Michael,Thanks for your intervention. I have been using FS pretty frequently since FS98 thank you but clearly I dont spend enough time visiting all the forums. (As you can see I don't come back to this one every day.) The only place where I have seen the Vis issue discussed is in this AS forum and I have only been using that since ASV. The trouble always seems to be that though everyone agrees that it is an FS problem, not AS, and of course I accept that, the precise details of what happens never quite seem to be discussed. Take Damian's reply above. He gives a very cogent explanation of what happens when the vis changes through 10SM, but the situation I was trying to get an answer to was with the vis constant (at 20kms, i.e. above 10SM) and the aircraft passing up, presumably, through the top of the FS haze layer. With the greatest respect, his answer doesn't come close to describing what I should expect in that situation, and nor have any previous posts I have seen. The approx height this occurs appears to vary but is often around 10,000 ft. The vis goes instantly to max (in fact, although I have 'max visibility' set to 30SM much as you suggest, I would strongly argue that the vis goes way beyond this in these situations). If you know of a post where this has been discussed and explained I would be grateful for the link. Just out of interest I haven't tried lowering the cloud draw distance to 30 miles - I find that you can see the outer limit of the cloud quite clearly even with it maxed out in FS (80miles) - bringing it closer just seems to lose even more cloud. At risk of incurring more wrath, I don't understand why with vis of 20km and cloud draw distance 80 miles I can still see the outer edge of cloud sheets above aircraft level - but I will guess that this too has also been discussed ad nauseam as an MS limitation.Thanks for your help,Mervyn

>seen. The approx height this occurs appears to vary but is>often around 10,000 ft. The vis goes instantly to max (in>fact, although I have 'max visibility' set to 30SM much as you>suggest, I would strongly argue that the vis goes way beyond>this in these situations).Mervyn,Like I stated above with the settings I described above (you have to follow them precisely) I do NOT get the sudden visbility changes at 10,000 ft. I have cloud draw distance set at 30 primiarily for the performance reason. I don't know if this has any influence on the visibility transition - haven't tested it. Also with the max visibility at 29 and draw distance at 30 I don't see any cloud drawing artifacts but it is entirely possible I missed something somehwere. We can discuss this topic for years to come but I don't think it is going to change anything - one has to adopt the view that what you see is what you get with the weather in FS9. Everyone has to find his/her own middle ground that gives you the least offending looking weather - it is a highly subjective topic.Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg

Hi Mervyn,"I was trying to get an answer to was with the vis constant (at 20kms, i.e. above 10SM) and the aircraft passing up, presumably, through the top of the FS haze layer. With the greatest respect, his answer doesn't come close to describing what I should expect in that situation, and nor have any previous posts I have seen. The approx height this occurs appears to vary but is often around 10,000 ft."With the default AS options, you have "Depict FS9 haze layer" and "Vis Graduation" enabled. This depicts the top of the haze layer at approximately 10,000ft or by the tops of the highest layer below 10,000ft. You will however only see this layer when flying above.. it is a very light-density "haze" via a variation of the cirrus cloud layer depiction. All handled by FS.When climbing above approximately 3,000ftAGL, graduation will kick in, slowly improving vis from REPORTED to MAXIMUM based on your altitude from 3,000ft to 2,000ft above the top of the haze layer (or 12,000ft if haze layer disabled).I will give an example.. you've just departed KSNA in reported 5SM visibility (clear clouds). Things are stable as you climb initially. At approximately 3,000ft, vis very slowly starts to increase as you climb. You won't really notice any change unless you look closely at the horizon (can be seen as very small visibility "mask" steps, showing slightly more range each step). As you approach approximately 10,000ft AGL, the "ambient" visibility will be at approximately 9.9sm. The very instant the vis reaches 10sm, you'll immedaitely get gray to blue sky color, and you'll get an apparent immediate increase of visibility, to what looks like about 20sm. Visibility continues to slowly increase to the MAXIMUM at approximately 12,000, and from there remains constant at the maximum. Descending, everything happens in reverse.Note that REPORTED means as stated in the METAR + some internal small variations for realism (for all intensive purposes, this is as per METAR). MAXIMUM is either as defined in your AS options "Maximum Visibility" range if "Enforce Visibility Limits" is enabled, or, if disabled, as defined in FS "Sight Distance" setting. Note that registered FSUIPC settings can interfere with this, so as always we recommend WX SETTINGS OFF (especially in visibility-related options).If you were to change your FS9 haze layer or vis graduation AS options, things work a little differently. First, the haze layer is hidden by extending it all the way to 99,999ft (you'll never see it). Second, vis won't clear as you climb, so it will maintain the vis as REPORTED regardless of altitude. Between horizontal wx areas, the vis will change with FSUIPC smoothing (if AS option "Vis Smoothing" is enabled), but is still subject to the 9.9SM instant shift problem.If you were to leave FS9 haze layer depiction ON, and turn off vis graduation and vis smoothing, you'd get the exact same effect as per FS9 default. Basically, as soon as you hit the top of the vis ceiling (anywhere from 3,000ft to 12,000ft) vis will instantly shift to FS9's "Sight Distance" maximum.By changing these options as described you might be able to find something that works better for you.FWIW I prefer using the default AS options and find this to be the best balance between features and limitations at this time.Hope that helps..Best,

Thank you Damian, that is precisely what I was after. All I wanted to do was to understand what was happening. In my current flight (over the Southern Alps of New Zealand, though this is of no relevance) the Vis started changing at 11,700 ft approx and changed in two steps quite quickly to what I guess is my sight distance set in FS at minimum (60 miles) not the 30 miles of the max vis setting with enforce vis limits set. This flight was with an offline weather template with 30SM vis which is also the value set for max vis. Presumably no changes occurred until I was high enough up in the FS vertical profile of vis for a change above 30SM to occur. My earlier flights would have been with lower visibilities and I would have seen the change begin lower, though it always seemed to be very sudden, despite using the default visibility smoothing in AS.I don't have a registered copy of FSUIPC so that shouldn't be a factor. However, it would seem that setting a maximum visibility with limits enforced has no effect?? One last question, which was the one I started with - is the 'vis ceiling' as you describe it around 12000 ft the same as the FS Haze Layer?Mervyn

Hi,Yes, "Vis Ceiling" is the top of the "FS Haze Layer".Best,