photogrl57 Loc: Tennessee

Welcome to Day 69 :) Today we are going to take another look at Aperture (part 2).. To be exact it is Focal Length, Aperture, and Shooting distance. How the three combine to affect Depth of Field.
Depth of field is described as the amount of distance between the closest and farthest objects in a photograph that appear in acceptably sharp focus.
Whether you have a shallow depth of field or a deep depth of field .. is a personal choice and can be quite subjective. What appeals to you might not appeal to another
photographer. You will never be able to please everybody, so the very best choice is the one that appeals to you.
There are a few factors that have a direct relationship with depth of field.. but we are only going to look at 3 of them today. Those are Aperture ,Focal Length, and Shooting distance.
We know that the aperture affects the amount of light that hits the sensors. So the larger the aperture (smaller fstop number) the bigger the opening .. the more light gets in.
The smaller the aperture (larger fstop number) the smaller the opening .. the less light gets in.
Light goes down in intensity the further it has to travel. So the light at the end of a longer lens is less intense than the light at the end of a shorter lens.
For example: If everything else stays the same ... the fstop and focal length (distance to the subject).. the light will be more intense on a 28mm lens than it is on a 50mm lens.
Less distance to travel. Last month we learned how to adjust the light using exposure compensation. This month we learn you can also adjust the light using the aperture
and focal length of the lens in combination. Both along with the distance to the subject affect the depth of field in your photograph.
I'm sure all this seems overwhelming.. but it's the best way for me to explain it and not include math LOL.
So for today's challenge ... just experiment ... shoot any subject you wish.. keeping 2 of the 3 factors the same and only changing the other one. (Aperture, Focal length, Shooting distance)

This first photo is a quick reference guide. The others are examples of the same shooting distance and aperture .. the only difference is the focal length of the lens.

I look forward to seeing what y'all come up with.
Click the download button to see them larger

depth of field quick reference guide


28-105mm lens @ f/5.6


55-250mm lens @ f/5.6


75-300mm lens @ f/5.6


100-400mm lens @ f/5.6


28-105 mm lens @ f/11


28-105mm lens @ f/11


28-105mm lens @ f/11

laskalass Loc: Land of the Midnight Sun

wow.....ok this is going to be fun...so I better get a good nights sleep and let this percolate in my brain over night.....lol G'night!

gerhel Loc: Sweden

Here is a link to play with showing aperature, shutter and ISO settings
http://www.kamerasimulator.se/eng/?page_id=2

Roadrunner Loc: Quebec, Canada

Thank you Gerhel.

martinfisherphoto Loc: Lake Placid Florida

Here's one example I found in the archives, will return tonight with some photos from today. Both photos taken of same object, but at different focal lengths. The second photo I zoomed in and it completely change the background to a soft focus.

f/4 32mm


f/2 158mm

mgstrawn Loc: Atlanta, GA

Great explanation and examples; I love the way you did the examples. Also, gerhel's link right under your 1st posting (pg. 1) to the app for IPhone/IPod/IPad is really cool and demonstrates how Aperture, ISO & Shutter Release (Exposure) work, separately & together! Thanks again for all your time consuming hard work! You are really going 'above and beyond!'

mgstrawn Loc: Atlanta, GA

Awesome link! I downloaded it immediately to my IPad2. Thank you for sharing, gerhel! (pg. 1)

martinfisherphoto Loc: Lake Placid Florida

Here's one more I found. I wanted to isolate this flower so I chose an aperture (f/stop) that would keep the One flower in focus and blur the surrounding flowers. Shot with 100mm lens at aperture f/5. The focus point was just above the center of the flower. Even the center flower is not 100% focus, because it's at an angle, which puts the front and back part of the flower different distances to the lens. If I had been standing back another 10 feet or so this would have been 100% in focus. The closer you are, the smaller the Focus Window(DOF), the further back you are the bigger the Focus Window(DOF)

martinfisherphoto Loc: Lake Placid Florida

Hibiscus Flowers were a tuff challenge for me in the beginning because they are sooo long front to back. If you've ever taken a photo of one you know that to get the entire flower in focus can be tuff. This shot I was 4feet away and zoomed in for close up. Most of my before tries I was putting the camera as close as it would focus, about 8inches, here I stepped back and zoomed in. Gave a much bigger Focus Window (DOF) F/22 PS My focus point was the yellow part(pollen) of the stem. If I had focused to the back of the flower the stem would have been blurry in the front section, Hope this helps Folks.

f/22 170mm

Roadrunner Loc: Quebec, Canada

Hey fstop..don't stop there LOL...Really nice reading you and thanx for sharing.

Bad day today, wife has errands...and I have to tag along....Surely we shall be back for General Hospital, and I'll probably take off then to practice.

Keyword for today,

''Yes dear, yes dear''

mgstrawn Loc: Atlanta, GA

Awesome, Roadrunner! You are a good husband, and I hope she gets you back in time for her to watch 'General Hospital' so you will still have some good afternoon daylight in which to shoot!

mgstrawn Loc: Atlanta, GA

Awesome, fstop! Your contributions really help me to further understand! (pg.1)

Roadrunner Loc: Quebec, Canada

Ha! you aren't the only one.....

PAToGraphy Loc: Portland ME area

Good Morning, All
Got the idea, downloaded the app, thanks for the examples PG, Fstop. Am looking for some.

Not really "with it" today...

RiverNan Loc: Eastern Pa

this is for Rufe..just so he knows there are others who need to keep milk on the brain. ok...im done promise...but I ran across this photo this am looking for red and well what can I say...I thought of you.