Lens or Sensor

[jmarcus]

When I shoot at f/22 with my Leica lens, I see lots of dust and what looks to be one hair. I mentioned this at a camera shop and they said if it shows up at higher apertures then it is on the lens not the sensor. I spray off my lens with compressed air before switching so where is this dust?
http://www.frolickinglama.com/lensorsensor.jpg
James

 

[arbib]

Have you looked at the sensor for anything on it? Sounds like from what you said about cleaning your lens off...It should be on the sensor.

Don't know about the using a SMALL aperture thing. I use small apertures on my DSLR without a problem. Plus the term "Higher" apertures is a uniformed term. the Old School and widely accepted terms are.....Wide Apertures (small #) and Small Aperture (large #) are the norm for people who understand What the Aperture number represents ......f/16 = 1/16th of the focal length. ...So on a 50mm FL lens..f/16 = a SMALL aperture opening of 3.125mm Therefore it is not a HIGHER aperture BUT a SMALLER aperture (an aperture IS AN OPENING size of the diafram)

 

[saxshooter]

Judging from your picture looks like the sensor has some dust on it.

 

[jmarcus]

The person at the camera shop said it has to be on the lens be cause it comes into focus with a change in DOF. It seems to make sense to me....

 

[jmarcus]

saxshooter,
Have you had similar issues? I'm pretty sure I had the sensor cleaned once and it took care of this issue, but it came back pretty quickly...

 

[saxshooter]

I see you have a couple of lenses. Shoot the others at f22 at the sky or a white wall and you'll have your answer (which is, the dust is on the sensor). Cheers.

 

[Matthew Allen]

When I shoot at f/22 with my Leica lens, I see lots of dust and what looks to be one hair. I mentioned this at a camera shop and they said if it shows up at higher apertures then it is on the lens not the sensor.

That's simply wrong. The standard way to check for dust on a sensor is to stop down to f16 or smaller and look for spots and particles on a shot of sky or a white wall. A typical dust spot looks like a blob and will not appear opaque.

What the shop people said doesn't really make sense. You can put a blob of something on your lens and it will probably be undetectable in photos because it is so far out of focus, but with dust on the sensor hundreds or thousands of photosites may be partly blocked by a single dust bunny.

Matthew

 

[saxshooter]

saxshooter,
Have you had similar issues? I'm pretty sure I had the sensor cleaned once and it took care of this issue, but it came back pretty quickly...

I pretty much have one lens on the camera and rarely change it, so I really don't have a dust issue.

 

[wintoid]

I was always told that the way to see dust on the sensor was to set a very narrow aperture (e.g. f/22.0), defocus the lens and point it at a bright white object. If you then do "autolevels" in photoshop on the resultant image, you should see the sensor dust in all its glory.

 

[jmarcus]

Thanks everyone.
The concensus is dust on the sensor.

 

[RML]

Thanks everyone.
The concensus is dust on the sensor.

Indeed.

It must be dust on the sensor. Ever seen a scratched front element of a lens? Ever used that lens? The scratch will not show up in the neg/print. The only thing that may occur is some extra flare.

Your shop is full of it. 🙂