"May New Moon Challenge!" Mon 06-May-13 08:02 AM by nrothschild
I thought I would try a challenge. If it works, maybe some contests?
May is about the last very favorable month to shoot the New(est) Moon and the following few days.
The challenge is simple: Shoot the earliest moon you can in May, after the New Moon that occurs on May 10 at 12:28am U.T. (Universal Time, or Greenwich Mean Time). In the USA this happens on May 9 at 7:28pm EDST. Optional: follow up with crescent moons up to 4 days old.
In the USA, for example, the first New Moon you can shoot will be the evening of May 10th, at sunset. If you want to shoot that moon, or you are somewhere in the world where you can shoot it from around 16 hours old to 24 hours, you can read more than you want to know about chasing an earliest moon here in my pinned post regarding shooting these very early (and very late) moons.
You can shoot it any way you want...
You can shoot a high resolution image, an image of the moon decked in clouds, or shoot a landscape at any focal length. I have a couple of examples in the linked post.
If you live in the Southern Hemisphere (that's you, Gary!), May is not as favorable in terms of chasing the newest possible moon. However, I think it can be very favorable on the following evenings, especially for landscapes.
You can also shoot Earth Shine, best done on the 2nd through 4th night of the new moon (May 11, 12 and 13 for the USA and Western Hemisphere). I did not talk about Earth Shine in my pinned topic. I should have but it was too long and complicated already
To shoot Earth Shine you have to overexpose the thin crescent in order to expose the very slightly lit "unlit" portion. This light is sunlight reflected off the Earth, to the moon, and back to the Earth. Not much light makes the round trip .
The Earth Shine exposure is approximately similar to a full lunar eclipse exposure, which is, on a fixed tripod, as long as you can get away with without too much blur. If you have a choice of long lenses, I would suggest very modest focal lengths, up to 300mm or so, and as fast as possible. And shoot wide open. Bracket ISO to see what you can tolerate.
The earliest moon I have shot, 21 hours old. April 25, 2009. D300 500 f/4 Ai-P @500mm (don't do as I do, do as I say ) f/4 1/13s ISO 400
Edit: In reviewing the full set of images, I see that I did initially shoot this at 300mm f/3.5 with my 300/2.8 AFSII, as I recommend here. After I had usable images I switched to my 500/4 Ai-P.
Increasing focal length did have the effect of increasing contrast, a very good thing, but at that point my exposure was 1/13s wide open at f/4, ISO 200. The 500mm shots were better, but many would find it far more difficult at that exposure level. This was shot from a Gitzo Series 4 alloy tripod. The head was probably a Markins M20 but could have been a full Wimberly (no notes on that).
A deep crop of the above, illustrating that for a moon around 24 hours old, or newer, there is not much useful detail to be seen. Given the issues of subject motion and other difficulties of shooting a very new moon, this is why I suggest 300mm max. But if you insist, like I did, have at it
A 2 day 5 hour old moon, Earth Shine exposure December 7, 2010 D700 500 f/4 AFS @500mm f/4 2s ISO 1600
A 26 day 5 hour moon (actually an old moon), probably the best Earth Shine photo I have taken. The D700 helped because noise tends to be an issue while trying to well expose the unlit portion while minimizing motion blur.
December 2, 2010 Nikon D700 500 f/4 AFS f/4 1/2s ISO 1600
A 26 hour old moon. One of my favorite new moon landscapes. D700 70-200 f/2.8 AFS @165mm f/4 3s ISO 800
#2. "RE: May New Moon Challenge!" In response to Reply # 0
P.S. If you are a morning person or your weather outlook is not good, feel free to shoot the last couple of days of the old moon.
For the East Coast USA, for example, it runs like this:
May 6 - Old Moon, 87 hours from new May 7 - Old Moon, 63 hours from new May 8 - Old moon, 39 hours from new May 9 - New Moon May 10 - 24 hour old moon May 11 - 48 hour old moon May 12 - 72 hour old moon
West Coast, add 3 hours to the above. Anywhere else, ask if you are unsure . But provide your longitude and latitude, at least to the nearest degree.
Very technically, on the morning of May 9, East Coast USA, the moon will rise as the old moon, about 14.5 hours from new. It is possible to see a moon 14.5 hours from new, but if you do, you need to lead this assignment next time. And in the Northern Hemisphere it is almost certainly not possible because the old moon is very unfavorable now, on the ecliptic where it is very shallow to the horizon.
Since you were just about to ask... ...
According to the USNO the record earliest moon seen was 12.1 hours old, with the aid of a telescope, and 15.5 hours naked eye. And they mention that these were "exceptional observations".
I suspect anything under 18 hours is exceptionally difficult, even on the most favorable month of the year. So here I wait for an 18 hour new moon on the East Coast, between February and May, more or less, and clear skies. I've been waiting many years .
Somewhere in the world, every month, someone gets an 18 hour old moon just after sunset. So I guess it's a matter of getting on a plane, like chasing an eclipse!
#3. "RE: May New Moon Challenge!" In response to Reply # 0 Tue 07-May-13 01:06 AM by nrothschild
Some basic pointers, especially if you try to tackle the newest possible moon.
1. Know ahead of time exactly where you will look for the moon (keep reading )
2. Be set up and ready to shoot the sun as it sets. Don't try to cut this close by setting up after sunset.
3. Shoot an image when the sun is as close to the horizon as possible but still a ball of light. This is your reference to the exact point of sunset when it is no longer obvious. You may need to refer to this as you search.
4. Record the time of sunset on your time piece. If you have a cell phone you have a watch .
5. Bring binoculars and know the approximate field of view (FOV) of those optics (within a degree or so). Typically they will be 6-8 degrees if 7-8x power, which I think is ideal for this. Lower power is bettter so you don't "get lost in the sky".
Large diameter objectives are not likely to be terribly useful but 35-42mm is probably ideal, 50mm if you don't mind the weight. But use whatever you have.
6. Bring a flashlight for camera settings and to read this tome, which you should print out and have with you!
Locating the Moon
First Opportunity May 10
Below for the first visible moon after the true new moon, the evening of May 10 in the USA and Europe.
This is actually an amazing (but difficult) post sunset with many opportunities. On the East Coast USA, the sun will set at about 294 degrees compass azimuth.
At sunset, the moon will be just over 8-9 degrees in altitude in the USA, and about 4 degrees altitude in the UK, and about 287 degrees azimuth, or about 1 binocular field width to the south/left of the point of sunset.
In the USA, I would expect to see the moon at about 4 degrees altitude, which should be in the FOV of the bins when the bottom of the FOV is at or very near the horizon and less than a binocular FOV width south/left of the point of sunset. The moon should be about half a bin FOV (3-4 degrees) south/left of the exact point of sunset.
In Great Britain it will be a 19 hour moon, which will be very challenging but perhaps doable with a very clear horizon. The moon will only be about 4 degrees altitude at sunset. I suspect if you see it there, you will first see it within a degree of the true horizon. Challenging indeed!
In general, new moons will be visible starting very roughly when the sun is about 4 degrees below the horizon, but that is a rough rule of thumb. That is about 15-20 minutes after sunset. But look earlier rather than later, your window is very short. In less ideal conditions it may take some time longer, right up to the expected time of moon set.
Keep scanning, in the bins, and naked eye.
On the West Coast USA, the moon will be 3 hours older and a little higher and to the South/Left - about 9 degrees altitude at sunset.
Now, the fun part. Both Venus and Jupiter will be close to the sun.
After sunset Jupiter should appear first, about 20 degrees altitude. A clenched fist, thumb up but tight to forefinger, spans about 10 degrees at arm's length. So two fists above the horizon.
Venus should appear next, probably 6 degrees or less from the horizon. A finger, at arm length, spans about 2 degrees, so about three fingers above the horizon.
Next we hope to see the moon, about one finger below Venus, and slightly to the left in the USA and slightly to the right in the UK
The moon sets 50 minutes after the sun in the USA, and about 37 minutes later in the UK. If you cannot locate the moon, this tells you when to stop looking, and why you need to note the actual time of sunset.
For my 21 hour moon, I first located it with binoculars and then got my first shot 17 minutes after sunset at an altitude of 8 degrees. It was more favorable than this month's new moon, even though several hours earlier in age. I would start searching immediately after sunset, but keeping this in mind. If you do see it, you may only have a window of 5-10 minutes or so to shoot it unless it is visible straight to the horizon and you have a clear view right to the true horizon.
Following Evenings of May 11-12
If you miss on the evening of May 10 don't jump off a bridge. My Challenge was just too tough for your location or skies but it wasn't my fault either. I didn't get to pick the time of the new moon
On the following evening (May 11) in the USA the moon will be at least a full 48 hours old and will set about 1 hr 45 min after sunset. Even in Europe it will be about 43 hours old and not a terribly difficult target.
About 20 minutes after sunset it should pop out, and will be higher, in darker skies, than the prior evening. You should not need binoculars unless it is murky, but always be prepared.
This is the best opportunity to complete the assignment. In many ways I think this is the best night to shoot Earth Shine.
If you miss May 11 then May 12 will be even easier. The moon will set about 2 hours and 20 minutes after sunset. It will still be a pretty crescent moon with plenty of Earth Shine.
The view on the evening of May 10. For subsequent evenings, the moon will be higher, to the upper left, following the white line of the Ecliptic.
#4. "RE: May New Moon Challenge!" In response to Reply # 0
I want to add that in addition to very nice images that can come out of this Challenge, the skills you will learn are foundation skills needed to do other astronomical and general photographic work. In particular if you try the longer Earth Shine exposures. And these skills will be learned even if you cannot do the earliest two newest moons.
You will learn the limits of your camera support, elements of long exposure and exposure at dusk, and focusing at dusk. The limits of your sensor when shooting high ISO images of moving celestial subjects.
This is applicable to shooting lunar and total solar eclipses, planetary conjunctions, comets, even the ISS when it flies overhead. And also general night and dawn/dusk landscapes.
When a great comet unexpectedly comes along (one is possible this November), or a lunar eclipse happens, that is not the time to learn these skills. It is best to learn them slowly over time. And it is something that cannot be learned in one or two nights. It takes a progression of iterative adjustments and tweaks to exposure and skills.
These are some of the reasons I decided to initiate this challenge. Hopefully you will have clear skies!
#5. "RE: May New Moon Challenge!" In response to Reply # 4
Wonderful info, Neil. I've come back to read several times. I'll give it a try, clouds willing.
One question, though. Expound a bit more on what factors make favorable conditions - that is, what makes one month better than another (and relative importance)? I would guess that in general you want the moon close to the earth so it is moving faster, and farther from the ecliptic so the angular separation is better, etc. Then specifically location, will you be in the right place to have it 18ish hours old. Why is May a "good" month?
Thanks for all the thought and detail that you have put into this.
Mark Smith Just like I previsualized it, more or less...
#6. "RE: May New Moon Challenge!" In response to Reply # 5 Sat 11-May-13 01:22 PM by nrothschild
1. Moon close to earth and moving fast- that is good because a fast moon is sort of like "cheating". If you have an 18 hour moon it will be further from the sun if it is moving faster than average during that 18 hours. I think you already understood that.
I've never studied this effect to see how much it can help or hurt. It is an obscure part of this puzzle that is likely swamped by other factors, perhaps giving you that one last degree of altitude.
2. The moon should be in the northern side of the ecliptic, where it has a high North declination (in the Northern Hemisphere; reverse in the South).
This is a complicated one. For fuller phases, the moon is always the most favorable when it is in the most northern end of the ecliptic, in the area of Gemini and Taurus. In that case when the moon transits the meridian (is due south) it will be as high as it will be that day, and the further north in declination the higher it will be. Simple relationship.
Each daily phase of those fuller moons has a most favorable month of the year. The first quarter most favorable in March, the 3rd quarter in September and the full moon most favorable in December
For a new moon, the tilt of the ecliptic as it cuts through the western horizon is more critical than the actual declination of the ecliptic. The first day moon is furthest north on the ecliptic in May.
But March-April are usually the best months for the new moon because of the tilt of the ecliptic. In those months the ecliptic (near the horizon) is almost vertical. And even Jan-Feb are good, and this year very good because the lunar tilt was favorable.
Edit: after thinking about this, the title of #2 should be:
"The ecliptic should be tilted at a high angle, the closer to vertical the better."
Again, this for the Northern Hemisphere, everything is backwards below the equator. These favorable tilts of the ecliptic always coincide with the ecliptic north of declination zero, but the best tilt occurs during the "runup" from Declination=0 to the mid-northern declinations.
By the time the sun is in Taurus/Gemini at the northernmost extent of the ecliptic, the ecliptic is curving downward again. That is why May-June is not the most favorable month.
On August 21 (about 60 days after the solstice) the sun is at the same declination as on April 21. But because the slope of the ecliptic is downward or less favorable, the sun, for example, an hour or so before setting, has a lower altitude than it does in April. The moon is similar, it being close to the sun in the first day of the new moon.
There is, in a sense, a favorable tilt on the southern end of the ecliptic but that has the effect of making a very bad situation a bit less bad . So it doesn't count!
Hope this makes sense; I don;t know how to articulate it better. You need to use a star map ephemeris like Cartes Du Ciel or Sky Map Pro to best visualize it.
3. The tilt of the lunar orbit relative to the ecliptic. This really complicates the situation. For a new moon, a southerly tilt is usually bad because the moon is then even lower in the usual case where the ecliptic tilts to the south.
If you look at the map above, you see the white line of the ecliptic tilting moderately to the south. The moon is south of that (left of the line). If the moon were on a northerly tilt it would be on the right side of the line. At the extreme northern swing of the orbit the moon would actually occult M45 (The Pleiades) shown on the map.
And you can see that if the moon occults M45 it would be a couple of degrees higher. That is the power of the tilt.
Pleiades Occultation of April 1, 2006 D2h 300/2.8 AFSII f/2.8 1s ISO 400
If you open my Chasing New and Old Moons thread and go down to the 2nd map marked Sept 16, 2012 Sunset, you will see a very unfavorable situation. It is September, 6 months away from most favorable March.
The ecliptic is badly tilted to the south- probably about the worst of the year. The moon is well south of the ecliptic. This is double trouble. It is so bad that 20 hour moon is setting at almost the same time as the sun, therefore impossible to view.
On that map I have a red line drawn, from the moon to the upper right. The pointer of the arrow points to about the northernmost possible extent of the tilt. If that had occurred, that 20 hour moon would have been at about 10 degrees altitude at sunset. During one of the most unfavorable months of the year in terms of the tilt of the ecliptic.
And interestingly, in May now, during a fairly favorable month, the moon is well south of the ecliptic. You can see from the above map for tonight that the moon will be lower and less favorable than it could be in Spetember - a usually far less favorable month.
Confusing? Yes. And I spent a number of years watching this before I came to fully appreciate that despite "conventional wisdom" that the season of the year is most important, I think the tilt of the moons orbit is far more important.
A bad lunar orbital tilt will make all but the best months very bad. But a good northerly tilt will make even normally unfavorable months "decent" to perhaps very good. And we are seeing this right now.
May is not a "very favorable" month, but it is about the last month with a reasonably good ecliptic tilt. Had I known how bad the lunar orbital tilt would be this month I might not have done the challenge this month. I was blind-sided because I did not model the sky May 10 before getting the ball rolling.
We are leaving a very favorable situation of the past 4 years or so where the favorable spring season coincided with the most favorable lunar tilts. Just a few years ago May was a far better month.
The lunar orbit precesses on an 18.6 year cycle.
4. Latitude. At the equator the ecliptic rises nearly straight up most of the year. At the North Pole the ecliptic barely rises above the horizon. Those are the extremes. Lower latitudes are more favorable than higher latitudes. Most of us are stuck with our latitude and would not fly to the equator to see a new moon
Longitude is a different beast. Longitude determines the exact age of the first moon after new. Each month we have a new moon. At some longitude on Earth the precise time of the new moon occurs at sunset.
Fifteen degrees of longitude west of that point we would see sunset one hour later, and therefore a one hour moon, followed the next day by a 25 hour moon. Thirty degrees west of that point we would see a 2 hour old moon, followed the next day with a 26 hour moon. And so on.
Over the long haul there is no better or worse longitude but any given month results in a certain longitude having the moon you would like to see.
In general there are two factors affecting favorability. First, the altitude of the moon above the horizon. Second, the elongation of the moon from the sun. That is the angular separation.
Both are needed and both are important to see a new moon. The larger the elongation the darker the sky. The higher the altitude the more chance you even see it (avoiding clouds or murk) and the less "atmospheric extinction" when the moon is very low.
In a month where both the ecliptic and lunar tilts are unfavorable you may have decent elongation but zero altitude, as on Sept 20, 2012.
When the moon's orbit is tilted to the North you get more altitude but you also get a further kick because the elongation is the hypotenuse of a right triangle where the long side of the right angle is a line starting at the sun and ending on the ecliptic at the declination of the moon. A line drawn from the ecliptic to the actual position of the moon is the short side of the right angle (half the red line in the Sept 20, 2012 map). That lunar orbit tilt adds a modest kick by lengthening the hypotenuse of that right triangle, extending the angular separation of the moon from the sun.
That northerly lunar orbital tilt is critical in many ways.
I know the above is very difficult to visualize without maps. I would have to assemble a year's worth of new moon maps for you to see the progression.
You can do that yourself by downloading Cartes Du Ciel, a free astronomical mapping and ephemeris app. This is a must have for anyone interested in the moon.
It has a very important feature... it can advance time in units of lunations. So you can set it to one lunation, find a new moon date or a first day after date and then advance, with one click to each successive or previous new moon. This is a huge pain with Sky Map, which has been my chart of choice for maybe 15 years now.
Once you get set up and oriented you can quickly model a full year of first day moons, watching the tilt of the ecliptic and the seasonal change of the lunar tilt at the time fo that first day moon.
Because of all the complexity above, and because of somewhat contradictory "rules of thumb" such as the seasons, it is simply necessary to model each new moon in Cartes to check the altitude of that first day moon at sunset. From there you can guesstimate the altitude you would first see it by advancing time about 15-20 minutes past sunset.
#8. "RE: May New Moon Challenge!" In response to Reply # 0
I don't have the photo details listed because my computer is very old and I couldn't process the RAW files, only the jpg. However, am getting my new one tomorrow and will see if I can improve upon the quality processing the RAW files instead. I'm relatively new to all this, so was excited for the challenge. I use The Photographer's Ephemeris to help me know when, where, etc. the moon will rise/set in relation to where I will be and as in my previous experience with it, it was dead-on. I took them at about 7:50PM, so does that mean it was less than 12 hours old? Not sure how to calculate that. I'm in Northern Arizona and luckily, the clouds moved out of the way just in time.
#9. "RE: May New Moon Challenge!" In response to Reply # 8 Sat 11-May-13 11:17 AM by nrothschild
Well done! And you got a nice composition with Venus, which was exactly where I predicted. I am very pleased that we got at least one good image of the new moon. I was having a thunderstorm at the time . I similarly have little chance tonight, and maybe a shot at Sunday night's 3 day crescent.
That is a rare photo, treasure it
I figured if anyone would get this, it would most likely be a mountainous area in the dry desert Southwest.
If you have the time you should try to image the moon tonight again, as well as tomorrow night. It is very interesting to see the changes of the moon from day to day.
And it is almost impossible, on a practical level, to ever perfectly reconstruct that by shooting daily phases of different months. And, of course, keep going each night beyond that until your energy or motivation wears out .
>> I took them at about 7:50PM, so does that mean it was less than 12 hours old?
As mentioned in the OP, the New Moon occurred on May 10 at 12:28am U.T. (Universal Time, or Greenwich Mean Time). The East Coast USA, is 5 hours behind UT, Central time zone is 6 hours behind, Mountain Time 7 hours in time, and the Pacific time zone 8 hours behind.
So you are 7 hours behind UT, but Daylight Savings Time reduces that by one hour so by your civil clock you only 6 hours behind. The moment of new moon was 5:28pm May 9, Mountain Time.
The sun set at 8:18pm Mountain DST and looking at the image, you probably shot that about 30 minutes later. The window is very small so we can assume you shot it at 8:48pm, or 02:48 UT May 11. That puts a calculated age of the moon at about 26 hours 20 minutes.
Just to be clear, the precise age of the same moon varies continuously by longitude. Someone on the far eastern side of the time zone sees a moon about 1 hour newer than someone on the far western side of the same time zone. But this stuff is complicated enough without constantly cutting those decimal places .
When I discuss new moons I will generally give times relative to the far eastern side of the Eastern USA time zone where I live, at about 75W longitude. You would add 2 hours because you are 2 hours behind me. More precisely about 2 hrs 24 minutes because Phoenix is just slightly east of the middle of the Mountain time zone..
Universal time is based on the time in Greenwich, UK, very near London. Hundreds of years ago, then England/Great Britain was the master of the seas.
They spent relatively large sums for the astronomical calculations required to compute longitude based on their ship's chronometers. The Royal Observatory was located in Greenwich so that became the center of the universe for these computations
Greenwich is zero degrees longitude. Each time zone is constructed to span about 15 degrees longitude and in fact the sun will rise and set one hour later for each 15 degrees longitude you move west.
So for example, Phoenix is about 112W longitude. You are precisely 112/15 = 7.47 hours, or 7 hours 28 minutes west of Greenwich UT time. When you get your computer situated and can view the EXIF you can then compute the precise time of the moon in your image.
For this reason, I keep my camera clocks set as precisely as possible, and check accuracy several times a year, and before any important astronomical sessions such as this. My cameras are set within 1 second, and I wish our cameras had built in GPS stamps so we could always know precise longitude, latitude and time.
I highly encourage everyone here to do the same, even for more pedestrian images such as a first quarter moon. I should have added that in my basic instructions. For astronomical imaging it is always important to know the altitude of the subject when the image was shot, and for that you need accurate time.
For those that want it, astronomical software will give you exact position of all celestial objects, including altitude, for your longitude and latitude, avoiding all these computations.
And yes, the Photographer's Ephemeris should be a very good tool for much of this work. I do not use it, only because I use software I've had for over 10 years and have a procedure long worked out. I would like something better for my smart phone, though, but it is about out of memory for new apps.
#10. "RE: May New Moon Challenge!" In response to Reply # 0 Sat 11-May-13 01:29 PM by nrothschild
Just a heads up - Mercury, Jupiter and Venus are moving into an interesting conjunction that can be shot at the end of the month for some number of days.
I will say more about this later, with a post containing some charts. But at a quick look I think May 26-29 may be the best, in terms of the ideal most compact arrangement. So try to keep your calendar open
Circumstances will be similar to this new moon challenge. You will need a clear western sky and an unobstructed view low to the horizon. Venus will not have moved much, relative to the just setting sun. But as Sara illustrates, it is very visible just after sunset. Jupiter is too. Mercury is always challenging and always the tough nut, but easier than a Mars conjunction (brighter).
I really enjoy shooting Mercury and it is always close to the sun.
This is basically an astronomical landscape opportunity, and ideal for shorter lenses. With a long lens all you get are 3 dots . Even if all you have is a standard wide-normal zoom lens you can do this!
#16. "RE: May New Moon Challenge!" In response to Reply # 13 Mon 13-May-13 10:35 AM by nrothschild
Great shot Mark! This is the kind of image I was hoping to be posted.
Is that Jupiter just lower right of the moon, and Venus in the lower right? I think so. The position is right. We may have two challenges in June, one for the moon and an even better planet grouping, and another planet grouping without the moon.
The nature of this new moon challenge is that few people can get that first moon. I just wanted to introduce the idea, and get everyone thinking about a suitable location. This is something that can take months or years before everything coincides and the shot happens.
#17. "RE: May New Moon Challenge!" In response to Reply # 14
Nice shot, Anthony!
As you can see, the 3rd day moon is an interesting very high contrast scene. The rim is just short of blown (your exposure is perfect), yet has no detail.
I've never done it, but I usually well bracket this moon because some day I may go back and do HDR's to try to better image the "too hot" rim.
Just an idea for things to play with here. If the image was actually shot this way, and nothing was blown, it may not even be necessary to composite multiple frames. It should be doable by layering a couple of raw renderings of the same shot, with exposure adjustments. Or any other approach that results in the same end result.
#18. "RE: May New Moon Challenge!" In response to Reply # 12
Thanks for the note, Mark. It is hard to keep track of the different applications of DST, which is why astronomers often work strictly in terms of UT.
I did my calculations before noting that Sara indicated a time. I saw that just as I posted but didn't want to go back and change it, and I guess I missed the DST issue . I was just happy that my "independent" estimate was within two minutes of her indicated time .
As an aside, when reviewing old astro images shot around March/April and October-November I have to Google the DST date ranges for that year just to keep things straight.
One of the things I like about PhotoMechanic is that it has a tool to quickly adjust the EXIF shot taken time stamp by an offset. I typically forget to change my cameras on the morning of the time switch, so that tool gets some use twice a year .
Without Photomechanic, I guess I would use EXIFTools to do that. Seems to have the same "time shift" tool although I've never actually used it for that purpose.
I've also done EXIF time shifts in the rare case where I let my camera clocks drift and discover that right after an astro shoot where I care about extreme accuracy.
#22. "RE: May New Moon Challenge!" In response to Reply # 0 Mon 13-May-13 09:20 PM by nrothschild
I am re-reposting, with permission, Mark's very fine landscape image with a few annotations.
I added the line of the ecliptic. This is the imaginary line that represents the path of the sun as it seemingly travels through the celestial sphere. At the present time Venus and Jupiter lie almost exactly on the ecliptic. For illustration purposes I shifted the ecliptic just slightly to the right in order to avoid overlaying the two delicate planetary images.
I also added pointers to Jupiter and Venus.
The print screen from SkyMap Pro was set up and cropped to approximate Mark's image in time and also his crop. The Skymap display includes the ecliptic, the planets, and also some brighter stars.
Here the angle of the ecliptic, as it cuts through the horizon, is relatively steep. Around April it is almost vertical. Other times of the year it is very shallow.
Depending on what you are doing, some things actually work better when the ecliptic is "unfavorable" with a shallow angle. The idea of "favorable" is strictly in the context of imaging something as close to the sun as possible, for example the newest moon.
For an example when unfavorable is really more favorable , for this 3rd day moon we would generally want the moon as low as possible to the horizon so that we can use the longest focal length possible in order to make the moon as large as possible. But there are always trade-offs. With a more shallow ecliptic slant, we would have a brighter Jupiter but likely have lost Venus, which would have been too close to the horizon.
There were 3 bright stars that could have been in the image... Aldebaran (Alpha Tauri), the eye of Taurus the bull and a massive red giant star. Also the two shoulder stars of Orion, red giant Betelgeuse (Alpha Orionis) and blue giant Bellatrix (Gamma Orionis).
These 3 stars range from magnitude 0 to about 1.6. Had circumstances been different, shot just a bit later at dusk, these 3 stars can be easily imaged.
With a long enough exposure in a dark enough sky, all the stars indicated on this chart can be imaged although the dimmer stars would need to be imaged on a motorized mount if you want to avoid star trailing. (well, maybe not, but that is a subject for another day when I have an image I will post)
I mention this because a knowledge of the relative brightness of the stars and access to charts are helpful to figure out what those dim points of light are in your dusk and dawn images. These tools are critical in the case where you are planning images and attempting to pre-visualize what will show up in the final image.
In SkyMap Pro I can set up and insert rectangles that represent the FOV of any focal length. I typically place these on a map when I am planning an image that includes stars and/or planets. It also helps me to pre-select a focal length.
Last night, Venus was magnitude -3.9 and Jupiter -1.9. Lower magnitude objects are dimmer than higher magnitude objects. Here Venus is "more negative" and therefore higher magnitude (brighter) in the context of the standard conventions. And we see that while Venus is quite visible in the image, you might miss Jupiter if you did not know what you were looking for.
Magnitudes of "point sources" of light are predictable and can be related to each other. For those purposes the planets can be considered point sources although technically they have some dimension, visible in a high power telescope or imaged with a long lens.
Magnitudes of extended objects such as galaxies and nebula are tricky because the magnitude represents the total integrated light that is spread out over the image (or visual view). In general extended objects of a given magnitude do not image as brightly as a point source of the same magnitude. We are only concerned with point sources here but I mention this just for completeness.
I enjoy incorporating landscapes into these celestial scenes when there are nearby planets and sometimes bright stars. In that way this image is just as cool as Sara's, but in a very different way!
Each successive stellar magnitude represents an approximate doubling of brightness- roughly 1.5 photographic stops. Our brightest star, Sirius, is magnitude -1, or about 1.5 stops dimmer than Jupiter. All other stars are dimmer. There are a few magnitude zero to one stars sprinkled about the sky. Those stars are of most interest for these images.
As you can see, the timing of the shot is such that none of the 3 bright stars was imaged. That is typically the case in an early dusk shot incorporating planets near the sun.
If Mark had shot this again, about a half hour later, Venus would have long set, out of the image. The moon would be lower in the sky, allowing for tighter framing and a bigger moon. Jupiter would be brighter, partly because point sources image better with longer focal lengths, but mostly because the sky would be darker, with more contrast between star and sky, and the exposure longer.
If Mark had done that, I suspect the brightly lit building would not balance well with the celestial objects of interest. A different scene might be needed for that, but he should try it because it is a potentially interesting scene. Perhaps with a strong grad filter??
Such is the difficulty of assembling some of these compositions. No one ever said this stuff is easy! But it can be a lot of fun - and quite challenging - to try to put these images together and work through the various exposure and dynamic range issues.
I will talk more about this in next month's challenge (there may be two!). I just wanted to introduce some concepts here, having such a nice image to use as a good example.
As mentioned previously, Cartes Du Ciel is freeware and provides most of the same functionality as the SkyMap Pro app that I am accustomed to using. It even has at least one feature I would dearly like to have in SkyMap.
First, Mark's fine image, previously posted above:
(edit: the line of the ecliptic I drew here is a rough approximation of a slightly arced path. When discussion the practical effect of the slant of the ecliptic, a straight line should be "good enough".
And the Skymap Pro map scene at 8:55pm my local time and location. Probably very similar to Mark's setup.
#23. "RE: May New Moon Challenge!" In response to Reply # 0
Unfortunately, the newest Moon that I was able to see this month was tonight's approximately 4 day old crescent. Stormy and cloudy conditions in the NE persisted through Sunday. Even after a cold front passed through on Saturday night, clearing on Sunday was slow and incomplete. The Sun set on Sunday night into a bank of clouds along the western horizon, obscuring the Moon/Jupiter configuration.
Here is a shot of the crescent moon tonight, using a 300 mm f/2.8 with TC20 III on a Nikon V1. Crop is about 54% of the vertical frame height. A full size version can be viewed here.
This shot was taken at dusk, about 8:24 pm EDT, so the sky was still fairly bright. Soon after, the Moon once again dropped through some clouds. This photo is very similar to one that I took in March 2012 of a crescent Moon of almost the same age.
#24. "RE: May New Moon Challenge!" In response to Reply # 23
Nice job, Gerry! Sounds like my weather.
Good to see another Nikon 1 image. I think that is an interesting astrophotography camera. Partly the sensor density but maybe more importantly, the electronic shutter. And of course, that FT-1 adapter
Interestingly, your gallery includes a lunar image, shot 3/26/12, at 4 days 6 hours age, almost exactly the same phase as last night's shot at exactly 4 days 0 hours.
Despite the fact that they "should" look the same, there is a significant difference in the craters visible in the north (upper right) "horn". Two large craters are much further from the rim and therefore more visible.
Interestingly, at least to my eye, the balance of the features look about the same. If you were to layer the two images, with the top layer partly transparent, you would likely see other differences.
This is a good example of Lunar Libration, a wobbling of the moon. Per Lunar Phase Pro, the recent shot has a northern bias of about 4-5 degrees relative to last year's image. The east/west bias is about the same.
The practical implication of Libration is that two images of the moon, shot on different dates, will rarely be the same, or even nearly the same, no matter how carefully you match the age or phase.
#25. "RE: May New Moon Challenge!" In response to Reply # 8
Finally was able to get the stats for everyone. Shot with a D300, VR70-300mm lens at 300mm, f10, 125, manual focus (it wouldn't focus on its own), matrix metering, ISO 1600. Many things I would love to play with to improve it. I started at a higher ISO, but the noise was pretty bad, so adjusted. Think I could have dropped it even further, actually, but ran out of time. It was sinking fast. Haven't processed the RAW files yet (I work at a university and it's the end of the year - busy), but I'll update if there's a significant difference in quality.
#28. "RE: May New Moon Challenge!" In response to Reply # 27
Thanks to all for the kind words. I have enjoyed using this setup, and the results have exceeded my expectations.
I have had the 300 mm f/2.8 for several years. I originally used it for shooting a variety of sports, both HS and some college. Unfortunately, I did not make enough money to pay for it! So I guess that I can't really afford it either! I have also used this lens with and without TCs for shooting wildlife, mostly birds.
A few years ago, while the 300 mm was sitting on my tripod, I noticed that it looked a lot like a telescope. Soon after that I tried some shots of the Moon, using it with a TC-14E II on my D90. Those shots were ok, but the image was a bit small for the DX frame, and detail was not very good. I later got a TC-20E III to increase the image magnification when shooting small birds, but did not try shooting the Moon again until last year when I got the Nikon 1, V1.