G12 and DOF

[Gtsmith]

How can you control DOF with a G12?

 

[BobbyT]

A small-sensor camera inherently has extreme DOF, and it is difficult to impossible to get shallow DOF.

If you do a search you can find great detail about this phenomenom. Bottom line, there is little you can do about it. To obtain shallow DOF, you need a camera with a larger sensor, such as a DSLRs or MFT.

 

[bcalkins]

Get the camera closer to the subject, and the subject further from the background...

 

[gordonsbuck]

By "control", I assume that you are asking about blurring the background. I made a sort of study of this using my G9 because I was convinced that I could find some combination of settings and distances that would blur the background. This post in my blog, http://lightdescription.blogspot.com/2009/02/g9-blurring-background.html , has links to the other posts that describe my efforts. However, all this was in vain as I did not find a workable procedure. I now have a G12 but there's no point in repeating those experiments since the results would be virtually identical.

As one of the other responders noted, the trick is to get a significant relative distance between your subject and the background. In the case of the G series cameras (really, any small sensor camera), that separating relative distance must be very large.

--
Gordon
http://hornerbuck.com
http://lightdescription.blogspot.com

 

[Lippy1223]

It also helps to use macro.
--
http://newyorkandelsewhere.blogspot.com/

 

[johnjw]

and, use full zoom - longest possible focal length. DOF is shallower at longer focal lengths.

Obviously, using long focal length works against getting a short distance from camera to subject, unless you are taking pictures of relatively small things - e.g. headshots. If you are taking pictures of larger things at full zoom, then the background has to be just that much farther away - distant mountains work well!

 

[gordonsbuck]

The maximum aperture on the G series is a function of the focal length; that is, you can't use (for example) f2.8 at full telephoto. So I set up tests to find a suitable distance for head shots at various zoom settings and using the maximum aperture.

I'm pretty sure that the "macro" setting is just a focusing aid for automatic focus. To demonstrate this, obtain focus in "macro" mode then switch to manual focus. Play around with it and notice that you can dial in the minimum focus distance in manual focus mode without having to designate "macro".

--
Gordon
http://hornerbuck.com
http://lightdescription.blogspot.com

 

[Gtsmith]

By setting the scene selection to "portrait" you get the blured background, exactly what is desired.

 

[tc333]

Not true as you still must use longest zoom position as well as consider distance to subject and background. Portrait position is just one of those dumb auto modes.

By setting the scene selection to "portrait" you get the blured background, exactly what is desired.

--
Tony

 

[joharis]

How can you control DOF with a G12?

Just as in all other cameras, the DOF is controlled by the absolute size (in mm) of the aperture. Small size: great DOF, big size: shallow DOF.

The absolute size of the aperture depends on the focal length and the used f-number. Long focal length: larger, short focal length: smaller. Low f-number: larger, high f-number: smaller.

Two examples: G12 at wide end and f8: aperture size=focal lenght divided by f-number: 6.1/8=0.76mm
DSLR full frame with 28mm wide angle lens and f8: aperture size = 28/8=3.5mm

That's why DOF is so much shallower on full frame than on compact, the (absolute)aperture size is about 5x larger.
--
http://www.flickr.com/photos/joharis/

 

[Gtsmith]

Perhaps what needs to be done is to put the camera on manual focus and focus on a point closer than the subject thus pulling in the far end of the DOF.

 

[joharis]

Perhaps what needs to be done is to put the camera on manual focus and focus on a point closer than the subject thus pulling in the far end of the DOF.

You can calculate how much that helps here:
http://www.dofmaster.com/dofjs.html

You must fill in the real focus length (not the 35mm equivalent), for the G12 focal length is 6.1 - 30.5mm

Remember that at tele the DOF is shallower but for the G12 the widest aperture at full tele is f4.5.
--
http://www.flickr.com/photos/joharis/

 

[gordonsbuck]

Perhaps what needs to be done is to put the camera on manual focus and focus on a point closer than the subject thus pulling in the far end of the DOF.

This seems to be a good idea but actually is not as effective as it would appear. Try it.

--
Gordon
http://lightdescription.blogspot.com