You are perfectly right. Simply Ubi didn't ask for the filter, this was the fastest solution found by Luthier but certainly not the best for framerate (most shooters display huge explosions, yet pass the epilepsy tests, and still have an excellent framerate).

The RU version doesn't have the Epilepsy Filter, and while most of the game is the same, its not exactly the same either. When I was still using it, I had to grab a keygensis (something like that anyways) to change the language, and update patches. Wasn't worth the hassle before long, so I got the EU version after a bit. That was the first time I needed to turn off the Epilepsy filter, or delete the Ubi logo.wmv.

I've never heard of epilepsy filters until this thread.

It's in your graphic options by SSAO and V-sync, turn it off and you will see a few more fps.
My theory about the filter is that it was put in because of the strobe effect that used to happen when flying through clouds. I haven't noticed that for a while though, I try not to fly through clouds where possible due to icing of the carb. I really need to map that pitot heater to somewhere convenient.

Would you get icing flying through clouds at 3000m in British summertime?
I have no idea.

Your right I should have said UBISOFT asked for the problem to be fixed, which was my meaning. Luckily UBISOFT relented and allowed the developer to just provide an optional Epilepsy filter, otherwise we might still be waiting for the Western release, and more probably the cancelation of the sim in the west.

I would have thought it was looking thru the prop, but according to Luthier in his statement below there are quite a few causes.

As I explained in the clumsily-translated Russian article, everything in our game causes seizures - gunfire, explosions, fire, sun passing behind canopy framework, etc. Basically flight sims are an epileptic's nightmare.

This is speculation, but i think the same indeed. Cancellation could have been temporary (as temporary as our waiting for a patch) until new graphic engine is done, though. But that anti epilepsy legislation sure came at the wrong time for the sim, and i wonder too if Ubi did not over react to it.

I think that is very possible, when I used to fly I would occasionally have to apply heat at that altitude...conditions dictate...more chance of icing in the summer that in the winter, dew point/humidity the main players

I've gotten ice at 3000 feet in the sim. (What's the lowest altitude you can get ice in the sim?) The dewpoint and temperature in the sim are unknown but using a freezing level of 3000 feet and an average lapse rate of 2C/3.5F degrees per 1000 feet, that means the temperature at the surface would be 6C/42.5F degrees. Again, was it that cold in August 1940? I've not researched it so I don't know.