Blur background with kit lens

[robbyrob]

Ok I am a noob at photography and never realized the thinking that went into taking some of the awesome pictures I have seen here. I see most portraits have blurred background. I have been reading my manual and specs on most pic in flickr and see that most pics were shot with a low aperture of f1.2 to 2.4. Reading another thread on here of prime lenses I saw a link to a page which showed a picture shot by a cannon at f3.5 which had the background blurred. This leads me to beleive I can get the same effect with my kit lens.

Ive tried to shot in A mode at f3.5 but it doesn't seem to come out with background blurred. any tips you guys can give me or something I could be missing. I try to focus on one item of person but photo comes out all in focus. I was thinking maybe changing my focus to single focus and maybe that would do the trick.

Thanks

Rob

Sony A390 with kit lens

 

[Mach0]

http://www.cambridgeincolour.com/tutorials/depth-of-field.htm

 

[o hey tyler]

Ok I am a noob at photography and never realized the thinking that went into taking some of the awesome pictures I have seen here. I see most portraits have blurred background. I have been reading my manual and specs on most pic in flickr and see that most pics were shot with a low aperture of f1.2 to 2.4. Reading another thread on here of prime lenses I saw a link to a page which showed a picture shot by a cannon at f3.5 which had the background blurred. This leads me to beleive I can get the same effect with my kit lens.

Ive tried to shot in A mode at f3.5 but it doesn't seem to come out with background blurred. any tips you guys can give me or something I could be missing. I try to focus on one item of person but photo comes out all in focus. I was thinking maybe changing my focus to single focus and maybe that would do the trick.

Thanks

Rob

Sony A390 with kit lens

It may have been this photo that you saw, I might have posted it in a prime lens thread because I am huge fan of prime lenses.

I shot this at f/3.5, but I did so with an 85mm focal length on a full frame camera, which gives me more reduced DoF than on an APS-C camera w/ the same settings, focal length, and subject framing.

The longer your focal length, the shorter the DoF at f/3.5... So for example, if you're shooting at 18mm @ f/3.5 your DoF is going to be 1.48 meters. If you're shooting at 85mm @ f/3.5 your DoF will be .05 meters.

As you can see, there's a drastic difference that focal length will make at a constant aperture. So the least DoF you can get with your current setup is 55mm on your kit lens at f/5.6 which would be .15 meters (without knowing the close focus distance of the lens).

 

[Josh66]

Just make sure the background is far from the subject (and you are close) and it should be doable.

 

[robbyrob]

thanks you all for your help with this.. Mach0 and o hey tyler thanks for the technical aspect. It helped me learn and understand DOF in relation to the subject and lens. http://www.thephotoforum.com/forum/members/22540.htmlO|||||||O thanks for the layman's terms. Sometimes I need to hear the "for dummies" version to understand the technical. in all I took this picture which i think put what all you said into perspective. I wasn't worried about composition or didn't even do any post production. That's a whole other war going on in my head. Just trying to do it one technique at a time and actually have fun taking pictures. Well here the pic I took which had the effect I wanted and didn't even need to get another lens to do it..

thanks guys

 

[Crollo]

That looks pretty good. Just get a farther background and stick a human face in the middle [or wherever fits compositionally] and you're golden.

 

[rickztahone]

Just so that you know, the technical term is bokeh. As you noticed, the LARGER the aperture, the better the bokeh. As o hey tyler explained, this has to do with DOF (depth of field). The closer the subject is to the lens the easier it is to get bokeh but a lot of it depends on the lens as well.

The following photograph depicts bokeh at f4. The lens has a 2.8 potential but you can see that the bokeh is still there. some lens just have a harder time with the DOF.

Griffith Plant by rickztahone, on Flickr

 

[MTVision]

Just so that you know, the technical term is bokeh. As you noticed, the smaller the aperture, the better the bokeh. As o hey tyler explained, this has to do with DOF (depth of field). The closer the subject is to the lens the easier it is to get bokeh but a lot of it depends on the lens as well.

The following photograph depicts bokeh at f4. The lens has a 2.8 potential but you can see that the bokeh is still there. some lens just have a harder time with the DOF.
http://www.flickr.com/photos/rickztahone/6879527139/
Griffith Plant by rickztahone, on Flickr

You get a shallow depth of field from large apertures not small.

 

[rickztahone]

Just so that you know, the technical term is bokeh. As you noticed, the smaller the aperture, the better the bokeh. As o hey tyler explained, this has to do with DOF (depth of field). The closer the subject is to the lens the easier it is to get bokeh but a lot of it depends on the lens as well.

The following photograph depicts bokeh at f4. The lens has a 2.8 potential but you can see that the bokeh is still there. some lens just have a harder time with the DOF.

Griffith Plant by rickztahone, on Flickr

You get a shallow depth of field from large apertures not small.

lol, yeah, sry that's what i meant. It still confuses me at times.

OP, LARGER aperture's for bokeh

(FIXED)

 

[DiskoJoe]

Go get you a Minolta 50mm f1.7

They are pretty cheap and give you almost a full range of aperture.

 

[rickztahone]

also, Rob, what specific lens are you shooting with?

 

[rickztahone]

Go get you a Minolta 50mm f1.7

They are pretty cheap and give you almost a full range of aperture.

This.

I was actually going to get the 50 1.7 but i think i might go with the Sigma 50 1.4 instead. But i have heard nothing but good things about the 50 1.7

 

[DiskoJoe]

Just so that you know, the technical term is bokeh. As you noticed, the smaller the aperture, the better the bokeh. As o hey tyler explained, this has to do with DOF (depth of field). The closer the subject is to the lens the easier it is to get bokeh but a lot of it depends on the lens as well.

The following photograph depicts bokeh at f4. The lens has a 2.8 potential but you can see that the bokeh is still there. some lens just have a harder time with the DOF.

Griffith Plant by rickztahone, on Flickr

You get a shallow depth of field from large apertures not small.

lol, yeah, sry that's what i meant. It still confuses me at times.

OP, LARGER aperture's for bokeh

(FIXED)

Bokeh refers to the quality of the blur. The large aperture makes it blurrier not better. Things like more aperture blades and better quality glass make better bokeh.