Can't Use Backgorund Blur Setting - Creative Auto

[eejohnson622]

I am in creative auto and when I try to select the "background blur" option it only will let me select the 3 closest to sharper. Anyone know why the 2 closest to blur won't work? 

I'm using the Canon T7i with the EFS 18-55mm lense. This is my first camera so I'm doing a lot of learning.

Thanks!

[jrhoffman75]

Page 86 of your manual.

Depending on the lens maximum aperture not all setttings will be possible

[TCampbell]

The amount of background blur is based on three things...

1.  Close subject distance... but distant background.

2.  Low focal ratio ... lenses that can provide f/2.8.... or f/2 ... or f/1.4, etc.  The lower the focal ratio, the stronger the background blur.

3.  Long focal length lenses.   Wide angle lenses naturally produce a very broad “depth of field”.  Depth of field is the range of distances at which things will appear to be acceptably focused.  The opposite... long focal lengths, naturally produce a narrower depth of field.

If you combine long focal lengths with low focal ratios and then shoot your subject at a close distance to the camera with a very distant background... you’ll get extreme background blur.

Canon makes a few 50mm lenses... the EF 50mm f/1.8 STM is a bargain at about $125.  If you were to use that lens with a close subject and distant background, you would get a pretty decent background blur.

If you used even longer lenses... such as the 85mm f/1.8... or the 135mm f/2... you’d get much stronger blur.

The Canon EF 70-200mm f/2.8L IS USM II is a very popular lens for portraits because the 200mm focal length with f/2.8 focal ratio creates quite a beautiful background blur.  I often back mine off to about f/4 and it still has quite a pleasant background blur.

[Waddizzle]

Because you are new to DSLR cameras, it is hard to know where to begin.  Canon has a Digital Learning Center.

http://www.learn.usa.canon.com/galleries/galleries/tutorials/eos101_cll.shtml

The above link is to the first in a series of videos that teach you about the three legs of the "exposure triangle": shutter speed, aperture, and ISO.  Canon also offers tutorials and onlne courses.

I would also suggest that you do web searches for " exposure triangle " and " depth of field ".

[Tim]

Hello eejohnson622, 

Depending on the lens you have in use not all of the settings will be available.  It comes down to a lenses maximum aperture. This is why the two are not selectable as you would need a lens with a larger relative aperture to get the full effect of this function.

The aperture number is expressed as the f/number on your lens.  A larger f/number, such as f/2.8 or f/1.8 will allow more pronounced out of focus areas due to depth of field.