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Smaller focal length is better and allow's more light in please read
http://en.wikipedia.org/wiki/Aperture
under In photography to the right is a disgram that clearly explains the focal lenght.
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Posted: 2008-11-04 17:51:47
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centur
I have re-edited my first post and the pics are to the correct scale.
number1
Thank you for the link. I will try it now.
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Posted: 2008-11-04 18:00:18
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Yes number1, you are right. I now know that smaller the focal length, there are provisions for more incoming light. At wikipedia every terms are shown like this f/5 or f/3. But none of these notations are there in the tags of both the phones. I suppose then the must be f/4.2 for C702 and f/5.2 for the K800.
Then again what avout the ratios. 1/x.x
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Posted: 2008-11-04 18:16:03
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Thats correct f/4.2 focal length of 4.2 for the c702 & 5.2 for the k800, the smaller focal length will also give a more wide angle picture, i'm not sure about aperature the focal length and aperature go together.
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Posted: 2008-11-04 18:24:30
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you're misleading two things which are focal length and aperture size. simplest possible, and to be honest not very nice, explanations are:
1. focal length controls angle of view and zoom. shorter length = wider angle of view, longer length = narrow angle of view (which also means big zoom)
2. aperture size controls amount of light reaching the sensor. bigger value = less light
both values are constant which means no fun - no zoom, no aperture size vs. shutter speed combinations
should I include pictures as examples?
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Posted: 2008-11-04 19:04:23
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Would explain, why my c702 1/5 iso640 pics are a tad darker than my old k800i 1/5 iso 640 pics, but i'm sure the smaller focal length would mean more light, the aperture on the c702 is controlled by that little black regtangle frame around the lens.
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Posted: 2008-11-04 19:10:32
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On 2008-11-04 18:16:03, bishshoy007 wrote:
Yes number1, you are right. I now know that smaller the focal length, there are provisions for more incoming light. At wikipedia every terms are shown like this f/5 or f/3. But none of these notations are there in the tags of both the phones. I suppose then the must be f/4.2 for C702 and f/5.2 for the K800.
Then again what avout the ratios. 1/x.x
The k800i aperture is f2.8, don't worry about focal lengths when comparing the c702 and k800i since it makes no sense to, 5.8mm is the lens size for the k800i, the real issue is the aperture, f/2.8 is OK, it's about as good as you're going to get on a lens that small, the c702's is f/3.2 which is now getting into crappy territory when it comes to light but which should be expected when we see that it has a significantly smaller lens size. The C905 has a 5.91mm lens with a f/2.8, like the k800i. So long story short the K800i has the better lens over the c702.
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Posted: 2008-11-04 19:26:54
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both values are not really important if we are not talking about anything else better than camphone. earlier I forgot to mention that depth of field (DOF) is also dependent on aperture size
Would explain, why my c702 1/5 iso640 pics are a tad darker than my old k800i 1/5 iso 640 pics
it's quite easy to explain:
fully opened aperture = f/1.0
K800 = f/2.8
C702 = f/3.2
the aperture on the c702 is controlled by that little black regtangle frame around the lens.
this may be true until 'controlled' equals 'constant'
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Posted: 2008-11-04 20:33:43
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On 2008-11-04 20:33:43, Raiderski wrote:
Would explain, why my c702 1/5 iso640 pics are a tad darker than my old k800i 1/5 iso 640 pics
it's quite easy to explain:
fully opened aperture = f/1.0
K800 = f/2.8
C702 = f/3.2
Does that mean due to smaller aperture size of K800 in comparison to c702, it ( the K800) takes 'a tad' better pic at low light conditions.
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Posted: 2008-11-06 11:18:04
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On 2008-11-04 19:26:54, Bialynia wrote:
The k800i aperture is f2.8, don't worry about focal lengths when comparing the c702 and k800i since it makes no sense to, 5.8mm is the lens size for the k800i, the real issue is the aperture, f/2.8 is OK, it's about as good as you're going to get on a lens that small, the c702's is f/3.2 which is now getting into crappy territory when it comes to light but which should be expected when we see that it has a significantly smaller lens size. The C905 has a 5.91mm lens with a f/2.8, like the k800i. So long story short the K800i has the better lens over the c702.
Can you verify this with some pics.
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Posted: 2008-11-06 11:21:52
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