Semsor indeed....I wonder if I can spell CCD correctly?

The CCD is a Charge Coupled Device, in other words it carries an electrical charge when switched on. Electrically charged objects attract dust. This is why it's important to switch it off when changing lenses.

I'm not sure - no shadow on other images in the same place - it's certainly not a problem on prints. This is only a tiny section of the overall image, perhaps 15% of the area of the CCD.

I'll try a more critical test when I can.

Try refreshing the page, but posting pics does seem a little fraught at times. This should be OK, I posted it on pBase.

OK, here's a sky shot at f8, perhaps that will do for now:




Pentax K10D, SMC Pentax-DA 16-45mm, 1/350s, f8

Dan, just for you I will do the requested test and we shall see....

You might be amazed, or alternatively I might have to hang my head in shame and retreat back to my darkroom.

As soon as I can I'll post something, but it's likely to be a few days.

Hello and welcome to the forum.

Yes, you can clean the sensor yourself - there are suitable kits available from dealers. Sometimes, inevitably, some dust gets on to the sensor and it can be quite annoying.

The best cure is to keep the dust at bay as much as possible. So always turn off the camera before changing lenses. Change lenses in clean areas away from wind and dust. Keep the camera pointing down to minimise the chance of dust ingress whilst a lens is being changed.

This will help, but every time you press the shutter there are a mass of moving parts within the camera and the potential is there for dust to be stirred up.

I have been using DSLRs for maybe 3 years or so now, and so far have not had to clean a semsor, but it's just luck, helped by sensible technique as detailed above.

If you think about it, all 645 lenses fit the same 645 KA mount, so all rear lens caps have to be the same.

I'd try phoning around second hand dealers, perhaps try a camera fair, but first I'd do a search on eBay.

Somebody had to say it...

In the days of film, a backup body could have different film stock in it, or maybe colour in one body and mono in another.

With digital, there is no longer any need for a second body as colour/mono/slow ISO/fast ISO is just a button away.

As regards reliability, in 35 years I have not had a failure in the field, so the chances must be very low. On holiday I would buy a K100D to cover if it ever arose. At a wedding, Sue and I both have a K10D so we would make do with one of them.

The final backups are out pocket cameras. Sue uses a S5i and I use an A20, not ideal, but serviceable in extremis.