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Two phone camera problems |
adsada
Joined: Aug 23, 2008
Posts: > 500
From: Scotland
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1. Hi, now I think most phone cameras have this problem, but I was just wondering, is there anything to do to change it? OK well it's basically light balance. On a cloudy day if I am taking a picture of something on the ground, and a bit of the sky is in it, it will be totally white. However if I point the phone to the sky it, shows the sky nicely but now the ground is close to black. This is very annoying and a lot of my pictures have white skies. This works the same for video so I made a film and uploaded it to show you what I really mean:
http://www.youtube.com/watch?v=es6-PJUUO_Q
What can I do to fix this sort of... Oh yeah this also happens when inside, if you point the phone to a wall the window is white and if you point it to the window the wall is now black.
2. How this is another problem I have. On my K850i, the flash has three options they are Auto, Red-eye reduct and Off. Unfortunately there is no 'on' option as I would sometimes like the flash to go off when the lighting conditions are good. How could I change this, I mean what I do now is trick it by covering it up so it thinks it is dark and then quickly taking the picture. Is there not an easier way? I have the very first firmware btw if that is anything important. Thanks for the help
[ This Message was edited by: adsada on 2008-09-24 15:23 ]
[ This Message was edited by: adsada on 2008-09-24 16:06 ] |
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number1
Joined: Sep 12, 2007
Posts: > 500
From: UK,kent,Sittingbourne
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Theres nothing you can do about the light metering maybe adjust the ev,
It is possible to mod the k850 camdriver to give it force flash. |
Hiron
Joined: Aug 16, 2007
Posts: 435
From: Denpasar - Bali, Indonesia
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First problem could be due to limited dynamic range because of small pixel size on camphone sensor... Adjusting EV could help a little bit...
If you want to get a broad dynamic range, use DSLR instead.
And I would recommend you to update your firmware... There is some noticeable differences... 
Dunno about other better solution regarding force flash. Already mentioned by number1
Hiron |
Raiderski
Joined: Jul 03, 2006
Posts: > 500
From: Poland, Hell, Mountains
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1. it's normal even for good digital cameras. sensor cannot 'see' dark and bright objects at the same time, it's all about luminosity of various objects. this was the source of HDR photography as a solution
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number1
Joined: Sep 12, 2007
Posts: > 500
From: UK,kent,Sittingbourne
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It's not dynamic range it's light metering different brands & devices will have different light metering here's a example
sony ericsson c702
http://www.esato.com/phonephotos/viewphotos.php?pid=12746
samsung digi cam
http://www.esato.com/phonephotos/viewphotos.php?pid=12745 |
Raiderski
Joined: Jul 03, 2006
Posts: > 500
From: Poland, Hell, Mountains
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dude, what happened to your basic knowledge?
does C702 and Samsung digi cam have identical sensors and algorithms? is this strange for you that results for different hardware and software are different? it's not for me and I don't know what idea was behind this comparision
light metering? read it one more time:
On a cloudy day if I am taking a picture of something on the ground, and a bit of the sky is in it, it will be totally white [OVEREXPOSURE]. However if I point the phone to the sky it, shows the sky nicely but now the ground is close to black [UNDEREXPOSURE]
not a dynamic range of sensor?
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adsada
Joined: Aug 23, 2008
Posts: > 500
From: Scotland
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Hi, looks like you know the problem, but I might as well not let this video go to waste.
http://www.youtube.com/watch?v=es6-PJUUO_Q
So are there any tips on solving it, like changing the light balance?
On 2008-09-24 16:39:04, Hiron wrote:
First problem could be due to limited dynamic range because of small pixel size on camphone sensor... Adjusting EV could help a little bit...
If you want to get a broad dynamic range, use DSLR instead.
And I would recommend you to update your firmware... There is some noticeable differences...
Dunno about other better solution regarding force flash. Already mentioned by number1
Hiron
What are the main changes you can tell, and how much different is the camera?
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number1
Joined: Sep 12, 2007
Posts: > 500
From: UK,kent,Sittingbourne
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On 2008-09-24 17:15:39, Raiderski wrote:
dude, what happened to your basic knowledge?
does C702 and Samsung digi cam have identical sensors and algorithms? is this strange for you that results for different hardware and software are different? it's not for me and I don't know what idea was behind this comparision
light metering? read it one more time:
On a cloudy day if I am taking a picture of something on the ground, and a bit of the sky is in it, it will be totally white [OVEREXPOSURE]. However if I point the phone to the sky it, shows the sky nicely but now the ground is close to black [UNDEREXPOSURE]
not a dynamic range of sensor?
i never said the c702 & digi cam were anything alike lol, it's not strange they produced completey different results i was just showing different light metering in different devices the whole idea is that there very different.
pretty sure it's light metering
K800
http://i222.photobucket.com/a[....]d234/sniper100590/DSC00021.jpg
c702
http://i222.photobucket.com/a[....]d234/sniper100590/DSC00110.jpg
more simlar devices but the light metering is very still very .different |
Raiderski
Joined: Jul 03, 2006
Posts: > 500
From: Poland, Hell, Mountains
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adsada
you cannot do much because it's hardware limit. you have only 2 tips which can help a bit
1. EV compensation
2. autoexposure (AE) lock
number1
you really don't understand much from described issue. maybe you should take a look at posted video? ok 2 questions for you:
what will happen if you will use high dynamic range sensor? will you be able to see ground and sky together without any problems?
if we "fix" light metering? will you be able to see ground and sky together without any problems?
_________________
K800 R1KG001
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[ This Message was edited by: Raiderski on 2008-09-24 16:42 ] |
max_wedge
Joined: Aug 29, 2004
Posts: > 500
From: Australia
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Yep, this is a hard one. The only real solution is HDR. Combining images also is pretty effective, but at the cost of dynamic range (compared to an original pic). HDR gives the dynamic range back plus some.
Sometimes Colour correction can help a little.
Otherwise, what I do is go as low as I can on the exposure to get blue skies, and so that the dark areas still show a reasonable amount of detail (even if it's darker than I'd prefer). It's about the best compromise I can think of. Then if you want to you can use photoshop to put a graduated contrast/brightness filter to bring out the detail in the foreground without whiting out the sky.
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adsada
Joined: Aug 23, 2008
Posts: > 500
From: Scotland
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On 2008-09-24 17:32:47, Raiderski wrote:
adsada
you cannot do much because it's hardware limit. you have only 2 tips which can help a bit
1. EV compensation
2. autoexposure (AE) lock
Sorry, please don't hate me. Can you explain what these mean? Well like how I can use them on the phone. I tried to read up about them but well...
anyway I really appreciate the help, thanks |
Raiderski
Joined: Jul 03, 2006
Posts: > 500
From: Poland, Hell, Mountains
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adsada
no, I will not hate you we are here to discuss and help each other give me some minutes for answer
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number1
Joined: Sep 12, 2007
Posts: > 500
From: UK,kent,Sittingbourne
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On 2008-09-24 17:32:47, Raiderski wrote:
number1
you really don't understand much from described issue. maybe you should take a look at posted video? ok 2 questions for you:
what will happen if you will use high dynamic range sensor? will you be able to see ground and sky together without any problems?
if we "fix" light metering? will you be able to see ground and sky together without any problems?
yes & yes |
Raiderski
Joined: Jul 03, 2006
Posts: > 500
From: Poland, Hell, Mountains
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yes (CORRECT) & yes (WRONG)
the real problem are photons on sensor which is not able to catch them all. your answer is really weird, what do you want to do with light metering algorithm if your problem is called photon? fixed (whatever this mean) light metering will not change your poor sensor to HDR sensor. if I'm wrong then why overexposure and underexposure is still big problem even in professional cameras?
can you pour 1,5L of water into the 1L bottle?
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Raiderski
Joined: Jul 03, 2006
Posts: > 500
From: Poland, Hell, Mountains
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adsada
ok, it's hard to explain everything especially if I don't want to complicate this. I hope this helps, you can also use Google to search interesting sites (a lot) about this, for example:
http://www.megapixel.net/html/articles/article-contexpo.php
1. Exposure Value (EV) compensation
autoexposure
EV -2.0
use negative EV if you want to reduce overexposure (too bright)
EV +2.0
use positive EV if you want to reduce underexposure (too dark)
of course you have to know that this isn't magic solution which will make wonders. it can help only if overexposure/underexposure problem is not too big
2. AutoExposure (AE) lock
use half pressed shutter key (this one which you're using to focus and taking pictures) to lock AE. it will be locked just before autofocusing process. with locked AE you can point your camera everywhere and exposure will be 'freezed'. release shutter key and you will unlock AE
AE locked (overexposure)
exposure locked at dark object and then camera pointed at bright object (screen)
AE locked (underexposure)
exposure locked at bright object (screen) and then camera pointed at dark object
how to use it? move your camera to find good exposure for your scene (e.g. well balanced sky and ground brightness for landscape). lock AE and now you can move your camera more to sky or to ground without any problems with brightness
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Posted: 2008-09-24 16:20
