Monday, January 12, 2009

The beauty of a 50 mm, 1.8 lens

The best 85 bucks I've spent in awhile was on my new 50mm, 1.8 lens and here is why:

The 50mm is perfect lens! 
-Great for portraits since it can reach the lower f-stops meaning higher apertures resulting in shallower depths of field.
-Great for everyday since it doesn't need as much light, meaning faster shutter speeds and less blur.
-Great for travel since it is so light and not nearly as big as most zoom lenses.
-Great for the pocket book since you can get one for uner $100.

So here it is!

The following is an example of the difference between the lens I was primarly using, a 18-55 mm (zoom), 3.5 to5.6, to the new 50 mm (prime), 1.8. 

The two pictures below were both taken with a shutter speed of 1/30 sec and the lowest f-stop the lens would allow, 5.6 for the zoom lens at 50 mm and 1.8 for the prime lens. 

This picture was taken with the zoom lens at approximately 50 mm, 5.6 f-stop, 1/30 sec.

Here is the prime lens at 50mm, 1.8 f-stop, 1/30 sec.

As you can see the ability to reach lower f-stops, which means larger aperatures, with the prime lens allows much more light in at the same shutter speed. 

*In case you were wondering the relationship between f-stops and apertures here it is straight from Complete Digital Photography by Ben Long. "F-stop values are simply the ratio of the focal length of the lens to the diameter of the opening in the aperture." 

Now that's covered, here are a few samples of the 5o mm in action. 

A portrait of Coach.
Notice the shallow depth of field, only his face is in focus.

A bokeh shot.
Notice the blurred light circles in the background.  

Musical bokeh. 
This was created using a tutorial from
Finally, I feel obligated to mention one more thing about the 50 mm. The auto-focus is much slower than with the 15-55 mm. If you are trying to caputure children and pets this may take some getting use to and some planning ahead on action shots. 

Okay, so that's the tale of my love affair with the 50 mm, 1.8 lens. I must get back to playing with my new toy! 


Amy Kingman said...

GREAT POST! Thanks for the this vs that photos. It's a confusing thing talking fstops and shutter speeds, but you did a great job breaking it down! We're sold on the 50 mm as our next lens purchase, it's just a matter of getting the gift cards down to the camera shop! Your portrait of coach is AWESOME! Can't wait to see more bokeh experiments! :D

Kingsler34 said...

Fantastic article. Understanding the differences between lenses has always been a difficult process for me. This helps a TON. Picture examples were a nice touch.

Beth Carter said...
This comment has been removed by the author.
Beth Carter said...

Sweet Pics Steph.
Thanks for the break down in the lenses, it helps me to understand the differences a little better.