Could someone explain how to achieve this type of Skin smoothness? My camera is a Sony a6000.
Edit: I am wondering what smoothing and blurring filters or some sort of technique they are using to remove any blemishes on the face. But the skin still looks natural, you can see the pores, and the lighting is still realistic. I find when using various applications to remove skin imperfections it kind of looks more blurred and a lot of detail is lost.
It looks like you're looking for a circular or ring flash:
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A ring flash helps you achieve similar effects (particularly with the circle in the pupil), but the rest is make-up and Photoshopping; smoothing and blurring. I suggest reading this article about creative ways of using ring flashes.
But, as several people mentioned, please do specify more precisely what exactly you mean.
A ring flash also helps you take pretty cool pictures in macro in combination with a diffuser.
If you really want to take photos of women that make them look like plastic dolls, you need young women, lots of make-up, and good patience and skill in Photoshop. Use a tiny "brush" when touching up and you won't lose the "detail". Personally, I hate photos that look like the ones you posted. It's such an unnatural look and it leads to unhealthy body image issues for women (and some men). As photographers who are also human beings living in a world we want to make better, we should not be perpetuating the distorted view of "beauty" the cosmetics industry attempts to promote.
From the photos you used as an example, it does not matter what camera you are using.
The effect is non-photographic; but, is subject "doll-up."
You achieve this "effect" by hiring an experienced, professional make-up artist to work on the model you wish to photograph.
Then, you use "butterfly" or "glamour" lighting which is diffuse and broad. In your first and last examples, a "ring-light" was used as the sole source rather than a "normal" studio set-up. In your second example, the lighting used a hybrid gobo (mask) in the shape of a "+"
