So, why is this photo so blue? I used a blue-ish LED light – a tiny little keychain torch.
First, I had lit the same subject with my regular lamp light, but that causes a problem. It’s a problem I’ve been aware of for quite some time now (I think I first noticed it about half a year ago, when I started doing more indoors photos), but up till now I just edited it out in PhotoShop. It’s time I’d find out what causes it though, so I figured I’d show it and hopefully someone can tell me what is wrong.

Here’s a photo that shows the problem quite clearly:

From top left, all the way to top right, then curving down to bottom right, there is a red line in the image. Or rather, a double red line with white between the lines. At first I thought it was caused by the angle of the light coming into the lens. I’m using a fixed lens camera, and the lens is behind a rectangular opening (even though the outside looks round). The lamps I use indoors are in a red shade, so I figured that the red light coming in from a certain angle would sort of bounce off the rectangular opening and cause the extra red colour.

But.. I tested. I put the lamp on the other side – the line did not move to the other side of the photo. I put the camera sideways, and still, the line did not move from its place. No matter if I photograph directly into the light, or light the subject with the lamp behind my camera, the red line stays and does not move.

However, outdoor photos never show the red line. And as you can see in the first photo above, making sure there is no red light, also gets rid of it. (although, when playing in PhotoShop with curves and sliders, I can make a vague discolouration visible where the red line normally is).

Is this a problem with my lens? My sensor? Something else? Is it something that a new camera would fix, or would it simply be caused by the light I’m using and in reality there is no real problem with my camera? I’ve had this one for almost 6 years now (took my first photo with it on April 13, 2004), and my next one will surely be a DSLR, but if this is a problem that just occurs for regular reasons with some cameras, I’d like to know what it is so I can look out for it in a new camera, and avoid it.

So… anyone have an idea? Seen it before maybe?