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View Full Version : d40x - new lens - coloured dots.



leonhart83
12-05-2011, 12:26am
Hey guys,

I got a new lens 18-55mm and I was using it to take maternity pictures of my sister and I noticed that there are coloured dots in all of the photos in same spots across all the photos.

I have taken a photo of just a brown blanket and attached it to the post so you can see it. Due to the file size restrictions the dots aren't as visible, but I counted at least 6 (one in the middle, top middle, 2 bottom right are the most prominent).

I have tried different lenses and they all have the same dots so I am pretty sure that it is the camera body that is having the issue. I have used a blower on the inside but didn't help.

What is the best way to go about this? is it damaged, something easily fixed? Costly?

EDIT: WOW I just realized how bad this picture actually shows the issue. I can't barely see any of them and they are REALLY visible in the real photo. I have attached a smaller photo but there is quite a few similar to this on the photo.72195

Speedway
12-05-2011, 12:46am
Thathot dosen't show the spots very well. Try taking a photo of a plain flat light coloured wall or blue sky at f16-f22 and if you see dots over the image you have dust bunnies (dust on the sensor). Sensor cleaning is fairly simple using something like the copper hill kit, but if your not confident take it to your nearest specialist camera shop and have the sensor cleaned.
Keith.

arthurking83
12-05-2011, 4:59pm
That spot(and I'm guessing any others you've found) have nothing to do with the lens.
This spot in particular is what's known as a 'dead pixel'.

I'm assuming that the crop is at something like 400% or more.

I'm guessing it also has something to do with the ISO1600 setting too.
Higher ISO settings such as this(on a D40x) will make the sensor more liable to producing dead pixels.
Another term for dead pixels is hot pixels.

Try another test shot, making sure that the ISO is set to base ISO(ISO 100 I think). Exposure time wasn't too bad at 1/6s but even that can have more of an effect on the numeracy of dead pixels as well.

Hope that helps.

:)

Speedway
12-05-2011, 10:16pm
The first picture looked like dust this one shows a hot pixel.
Keith.

lay-z
12-05-2011, 10:24pm
I experienced the same issue with my D80 but not to the same extent as yours. As bizzare as it sounds, I continued shooting with my D80 and the hot pixel eventually disappeared over time and everything was normal again. So go figure!