Wat, I took pictures of the eclipse too, but my focal lengths were 600mm EFL on my M43 gear....what focal length and what kind of exposure would be needed to get the moon and Uranus in the same frame?  I tried to do it handheld and I was using some high ISO ..... a typical shot for me was ISO 4000 1/4 sec shutter speed f/6.7 at 300mm (600mm EFL)...yes I did that handheld lol.


What's the ideal focal length for both total lunar and total solar eclipses (since I am going to be traveling to Syracuse or further north to see the one on April 8, 2024)?

For lunar eclipse I was photographing at 300mm, 800ISO, about 2s exposures. But exact exposure settings vary throughout the eclipse, especially between partial phase and totality. It's best to experiment and see what works. With a lunar eclipse you have plenty of time to take a shot, review on the camera screen, adjust and try again.

For the total solar eclipse, settings were roughly the same except the exposure time covered a much wider range.

"Total lunar eclipses are more difficult to photograph than total solar eclipses"

Having done both, I strongly disagree. Total solar eclipses don't last as long, and the corona has far more dynamic range. It is not hard to get photos of totality, but it is more difficult to get good photos of totality.

Yes the total solar eclipse lasts a mere few minutes but when I asked dpreview photographers they said they meant that total lunar eclipses are much darker and harder to achieve autofocus on and require higher ISO and longer shutter speeds.
But the time factor with the total solar eclipse and also budgeting time between viewing and photography makes me lean in your direction.  It was also suggested I would need different sets of exposures to capture the corona vs capturing the pink prominences I really want to get.  And may even need two different focal lengths   So for the pink prominences a longer focal length since they are very small, vs a shorter focal length for the corona.....something like 2000mm EFL vs 600mm EFL perhaps?

Caught the occultation of Mars by the full Moon tonight, through thin clouds and high winds. Pretty neat. I have seen bright stars occulted before, but not a planet.

Omg it was cloudy here until close to morning!  What time did it happen and would it have been visible here in NY too if it had not been cloudy?  The color contrast between the moon and Mars must've been amazing!  I was wondering why this wasn't publicized more-- when will the next one be (of the moon and Mars or of any of the brighter planets with the moon?)

I find 2400mm good for Moon shots.  For a total solar eclipse, however, something around 500mm sounds good in order to capture the corona.

Solar eclipses are definitely more difficult to photograph since you need a filter during the partial phase, and because of the high dynamic range of the corona.  Also, a total solar eclipse is over in a matter of a few minutes at most, so much more stressful to photograph.  Actually, make solar eclipse photographing as little complex as possible and rather enjoy the experience.

Yes, I'm already stressed out about the photography aspect of it because of needing to budget the time between that and viewing.  I also have an option of going to an area near the edge of totality (Syracuse, NY) where totality will only last for 1.5 minutes vs closer to the middle of the totality zone (Watertown, NY) where totality will last for 3.75 minutes.  Is being in the middle of the totality zone the best place to be for getting the best experience (both visually and photographically)?

Yes the total solar eclipse lasts a mere few minutes but when I asked dpreview photographers they said they meant that total lunar eclipses are much darker and harder to achieve autofocus on and require higher ISO and longer shutter speeds.

The outer parts of the corona require similar or even longer exposure to capture than the umbral shadow on the Moon. Again, what makes total solar eclipses tricky is the enormous range of exposures needed to capture all of it, under extreme time pressure, while at the same time not forgetting the most important part which is to actually see it with your own eyes.

Regarding autofocus... don't. It can fail during total solar eclipses too. Use manual. Focus on a distant object before the totality and lock it, or adjust with live preview.

"Is being in the middle of the totality zone the best place to be for getting the best experience (both visually and photographically)?"

I very much think so. Both because totality lasts longer closer to the centerline, and also for the symmetry. You will see the entire shape of the shadow in the sky, and areas outside the totality will glow all around the horizon. The only real perk of being very close to the edge of the shadow is to have a longer-lasting diamond ring and Bailey's Beads effect. But I think seeing the corona for more time and having the shadow completely surround you is a lot better.

It's also not critical to be exactly on the centerline, should a better location a short distance away be more suitable. The duration of totality decreases very slowly with distance from the centerline at first and you can move many kilometers from it and lose only a few seconds. The totality duration changes most rapidly near the edges of the path.

"What time did it happen and would it have been visible here in NY too if it had not been cloudy?"*

The Moon did not pass in front of Mars as seen from New York City, but it was very close (just south of the occultation path.) If weather had permitted then you would have seen the Moon graze just above of Mars in the sky, just a few arcminutes separating them.



The disappearance and reappearance times depend on location. Later, farther east. For me the disappearance happened at 6:53 PST. For you, closest approach was around 11:00pm local time.

You can predict future occultations using the free software Occult. It also does solar and lunar eclipses, occultations of stars by asteroids, moons of the giant planets passing in front of or casting shadows on each other, and so on.

Yes the total solar eclipse lasts a mere few minutes but when I asked dpreview photographers they said they meant that total lunar eclipses are much darker and harder to achieve autofocus on and require higher ISO and longer shutter speeds.

The outer parts of the corona require similar or even longer exposure to capture than the umbral shadow on the Moon. Again, what makes total solar eclipses tricky is the enormous range of exposures needed to capture all of it, under extreme time pressure, while at the same time not forgetting the most important part which is to actually see it with your own eyes.

Regarding autofocus... don't. It can fail during total solar eclipses too. Use manual. Focus on a distant object before the totality and lock it, or adjust with live preview.

"Is being in the middle of the totality zone the best place to be for getting the best experience (both visually and photographically)?"

I very much think so. Both because totality lasts longer closer to the centerline, and also for the symmetry. You will see the entire shape of the shadow in the sky, and areas outside the totality will glow all around the horizon. The only real perk of being very close to the edge of the shadow is to have a longer-lasting diamond ring and Bailey's Beads effect. But I think seeing the corona for more time and having the shadow completely surround you is a lot better.

It's also not critical to be exactly on the centerline, should a better location a short distance away be more suitable. The duration of totality decreases very slowly with distance from the centerline at first and you can move many kilometers from it and lose only a few seconds. The totality duration changes most rapidly near the edges of the path.

"What time did it happen and would it have been visible here in NY too if it had not been cloudy?"*

The Moon did not pass in front of Mars as seen from New York City, but it was very close (just south of the occultation path.) If weather had permitted then you would have seen the Moon graze just above of Mars in the sky, just a few arcminutes separating them.



The disappearance and reappearance times depend on location. Later, farther east. For me the disappearance happened at 6:53 PST. For you, closest approach was around 11:00pm local time.

You can predict future occultations using the free software Occult. It also does solar and lunar eclipses, occultations of stars by asteroids, moons of the giant planets passing in front of or casting shadows on each other, and so on.

Thanks, I have a plan and maybe you could tell me if this is a good one.  I'm going to bring two cameras and two tripods.  The two cameras will be the Nikon P900 at 2000mm to capture solar prominences and an Olympus EM10 Mk2 for the corona at 600mm.  The Olympus has a larger sensor and more DR so better for the corona and a lower focal length (I assume 600mm will frame the entire corona?)  The Nikon will be able to zoom in more to capture the prominences (I've seen pictures taken of them with this camera from the August 2017 total solar eclipse.)   Do you think I might need a tracking mount for either (or both) of these (especially for the one at 2000mm?)  Based on experimentation I've found that I can do up to 1 second exposures at 2000mm and 2 seconds at 600mm without tracking. For totality no solar filter is necessary is it (for viewing or photography)? I'm bringing a couple along for safety's sake but I think unfiltered looks the best during totality.

It sounds like for focusing you're in favor of using hyperfocal distances and focus lock, something I like to do, so it works for me   I usually focus on something 200 ft or farther away.

Thanks I'm going to download Occult.  I think the Mars occultations are the most spectacular, especially because of the contrast between the ruddy Mars and the whitish Moon.  The last one was in September 2020, so they do happen every 26 months or so and the next one is in January 2025, though I don't know if that will be a close approach or an occultation here.  Do these always happen when Mars is at or near its closest approach to us?  Did you have a certain photographic setting you used that was able to encompass the wide DR between the Moon and Mars (focal length, shutter speed, f-ratio, ISO), Wat?  The next time it happens I want to use the P900 at 2000mm to see if I can expose both well enough to get crater detail on the moon plus that dark streak (it's a canyon I think?) in the middle of Mars, which I've seen other P900 photographers get when they capture Mars.

I found this description I found absolutely spectacular:

https://www.space.com/mars-at-oppositio ... ec-07-2022

it was closest at 10:56 pm

Mars was one minute south of the southern edge of the moon

For places like Huntsville, Knoxville, Philadelphia and New York, Mars will come to within just 1 arc minute of the moon's limb; they'll almost seem to touch each other. To the naked eye, Mars will look like an amber jewel on the bottom edge of the moon. From Boston the gap between Mars and the moon's limb is even smaller: just 0.6 arc minute, roughly equal to the apparent width of two Mars diameters!

Where to see the moon eclipse Mars

As a bonus, those who are located north and west of a line running roughly from Piedras Negras, Mexico to Louisville, Kentucky to Seabrook, New Hampshire will see the moon occult Mars. Refer to the US map. Those positioned south and east of this line, however, will see the moon miss the planet entirely, barely passing just above it (called an appulse).

But for an observer fortuitously positioned exactly on, or immediately adjacent to that line — it's actually a narrow path about 21 miles (34 km) wide — the lower limb of the moon will appear to literally graze Mars as it passes by.

For those fortuitously situated along the northern edge of the path, the planet's dazzling topaz disk may appear to disappear completely, then reappear intermittently in lunar valleys. In contrast, along the southern edge of the path, Mars' northern edge will only briefly touch the limb of the moon.

Among towns and cities located within the path are Morgantown, WV; Scranton, PA; Hudson, NY; Northampton, MA; Lowell, MA and Seabrook, NH. Refer to the Mars occultation graze path maps.

Unlike a star which is a pinpoint of light and would disappear and reappear in an instant, Mars appears as a small disk in telescopes; owing to its relatively large angular size (17.2 arc seconds in diameter), the occultation will occur at a rather "leisurely" pace. So the disappearance of Mars behind the moon's bright limb for most places, will take anywhere from about 40 seconds to almost a minute (or even longer where the moon's limb approaches it at a slant).


A separation of one arc minute at NY is pretty close, I think I could have framed both Mars and the Moon inside 2000mm!

"Do you think I might need a tracking mount for either (or both) of these (especially for the one at 2000mm?)"

Not strictly required. You can capture all but the outermost details of the corona within 2 seconds, and the exposure time needed for prominences is extremely short, you shouldn't get any blurring.

For totality no solar filter is necessary is it (for viewing or photography)? I'm bringing a couple along for safety's sake but I think unfiltered looks the best during totality.

No filter during totality. You (and your camera) would not see a thing through one. It's safe to remove filter from camera about 30 seconds before totality. You can catch the diamond ring that way. Don't forget to either put the filter back on or point camera away from Sun after totality is over.

Did you have a certain photographic setting you used that was able to encompass the wide DR between the Moon and Mars (focal length, shutter speed, f-ratio, ISO), Wat?

Not really, they had relatively similar surface brightness. Mars has a higher geometric albedo than the Moon, but its greater distance from the Sun more than makes up for it, and it works out to about 60% the surface brightness of the Moon. Any setting that captures the full Moon well without overexposure will also capture Mars, with Mars just a bit darker.

Thanks Wat, you've got me well prepared for the solar eclipse and for the next occultation.  I'm particularly excited about Mars occultations by the Moon because of the contrast in color, but also about Saturn occultations because of the rings.  And I believe Uranus's rings were discovered when it occulted a star?  So aside from photogenic value, there is some scientific merit to be had in observing and photographing these interesting events!

The perfect shot would be an occultation of a planet during a solar eclipse.  I wonder how often that happens, whether the timescale would be once in a million years or less.  It would be a challenging exposure, but I think doable.

The perfect shot would be an occultation of a planet during a solar eclipse.  I wonder how often that happens, whether the timescale would be once in a million years or less.  It would be a challenging exposure, but I think doable.

Wow that would be absolutely amazing-- I wonder if it has ever happened?  That would in effect be a double eclipse..... I'd even settle for an occultation of a planet during a total lunar eclipse haha.

The perfect shot would be an occultation of a planet during a solar eclipse.  I wonder how often that happens, whether the timescale would be once in a million years or less.  It would be a challenging exposure, but I think doable.

That would be spectacular. The best ones would be either Venus or Jupiter when they are on the far side of the Sun (a superior conjunction). Mercury or Venus being between Earth and Sun (an inferior conjunction) would be nearly invisible.

For a very crude estimate, we could calculate the average time between superior conjunctions of the planets, multiply by the probability that they pass directly behind the Sun per conjunction, consider that such an event would last for a few hours, and then factor in how probable it is for a total solar eclipse to occur in the same period.

The average time between oppositions of a planet with orbital period A seen by a planet with orbital period B is given by (abs(1/A - 1/B))^-1. For the 5 planets easily visible to the naked eye, these are:

Mercury: 115.9 days
Venus: 583.9 days
Mars: 779.9 days
Jupiter: 398.9 days
Saturn: 378.1 days

A simple approximation for how likely a planet is to pass directly behind the Sun is to divide the angular diameter of the Sun (0.5 degrees) by twice the inclination of the orbit. For example, Jupiter's inclination is 1.3 degrees, so the probability it passes behind the Sun during an opposition is approximately 0.5/2.6 = 19%, which is about 17% per year. Venus is about 7% per conjunction, or about 6% per year. (Transits of Venus in front of the Sun are even more rare, since the distance between Venus and Earth is comparatively small so it's easier for Venus to "miss" the Sun.)

Sum these up, and the total probability for any of the above planets to pass behind the Sun is about 50% per year. Any event would last for a few hours.

What's the probability for a total solar eclipse to happen at the same time? Well, the totalities are much shorter, so it's the duration of the occultations that matters. The probability for an eclipse to happen at the same time is the fraction of the year that an occultation lasts (let's say 6 hours on average, which is 6.8e-4 of the year), squared (4.7e-7), times the probability of an occultation in a year (50%), times the probability of a solar eclipse (about 66%) in a year. That's 1.5e-7 per year, or about 6.5 million years between such events, on average.  

A more complicated calculation could give us a more precise answer, but I would wager that this estimate is accurate to within a factor of 5. In other words, I feel confident that, on average, it is at least a million years between times that any of the easily visible planets are occulted by the Sun while the Sun is eclipsed by the Moon.

Thanks Wat, you've got me well prepared for the solar eclipse and for the next occultation.

Happy to help getting prepared. Best of luck seeing it!

I'm particularly excited about Mars occultations by the Moon because of the contrast in color, but also about Saturn occultations because of the rings.  And I believe Uranus's rings were discovered when it occulted a star?  So aside from photogenic value, there is some scientific merit to be had in observing and photographing these interesting events!

Although spectacular to see, there is little scientific value for observations of planets occulted by the Moon. However, occultations of stars by planets or their moons is scientifically valuable for detecting faint rings, thin atmospheres, and any other objects around them. 

It's also extremely valuable to get observations of stars occulted by asteroids -- this helps determine the asteroid orbits more precisely, as well as their size and shape and the presence of any moons. This is something that many amateur astronomers contribute to. It's also neat to see. If the asteroid is much fainter than the star, then an occultation looks like the star winking out for a few seconds, or maybe even a fraction of a second. If multiple observers are located along a path perpendicular to the expected occultation path, then the combination of observations (whether the star vanished or not, exactly when, and for how long) determines the outline and actual orbit of the asteroid.

What's the probability for a total solar eclipse to happen at the same time? Well, the totalities are much shorter, so it's the duration of the occultations that matters. The probability for an eclipse to happen at the same time is the fraction of the year that an occultation lasts (let's say 6 hours on average, which is 6.8e-4 of the year), squared (4.7e-7), times the probability of an occultation in a year (50%), times the probability of a solar eclipse (about 66%) in a year. That's 1.5e-7 per year, or about 6.5 million years between such events, on average.  

Thanks for the rough calculations.  That the timescale indeed seems to be in the millions of years does seem reasonable.  However, an eclipse happening during the middle of the occultation is no fun.  We need the planet to touch the rim of the Moon during the eclipse.  The Moon's shadow takes some time to travel across the Earth, but less that those 6 hours.

Thanks Wat, you've got me well prepared for the solar eclipse and for the next occultation.

Happy to help getting prepared. Best of luck seeing it!

I'm particularly excited about Mars occultations by the Moon because of the contrast in color, but also about Saturn occultations because of the rings.  And I believe Uranus's rings were discovered when it occulted a star?  So aside from photogenic value, there is some scientific merit to be had in observing and photographing these interesting events!

Although spectacular to see, there is little scientific value for observations of planets occulted by the Moon. However, occultations of stars by planets or their moons is scientifically valuable for detecting faint rings, thin atmospheres, and any other objects around them. 

It's also extremely valuable to get observations of stars occulted by asteroids -- this helps determine the asteroid orbits more precisely, as well as their size and shape and the presence of any moons. This is something that many amateur astronomers contribute to. It's also neat to see. If the asteroid is much fainter than the star, then an occultation looks like the star winking out for a few seconds, or maybe even a fraction of a second. If multiple observers are located along a path perpendicular to the expected occultation path, then the combination of observations (whether the star vanished or not, exactly when, and for how long) determines the outline and actual orbit of the asteroid.

I was just thinking how rare it must be to have  a star occulted by a planet or a star occulted by an asteroid simply because the very small apparent side of planets and asteroids-- though it should be more common in telescopes because of the much dimmer magnitudes of stars that can be seen in telescopes (and the larger apparent size of planets at least-- not sure about asteroids-- they still look very small in telescopes, no?)  An occultation of a star by a moon of another planet must be very rare too, that would be exciting to see in a telescope.

That's very interesting about determining an asteroid's orbital path that way-- I wonder if that's how the orbits of asteroids like Ceres and Vesta were determined?  It would be interesting if they actually had moons, that would be like a smaller rock (pebble sized perhaps?) dancing around a larger rock!  I saw the very excellent Planet series on Nova where it was mentioned that Ceres was on its way to becoming a planet and even had an ocean and an atmosphere in its very early days.  Did Jupiter interfere with its orbit and cause it become an asteroid instead?  The wandering of Jupiter from its previous position in the solar system is interesting-- it might be another reason why complex life (if it's out there somewhere) could be rare....Jupiter probably played a large role in the habitability of Earth.

Something else just occurred to me.  During an occultation of a star by a planet, asteroid or another planet's moon-- could that help determine how thick the atmosphere of the occulting body is and what it's composed of? I was thinking that if the body has an atmosphere, rather than the star winking out, there should be a decrease in brightness first (and an increase in brightness on the other side as the star comes out of the occultation)?  Maybe this would only be noticeable with a telescope or captured on some sort of photometric equipment though.

The perfect shot would be an occultation of a planet during a solar eclipse.  I wonder how often that happens, whether the timescale would be once in a million years or less.  It would be a challenging exposure, but I think doable.

That would be spectacular. The best ones would be either Venus or Jupiter when they are on the far side of the Sun (a superior conjunction). Mercury or Venus being between Earth and Sun (an inferior conjunction) would be nearly invisible.

For a very crude estimate, we could calculate the average time between superior conjunctions of the planets, multiply by the probability that they pass directly behind the Sun per conjunction, consider that such an event would last for a few hours, and then factor in how probable it is for a total solar eclipse to occur in the same period.

The average time between oppositions of a planet with orbital period A seen by a planet with orbital period B is given by (abs(1/A - 1/B))^-1. For the 5 planets easily visible to the naked eye, these are:

Mercury: 115.9 days
Venus: 583.9 days
Mars: 779.9 days
Jupiter: 398.9 days
Saturn: 378.1 days

A simple approximation for how likely a planet is to pass directly behind the Sun is to divide the angular diameter of the Sun (0.5 degrees) by twice the inclination of the orbit. For example, Jupiter's inclination is 1.3 degrees, so the probability it passes behind the Sun during an opposition is approximately 0.5/2.6 = 19%, which is about 17% per year. Venus is about 7% per conjunction, or about 6% per year. (Transits of Venus in front of the Sun are even more rare, since the distance between Venus and Earth is comparatively small so it's easier for Venus to "miss" the Sun.)

Sum these up, and the total probability for any of the above planets to pass behind the Sun is about 50% per year. Any event would last for a few hours.

What's the probability for a total solar eclipse to happen at the same time? Well, the totalities are much shorter, so it's the duration of the occultations that matters. The probability for an eclipse to happen at the same time is the fraction of the year that an occultation lasts (let's say 6 hours on average, which is 6.8e-4 of the year), squared (4.7e-7), times the probability of an occultation in a year (50%), times the probability of a solar eclipse (about 66%) in a year. That's 1.5e-7 per year, or about 6.5 million years between such events, on average.  

A more complicated calculation could give us a more precise answer, but I would wager that this estimate is accurate to within a factor of 5. In other words, I feel confident that, on average, it is at least a million years between times that any of the easily visible planets are occulted by the Sun while the Sun is eclipsed by the Moon.

Wow I find this fascinating-- are there any historical records of such an event happening in the past?  It might be considered something that would "inspire" one of our world religions haha.

I also find the calculation fascinating, is twice the inclination used for the occultation calculation because the planet could be that amount either "above" or "below" the sun?

What's the probability for a total solar eclipse to happen at the same time? Well, the totalities are much shorter, so it's the duration of the occultations that matters. The probability for an eclipse to happen at the same time is the fraction of the year that an occultation lasts (let's say 6 hours on average, which is 6.8e-4 of the year), squared (4.7e-7), times the probability of an occultation in a year (50%), times the probability of a solar eclipse (about 66%) in a year. That's 1.5e-7 per year, or about 6.5 million years between such events, on average.  

Thanks for the rough calculations.  That the timescale indeed seems to be in the millions of years does seem reasonable.  However, an eclipse happening during the middle of the occultation is no fun.  We need the planet to touch the rim of the Moon during the eclipse.  The Moon's shadow takes some time to travel across the Earth, but less that those 6 hours.

To add further to the calculations, we could calculate what the average return time is to see such a special event on any one location on the Earth.  I assume that if an occultation happens during a total eclipse that there will be some location somewhere that witnesses the total solar eclipse that will see the exact "enter" and/or "exit" moment of the occultation.

I wonder if the odds of occultation are higher with a total lunar eclipse?  They should be since those last much longer and cover a much larger area?