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-   -   Reducing Glare on the Sea (http://www.aoaforums.com/forum/digital-image-photo-video-audio-editing/30470-reducing-glare-on-the-sea.html)

danrok 11th April, 2005 03:46 PM

Reducing Glare on the Sea
 
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This is a raw photo straight from the camera taken in full-auto mode.

You can see the problem, the sea is over-exposed from the sun's glare. The rest of the photo is fine.

Fixing the sea would be tricky because that area is almost literally white/blank.

danrok 11th April, 2005 03:50 PM

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To reduce the glare and over-exposure on the water you can "stop-down". This will under-expose the shot slighty.

Here's the same shot but with the camera in A/S/M mode with stopping used.

Now the sea looks much better, but everything else is too dark!

danrok 11th April, 2005 03:52 PM

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However, this can be fixed using image editing.

Just used basic adjustments to contrast, brightness and colour.

danrok 11th April, 2005 03:54 PM

You can get even better results if you were to merge the two original images. In other words take the sea from the darker photo and merge it in to the other image which has an over-exposed sea.

dod 11th April, 2005 06:41 PM

Good quick guide :) Only thing I'd say though is that "stopping down" usually refers to the setting of the aperture size. What you've actually done is adjust the exposure by underexposing, which you can do by either reducing the amount of time the shutter is open or by choosing a smaller aperture, depending on what the camera is telling you it wants to use.

Both will reduce the amount of light hitting the film/sensor but depending on the situation can give very different results.

danrok 11th April, 2005 06:46 PM

Wouldn't suprise me that I'm using the wrong term. LOL

I'll just check the manual to see exactly what I was doing...

Gizmo 11th April, 2005 06:48 PM

So, can one of you guys put together a n00b's guide to photography, or suggest a good place for same? Like, what does changing the aperture do as opposed to adjusting the shutter speed? I've got a Canon AS70 that I'd like to do a bit more with.......

danrok 11th April, 2005 07:08 PM

I was using "exposure compensation" which has a range of -2.0 to +2.0.

Normal auto exposure was: F4 at 1/400th sec
With "exposure compensation": F4.5 at 1/800th sec

So, it adjusted speed and aperture by the look of it.

dod 11th April, 2005 07:35 PM

When you say A/S/M mode which one was it? Usually A is aperture priority where you select the Aperture and the cam picks the shutter speed. S is Shutter priority where you pick the shutter speed etc and M is manual where you choose both. Normally it's a matter of picking one of them. What camera are you using again?

danrok 11th April, 2005 07:57 PM

Quote:

Originally Posted by gizmo
So, can one of you guys put together a n00b's guide to photography, or suggest a good place for same? Like, what does changing the aperture do as opposed to adjusting the shutter speed? I've got a Canon AS70 that I'd like to do a bit more with.......

Quick explanation:

Aperture is like the pupil in your eye and it's size is represented by an f number, e.g. f2.8, smaller number = wider aperture. Just like your pupil, a wide aperture is needed in lower light and will also reduce the depth of field. A small depth of field will put the background out of focus. So, you might use a wide aperture in good light just for this effect. If you want everything in focus you may need to use a smaller aperture.

Shutter speed will determine how long the film/sensor is exposed to the light entering the aperture. So, if you are using a small aperture this can be compensated for by a longer shutter speed. But, the longer the shutter is open for the more likely you are to get camera shake. If taking shots of moving objects you'll need to use a fast speed in order for the moving object to appear sharp.

Really need to mention film speed, as well. Digital cameras do have a film speed setting even though there is no film. Fast film can be used in low light conditions, but has a grainy appearance. Slow film gives better definition but needs a longer exposure time.

These would be the 3 main 'controls' without considering the lens (wide/telephoto/filters, etc). Exactly how you work aperture and shutter will depend on the type of shot you are taking. You can use them in a creative way not just according to fixed rules.

The best way to learn, I think, is to learn one type of shot at a time and master it. Playing with depth of field is probably a good starting point and is very useful.

danrok 11th April, 2005 08:03 PM

Quote:

Originally Posted by dod
When you say A/S/M mode which one was it? Usually A is aperture priority where you select the Aperture and the cam picks the shutter speed. S is Shutter priority where you pick the shutter speed etc and M is manual where you choose both. Normally it's a matter of picking one of them. What camera are you using again?

Must have been in the default AP mode, so I don't know why the shutter speed changed. It must have metered the shot differently.

It's an Oly C750UZ.

dod 11th April, 2005 08:55 PM

Quote:

Originally Posted by danrok
A small depth of field will put the background out of focus. So, you might use a small aperture in good light just for this effect. If you want everything in focus you may need to use a larger aperture.

Tsk, tsk ;) You need a small aperture (bigger F Number) for greater depth of field :)

Only thing I'd add is that the camera's built in light meter will make a pretty good job of estimating what the shutter speed and aperture should be to give the correct exposure. The meter is designed to assume that any given scene will have an average light reflectance of 18%. Most cameras by default take the reading from around the central part of the image, it’s known as “centre weighted”. More advanced models give whats known as multi segment (from a number of different parts of the shot) or spot metering which can be as little as 1% of the image.

Because of that very bright scenes or very dark scenes can fool the meter. If it’s very bright the camera will assume that less light is needed so you actually need to ADD to the cameras calculated exposure. For example let’s say you’re taking a photo of a light bulb which is on. The camera might say F8 and 1/500th of a second. Because it is being fooled by the bright light you may need to reduce the shutter speed to say 1/250th to get enough light in to get the correct exposure.

danrok 11th April, 2005 09:15 PM

Quote:

Originally Posted by dod
Tsk, tsk ;) You need a small aperture (bigger F Number) for greater depth of field :)

Oops! Started out the right way round and then wrote it all arse about face! Corrected the text above.

I think the clearest way to remember is small f number means small DOF. :D


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