Before I take a trip in my prefered simulator I usually check temperature, dew point cloud cover... and sometimes the conditions out of the window when i fly from my home airport to determine visibility at ground level. I wish I lived in the US when it comes to this, because there seem to be better METAR visibility measurement there, but I live in Europe. I feel I have gotten this procedure quite right now so I get the ground level visibility somewhat right.However visibility aloft is a different issue for me. I don't fly to much in real life (sadly), but on the flights I've had I've been surprised by the low visibility at higher altitudes. THE DEFAULT UNLIMITED VISIBILTY ALOFT IN FSX SEEM VERY UNREALISTIC.So my question, what's a good setting for visibility aloft?Can I calculate based on ground visibility? (10 miles at ground level equals 60 miles aloft for instance.)How about winds aloft? Is visibility better in the jet-streams for instance?What about temperature aloft? Does higher temperature cause lower visibilty?What about distance from equator? Would I get worse visibility in Egypt tham Northern Europe?What about mountaious regions vs flats vs ocean?I have many questions but know little so any help is very appreciatet :)I won't stop til I get it "AS REAL AS IT GETS" :)-Kinetic

Kinetic,> I won't stop til I get it "AS REAL AS IT GETS" :)There are many, many problems with the way simulation handles weather. The real weather is a very complex phenomena and what we have in FS is still in its absolute infancy. Everything from visibility through atmospheric pressures, winds aloft, temperatures, icing, thunderstorms - the list is long, suffer from very obvious problems. You may go to Hi-Fi or REX (two popular weather add-ons) forums for more in depth discussion about best weather settings but do not count on anything approaching AS REAL AS IT GETS when weather is concerned, be realistic.

I set mine to 60 miles... Too far out in both sims (meaning visibility) makes the sim look like crap especially in FS9. I never go above 60-70 miles no matter what altitude as that gives me much of what I see in the real world. I'll check when I get home to make sure 60 is the right number I have set. Too much distance visible unless your way up in FSX's stratosphere doesn't look quite right. I mainly use FS9 and I'm pretty satisfied with a reduced setting.

I set mine to 60 miles... Too far out in both sims (meaning visibility) makes the sim look like crap especially in FS9. I never go above 60-70 miles no matter what altitude as that gives me much of what I see in the real world. I'll check when I get home to make sure 60 is the right number I have set. Too much distance visible unless your way up in FSX's stratosphere doesn't look quite right. I mainly use FS9 and I'm pretty satisfied with a reduced setting.

I live in the desert southwest--our real world visibility here can be stunning. Regularly 120 miles plus and from time to time, especially when I am flying on business between Salt Lake and Phoenix, it is not uncommon to see Vegas lit up well over 150 miles from our route of flight.I had many challenges with "haze" and the way it looked in both FS9 and FSX. Regardless of the vis, the horizon line was rather sharp. I edited the environment bitmaps and made a couple of small add-ons for FS-X and FS-9 ("Soft Horizons"). Due to the current issues with the Avsim library, I believe they can only be found at Flightsim.com but it sounds like as soon as the library is up, Soft Horizons will be back.One thing that also helps me is I manually edit the vis. layer. I give it a depth of 99999 feet, then set my vis. Whether I have it set for 30 miles or 100 miles, I was very pleased after I made my environment edits.FS-X has an issue with very low vis--for some reason, anything below 10 miles looks lousy. Don't know why that is, although the issue can be helped a bit if you put a low level cloud layer down. Anyway, feel free to try my set of files if you don't have any environment add-ons of your own. I think they greatly help. I fly IRL often (just a few days ago in fact) and find my simming vis and appearance is about as close as I find regardless of the flight level I am in.Regards,John

I am learning about this topic from an artist's perspective rather than a scientific one, although when it comes to colour theory, there's sort of a mash of both disciplines.From what I know, your "visibility" is a product of "atmospheric perspective". Basically, things that are farther away are less distinct and will have a bluish cast to them under normal lighting consitions becasue of all the air molecules between your eye and the distant object. Most air molecules scatter part of the red/green/yellow spectrum and either reflect, refract, or pass through blue. That's really oversimplifying the optics, but the basic part is that air is not invisible, and the more air you got (either bigger molecules or more of them), the more visible the air. In Los Angeles, for example, the air molecules are roughly the size of basketballs. How does this happen? Humidity is a factor that increases the density of air molecules, maybe the biggest factor. Altitude, air pressure, temperature, maybe wind would other factors I can think of. Warm, humid air holds the most air particles. Combine low-level fog or moisture with airborne pollutants, and you get smog. In LA, you have high humidity from the ocean, thermal inversion from the mountains, and gunk in the air from industry and transportation: the infamous brown blob that covers the city.Dry cool air won't hold as many air particles, so arid, high-altitude locations should generally have clear air. In your weather reports, you could look for ice crytals aloft as a rough indicator of humidity at high altitudes. As far as Flight Sim is concerned, FS9 and FSX come from two different philosophies. FS9 uses a global visibility value to decide how far you can see, while FSX depends on you making a custom visibility layer in the weather menu. This is different from the level of detail radius you set in the graphics menu! A visibility layer is set up the same way that you manually would set up clouds, just look for the "visibility" tab (you can also set custom temperature and humidity layers). Like other people have mentioned, 60 nautical miles is probably a realistic average distance for viz. Sometimes you will see more, sometimes less. "Realism" is such a difficult goal to achieve with Flight Sim. I think it's better to try for personal aesthetic appeal rather than realism - it's way more fun that way. Jeff ShylukSenior Staff ReviewerAVSIM

I think a lot of it has to do with where you fly and what you fly in FS, as to how convincing it can make things; which is why you're likely to get differing opinions on how believable a job FS makes of things as far as visibility goes.In real life, visibility is often spectacular up very high where the big jets cruise, with glorious azure skies overhead, whereas when in a GA aircraft, you are invariably below 10,000 feet, and at that altitude, you are often a lot closer to any inversion layer (an inversion layer is a rapid change in temperature at altitude - typically at about 4,000 feet - that prevents warm air rising further and traps clouds and pollution at that level, in case you're not familiar with the term).Being a lot closer to any inversion layer will mean you are looking through a lot of that layer when observing the ground, because of the slant range through all that clag to distant objects. Thus the apparent 'haze' can be greater at lower altitude near the layer whereas from an airliner up at 30,000 feet there is less slant range through any inversion layer to distant objects, so you'll see more by virtue of that, as well as by virtue of being up higher. FSX is not great at that sort of thing because it does not emulate the way the real atmosphere absorbs certain light wavelengths. But it does mean that depending on whether you fly a Cessna or an Airbus, the same visibility setting in FS will look great for one in the cruise, and not for the other, and yet they may both see the same beautiful azure sky overhead.To explain what is going on, and why that makes things look typically more blue. The well known saying, 'red sky at night, shepherd's delight' has a basis in this theory and is useful for understanding matters: It refers to the fact that when you look at the sun setting in the west, because the prevailing wind is often from that direction, the weather you are likely to get in a few hours is also from that direction. The sun over the horizon (when set) is throwing a lot of red wavelength light over the horizon and making the sky glow red. Normally, clouds will tend to absorb the red light, but with few clouds in the way to absorb longer light wavelengths, it is indicative that there is not much cloud a long way off to the west, which means that there's a good chance that the weather on its way to you is fairly decent. On the other hand, when things look more blue, the opposite is happening, with clouds snatching the red light wavelengths out of the air and making stuff look more subdued. The effect is often enhanced by the fact that our eyes are more sensitive to the shorter bluish wavelengths than the longer red ones.Until FS has a weather system that can intelligently tweak the palette of colours we see based on the level of clouds we are looking through from a particular distance and altitude, and can take into account how they absorb elements of the electromagnetic spectrum, rather than simply loading up a 'sunset texture' or whatever, then we'll never really have totally convincing haze for the particular meteorological conditions at all altitudes. But knowing what is going on and taking into account how you personally like to fly in FS - up high or low down - can assist you in perhaps offsetting some of the limitations of FS, with texture and clouds enhancements that create a palette best suited to how you fly.Hope that helps a bit.Al

Thinking about this topic some more:Why not just fly at night?Jeff ShylukSenior Staff ReviewerAVSIM

How does this happen? Humidity is a factor that increases the density of air molecules, maybe the biggest factor. Altitude, air pressure, temperature, maybe wind would other factors I can think of.

Humidity actually makes the air less dense. Lets look at molecular weights of these elements. O₂ which is the most prevalent form of oxygen down in the troposphere has an atomic mass of 16 because of the two oxygen atoms weighing 8 each. Water, H₂O, is two hydrogen that weigh 1 each and one oxygen that weighs 8 giving it a total of 10 on the atomic weight. Any time there is an increase in humidity it always makes the other gasses in the atmosphere decrease their partial pressure proportionately. Because of the hydrogen bonding capabilities of the water molecule they can bond or easily attract other molecules and particles which eventually turn into; clouds, fog and smog which reduce visibility.

Trying to make a quick summary:* 60 miles seems like a good visibility default aloft.* In desert areas you may see very far in certain conditions.* Improved horizon graphics can make a big difference (I'll check that one out).* More warm/humid air causes lower visibility. High/colder areas has better visibility.* Visibility at altitude may be much better because of less air between the aircraft and the ground at distance.* While humid air is less dense, it forms fog/clouds so the visibility often will be reduced.And...* Sadly FSX weather/visibility has a longway to go.Thanks for all the answers! The discussion got very in depth and interesting!-Kinetic

Trying to make a quick summary:* 60 miles seems like a good visibility default aloft.* In desert areas you may see very far in certain conditions.* Improved horizon graphics can make a big difference (I'll check that one out).* More warm/humid air causes lower visibility. High/colder areas has better visibility.* Visibility at altitude may be much better because of less air between the aircraft and the ground at distance.* While humid air is less dense, it forms fog/clouds so the visibility often will be reduced.And...* Sadly FSX weather/visibility has a longway to go.Thanks for all the answers! The discussion got very in depth and interesting!-Kinetic

Sounds pretty good to me!