Is my sensor buggered?

[rflower]

Went to Sydney for the weekend.

On Saturday we went to Circular Quay, and I started taking photos.

All photos were taken with Nikon D80 (approx 20k shutter releases), and Nikon 18-200 VR lens. Lens was not removed from camera between these shots. These are all straight out of camera, with nothing done to them ... Photos were taken around 5pm.

Image 9448


Image 9448 - 100% crop from top right

Looks OK (Don't worry about composition etc)

Image 9450


Image 9451 - With lots of Dust Bunnies ...


Image 9451 - 100% crop from top right - exactly same area as 9448


These dust bunnies appear on all shots taken with bright pale background (eg sky), and will make the shots I took, intending on panoramas a bit harder to complete ...

All images are clickable to bigger versions.

Anyone got any ideas? I was not really pointing the camera at the sun for a long time, nor really aiming at the sun. Has my sensor started to melt?

I have not done anything with the camera yet. I am thinking about taking it to Collingwood Camera Clinic for a sensor clean - for $77 or purchasing the stuff over the internet (Quality Camera Sales sells the sensor cleaning stuff for $77). Any thoughts?

Thanks

Russell

[aim54x]

I have never seen anything like that. I would probably have a look to see if it can be cleaned, but I do think it is unlikely that your sensor is dirty.

[DaveB]

It definitely DOES look like crap on the sensor filter, which a clean should remove.

#9448 looks like it was taken with a relatively wide aperture (especially compared to #9451) but even then the big OOF blob to the right of the flags stands out (it's hidden against the bridge in #9451).
The difference in apertures is enough to explain the differences between these shots.

Don't know how the crap got in there, but get it cleaned!

[DebT]

assuming you have changed lenses to provie it's in camera I'd be taking it to the shop asap - you can always purchse the kit for next time
DebT

[Mr Darcy]

Looks like dirt on either the sensor or lens to me.
Clean front & rear of your lens AND the sensor, and I'm guessing the problem will go away
Incidentally, it is not hard to clean the sensor. Scary the first few times, but not hard.
Have a talk to Stuart for the right kit for your camera. The cost will be less than a single "professional" clean.

As Dave says, visibility of Dust Bunnies will depend on the aperture you have the lens set to. As you have removed EXIF data, it would be just a guess, but Dave's comments look spot on to me.

They look like water droplets that have dried to form rings. You haven't breathed into the sensor area by any chance?

[Lucifer]

Looks like water droplets darcy has said, but I think this is on the lens.

You been around the harbour so you WILL get seasalt droplets in the air.

Clean your lens and try again.

Set your camera to high aperture will help to show up dust on the sensor.

[DaveB]

Gunk/droplets on the lens' front element won't show up as in-focus as this does. Even stuff on the rear element of the lens wouldn't be as in-focus as this.

It would catch the light with the sun in the frame to cause the flare spots, but so would gunk on the sensor filter.

[surenj]

Gunk/droplets on the lens' front element won't show up as in-focus as this does. Even stuff on the rear element of the lens wouldn't be as in-focus as this.

If the rear element is not in focus, how does the dust on the sensor be in focus?? I thought the field of focus was continuous (ie 3m to 150m for example, or 0m to 1500m rather than 0-1cm then 10cm - 300m with a gap!)

[DaveB]

You can think of it as two planes of focus, that each get larger as you stop down the aperture. One centered on the subject, and one centered on the sensor.


Or think about it this way: with a pinhole lens (i.e. one with a tiny aperture) the light coming down to the sensor will cast sharp shadows of any dust on the sensor's surface, but as the dust gets further away the shadows will be softer. Something a cm or two above the sensor will be waaay "out of focus".
In fact there's rarely dust on the surface of the sensor itself: it's usually sitting on top of a filter a couple of mm away.

As you open up the len's aperture the shadows become softer and softer, until you can imagine the lens as a big fat "pipe" with light coming down from lots of different angles and leaving VERY diffuse shadows. In comparison a softbox rather than a point light source.


The result is that at wide apertures your DOF on the subject is shallow (dependent on the focal length and distance of course) and at the same time dust would have to be physically sitting on the sensor surface (below the filters) to show up.
At smaller apertures the DOF grows, and the clarity of dust will grow also...