When it comes to fog in landscape photography, photographers get picky. Our Fog Veil algorithm detects fine, localized layers of fog that can appear after clear nights in grasslands or over bogs, for example, as well as dense fog in river valleys. Just search for a photo spot when the parameter suggests it to you.
From the parameter menu choose screening smoke. The weather parameter will now be an overlay of the map. The more transparent the map, the higher the probability for screening smoke. Best chances are at sunrise.
Screening smoke will be found in valleys or flat land. You will see that the probability is higher in valleys, compared to the surrounding hills.
For the most success, choose photo spots located in valleys or with a good view over a valley. Simply click the photo spot icon on the map. VIEWFINDR only shows photo spots which are suitable for screening smoke, when chosen. Choose photo spots in the areas with a transparent map.
The fog parameter predicts fine fog veils on meadows, moors, lakes. In narrow river valleys in the mountains, the “fog” parameter indicates whether they are filled with fog. For supra-regional dense fog, which also penetrates into cities and fills whole areas, see the “Dense fog” parameter. The transition from soft veils of fog to dense fog is smooth. If you want to predict fog, look first at the “Fog” parameter and then at the “Dense fog” parameter to estimate the thickness and height of the fog.
In most cases, fog forms overnight. The probability of fog is highest at sunrise. The fine veils of fog dissipate shortly after sunrise. Sometimes fog veils can occur in the evening as well. Use the timeline to change the time of the forecast shown. Look for fog first at sunrise.
The scale indicates how likely fog haze will occur at a location if it meets the conditions (meadow, bog, heath, floodplain, lakes, and river valleys). The overlay works like a template. The more visible the background map, the higher the probability.
The yellow color marks places with especially high probability. This is a numerical calculation of fog fields by the weather model.
The red color marks places where fog appears below freezing point temperatures, resulting in hoar frost deposit.
The “Fog” parameter always indicates a much larger area covered by fog compared to the “Dense fog” parameter. If the fog layer has a thickness of less than ~50m in clear, visible sky or if it is only small fog swaths on a meadow, the fog is predicted only with the parameter “Fog”.
The fog will always be most thick in the center of the predicted area that will be covered with fog. There is always a smooth transition between fog-free areas and the center of the fog layer, where the densest fog is located.
If a fog layer with a thickness of more than ~50m is predicted, the layer will be covered by the weather parameter “Dense fog”. It is important to always compare both parameters to know how thick the fog layer will be. In this example, the “Fog” parameter covers a larger area than the “Dense Fog” parameter.
If fog occures in air which is below the freezing point of 0°C, the undercooled droplets will freeze, if they hit surrounding structures, like trees, grass, and stones. If the fog continues while the temperature stays below freezing point, the deposited hoar frost thickens. After several hours a nice layer of hoar frost built up, resulting in a nice winterly landscape.
Over the years we discovered some rules of thumb, regarding the amount of time a landscape needs to stay within freezing fog to have a useful amount of hoar frost built up:
> 6h the hoar frost is noticeable
> 12h the hoar frost is good visible
> 24h the hoar frost is utterly beautiful
If you want to visit a photo spot, you need to check the weather data hourly and count up, how many hours one place will stay inside the ice depositing fog. You need to check the fog parameter every day, when the period is more than 24h.
As soon as the fog will dissolve for the place where hoar frost deposit was forecasted, the hoar frost will start falling of the trees. You have to visit the place asap after.
The biggest factor in predicting fog is the terrain in which the fog is predicted to occur. It’s best to think of fog as a liquid being poured onto the landscape. So be sure to note which of the categories your photo region fits into:
1. vast flatlands
If our “fog” parameter shows a high probability or even the yellow color markers, then you can expect fog veils up to a height of ~50m above the ground on meadows, moors, lakes and in the floodplains. The fog layer is uniform for kilometers. The higher the probability and the more yellow areas shown, the denser the fog. Fog that reaches a thickness of >50m is covered by our “Dense fog” parameter.
2. hilly terrain
In hilly terrain, fog accumulates in the valley bottoms. Therefore, at photo spots that are located in a local valley bottom, there will be significantly denser fog. Hills may locally peek out of the fog, although the weather forecast looks like the fog is uniform across the landscape. The local weather model has a resolution of 2.8km x 2.8km, structures of the landscape smaller than this are not resolved.
3. narrow river valleys and lakes in the mountains
Narrow river valleys and lakes in the mountains are an exception. The water increases the humidity in the valley enormously, so that if there is a high probability of fog, the river valley is often completely filled with fog, while there is much less fog in the flat surrounding area.
The problem: Those very river valleys are often much smaller than the weather model can resolve. Therefore, it looks like there is the same probability in the river valley as in the surrounding area. In reality, the probability of fog in the river valley is always significantly increased!
High probability of fog in the plains of northern Italy. Even if it indicates fog inside closed cities, there won’t be any.
The weather model can detect low clouds clinging to mountain peaks and interprets them as fog. In this case, isolated yellow markings appear on the map in mountainous regions. With the help of the background map “Outdoor” it is possible to recognize which mountain peaks will be covered by fog. With the eye tool, the overlay can be easily hidden, making it easier to examine the map.
The background map should be set to “Outdoor”. Now valleys and hills can be seen. The fog will always gather in the valley.
Local yellow color overlay over a mountain top indicates that this specific top will be covered with fog. Compare with the altiude indicator lines.
The weather model sees the landscape idealized and cannot resolve small towns and villages. Even if there is a high probability in the forecast for your city, there will not be any delicate fog patches in urban landscapes. Therefore, it is important to choose the right location.
Seek out places in valleys and lowlands if the probability is high. Choose places like bogs, meadows, floodplains and lakes. In narrow river valleys with steep slopes, the fog may well be very dense; in the flat country, it is more likely to be fine veils of fog. A high probability refers exclusively to these landscapes.
Set the filter for the views to “Weather specific” to get only views shown that can be photographed well with fog veils.
Due to the limited resolution of the weather model, small local valleys cannot be captured. However, the weather is stable over short spatial distances and there is a deviation that you can neglect.
If fog is predicted in the next larger valley, then the same probability applies to the small, local river valley that cannot be captured by the weather model if the large and small river valleys are similar in nature: Elevation, vegetation, amount of grassland, etc.
The weather forecast in VIEWFINDR is a computer simulation that very realistically forecasts the coming weather. However, the forecast is not exactly the reality and there will be deviations.
In VIEWFINDR new weather data is provided every 3h. For example, if you check for the probability of afterglow after sunset in the morning hours, the forecast will change several times over day. This is perfectly normal and that’s a good thing!
The closer the deadline, i.e. the sunset in the evening, the smaller the deviation of the computer simulation from reality becomes. The forecast becomes more precise. Before you finally set out to take pictures, you should therefore take another look at the current forecast.
You should therefore check the forecast again before you start your photography tour to see, if the probability is still high. Don’t be mad if the forecast probability changed into worse, it probably saved you from a bad outcome!
The weather forecast in VIEWFINDR is limited to 24h for local weather models and 72h for continental weather models. It is not useful to look into the future for a longer period. The forecast becomes inaccurate and is not reliable. Weather apps that allow forecasts of more than 3 days but do not provide any indication that the forecast is extremely inaccurate are a disgrace. This gives the
Just as the resolution of your camera is limited, i.e. it cannot take an “infinitely” sharp photo, the resolution of the weather model is also limited. This is 2.8km for Central European weather data and 7km for European weather data.
Structures and features of the landscape that are not that large are averaged by the model. For example, if a mountain is 800m high, and the valley next to it is 400m high, then the landscape for the weather model in that “pixel” is 600m high, corresponding to the average altitude.
This means that small structures, like narrow mountain valleys or local small river valleys cannot be properly captured by the model. This is not a problem, you just have to learn to deal with it. If a valley in the mountains is much smaller than the resolution of our weather model, then you have to interpolate.
Small valleys always end in larger valleys. You can therefore use the weather in the next larger valley as a good reference for the weather in a smaller, adjacent valley. In the example, you can see that the large valley is filled with fog. It is almost certain that the small valley is also filled with fog.
Due to the limited resolution, it makes sense not to use too much zoom. It is important that you look at the overall context. Therefore, consider the weather forecast not only for your location, but at least for the entire region where you are shooting.
This example show how the weather model sees the landscape. It is pixelated because of the limited resolution.
Due to limited resolution, this layer of low clouds/fog will not indicate fog in valleys with a size below the resolution.
When uploading a new photospot you guide other photographers. Connecting a photospot to the screening smoke parameter is not “making a wish”. Only connect photospots which actually can be photographed with screening smoke. Look at our example images.
You probably know those kind of sunrises with a thin layer of fog over the grassland. When we enter a night with a clear sky, the surface gets cold. The earth radiates heat into space and cools down as a result. After some time, a thin layer of smoke arises.
For the smoke layer to not be destroyed by wind, it need to be calm. VIEWFINDR developed a weather forecast algorithm to forecast the probability of screening smoke for the needs of landscape photographers. We calculate cloudiness, wind speed and air humidity into out screening smoke parameter.