Teacher: Kenji Tachibana Digital Photography I. Aperture – Lens Opening 14 slides Copyright © 2003 – 2009 Kenji Tachibana

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening (f/stop) M echanics: Light enters the camera through the lens opening referred to as the aperture. Lens opening are set to specific sizes called f/stop. Correct exposure is a balance of two (2) things: 1.Lens opening controlled by f/stop. 2.Lens open duration controlled by shutter speed. Both share whole stop setting such as: F/stops like: Speeds like: 1/125 1/60 1/30 1/15

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening & f/stop Whole Stop: Whole stop difference means that the amount of light entering the lens either doubles or halves. It doubles when going from f/4 to f/2.8. It halves when going from f/4 to f5.6. DoublesHalves DoublesHalves More lightLess Light

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening & f/stop F /Stop: Range The compact digital aperture range usually goes from f/2.8 to f/8 which is a 3 whole-stop range as shown below. F/2.8 lets in the most amount of light. And f/8 lets in the least amount of light.

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening & f/stop F /Stop: Compact digital limits You can’t let in more light through the big lens opening than the ‘wide open’ f/2.8. Wide-OpenFully Stopped-Down You can’t let in less light through the small lens opening than the fully ‘stopped down’ f/8. DSLR lenses have different wide open and fully stopped down settings of f/3.5 wide open to stopped down f/22.

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening & f/stop F /Stop: Dangerous limits Stay away from the limits. It tends to give less than optimal image quality results. Avoid using f/2.8 (DSLR f/3.5) or f/8 (DSLR f/22). Wide open can suffer from soft edge detail. The fully stopped down image can have an overall loss of image quality.

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening & f/stop F /Stop: Increments Whole stops are sub-divided into 1/3 stop increments as shown below. 2.8 I I 4 I I 5.6 I I I I 4 I I 5.6 I I

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening & f/stop F raction Notations: Human eye is /2.81/41/5.61/81/111/16 1÷2.81÷41÷5.61÷81÷111÷16 1:2.81:41:5.61:81:111:16

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening & f/stop F /Stop: Useable range The high image quality f/stop range on a compact digital is from large f/3.2 to small f/6.3 lens opening Avoid using apertures smaller than f/6.3 if you want maximum optical sharpness. Aperture range from f/7.1 to f/8 suffer from lower resolution because of light diffraction. Use the wide open f/2.8 on emergencies only because of lower image quality.

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening & f/stop F /stop: Toy camera range The f/2.8 to f/8 are the default lens 3-stop range found on most compacts. And even that limited 3- stop range is available only on the wide zoom setting. The telephoto is limited to 1.4-stop range going from about f/4.5 to f/8. A simple explanation for this has to do with the light travelling further to reach the sensor when the ‘longer’ telephoto zoom setting is used.

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening & f/stop F /stop: Comparison The f/2.8 to f/8 are the f/stops for the largest and the smallest apertures on a most compact digitals. The range is a limited 3 stops. Compact 2.8 | | 4 | | 5.6 | | 8 Wide OpenStopped Down Wide OpenStopped Down DSLR 3.5 | | | 5.6 | | 8 | | 11 | | 16 | | 22 Wide OpenStopped Down The f/3.5 to f/22 are the f/stops for the largest and the smallest apertures on a most DSLR’s. The range is a much larger 5.3 stops. A more expensive ($1,500?) lens can be purchased with an f/2.8 wide open aperture and that would result in a 6 stop range.

Teacher: Kenji Tachibana Digital Photography I Aperture: Lens opening & f/stop S ummary: It’s through high image quality that an Image Maker conveys love for the medium. Although high image quality without a meaningful story is usually not that interesting. It would be like looking at a never-used chrome plated car engine, a waste of resources… Turn to the next slide for a bonus point opportunity

Teacher: Kenji Tachibana Digital Photography I Bonus Assignment: T hree Things Learned: Write 3 paragraphs about three new things learned from this ‘Digital Camera’ PowerPoint show. File Name:firstnameLearnAp (kenjiLearnAp.doc) Due Date: Turn in next class if you want to earn the bonus points. Use: Turn to the next slide to see the Word™ layout and requirements.

Teacher: Kenji Tachibana Digital Photography I Knowledge Gained Writing Format: Student Name: First and Last Assignment: I Learned Class: Art 114 or 115 Digital Photo Campus: South Campus Date: Actual creation date Report Title: Aperture Learned 1: In the slide x, I learned that ….. ……… ………… ……….. ……. ….. ….. ….. ….. ….. ….. Learned 2: In the slide x, I learned that ….. ……… ………… ……….. ……. ….. ….. ….. ….. ….. ….. Learned 3: In the x, I learned that ….. ……… ………… ……….. ……. ….. ….. ….. ….. ….. ….. Use Ariel 12 or 13 font and don’t double space (conserve paper please). And use Word’s ‘default’ page layout with 1” x 1” x 1” x 1” margins Right aligned the header info Center align the title Left aligned the paragraph titles Don’t include gray text Don’t include the red text

Teacher: Kenji Tachibana Digital Photography I x End