Read more on understaning lenses here
Saturday, September 22, 2007
What is the F-number?
The earlier specification also had a F-number,
Lens aperture - F/3.5-5.6
This is another interesting number, although u don't have to worry about it much. It just says the size of the aperture under two situations - fully zoomed out (no zoom) and full zoom. Smaller number means bigger aperture. It starts with F/1.0. Bigger aperture is better. And lenses that stop at 3 points of there minimum generally perform better.
Lens aperture - F/3.5-5.6
This is another interesting number, although u don't have to worry about it much. It just says the size of the aperture under two situations - fully zoomed out (no zoom) and full zoom. Smaller number means bigger aperture. It starts with F/1.0. Bigger aperture is better. And lenses that stop at 3 points of there minimum generally perform better.
How do i read my lens spec - EFS 18mm-55mm
Here are the specification of my EFS lens
Thats quite a bit to chew! So first thing is to know how far can i focus? This is basically focal length. You can read more about focal length, but it just says how much far can you focus. So in the above specification, 18mm and 54mm are the focal lengths in two situations - fully zoomed out (no zoom) and full zoom. This also lets you know that zoom ratio is 3. Focal Length goes 3 times its minimum - 18mm. So optical zoom is 3X. There is also something called digital zoom - which is, after u have taken a photo the pixels can be stretched to create a bigger picture - ofcourse more u stretch less the quality.
Now 18mm also fixes the minimum distance u can focus on. That is also given in the specification - 11in.
- Length - 3 in
- Weight - 6.7 oz
- Dimensions - Diameter:Diameter -2.4 in
Lens System
- Type - Zoom lens Zoom
- Lens aperture - F/3.5-5.6
- Focal Length - 18 mm 55 mm
- Optical zoom - 3 x
- Min focus range -11 in
- Manual focus - Manual, Automatic
- Max view angle- 74.3 degrees
- Lens Construction - 9 : 11
- Filter size -58 mm
- Lens system mounting type - Canon EF-S
- Lens system features - Aspherical lens, Internal focusing system
- Equivalent 35mm focal length -28 - 90 mm
- Zoom adjustment -Manual
- Lens Coating - Coated
- Diaphragm Blades - 6
- Min View Angle - 27.8 degrees
Thats quite a bit to chew! So first thing is to know how far can i focus? This is basically focal length. You can read more about focal length, but it just says how much far can you focus. So in the above specification, 18mm and 54mm are the focal lengths in two situations - fully zoomed out (no zoom) and full zoom. This also lets you know that zoom ratio is 3. Focal Length goes 3 times its minimum - 18mm. So optical zoom is 3X. There is also something called digital zoom - which is, after u have taken a photo the pixels can be stretched to create a bigger picture - ofcourse more u stretch less the quality.
Now 18mm also fixes the minimum distance u can focus on. That is also given in the specification - 11in.
DSLR - One line
Digital Single Lens Reflex uses mirror to reflect the incoming image to optical viewfinder, comapred to point and shoot where viewfinder is a separate assembly - thus in SLR "What you see is what you get"
So whats a DSLR?
http://www.circuitcity.com/ccd/genericContent.do?oid=167664
is a very succint and nice description of DSLR.
is a very succint and nice description of DSLR.
Want to build a new hobby
Thats what i wanted to do. Fundamentally a technologist, i tried music - but it was not ready to try me. Then after few more hits i learnt that photography is something i can try as an amateur. And then i am starting learning step by step and noting the steps here. As of now, i know nothing about photography, except for sometimes i say Aha! on seeing a good photograph.
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