Photography Friday-- The 50mm Lens & Portraits

So, last week we talked about my recommendations for a starter dslr camera bag. This week, I want to talk a little bit more about both portraits and the 50mm lens. As I mentioned in last week's post, the 50mm f/1.4 or f/1.8 lens--which I shall call the "Nifty Fifty" from here on--is a great add-on to the starter dslr camera bag. It's a great portrait lens with a low f/stop (which allows for great bokeh!), and it's inexpensive--my f/1.8 was around $80! That said, the 50mm lens can also be really frustrating, and we'll talk about why later on in the post. First of all, I want to talk about some portrait basics.

Waaaaaaaaaayyyyyy back in high school photography with a 35mm camera, we learned to always take portraits with a lens somewhere between 75mm to 135mm. If you went much closer than 75 mm, it tended to flatten out the subject's nose (making it appear wider than it really was), and if you went much further than 135mm, the contours of a face tended to flatten. So, you may be wondering why I'm recommending a 50mm lens for portraits, and that is an excellent question.

Most of us who are just purchasing a dslr for the first time will not purchase a full frame camera because they are significantly more expensive than entry-level dslr cameras (some examples of full-frame cameras are the Canon 1Ds, 1Ds Mark II, 1Ds Mark III,  5D, and 5D Mark II or Nikon D3, D3x, D3s, and D700). Now, if you have an entry-level dslr camera like I do, you need to know that our cameras have a crop factor of 1.6. I don't want to go super in depth about the implications of a crop-factor, but you also need to know that when you're looking to buy a lens, the focal length is being described as it functions on a full-frame camera, NOT on a cropped frame camera. In order to find out how the focal length of any lens is going to function on a cropped-frame camera, you need to take that focal length and multiply it by 1.6. In other words, when I put a 50mm camera on my Canon Rebel XS, it is actually functioning as a 75-80mm lens (50mm x 1.6 = 80). This is why even though you may hear pros blog about how great their 75mm portrait lens is, it may not be the best portrait lens for your camera, and if you don't have a full-frame camera, you may already have something similar in your camera bag!

Whew. Was that about as clear as mud? I promise that this next part is a lot more simple. FOCUS. In terms of portraits, focusing on the eyes is so, so, so important. Nailing that eye focus is really what makes the difference between a ho-hum portrait and an amazing portrait.




Do you see the photo on the left compared to the photo on the right? All of my settings were exactly the same--the only difference is that in the photo on the right, I actually nailed the focus on her eyes. The photo on the left is still mostly in focus and it isn't an awful photo persay, but it isn't as good as the photo on the right, where the focus is sharp in her eyes. Let's talk some more about that.

When I first started shooting with the Nifty Fifty lens, I'll admit that a lot of my portraits looked more like the ones on the left. And I was frustrated. 'My kit lens wasn't nearly this finicky about focus,' I thought. But in retrospect, I suspect it might have had more to do with the lower f/stop of the Nifty Fifty.

Take another look at the photos above. Notice how there's some nice blur going on in the background? Okay. That nice blur was a result of shooting with an f/stop of 1.8 and is helping to put the emphasis on Lizzy, rather than on the couch or pack and play in the background, due to the small depth of field (the amount of the photo that's capable of being in focus). On the other hand, if I had taken the same shots but with an f/stop of 22, EVERYTHING in the background also would have been in focus due to a larger depth of field.

Note: A number of factors, including the distance of the camera to the subject, have an influence on depth of field. However, to keep things simple, I'm only going to be talking about it in terms of f/stop & aperture today. 

I like to think of my focal point as something that fades out. The rate at which it fades out is totally dependent on the depth of field. This next image was pretty quickly whipped up in Photoshop and is probably WAY oversimplified (and kind of reminds me of those kids portraits that were popular in the early 90's but make me cringe now), but it helps me visualize the concept:




In the picture on the left, the gray area is sort of what I like to think of as a focal buffer zone. The focus hasn't faded out of the focal point area quite so quickly, so anything in that area would still be pretty close to being perfectly in focus. If I had shot the picture with a higher f/stop, it wouldn't have been quite so crucial to nail the focus EXACTLY on Lizzy's eye. Even if I focused on her ear, her eye would also still be pretty close to being in-focus. If I zoomed in super close, I would have been able to see that the focus was on her ear rather than her eye, but at normal printing sizes, it wouldn't have been THAT noticeable. However, when shot at a lower f/stop, the depth of field is much smaller, so the focal point fades out much more quickly.

This concept is important to understand with the Nifty Fifty lens because you have the capability to shoot at a much lower f/stop, which means a much lower depth of field. I've found that if I'm shooting in auto or even p mode, my camera usually defaults to the lowest available aperture, so when I was shooting portraits in P mode (as I was when I started out, even though P mode doesn't stand for "Portrait") with the Nifty Fifty lens it was MUCH more important to nail my focus on the eyes than it was when I was using my kit lens with a much higher f/stop.

Bottom Line?
-It's important to understand the appropriate distance the camera should be from the subject--with a 50mm lens, you are not going to be able to shoot 6 inches from your subject.
-The Nifty Fifty may not be the best portrait lens for you if you own a full-frame dslr.
-Learning how to nail focus on the eyes is SUPER important when it comes to portraits.
-Aperture can be intimidating, but having a good understanding of it is SO worth it when you have a good understanding. If you have ANY questions about either of those topics, please go check out Pioneer Woman's Post {What the Heck is an Aperture?}.
-If your portraits are still looking funny, you may be experiencing perspective distortion. Shooting from a distance too close or too far can cause the subject's features to look off. Take a look at {this page} that shows the same model from different focal lengths.