This feels like an expensive foundation in the hand - the glass bottle has a nice weight, the cap isn't flimsy, and the pump (every foundation should have one!) dispenses a reasonable amount of product. Not only does it feel luxurious, the bottle looks beautiful sitting on the vanity. Expensive, yes, but at least it looks the part.
Luminous Silk is a typical liquid foundation viscosity. I find that the pump of product doesn't run off the back of my hand unless I tilt it aggressively, but it is much more runny than a typical BB or CC cream. On my dry skin, one pump of product gives me light, seamless, invisible on the skin coverage. I would recommend two pumps (three tops) for photography and special events.
This foundation builds decently and works best either patted into the skin with fingers or applied with a damp beauty sponge (my favorite - the Real Techniques miracle complexion sponge). On me, the finish is a natural luminous satin.
I have dry skin and this foundation works well for me, but I prefer something more emollient and creamy when I am dealing with eczema patches or flaky, irritated skin. I think this formula would work well for dry, normal, or normal to oily skin, and not as well for super dry or super oily skin.
The lasting power of Luminous Silk with no primer and a very light setting powder is pretty average. After 6 - 8 hours, I want to powder my skin to blot away shine. With a touchup, I can happily wear Luminous Silk for 10 - 12 hours. I don't wear primer or use setting sprays because I have dry skin and rarely have longevity issues with bases, but I'm sure either one of those products would help you prolong wear.
As always, swatches are on bare, unprimed skin. Please pardon the dirty windowsill.
Before & After
This before & after photo shows the coverage and finish of Luminous Silk applied with a damp beauty sponge. You could build it up and go for a second pump, but I am happy with the coverage provided with one. Close ups on skin texture aren't particularly flattering, but Luminous Silk does a good job providing natural looking coverage for facial redness, pigmentation spots, and doesn't highlight pores. I can still see freckles and that pimple lurking by my mouth, but my skin looks overall healthy, even, and natural.
Comparison to L'Oreal True Match foundation
The most similar foundation in my arsenal to Giorgio Armani Luminous Silk is my favorite drugstore foundation - L'Oreal True Match. My shade in True Match, N1 Soft Ivory, is a little more pink and a hair lighter. True Match has a similar viscosity but a little more opacity and coverage - I find that it takes a little more care with application for the finish to look like skin. Compared to Luminous Silk, True Match has a more flat finish, but still looks more natural than fully matte. I find that True Match lasts a little bit longer (perhaps by an hour). True Match has broad spectrum SPF in the formula, while Luminous Silk does not, making it more appropriate for photography. My bottle of True Match doesn't have a pump, which is a big downside for me.
I don't think these are dupes, but I think there is a pretty good chance that fans of one formula will like the other. I like them both, but I feel prettier in Luminous Silk because of the finish.
Overall, this is a great foundation for weddings and heavily photographed occasions. *whew* that was a long one! Thanks for sticking around :)