Tuesday, February 16, 2010

Tech Talk Tuesday

Let's Talk About Focal Length

First of all, remember these posts, (for now), are bare bones, just the basics.  I get questions from beginners, and/or  'point and shooters',  who are after simple solutions so their family and travel photos are worthy of the time it takes to paste them in the scrapbook.  

Most point and shoot cameras now days come with great zoom capabilities, going from wide angle to telephoto.  Sometimes you zoom in or out to include or exclude what you want in the photo, but then are disappointed with the results.  Somehow things just don't look right; maybe distorted or blurry or appearing farther away or somehow different than how it looked on the LCD or viewfinder.  Today I'm going to talk about how different focal lengths can change the look of your picture.  I'm keeping this simple, so for all the following photos I put my camera on auto, shot indoors using natural light, had my ISO high at 800, and framed my shots with the strawberry as close to the lower left corner as possible.  A simple setup you can try for yourself.  I'm not going to talk about all the other adjustments that can change how your final picture will look, only the focal length and where you focus.  So here we go:
Here I used a telephoto lens with a focal length of about 200mm.  In other words, I zoomed in close.  In order for me to get the strawberry in the lower left corner and still get part of the flowerpot in the frame,  I had to be about 6 feet away.  I focused on the strawberry, and as you can see, everything else is blurred.

Here I used the same focal length and the same distance from the strawberry.  But look what happened when I focused on the little red hearts behind the strawberry.  There is a small band of the picture in focus, but everything in front and behind is out of focus.  (Although if you notice, the flowerpot is not as blurred as in the first shot because I focused closer to it.)

So now you get the idea.  When I focused on the flowerpot in this shot, it is in sharp focus while everything in front is out of focus.  As you can see with these three photos, where you focus is critical to the look you are trying to achieve.  In this still life, I like the strawberry in sharp focus, but there are many times when you could purposefully choose another area of the frame to be in sharp focus to make your picture more interesting.

A medium telephoto lens is a good choice when taking portraits, because, as in the first shot, when you focus on your subject in the foreground, the softly blurred background eliminates distractions and creates separation.  But it is important to remember to focus on the most important part of the face and that is the eyes.  The eyes must be in sharp focus for a portrait to look good (unless you are going for some artsy unusual look).  Even the difference in distance from the tip of the nose in relation to the camera, compared with the distance from the eye to the camera, can be critical in determining if you have a good portrait or a great one.  So focus specifically on the eyes, not on the nose or anywhere else on the person.  O.K., now for another look:

Whoa, what happened here??  Now I have gone to the other extreme and have a wide angle photo length of around 20mm.  Isn't it amazing how this changed the perspective of the scene and how much more you can see.  Again, I framed this so the strawberry was in the lower left hand corner.  But to get it there, I had to be about a foot away.  (If I had stayed 6 feet away, the picture would have looked a bit more in proportion but would have included a lot of the tabletop and floor in front of the strawberry.)  This looks totally different from the first three shots with the 200mm focal length.  The strawberry is HUGE, and looks like it is a mile away from the flowerpot.  This demonstrates why photographers don't use extreme wide angle lenses for portraits.  And that is because of the distortion in the size and shape of features.  If a head shot you've taken somehow does not look quite right, check your focal length.  If her cute button nose looks like the size of the above strawberry, you might have been using a wide angle focal length too close!!!   Photographers do, however,  use wide angle lenses when they want to be creative and purposefully produce a unique perspective like the above shot.  More often, however, wide angles are used to include more of the scene from side to side and from foreground to background.  For example, a real estate agent would use a wide angle lens to take photos of her homes because she can get more of the room in the picture, and a landscape photographer would use a wide angle lens to include more of the scene in the frame from the flowers in the foreground to the distant mountains in the background.  In this shot, notice once again that I focused on the strawberry and everything else is blurred.

Here I've focused on the little red hearts in the center.  The strawberry is really out of focus, but the flowerpot is not nearly as blurry as when I focused on the little hearts with the 200mm focal length, and you can see much more detail behind the flowerpot.

In this shot I focused on the refrigerator in the far background.  Now the flowerpot, hearts, and strawberry are all out of focus.  (If I were shooting a landscape there are other 'rules' for getting the sharpest focus possible throughout the image, but that discussion is for another day.)

I hope this shows you visually why it is important to know how different focal lengths and focusing points will change the look of your photo.   With a little forethought in visualizing how you want your photo to look, and having the know how to take advantage of the capabilities of your camera,  you will have the best chance of taking a picture you'll be proud to paste in that scrapbook!


Well, actually, this one is really for Jeff.  I have to tell you my Valentine story.  Jeff's favorite treats are chocolate covered strawberries.  My tradition is to give him chocolate covered strawberries every Valentine's Day, and he looks forward to them with great anticipation.  Well on Saturday, the day before Valentine's Day, I was so busy and I had lots on my mind.  I attended a class all morning, ran errands, then took wedding photos in the afternoon until evening.  I was gone all day and came home late and tired, totally forgetting Valentine's day.  Jeff knew I had forgotten.  Later that evening he brought me red roses, and he also bought himself strawberries and chocolate dip and proceeded to make his own Valentine gift!  I know, I know, I'm soooo ashamed!!  Since I didn't make you chocolate covered strawberries this year, Jeff, I took a picture for you!  Let's hope I do better next year!! 



Riet said...

Thank you for this lesson and for visiting my blog. I am still a beginnening photo amateur so I try to learn every day.

Bull Rhino said...


Great visual explanation. A few months back I did a post on the focal length effect too. Mine was mostly about how zooming in compacts the photo shown on a much larger scale. Of course your examples are so much prettier and tempting than mine.

Speaking of Valentine's day, I am terrible at holidays - lazy I think. My wife loves flowers and I sometimes get her flowers but this year I had to work late Saturday and I warned her that I had not got her anything for Valentine's and she was not to get me anything. When I came home about 9:30 Saturday night there on the counter was a beautiful bouquet of red and white flowers with a card TO ME. I had to laugh at how clever she was. I'm thinking of getting her a new flash for my camera LOL!!!

Saratoga Six said...

Now THAT is real love! Great story.

Karen said...

Scott, I'm positive she'd love a flash for your camera!!

janc@mac.com said...

I feel like I've eaten delicious chocolate covered strawberries all the while I read your post. Very clever.

Lloyd said...

Funnily enough my wife made some Chocolate covered strawberries for me this year. She has finally come around to liking them. YAAYYYY!!! Guess I am slacking as a photographer because I could NOT make myself stop and take a picture. Just had to eat!!!

As a thank you I took her to get a Manicure and Pedicure on Tuesday while all the kids were at School. Shhh! Don't tell anybody but I got a pedicure too!

Have a good one!