Tonights Lunar Eclipse

Mike Kennedy · Feb 20, 2008

I'd like to have a go at photographing this but am confused about which lens to use.One web site said wide angle (28mm) another stated that one should use their longest lens (300/400/500mm).
Any sky shooters out there who would like to lend their advice?

Thank You

Mark_S · Feb 20, 2008

If your intention is to get detail of the moon itself, you will want to be using a long lens. The moon is approx 18% grey, and is illuminated directly by the sun, so you can figure exposure using the sunny 16 rule.

If you use a wide angle lens, you will get a broader swath of the sky, and the moon will be one tiny spec in that sky.

Akki14 · Feb 20, 2008

And remember the moon is tinier than you think when photographing so I'd opt for the longest lens possible. i only have a 200mm lens and the moon was pretty tiny on my negatives. Had to raise my enlarger head up nearly all the way to get a moon a little larger than 1inch across.

editing to add that my exposures weren't far off sunny-16 but with a slight cloudy factor... so f/8 at around 1/100th for delta100. Longer might overexpose so you don't get detail out of the moon (white dot or crescent shape instead of a white and gray mottled dot)

cowanw · Feb 20, 2008

During an eclipse the moon is not lite by the sun. so I don't think the sunny 16 rule will work. But I don't know what will. ? try a spot meter in camera with a large telephoto lens?
Regards
Bill

jpeets · Feb 20, 2008

Definitely a long lens. As noted, the moon is a tiny object in the sky, and the eclipse will not be impressive unless you get a significant portion of the frame filled.

As far as exposure is concerned, the sunny 16 rule applies, but only if the moon is full. Once it goes into the earth's shadow, you may want to open up and bracket. This could blow out the highlights somewhat (use a ND grad??), but might keep the shadow areas from being too dark. At full eclipse, bracket like crazy.

I will be out there - good luck!

Ole · Feb 20, 2008

100mm focal length gives 1mm moon on the film.

So 200mm gives a 2mm moon, 1000mm gives a 10mm moon and so on.

This is of course only approximate, but it's very close.

Akki14 · Feb 20, 2008

So this is why I got a tiny grainy moon. I knew there was some ready reckoning of moon to film size somewhere...

Mike Wilde · Feb 20, 2008

Lucky me

Last year my father in law won a 'junk scope' in a hospital fund raising lottery.

No fine adjustments for movements, flimsy mount, etc. Margianlly acceptable coatings on the glass. All up the $200 it might have been sold for should have been saved to spend about $700 to consider even having a marginally acceptable telescope.

The only thing going for me when it got handed to me was a bit of mechanical ability. The flimsy mount hinge pins got replaced with stove bolts and wing nuts to allow the worst of the wobbles to be conquered.

The main mount at the eyepiece has a thread section that almost perfectly fits an m42 screw mount lens adapter plate I was gifted. So presently my old minolta srt101, with its mirror lock up ability is hanging off the back of the telescope, mated to what is effectively an f/10 700mm lens.

Hopefully the sky will not be clouded over.

Lee L · Feb 20, 2008

Info on lunar eclipse photography from someone who knows what he's doing:

http://www.mreclipse.com/LEphoto/LEphoto.html

And the NASA eclipse summary page for tonight that he assembles. Times are UTC, so it's Feb 21st, although in the western hemisphere it will still be the evening of the 20th.

Dead Link Removed

Lee

pauliej · Feb 20, 2008

We got some snow this am here in Indianapolis today, but it seems to be clearing now. I hope we will have good clear weather late this afternoon for the eclipse. The squirrel eating the neighbor's offering is easy to spot on the white ground, I wonder if the animals notice the eclipse and freak out (or not). Good (eclipse) hunting to all tonite.

paulie

colrehogan · Feb 20, 2008

I looked at my calendar and tomorrow is supposed to be a full moon. Have any LF'ers considered shooting the moon during the eclipse?

Ole · Feb 20, 2008

Lunar eclipses can only occur at full moon, so that's hardly a surprise...

I won't be shooting anything, since not only am I in the middle of the North Sea, but there's a storm out here...

walter23 · Feb 20, 2008

I found DOF was a huge problem with the last lunar eclipse (I was trying to get a foreground object in as well, using a 200mm lens). Sure, you can stop down all you want, but the moon is moving / earth is rotating, so anything longer than ~ 1 second and you've got a blurry moon. The eclipsed moon is very dark.

With a wide angle lens it's just a red dot in the sky.

colrehogan · Feb 20, 2008

Ole said:
Lunar eclipses can only occur at full moon, so that's hardly a surprise...

I won't be shooting anything, since not only am I in the middle of the North Sea, but there's a storm out here...

Oops, sorry I didn't know.

johnnywalker · Feb 20, 2008

Neither did I. Maybe it's obvious, but why is that?

Lee L · Feb 20, 2008

johnnywalker said:
Neither did I. Maybe it's obvious, but why is that?

http://www.mreclipse.com/Special/LEprimer.html

Lee

thebanana · Feb 20, 2008

The skies are clear here, but the bad news is that tonight will be -35c, so I think I'll stay indoors

Vaughn · Feb 20, 2008

I photographed the last good one we had around here. My exposures of the moon reflecting sunlight were fine...once it was in totality, even though I increased the exposure a couple stops, it obvious that I underexposed and no image on the moon is on the negative.

I was going after the whole show on one negative (an image every ten minutes), using my 8x10 w/ 300mm lens. I ran out of negative before the moon completely came out of totality...one needs a wide angle lens to capture that. It was still a fine experience.

Great exposure chart here: from it, one can see why my exposures of the moon in totality were way under-exposed!

http://www.mreclipse.com/LEphoto/LEphoto.html

Vaughn

c6h6o3 · Feb 20, 2008

johnnywalker said:
Neither did I. Maybe it's obvious, but why is that?

Because that's the only time the earth can come directly between the sun and the moon. For a similar reason, a solar eclipse can only take place during a new moon.

As far as exposure is concerned, you can use the exposure formula that Ansel Adams used to get the moonrise picture, which is:

At a shutter speed equal to the luminance in candles / sq.ft., the aperture to achieve 18% neutral gray is equal to the square root of the film speed.

The luminance of the sunlit portion of the moon is 250 candles/sq. ft. So, if your film speed is 100 the correct aperture at 1/250th for Zone V would be f/10. Since the only time there will be no sunlit portion of the moon is totality, this should be useful. Luminance of a totally eclipsed moon? I have no idea.

Remember that's Zone V. Adams always shot the moon for Zone VII. So after you compute the formula, open it up two stops.

Raphael · Feb 20, 2008

What I use for lunar eclipse exposure

Hello all,

What I am used to rely on is the now old but still useful Barry Gordon's book, "Astrophotography featuring the fx system of exposure".

Of course, I don't pretend to be well understandable without showing the tables given in the book, but let's try :

To be very elliptic, full uneclipsed moon is given (by experience) in the book with a fx=10 to 12.

To equal this, we can add, for example, Iso100 (fx=3), lens at f/10 (fx=3), and 1/250th (fx=4), and this is matching the parameter given by "c6h6o3", in the previous message. We can even consider the full moon is fx=12, so it's still match the two more stop opening given by Uncle Ansel for the zone VII moon.

So, now, from Barry Gordon, Moon totally eclipsed in umbra should be considered fx=22 to 24, or partially in umbra is fx=20. For example, it can be declined with the parameters, iso100 (fx=3), f/2,8 (fx=7), and 1/4s (fx=10). So a fast film and fast lens are always a must go during lunar eclipse..

Hope this helps a little,

Best regards,

RaphaelView attachment 9876

Sirius Glass · Feb 20, 2008

cowanw said:
During an eclipse the moon is not lite by the sun. so I don't think the sunny 16 rule will work. But I don't know what will. ? try a spot meter in camera with a large telephoto lens?
Regards
Bill

Yes it will if you remember that the albedo of the Moon is 0.5 and therefore the sunny 16 => sunny 11 as a starting place and open the aperature as the Moon gets darker. Also the Moon moves 15 degrees/hour or 0.25 degrees per minute.

Steve

Ian Tindale · Feb 20, 2008

I shot the last one we had here digitally, and it's amazing how much hidden detail shows up at the moment of totality: http://www.flickr.com/photos/iantindale/410487521/

Michel Hardy-Vallée · Feb 20, 2008

Alright, so it's happening right now! I'm using E200 with a 200mm. I think we're nearing 1/125 for f8.

mark · Feb 20, 2008

Fu**ing clouds.

Craig · Feb 20, 2008

It's nice and clear here and right around freezing, so I had the F1 and 500mm lens out. I bracketed widely, so we'll see what comes out.

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