Cleaning an SLR camera reflex lens

<p>Hi, thanks to everyone who answered my recent query on how to clean an SLR reflex mirror.<br>

However, i have recently taken a couple of photos with my Nikon D40, and dicovered that 'although' there is no sign of any debris via the viewfinder, there are small 'specks' appearing on the actual photos themselves. This i am confused about as i thought when you looked through the viewfinder, that you were looking through the camera lens via the reflex mirror.<br>

Does anyone have any suggestions on what the problem is here?<br>

Thanks<br>

Colin J </p>

<p>You may have dust on the camera's sensor.</p>

<p>Jim Marby</p>

<p>Yep, sounds like dust on the sensor. You can try blowing the dust off by carefully using a Giotto's blower brush (I heard they're good, but since I shoot film, I don't need one). For example, see:<br>

http://www.2filter.com/prices/products/rocket.html<br>

Check your camera manual for info how to open the shutter and keep it open so you can get to the sensor to clean it.</p>

<p>Yup, dust on the sensor. You won't see distinct specks in photos from dust on the lens, even on the rear element.</p>

<p>There's no simple answer to the sensor cleaning issue. My recommendation? Carefully read everything on the websites of the manufacturers of sensor cleaning kits. Do that *first*. Then you'll be in a better position to evaluate the sometimes contradictory and conflicting suggestions from discussion forums.</p>

<p>While I've used the Giottos Rocket blower for several years without any problems, I'm a bit reluctant to endorse it without reservation. A fellow on another forum recently discovered that his new Giottos Rocket blower was actually discharging dust onto his sensor. It's possible the blower had aspirated airborne dust and then discharged it onto the sensor, but perhaps there was some residue from manufacturing. So be sure to inspect any bulb blower carefully first.</p>

<p>So far in 4 years with my D2H I have never needed to do more than puff the Giottos blower to dislodge a speck of dust or two a couple of times a year. The sensor has been cleaned only once, back in 2006 by Nikon during servicing for a minor problem. That's it. I've never cleaned it with a dry or wet brush, pads or wipes. And when I recently checked the sensor with a test photo for dust I found only a single speck. My home is extremely dusty (cats... grrr...) and I have no idea why it's not on the sensor, when I read dozens of reports every month from folks who say their sensors are dust magnets. Beats me.</p>