Sony A200 zoom lens and aperture settings.

Photokinesis

Suspended / Banned
Messages
3
Edit My Images
No
Hi.
I decided only last week to get into photography and got the Sony A200. I think I now know the basics behind aperture, shutter and ISO controls.
What seems to be getting me confused is the relationship between focal length on the 18-70mm F3.5-5.6 lens and my chosen f-stop.
If I zoom in or out my f-stop automatically changes. How do I control zoom and still get the depth of field that I want and which is the best mode to do this with - A, S or M?

Many thanks.
 
The maximum aperture is set for the lens at various focal lengths, you can not alter this.

i.e. at 18mm the maximum aperture will always be f3.5 and at 70mm it will always be f5.6. But between these f stops and the minimum aperture you can then choose the one you want.

The best modes for you to control DOF would be A or M. Auto or S would choose what the camera thinks is best.

There are lots of online DOF calculators that will give you the DOF at a given distance and f stop.
This is just one of them.

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