/hlritter/Blood+Moon/Mideclipse+1.jpg.html > < > http://gallery.leica-users.org/v/hlritter/Blood+Moon/Mideclipse+1.jpg.html > > > > Unfortunately, mid-eclipse will happen with the Moon nearly overhead as > seen from here, so no foreground this time unless I tromp through the snow > to get under a tree in the back yard. > > > Have to go to Home Depot now. We just moved back to Ohio, and when we last > departed we left our snow shovel behind. Eight inches fell yesterday, and I > need to clear a space for my tripod? > > > ?howard > > > > On 20Jan, 2019, at 0820, Jayanand Govindaraj via LUG < > lug at leica-users.org> wrote: > > > > Douglas, > > Whatever light you see will be reflected sunlight, only the area will > vary, > > but the exposure should stay the same. The theoretical settings will be > > your sunny daylight rule, because you are photographing sunlight, at the > > end of the day, - you can tweak it a bit if you want! :-) > > > > Cheers > > Jayanand > > > > On Sun, Jan 20, 2019 at 6:42 PM Douglas Barry <imra at iol.ie> wrote: > > > >> Nathan and Howard, it's not going to happen until 2029 again, so I think > >> I might make the effort as they think it's going to be clear here > >> between 5:15am and 5:45am - the period of maximum eclipse for us. The > >> position of it means all I have to do is throw open the glass doors, and > >> I can take a shot of it from inside the house with a pre-set up camera > >> and tripod before staggering back to bed. I presume Howard's settings > >> are no good for the actual shot as the light levels from the moon will > >> be lower. Has anybody got an idea of settings at f8? > >> > >> Douglas > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information