Posted by pavithra_uk
Almost every Elm and Hazel owners facing this problem Blue-Yellow lines appear on the night photos.
I start this thread for discuss it with experts
I suspect about these:
1. Image processing & Noise reduction problem
2. Camera module to CPU data transfer corruption
3. An Interferance or Sync problem
4. Senser have some weak pixels. these weak pixels capture day light perfectly but they faild with low/artificial lighting.
(to reduce cost, they making sensers with high fault tolerance????? may be?)
I have no idea this lines get wrose with age. Anyone experienced it ?
Posted by reeflotz
Bono found out that decreasing the ev value on dark shots lessens or eliminates these lines, while increasing ev value on dark shots makes them appear more visible. It appears on the screen itself even before taking the picture
Switching to twilight mode on night shots also helps lessen/remove these lines. I don't know if it's because the sensor is forcing itself to sense light in dark photos that in the process it strains itself then produces these horizontal lines
Some shots seems fine, as long as there is a single source of light enough to balance the image even if the rest is dark it seems these lines do not appear.
Btw, just sharing this, I really don't know anything much about those codes in cameradrivers, or those sensors on Elm/Hazel
Posted by xclbr
@reeflotz. So this means not all lowlight shots has those blue-red etc lines.. so this raises the possibility that a firmware update can fix this. Hurray! new hope.
Posted by pavithra_uk
This one is taken from Elm (from Esato photo gallery) and adjusted levels
This one is taken from C901 (from Esato photo gallery) and adjusted levels
even C901 photos has very faint lines.
Posted by pavithra_uk
On 2010-12-08 06:02:09, xclbr wrote:
@reeflotz. So this means not all lowlight shots has those blue-red etc lines.. so this raises the possibility that a firmware update can fix this. Hurray! new hope.
yes. if it hardware fault, every photos must contain these lines. it may be firmware bug that convert noise into blue line.
such lines can be seen in K750's viewfinder display while taking photos in low light condition. but its no visible as elm's since K750i has no noise reduction.
Posted by reeflotz
@xclbr
yeah I'm also hoping that this issue will be fixed.
@pavithra_uk
nice research, Elm/Hazel's horizontal lines does look like those classic lowlight color noise and are much more evident because the scattered color noise were removed and only the lines were left.
Posted by pavithra_uk
most of SE phones produce these lines but they invisible to human eye. to see such lines, you have to adjust contrast, brightness, gamma etc..
Posted by mriley
I think it's an issue with the sensor so can't be fixed
Posted by Bonovox
Its a shame really from such a good camera
Posted by pavithra_uk
On 2010-12-09 19:11:40, mriley wrote:
I think it's an issue with the sensor so can't be fixed
how you say its senser issue ?
will every senser has same issue or every senser has hadware fault even in differant production batch..?
Posted by reeflotz
well, whether it can be fixed or not it's okay with me, besides, Hazel doesn't have that good of a LED flash and I wasn't expecting much from it for lowlight when I bought it since it only has LED flash.
Posted by zAlbee
It looks like the sensor is overly-sensitive in those horizontal lines. That's why you don't notice it with low exposure -- it's there, you just don't see it. If it's a hardware fault, then firmware isn't going to fix it...
But I don't really know how the sensor works, so who knows.
Ah, and I am seriously considering buying this camera, I mean phone, too.
Posted by mriley
@pavi
I think they reduced cost by buying a poor sensor to put on the elm.
I own the elm and people say the camera is great but I dont really think it is. The phone can only take good photos in good light, and just about any decent camera can do that. It really is terrible in low light and the flash isnt a flash, its a camera light (they need to stop saying led flash)
Even in daylight photos you still get these lines across the photos, you can make them out in shaded areas where its smeared.
People see the elms camera as being very good because of the huge amount of sharpening it puts on its photos during in-camera processing which makes the photos very very sharp, sometimes unnauraly sharp
Posted by laffen
It is a phenomena called banding noise. It is often visible in low light and / or when high ISO is used. It is not an uncommon problem. Even Canon's most expensive camera at the time had this problem
Posted by mriley
Thanks laffen
now we finally know what this is.
Banding noise is highly camera-
dependent, and is noise which is
introduced by the camera when it reads data from the digital
sensor. Banding noise is most
visible at high ISO speeds and in the shadows, or when an image has been excessively brightened.
Banding noise can also increase
for certain white balances,
depending on camera model.
Posted by reeflotz
@ mriley
I would like to argue
I have not seen any lines on daylight photos even on those parts of the photo where it's dark, and no matter how much sharpening you put on a photo it will not improve it this much, you will need a huge amount of resolved detail by the sensor in order for sharpening to be effective. I think it's more probably that the lines are real sensor bugs in lowlight or driver issue.
I agree with laffen. For Elm/Hazel it seems these lines appear at ISO 160 or higher, the lowlight pictures I posted that had no lines were at ISO 160 (outside night shot) and ISO 80 (candle shot). (well there might be very feint lines but that's because I purposely searched for them, they are negligible and are impossible to see unless you zoomed and searched for them).
Here's another lowlight shot without or has very feint lines:
ISO 80
Exposure Time 1/20s
Original
still experimenting with some more lowlight shots, I wish there was a way to control iso, so far the only consistent photos with minimal/no lines are the ones having iso 160 or lower
[ This Message was edited by: reeflotz on 2010-12-11 12:47 ]
Posted by pavithra_uk
On 2010-12-11 11:36:08, mriley wrote:
@pavi
I think they reduced cost by buying a poor sensor to put on the elm.
I own the elm and people say the camera is great but I dont really think it is. The phone can only take good photos in good light, and just about any decent camera can do that. It really is terrible in low light and the flash isnt a flash, its a camera light (they need to stop saying led flash)
Even in daylight photos you still get these lines across the photos, you can make them out in shaded areas where its smeared.
People see the elms camera as being very good because of the huge amount of sharpening it puts on its photos during in-camera processing which makes the photos very very sharp, sometimes unnauraly sharp
I agreed with you. Elm produce poor low light photos due to small lens. flash is not enougf. I think it not a flash. its a torch that like found in Nokia 1100. the flash nothing can do with low light. even macro mode with flash, photos look washed out. and overexposure.
Posted by mriley
Sharpening makes a huge difference beyond 3mp
Posted by laffen
When optimizing photos for print, sharpening is the last thing you should do with an image. Image crop, noise reduction, size reduction and colour correction should all be done before sharpening. Photos taken with consumer cameras and mobile phones are often very sharp directly out of the camera because these images often are used as they are without any adjustments on a PC afterwards. Photos captured with cameras in the pro-segment are very often edited on a PC before being completed. Pro-cameras therefore have less sharpening and the final image will be better than if the sharpening was don at the time of capture.
[ This Message was edited by: laffen on 2010-12-13 00:26 ]