strugglin with aperture, unsure where to post

[Kieron Hill]

Hi everyone,

have been reading the forums for the last few days and find them very informative. Have been trying to put things I've read into use now I have a mains adaptor that won't chew through batteries.

However having believed I'd got my head around the concept I don't know if I'm missing something blindingly obvious that someone with more experience could point me in the right direction.

For Christmas I treat myself to an Olympus SP590UZ having spent several years with point and shoot digitals. I find it works just as I hoped it would in auto mode, however I wanted to start taking advantage of the extra features as I used to own an SLR in the pre digital days (an MTL5b for my sins) and wanted to be more creative with this bridging camera. I believed I'd got my head around aperture/depth of field and wanted to experiment as I wanted to capture the sharp foreground/blurred background effect.

I switched the camera into A(perture mode) and set the aperture at the low end of the scale 4.0, leaving the shutter speed to sort itself out, and started to take pictures indoors. of various scenes.

First of all I tried photographing my son asleep on the sofa from a distance of approx two feet. The whole picture remained in focus

Tried with my partner at the far end of the sofa, approx 6-8 feet away, same result

Cuddly toy on the breakfast bar from 1 foot

Outside the front door over the fields approx 50 feet away with the aperture on various settings

All the same result. To my mind there's some obvious setting I haven't changed, been through the camera menu but nothing stands out. Have tried re-reading the topics on the main site and several others but unless I've missed something there was nothing mentioned.

I'm hoping a penny will drop for someone here and it will be a case of "Oh yeah, press button A" as I would like to start utilising the camera's features and this is my first foray into the manual setting mode

[Kieron Hill]

Have just had a reply to the question on a different forum that says the DOF on bridging cameras is massive so changing the aperture wouldn't have had the desired effect. I was simply trying to get the camera to do something it's not equipped to do apparently.

So from my reckoning the aperture setting is purely to enable changing shutter speed primarily and would have little noticeable effect on DOF itself. Which effectively contradicts what the Olympus user manual says.

As a follow on question then, why do bridging cameras even in manual mode come equipped with an aperture function that has such limited effect and why bother with such a wide range of settings if it isn't going to do what an aperture setting traditionally does

[Swisstony10]

The aperture setting on a camera regulates how much of the light in the scene you're shooting comes through the lens - controlling depth of field is a by-product of how that works.

When I'm shooting a live band, I don't use an aperture of f1.8 because I want to get a shallow depth of field and be able to focus on the singer without the drummer ruining the shot by being all clear and crisp, I use it because I need to get as much light as possible through the lens. Similarly, when I'm shooting a guy kite-buggying on the beach and it's sunny, and I want to use a slowish shutter so I can get some motion blur, I don't use a smaller aperture like f22 because I want to have the other side of the Bristol Channel as in-focus as the guy with the kite, it's because I need to get a little less light through and not over-expose.

Depth of field is just one of the things that aperture controls.

Russ.

PS - My first SLR was an MTL5b too! Still got it, and it's still working.

[LeeR]

Camera manufacturers try to anticipate the needs of their markets. You have purchased a camera with some rather impressive features, including a 26x zoom, 12 Mp image, image stabilization and the capacity to take fast sequential shots. As the manufacturer sees it, people who buy this camera want above average features and are willing to pay for it. They want to be able to do the minds of things the average person cannot, but they are not willing to spend a great deal of time learn the craft.

[Kieron Hill]

thanks for the replies, love the camera and it's list of features, I can appreciate that customers would probably not want it for that particualr function and it's other specs more than compensate, as it was my first digital other than a point and play I guess with the aperture controls I was expecting it to do pretty much like the old 35mm slr's re depth of field. Not a major inconvenience as I can still achieve the same end result via photoshopping the picture and blurring the background.

[inkista]

I like manual mode on my P&S because if I want to underexpose, damnit, I want to underexpose and I don't want to have to struggle with the nanny-features on a P&S getting in my way.


(-2EV shot taken with my Canon S90, iso 80, f/8, 1/1600s).

Yes, trying to get DoF control via aperture with a small-sensored camera is relatively futile, but not hopeless. DoF is controlled by more than just the aperture. There are other factors that can make just as much of a difference (or more) in how much out-of-focus blur you can achieve.

1. Subject distance.

This is the big one. The closer you are to your subject, the more out of focus blur you can get. This is why macro shots always give you a blurred background. The farther away your subject is, the harder it's going to be to blur the background around them.

2. Focal length.

The larger your focal length, the less DoF you're going to get. The smaller your focal length, the more DoF you're going to get. This is actually where a small-sensored camera has its biggest disadvantage. While your camera specs probably read something like "35mm-400mm"--that's the 35mm-film equivalent, using a 5x or 6x crop factor. Your actual focal lengths are probably something more like 7mm to 70mm.

Secondly, nearly all P&S cameras have variable max. aperture zooms. They get slower the more you zoom in. You can only get f/2.8 at the wide end of the lens (zoomed all the way out).

3. Separation between background and subject.

The larger the distance between your subject and the background, the more you can get the background to blur. If your subject is standing against a wall, it's going to be pretty tough to get that wall out of focus.

While it's not easy to get background blur with a P&S, it's certainly possible.



Canon S90@22.5mm [130mm equiv.] iso 320, f/8, 1/250s. Macro mode.

[Kieron Hill]

thanks for the replies, other suggestions worth trying, I'll give the super macro a try