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Old May 12, 2006, 2:28 AM   #21
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Jim gave a clear explanation but I'd like to elaborate on it a bit further. Your camera has 4 modes: P, Av, Tv and M. Let's leave M (full manual control) alone for now. Starting with P (Program), it's the "almost full automatic" setting. It controls the speed (shutter) and aperture based on lighting conditions. However, itgives you the ability to change functionssuch as ISO, exposure, WB, flash, bracket andcolor effect. In Auto modethe only thing you can change is the picture quality.

Av is the aperture priority (Jim described it well). You set the aperture and the camera chooses the speed.The thing is, the wayretractable lens is designed, unlike the fixed lens used by the DSLRs,it gives a huge DOF whether you want it or not. Comparatively speaking, an aperture of f2.7 on the S2 (thelarger you can get)is equivalent to about f8.0 on a DSLR. Well, you can see the problem right here. An aperture of f8.0 on aDSLR gives you a great DOF already. In fact, an aperture between f8.0 and f11.0 on a DSLR is what gives you the sharpest image possible. Consequently,one can conclude that the S2 at f2.7 will not produce a veryblurred background. DOF will still be quite high.The answer is, what can you do to obtain a shorter DOF? Well, youposted the answer, which is,the use of zoom or macro. Themore you zoom a subject in, thesmaller the DOF. The same applies with macro/super macro. You were 7 ft away from the Tulipsso you zoomed in quite a bit to obtain such a close up. As a result, the wall became blurred. You can do a quick experiment. Get close to the subject and takethe samepicture choosing a large aperture (Av modewith lower f number). Then again with a smaller aperture (say f5.6). You'll see that the wall will look pretty much the same between the two shots.

Tvyou set the speed and the camera chooses the aperture. This mode is handy when you want to create effects such as the "cotton" look on water in motion (waterfall, river, etc) or when you want to freeze something that is in motion (sports, water, etc.). The higher the Tv setting, the quicker the shutter operates freezing fast moving subjects. Although the S2 offers speed up to 1/3200, you really don't need to go much beyond 1/1000 for 99% of moving objects you may want to photograph. The 3200 is more of a marketing tool than anything.

The important thing,as Jim pointed out, is to keep a balance between aperture, shutter and ISO (we did not talk much about the ISO but it plays a very important role in all this). I usually set my S2 to ISO 50, unless I'm in a low light situation and I really can not get a decent picture due to camera shake. Because aperture does not give you a whole lot of control over DOF on cameras such as the S2, I keep mine on P most of the time. I use Tv when I want to capture motion and that's about it.

Anyway, hope this helps.
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Old May 12, 2006, 3:14 AM   #22
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very clear~no problem, the aperture of aS2 can't be compared with a DSLR. But, in the same DC, I think that's diffrent~Especially the zoom. When you take a photo for a nature, f/5.6 or smaller is better than using f/2.7 or bigger.
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Old May 12, 2006, 12:21 PM   #23
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Your comment does not make a lot of sense. f4.0 is smaller than f5.6 but bigger than f2.7. So, is f4.0 good or bad? I'd say GOOD. In fact, f4.0 is probably the best aperture for landscape photography you can haveif your camera is not a DSLR. You get great sharpness and DOF.
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Old May 12, 2006, 7:36 PM   #24
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Tullio wrote:
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Jim gave a clear explanation but I'd like to elaborate on it a bit further. Your camera has 4 modes: P, Av, Tv and M. Let's leave M (full manual control) alone for now. Starting with P (Program), it's the "almost full automatic" setting. It controls the speed (shutter) and aperture based on lighting conditions. However, itgives you the ability to change functionssuch as ISO, exposure, WB, flash, bracket andcolor effect. In Auto modethe only thing you can change is the picture quality.

Av is the aperture priority (Jim described it well). You set the aperture and the camera chooses the speed.The thing is, the wayretractable lens is designed, unlike the fixed lens used by the DSLRs,it gives a huge DOF whether you want it or not. Comparatively speaking, an aperture of f2.7 on the S2 (thelarger you can get)is equivalent to about f8.0 on a DSLR. Well, you can see the problem right here. An aperture of f8.0 on aDSLR gives you a great DOF already. In fact, an aperture between f8.0 and f11.0 on a DSLR is what gives you the sharpest image possible. Consequently,one can conclude that the S2 at f2.7 will not produce a veryblurred background. DOF will still be quite high.The answer is, what can you do to obtain a shorter DOF? Well, youposted the answer, which is,the use of zoom or macro. Themore you zoom a subject in, thesmaller the DOF. The same applies with macro/super macro. You were 7 ft away from the Tulipsso you zoomed in quite a bit to obtain such a close up. As a result, the wall became blurred. You can do a quick experiment. Get close to the subject and takethe samepicture choosing a large aperture (Av modewith lower f number). Then again with a smaller aperture (say f5.6). You'll see that the wall will look pretty much the same between the two shots.

Tvyou set the speed and the camera chooses the aperture. This mode is handy when you want to create effects such as the "cotton" look on water in motion (waterfall, river, etc) or when you want to freeze something that is in motion (sports, water, etc.). The higher the Tv setting, the quicker the shutter operates freezing fast moving subjects. Although the S2 offers speed up to 1/3200, you really don't need to go much beyond 1/1000 for 99% of moving objects you may want to photograph. The 3200 is more of a marketing tool than anything.

The important thing,as Jim pointed out, is to keep a balance between aperture, shutter and ISO (we did not talk much about the ISO but it plays a very important role in all this). I usually set my S2 to ISO 50, unless I'm in a low light situation and I really can not get a decent picture due to camera shake. Because aperture does not give you a whole lot of control over DOF on cameras such as the S2, I keep mine on P most of the time. I use Tv when I want to capture motion and that's about it.

Anyway, hope this helps.
Photography and me are still rather new friends so a lot of what you are saying is Greek to me. I know there is much to learn with such a camera when you are usually used to dime store point and click or disposables. For the most part I think the photos I have taken are pretty good and I think all the talk of soft focus is making me seek it out in many instances. However, I cannot escape some aspects where things are indeed out of focus. Generally not an entire shot, just portions.

The three flowers shot from above is a good example. I'd like everything to be sharp but we have no focus to the left of the image. I think this is a metering thing as you mentioned earlier.

When posters speak of f.stops and such a lot of it goes over my head. I guess what I am seeking, as outlined in my one stop shopping thread, are some general settings I can keep the camera on for my trip. I don't have the knowledge right now to fiddle about with stops and such and I'd hate my experimenting on my trip ruining many good photos. I am really seeking something that will give me a good base to remain on that will usually produce good, sharp images.

At the moment I keep the camera on P following the suggestion of another thread and use the Vivid setting because I love the colors.

I will usually be shooting in sunny day light or cloudy skies (I use the Autio White Ballance to shift things accordingly). I tend to avoid indoor or night stuff at this point. I like the P setting and Vivid and think I should stick with that but do you have any other suggestions on some good settings that will generally perform well on the given circumstances?

You mentioned you usually keep the cam on P. What are your other settings?
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Old May 13, 2006, 12:31 AM   #25
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f/4.0 is bigger than f/5.6 - it's a ratio f/n - so as n gets bigger the actual aperture value gets smaller. The S2 IS is sharpest and has the least CA and PF at f/5.6. See the attached image for crops out of f/4 and f/5.6 images.

At smaller than f/5.6, for example at f/8, the aperture starts to act like a pin-hole and this tends to reduce the sharpness.

So if depth of field and shutter speed isn't an issue f/5.6 is probably a good choice. As shutter speed is often an issue I compromise and default to f/4.0, shifting to f5.6 if possible. If you're using a lot of zoom, and you want foreground and background landscape to be in focus, you might want to go for f/8. And, as already mentioned, if you want to narrow the depth of field and isolate the subject, then use lots of zoom and open up the aperture.

Tullio wrote:
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Your comment does not make a lot of sense. f4.0 is smaller than f5.6 but bigger than f2.7. So, is f4.0 good or bad? I'd say GOOD. In fact, f4.0 is probably the best aperture for landscape photography you can haveif your camera is not a DSLR. You get great sharpness and DOF.
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