Ok, so I have done a TON of photoshoots in my day... both as a model (mostly waaaaay back in the day) and fitness competitor... but also as the makeup artist. I have learned a thing or 5 about what they say on the internet, what other MUA's say and what is the actual truth.
First off, there is a LOT of rumor on the internet about Makeup Forever HD powder. Some pics show that there is a white haze on celebrities and they blame this AWESOME finishing powder...
I can honestly say this will happen with ANY powder and the wrong type of flash. If you plan on taking a lot of self portraits with your iPhone, you will DEFINITELY see this haze on your skin. The flash is LED and it's FAAAR different from a professional camera in a studio. I was kind of skiddish about using this before I heard the initial allegations (even though I had used it in MANY MANY photoshoots and had no issues), but I got brave and voila... no issues. Then I randomly took a pic of my makeup with my iPhone and CRAP, there's that haze... Son of a NUTCRACKER! This happens with LED flashes with HD Powder and MAC Prep and Prime Translucent finishing powder (which I LOOOOOVE). Moral of the story, no LED flashes...LOL
As of today, I have found the BEST foundation for a studio photoshoot to be L'Oreal Colorstay...
YUP...L'Oreal!!! No this is not a joke... It has a nice matte finish (but not cakey looking) and really looks better than my high end foundations. sooooooooooo, it's what I use. Additionally, there are TONS of colors, 2 formulas based on your skin type and it's inexpensive and easily accessible from most drug stores. Now, I find that some of the 'fair' color formulas are WAAAY too pink, so I may mix them with another yellow based color and it's perfect. In fact, this is what I have been reaching for over my Studio Sculpt :)
I used Color stay on ALL of my photo's from SuperShoots (including my main pic on my makeup page) Here is a link to my FB page so you can see... https://www.facebook.com/pages/Megan-Melone-makeup-services/202668816417684
I also used Colorstay on my photos for my website...YEAH even on myself...
The best advice I can give for photos is to AVOID mineral makeup... you WILL have a funny finish on the photos because of the reflective quality of the minerals... and find foundations with NO or LOW SPF (again, SPF reflects horribly in photos)
I hope this helps... Flawless skin in a photo is not that difficult as long as you have the right products :)