There is something I wanted to share for a while, so here it is. I hear al lot of people always go, you need the most expensive glass and the fasted apertures, Get the Canon 50mm 1.2L for the smallest depth of field and so on. But there is a catch especially with portrait work. And that is what I am going to talk about.
I have for my Nikon kit one lens I do almost everything with. This is the Sigma 24-105 f4! Yes f-FOUR!!! Not 2.8. So most people say, they are bad for creating a Small Depth of Field. But they always forget there is always focal length and distance to subject in the equation. I made a small table:
To make it a fair comparison I calculated everything with a 3 meter (30 feet) distance, with the most common used focal lengths. What you now can see is that with the Sigma 24-105 I can have a smaller Depth of Field at F4 than you can get with the 2.5x more expensive Canon 50mm 1.2L lens at 1.2.
This gives me also some extra advantages. I want to control my light, using strobes at 1.2 apertures is not really easy because a lot of studio strobes don't get that low and to kill the ambient light you have to start using ND filters. Also the compression for portraits at 105mm is beautifull. 50mm lenses are great for environmental portraits. But headshots are not flattering with 50m lenses. For people shooting portraits also take a look at an 85mm 1.8, you can get even smaller DOF with that than the 1.2
But whatever you do, never forget, a small DOF can be beautiful, but hell to focus. When people move maybe an inch it can make or break your shot. So a lot of time you even won't be shooting at maximum aperture, but more at f8 or f11. So you don't even need to buy the most expensive lenses to get great portraits.
With Cropsensor camera's
The table above is calculated on 35mm/Full Frame camera's. Nowadays there are also a lot of great (mirrorless) crop sensor camera's like the Fuji's. The Fuji 56 1.2 is a killer portrait lens! And for the table, on 1.2 at 56mm you can get a 0,14 DOF! So don't come with the story you can't get a small DOF with a Crop Sensor camera!
With Medium Format
Or take a look at an old Hasselblad like the 500c/m with a 80mm 2.8. These baby's may be analogue, but still rock! I currently use to and love shooting with them and the quality and look is so great! For the table, at 2.8, 80mm you get an 0.38 DOF, so also small. And I can tell you, you will shoot the camera at f8 or f11 almost every time, because getting focus at f5.6 or lower is a challenge!
And with some nice film like Tri-X or Fuji Velvia, Scan them big (you can scan then up to 60mp eqv) and print them.
So I hope this helps you not to feel bad at not having the most expensive fast glass. You can do it with less. And yes the expensive lenses will be sharper and faster and all that. But it is still the photographer who seek the light, creates the composition and takes the pictures!