# Canon Sx150IS



## feenix101 (Jan 18, 2013)

Hi there.

I had a canon SX150IS for christmas.  Now, as I understand it, to alter the depth of field, all that is necessary really is to change the aperture value.  First of all is this correct?  If so, how come changing the aperture value in AV mode or Manual mode does not alter the depth of field?  Is there some kind of setting on the camera that I need to alter?  Ive tried turning off all the auto focus elements, but that doesnt seem to help.  

I would be grateful for any information anyone may have about this.  This is my first post and am happy to be here. :mrgreen:

Cheers, guys.

Feenix


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## feenix101 (Jan 21, 2013)

Im starting to get shallow DoF now, but sporadically.  Is this normal for this type of camera or is there something wrong with my technique?  I just dont understand why if I go to take the same photo with the same settings in the same conditions sometimes the depth of field is shallow and sometimes not - its like the camera is compensating, even in M mode.  Any help would be appreciated.  Cheers.


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## lidiamartin (Jan 21, 2013)

I would advice you to change your camera if it is problematic. Instead you could use Sony cool pix as this camera is great. I own one of these and I never had a problem.
http://www.karinherzog.com/fr


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## feenix101 (Jan 22, 2013)

OK.  Is there no way I can stop the camera from overriding my settings though?  I mean, its pretty pointless having manual settings if the camera simply overrides them, right?


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## o hey tyler (Jan 22, 2013)

lidiamartin said:
			
		

> I would advice you to change your camera if it is problematic. Instead you could use Sony cool pix as this camera is great. I own one of these and I never had a problem.
> http://www.karinherzog.com/fr



First of all, no. This WILL NOT help the OPs situation.

OP- you likely won't notice a large difference in DoF on your compact bridge camera. They have fairly small sensors and not the most robust optics, so the ability to get a very shallow depth of field is severely limited. A few factors that control your depth of field:

1. The focal length you're shooting at. Longer focal lengths produce a shallower depth of field. 

2. Your aperture value. Large apertures will give you a shallow depth of field, but that won't mean much at <10mm on your bridge camera since the lens is so wide. Zooming in will likely make your aperture smaller. I would expect smaller than f/4 but you'll still have a better chance of achieving a shallow DoF at a longer focal length. 

3. How close you are to the minimum focus distance. The closer you are to how close your lens will focus also plays a large factor in the size of the circle of confusion.

Another thing that accentuates a shallow DoF is maintaining a large distance between the subject and background. 

If you're shooting on aperture value, set your aperture to the widest setting f/2.8 (wider) f/8 (smaller). So f/2.8 is where you would start (guessing that's your widest), then zoom in and focus on an object. Trip the shutter and check out your results. 

Hope this helps.


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## feenix101 (Jan 22, 2013)

Interesting information.  I think that there are a few things I can look at here, primarily the focal length and the distance between the subject and the background.  I think I will probably have to amend my expectations as well (theyre often rather unrealistic).  Cheers.


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## feenix101 (Jan 22, 2013)

Hmm.  I think the effect I was going for would only really be achieved with a macro lens - wide aperture, depth of field so small that it begins to affect the foreground image.  The lens would probably be ridiculous and expensive, and I would probably only use it a handful of times.  In short, my expectations were pretty wildly high and it aint gonna happen with a bridge camera - but I know that now so its cool.  Cheers to you both.  :mrgreen:


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