Nebie help with F stop and focusing

canonsx30is · Jan 4, 2012

hi there

i have a canon sx30is and i have been playing around with it and read the manual.

i have figured out the shutter speed and Fstop.

the type of photo i am trying to get is with a focused object like a bird and the backround blurry. blurry to the point where its almost one colour.

i put the camera on manual and played around with the f stop. when i zoom in or get close to an item the f stop that im allowed to play with is minimal. the range is f2.7 to f8.0, however when i try to focus on an object and get a close depth of field it adjusts itself and wont allow for a selection of a lower f stop number. it starts off at f2.7 but if i zoom auto goes to f4.5 and the backround is still somewhst in focus.

not sure what else to play with to be able to completely control f stop. or that f number thing lol.

Railphotog · Jan 4, 2012

The f/2.7 is your lens' maximum aperture, as you zoom out the effective aperture diminishes due to the lens being further from the sensor. There is nothing you can do to increase the aperture when zoomed out. A way you can get totally blurred backgrounds is to zoom in on closer objects such as flowers, and use the close up mode. That's what I do with my SX30.

Here is an example, shot at f/5.6, 1/200 sec.:

MLeeK · Jan 4, 2012

The problem you are going to have is the size of the sensor in your camera. Because the sensor is so small it causes your depth of field to be much more than it would be on a DSLR.
You will need to be closer to your subject than the subject is to the background-substantially closer; use no zoom so that you can use f/2.7 and hope it's enough. In a macro shot like posted above you should be able to do it. A bird in a tree? Probably not.

APHPHOTO · Jan 5, 2012

If you want to control whats in focus. Chose aperture priority and chose as small an f-stop as it will allow. The camera will chose the rest. It would also help to have pretty good distance between subject and back ground. I like to use my 70-200 2.8 and try to get some foreground elements between myself and subject and get some distance between subject and background so that you get some blur in front and behind the subject. It makes for some nice shots. Good luck. But the best advice I can give you is to read, read, read. Learn what aperture priority is, shutter priority, manual. When you can master those and when to use each. Photos seem to start looking like you know what your doing. Experiment, because playing around with you camera is the best way to learn to use it affectivley.