Question 1:
Vray rendering is resolution dependent?
Can I render, for example, at 3000*3000, with an irradiance map file rendered at 50*50?
The quality it’s the same?
Question 2:
Exist in vray material a similar option of the Max Standard material “2 sides” option?
Question 3:
The “store with irradiance map” option of a Vray light, decrease render time, but the
quality?
hi
1 : if you going to render an image of 3000 x 3000 you need to calc your IRR map at half the size to get a good quality image.
2 : Vray renders 2 sided all the time (sometimes)
3 : yes your right the quality does decrees and i tend not to use this feature where possible.
Natty: In regards to your first answer, when you say “good” is that just only good? I guess what I’m asking is if you put a rendering side by side a) IRR map at 1500x1500 and rendered at 3000x3000 b) IRR map at 3000x3000 and rendered at 3000x3000 … Will you see a quality difference? I wasn’t aware of that and if there’s really no noticable quality difference that could save me time 
why dont you test on a smaller image … see for yourself my friend
I have two projects going on and one is due really soon. my render times are really high. For a 1500x1125 its about 9 hours and for 3000x2250 its about 16 hours. I don’t have much time to spare 
I’ll try it afterwards then.
Thanks.
-Andrew
trust me … render your Irr Map half the size, AA = 0, 3 works well.
Look at one of the recent threads in this forum, there was much talk about this randering half size and reusing. The min max settings of the IR map do exactly this for you, so just lower these both by one and you’ll get the same effect as reusing a saved map of half the render size.