Depth of Field

Tim Robbins

Hi,
I was hoping to get a bridge camera for about 300 euros online that would give me good sharp images and a broad depth of field.

To get this I'd need a high f stop on the aperature setting but most cameras at this price go to 5.8 max.

For example, the Panasonic Lumix DMC-FZ28 which looks like a great camera has an aperature range of: F2.8 - F4.4.

So I don't think I'd be able to get a broad depth of field with this.

Any advice or tips?

Thanks

pete4130

Hey Tim,

The F2.8 - F4.4 means that at the shortest focal length the widest aperture the camera/lens will achieve is 2.8 and when you are fully zoomed in at the longest focal length, the widest aperture the camera/lens will achieve is 4.4

It doesn't mean that the smallest aperture is 4.4 at all. I'm guessing you'd need to check the specs more in depth to see how much you can stop the aperture down to.

Hope that made some sense?

Pete.

democrates

Hi Tim. A quick google for 'DMC-FZ28 minimum aperture' looks like F8 is the limit both in wide and tele on that camera.

I've seen some retail websites mistake minimum and maximum for aperture, they go by the f-number not realising that f2.8 is a bigger aperture than f8.

If you've got a particular question about a camera that the reviews don't answer and you want to know before you buy, best bet is to hit the manufacturers website and download the instruction manual, the devil is in the detail. But you can't go by specs alone, test shots from reviews will show you how the different cameras compare. Here's a review incl. test shots, ignore retail site 'reviews' they're a waste of time.

It's easy for camera lenses to achieve broad depth of field (dof). The trade-off of having such a small opening for light to get through is that the shutter may have to stay open for longer which means camera shake may be a problem, now you've lost the sharpness you wanted, especially at max zoom.
If you want a fast shutter speed to 'freeze the action' and avoid camera shake even with a small aperture, your last option to achieve an adequate exposure is to increase the sensor sensitivity from say ISO100 to ISO1600, but you get more noise in your shots at higher ISO's.

It's the shallow dof which is expensive to implement, so that f2.8 at wide angle is going to buy you faster shutter-speed, this will have a shallow dof but then that can make for very pleasing portraits or close-ups of flowers for example, the background blur is called bokeh, and only if the background and/or foreground is important will that be a problem as opposed to an advantage.

The camera choice will depend on which type photography is most important to you. To an extent they'll be all-rounders, but some will excel in certain areas, and you need one that covers your bases. I'm guessing landscapes are a priority, is that all you want from it?

nilhg

Hi Tim

DOF depends on various things but the three most important are subject distance, lens focal length and aperture, you've been looking at the possible apertures on the fz28 but the important figure for your needs is the (actual) focal length, 4.8 mm on the wide end.

With a short lens like that no matter what the aperture you use you will get large DOF, though at its longer end you should be able to do some interesting stuff.

Put the numbers into the online DOF calculator, all should become clearer.

sheesh

just to repeat what the others said in a different way

the numbers you mentioned are the maximum apertures possible within the zoom ranges of the camera

they can always go lower

e.g my 50 mm f1.8 lens can take photos at f22 so your camera will probably be able to take photos at f22

you will probably need a tripod (or someplace to rest the camera at apertures that small unless like today its really bright.

Also for best results if you do need to rest the camera somewhere put the timer on sothat there is no movement due to the button being pressed.

go for it

Tim Robbins

pete4130 wrote: »

Hey Tim,

The F2.8 - F4.4 means that at the shortest focal length the widest aperture the camera/lens will achieve is 2.8 and when you are fully zoomed in at the longest focal length, the widest aperture the camera/lens will achieve is 4.4

It doesn't mean that the smallest aperture is 4.4 at all. I'm guessing you'd need to check the specs more in depth to see how much you can stop the aperture down to.

Hope that made some sense?

Pete.

Good explanation. So does this mean:
At Shortest focal length I can have: F2.8 - F22
and
At Longest Focal length I can have: F4.4 - F22

So when checking PAertur range it's best to have low F numbers and therefore greatest range of aperature?

ThOnda

Well, it depends. What you want from camera. But as stade above, the aperture of the lense must be multiplied by the crop factor of your sensor to get equivalent aperture to 35mm film.

nilhg

Tim Robbins wrote: »

Good explanation. So does this mean:
At Shortest focal length I can have: F2.8 - F22
and
At Longest Focal length I can have: F4.4 - F22

So when checking PAertur range it's best to have low F numbers and therefore greatest range of aperature?

No, if you check the lens section of the FZ28's specification you will see that the min aperture is f8.

You have to remember that the FZ28 is a bridge camera, with a much smaller sensor than a DSLR, this means that it naturally has loads of DOF especially at its wider end.

There is no such thing as best when it comes to F numbers,its really a matter of picking a tool for the job.

If you are worried about the ability of the camera to do the job you want I would recommend doing a search for it on flickr's camera finder and seeing if others have been successful with similar shots.