DoF meaningless on G2 and other digicams?

[stephenshot]

In one of these threads which I can no longer locate, there was a fairly technical explanation of DoF on digital cameras which basically made it sound like, because of the small CMOS size, Aperture settings on the G2 and similar cams are really about 1/4th the size of their 35mm cousins.

If that is true, then using the Aperture to decrease DoF on a G2 is pretty much a waste of time? (For example, while shooting a portrait.)

Is there a better way to control it (e.g., zoom in, get close, use a tele-converter)?

Thanks!

[meow]

Do you mean that thread about Hyperfocal Distance maybe? The DOF is totally depending on the focal length. Long lens - short DOF. The film format (or sensor) comes into it only because the smaller the frame the shorter focal length is needed to get the same 'angle of view'. Max zoom on G5 is 28.8 mm. Put that on a 35 mm camera and you have a wide angle lens.

Yeah, zooming in helps. :D

[pradeep1]

If that is true, then using the Aperture to decrease DoF on a G2 is pretty much a waste of time? (For example, while shooting a portrait.)
Is there a better way to control it (e.g., zoom in, get close, use a tele-converter)?

Thanks!

The DOF is not useless. It is more than what you would expect from a 35mm setup, but still usable. Zooming in and using a large aperture can still produce pleasing blurry backgrounds.

http://www.photo.net/photodb/image-display?photo_id=2344666&size=md

http://www.photo.net/photodb/image-display?photo_id=1752538&size=lg

[Andy_T]

Hi,

I think you are both right ...

there's a rather technical thread over at the luminous landscape showing that the DOF on a digicam when using f/2 is somehow equivalent to using f/8 or even f/11 on a DSLR. This, of course, means, that it is very difficult to get a decent blurred background without tricks.

One of these tricks is using macro mode, because in this mode the camera somehow focuses differently (or so I think).

Pradeep,

these are two very nice macro shots that clearly show a very nice bokeh.

Does macro mode work as well for you for portraits?

Of all the trials I made to shoot people in macro mode over normal distances n order to blur the background, the result was that 99% of the pictures were totally blurred and - for that reason - utterly unusable.

Best regards,
Andy

[meow]

We weren't saying anything contradictory. :lol:

there's a rather technical thread over at the luminous landscape showing that the DOF on a digicam when using f/2 is somehow equivalent to using f/8 or even f/11 on a DSLR

That still would depend on the frame size of the cameras (assuming they use the same 35mm equivalent focal length lens). I mean, it differs pretty much. It's not like all DSLRs are the same. :P

[Andy_T]

We weren't saying anything contradictory. :lol:

there's a rather technical thread over at the luminous landscape showing that the DOF on a digicam when using f/2 is somehow equivalent to using f/8 or even f/11 on a DSLR

That still would depend on the frame size of the cameras. I mean, it differs pretty much. It's not like all DSLRs are the same. :P

Hi Meow,

I meant the controversy between the initial statement 'DOF is useless on a digicam' and Pradeeps demonstration that it is not (in a macro shot).

Sorry, I maybe was not precise enough. When I say 'digicam', I mean something with a 1/2 or 3/8" sensor like the Canon G series (as opposed to a camera with a larger sensor)

On the G series cameras, you are nowhere near the creative abilities of a DSLR (D30/D60/10D/300D/1D/1Ds) as far as DOF control is concerned.

Much to my dismay, I have to add, as I have not been able to get a shot with a decent blurred background with my G2, so far.

Best regards,
Andy

[meow]

I was just joking you. :wink: :P

My problem is that I don't get them sharp. :twisted:

[dbump]

I've been able to get reasonable DOF without macro mode:

http://home.comcast.net/~2bumps/Telluride.jpg

Obviously the mountains are out of focus, but even another branch within a foot or two of the focal point is fuzzy. I don't have access to my original image data right now, so I don't know what the exact settings were, but I know I shot it in P mode, no macro, possibly full zoom. I bracketed focus on the plant and then re-framed. I did use both a polarizer and UV filter, so my aperture is probably a bit more open.

[pradeep1]

Here are some more photos:

Click on them to see a much better sample

http://www.photo.net/photodb/image-display?photo_id=2433427&size=lg

http://www.photo.net/photodb/image-display?photo_id=2433431&size=lg

http://www.photo.net/photodb/image-display?photo_id=2433435&size=lg

The first and second pictures are at 1/160 at f/4.0 in macro. Very nice blurred background.

The third picture is at 1/60 at f/3.5 at full zoom, no macro, of course. The background is not the best, but I am sure I would have gotten a more pleasant blur if I had used f/2.0. The f/3.5 on my G3 seems to give me about what I would expect an f/8 on my 35mm camera would give me in terms of background blur at 130 mm focal length equivalent.

[dbump]

I glanced at my settings last night, and I believe my image was taken at 1/400, F4.0, 21mm (full)--I'm using a G2.
Nice images, Pradeep!

[dbump]

I glanced at my settings last night, and I believe my image was taken at 1/400, F4.0, 21mm (full)--I'm using a G2.
Nice images, Pradeep!

[s00pcan]

DOF is easy on digital with macros, but not as good with regular shots.

[pradeep1]

DOF is easy on digital with macros, but not as good with regular shots.

Yes, we are limited in that respect. Have to buy a 1Ds. :wink:

[dbump]

Yes, we are limited in that respect. Have to buy a 1Ds. :wink:

If only I could justify it...

The larger DOF can be really nice in situations where you're not trying to blur the background. And you can always add your own blur in post processing.
It is an effect I really enjoy, but I think I only shoot for it in a minority of my shots.