Comments on: Aperture: Why You Care

By: stopshootingauto

stopshootingauto — Fri, 26 Jun 2009 10:59:02 +0000

Thomas,

Yes, that’s exactly right! Write those two sentences on a card and put them next to you while you go play around with the camera and try different apertures. It won’t take very long at all before you no longer need the card– it will all just become second nature.

By: Thomas

Thomas — Fri, 26 Jun 2009 10:30:35 +0000

First of all – this site is outstanding. Just so I am clear in my own head…

small f/ = small area in focus = big hole for light

big f/ = big area in focus = small hole for light

Is that right?

By: Bonnie

Bonnie — Sat, 14 Mar 2009 03:31:06 +0000

The bigger the f Stop the smaller the aperture, the smaller the aperture the greater the depth of field. (From an old photographer in the 70’s)

By: stopshootingauto

stopshootingauto — Thu, 25 Dec 2008 05:26:33 +0000

Check out this online depth-of-field calculator. You feed it information about your lens, distance to subject, etc. and it calculates your depth of field for you.

http://www.dofmaster.com/dofjs.html

One thing to know is that one third of your depth of field will be in front of your focus point, and two thirds will be behind.

By: Steven

Steven — Thu, 25 Dec 2008 05:16:55 +0000

I understand the depth-of-field, but how will I know what is going to be in focus in front and behind my subject. Is 5 feet in front of the subject in focus while 15 feet behind it is also in focus at say f/11.

By: stopshootingauto

stopshootingauto — Sun, 07 Dec 2008 04:00:12 +0000

Sharon, look at the EXIF data on the images, and figure out what shutter speed and ISO you were using. Most likely, the problem was that your shutter speed was too slow.

I’m going to guess that you were using an ISO of about 100 or 200. If so, try setting it to 800 or 1600 (or higher if your camera can) and see if you can do better. That will let you use a faster shutter speed to freeze the motion.

By: sharon

sharon — Sun, 07 Dec 2008 02:34:05 +0000

I want to take action pics at an indoor sporting event. I thought my zoom canon 75-300 1:4-5.6 would be ok…it was not..the first shot of my series of shots was great…then they were all blurred. I have been told that this lens will be great for outdoor sports action..but I need a lower aperature number for indoor…Your recommendation? Thanks

By: Natasha

Natasha — Tue, 25 Nov 2008 17:39:27 +0000

That was a great aperture/lens explanation, thank you!

By: stopshootingauto

stopshootingauto — Sun, 18 Nov 2007 23:51:13 +0000

I have the Canon kit lens in front of me right now. If you look at the front, you’ll see the words:

CANON ZOOM LENS EF-S 18-55mm 1:35-5.6 II
CANON INC (circle)58mm

I’ll break that down. First, Canon zoom lens is obvious– it’s made by Canon, and it has a variable focal length (zoom) rather than fixed.

EF-S is the type of Canon lens mounts. It doesn’t matter much for your question, but it means that you can only use the lens on cropped-sensor cameras, not on full-frame sensor cameras like the 5D.

Now the interesting part: 1:3.5-5.6. Another way of reading that is f/3.5 to f/5.6. It means that when the lens is zoomed all the way out (18mm), the maximum aperture is f/3.5. When the lens is zoomed all the way in (55mm), the maximum aperture is f/5.6. When you’re in-between, the maximum aperture will be somewhere in the middle of that range. No matter what you do, you’ll never be able to open the lens wider than its maximum aperture. (Well, you might be able to with a crowbar, but that has its own set of limitations.)

the (circle)58mm part means that the lens uses a 58mm filter.

I just looked at the specs for the Quantaray 70-300, and it looks like it’s f/4.0-f/5.6. That means that at 70mm you can go as wide as f/4, and at 300mm you can go up to f/5.6.

If you want really shallow depth of field, there are some things you can do. One would be to buy a new lens. For an excellent Canon lens at a low price, I recommend the 50mm f/1.8. It’s a fixed focal length lens, not a zoom, but f/1.8 will get you a very shallow depth of field.

An even cheaper solution is to move closer to your subject. It’s not as good as having a lens that has a fast aperture, but it will help with background blur.

By: Tracy

Tracy — Sun, 18 Nov 2007 23:19:24 +0000

I have a question on aperature… I own a Cannon 18-55mm kit lense, a Cannon 55-200mm and a Quantaray 70-300mm lense. I have tried and tried to get the aperature value lower than 4. I cant seem to go any lower. I love the very small depth of field look. Do I need a different lense? or am I missing something? Just found your blog by the way and have a feeling I’ll be spending Lots of time here. Thanks so much for all the wonderful information. Tracy