Using Sitrec to plan your EU 2026 Aug 12th Solar eclipse viewing

It's handy for working out timings and viewpoints, especially if you plan on any photography involving landmarks/buildings etc.
Can you elaborate a little about how you are using it?

I will be travelling to Mallorca and have got as far as using Suncalc.org to work out that if I want to see the sun setting in the sea rather than disappearing behind land, I will need to move a mile or two south of where I'll be staying.

1785855031069.png


I'm thinking perhaps here, with the sun between the two (very flat) islets at totality. But the family might not be up for the long hot walk there (and back in the dark!) so perhaps not....

1785855154983.png
 
I just fixed some accuracy issues for precisely this type of thing. @ThomasH had a nice photo of the sunrise behind a building where the sun was horizontally off by half a degree and vertically off slightly. The exact DTLDs were known.

The fixes were firstly to account for axial precession -– the earth has tilted half a degree since the reference year. Secondly atmospheric refraction was not applying to buildings.

The precession fix is in. Refraction is mostly done, complete later today. But ENSURE YOU SWITCH REFRACTION ON especially for near the horizon shots. I'm going to make it be in by default.

Also, if anyone has any other photos of a moon or sun behind a large building - at high zoom with exact DTLDs, I'd love to use them to verify accuracy. It now matches @Thomas's image to <0.05°, so visually near perfect.
 
I don't think the terrain modelling is accurate enough to be very useful for the sunset use case... there seems to be a phantom pyramid out to sea!

1785858433906.png



Actually that seems to be an artefact of the 3D buildings layer.

To be honest though I think I'll just have to do a location scout the day before and imagine the sun 0.2 degrees to the left!

1785858963810.png
 
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I just fixed some accuracy issues for precisely this type of thing. @ThomasH had a nice photo of the sunrise behind a building where the sun was horizontally off by half a degree and vertically off slightly. The exact DTLDs were known.

The fixes were firstly to account for axial precession -– the earth has tilted half a degree since the reference year. Secondly atmospheric refraction was not applying to buildings.

The precession fix is in. Refraction is mostly done, complete later today. But ENSURE YOU SWITCH REFRACTION ON especially for near the horizon shots. I'm going to make it be in by default.

Also, if anyone has any other photos of a moon or sun behind a large building - at high zoom with exact DTLDs, I'd love to use them to verify accuracy. It now matches @Thomas's image to <0.05°, so visually near perfect.
Yes it's perfect now! The height is still depending of a lot of atmospheric things, so you have to tweak refraction pressure a bit to have a perfect match, but all in all extremely close.
But with refraction off, the height is way off so maybe it should be on as default?
Here is the matching in Sitrec

Refraction.jpg


....and my little TimeLapse:

Source: https://youtu.be/_DiOkfUbqXA
 
But with refraction off, the height is way off, so maybe it should be on by default?
It is now (2.114.0) on by default.

And it's quite dramatic at these zooms:

Refraction off (geometric ideal)
1785864666827.png


Refraction on (real life)
1785864724264.png


At the horizon, it's nearly 0.5 degrees. That does not sound like much, but it's about the diameter of the moon.
 
It is now (2.114.0) on by default.

And it's quite dramatic at these zooms:

Refraction off (geometric ideal)
View attachment 92456

Refraction on (real life)
View attachment 92458

At the horizon, it's nearly 0.5 degrees. That does not sound like much, but it's about the diameter of the moon.
Great.
It seems like photoephemeris.com, moon calc etc. use the refraction measure too, maybe just an average. Because when it says Moon a 0 degree it matches Sitrec with refraction ON
zero degree.jpg
 
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