Dust in the Lens or on the Sensor?

Sample Photos: Changing the Focal Length | Sample Photos: Changing the Aperture | Dust Recognized on Older Photos

Here, I show some sample photos where I investigated the dust issue and some older photos on which I also recognized the dust issue.

 

Sample Photos: Changing the Focal Length

    
     
 
     
 

Photos: Sample overview and section photos demonstrating the issue for three focal lengths: 70 mm, 50 mm, 34 mm (equiv.). At 34 mm, the dust has moved out of the image (click images to see the original photos). See also the movies that demonstrate this.

 

Sample Photos: Changing the Aperture

    
     
    
     
    
     
    

Photos: Sample overview photos and 50% section photos demonstrating the issue for four aperture values (f/16, f/11, f/8, f/6.4) at a focal length of 70 mm (equiv.); at f/6.4 mm, the dust is hard to see but can be recognized in the original photo (click images to see the original photos)

 

Dust Recognized on Older Photos

After Easter 2015, when I prepared images for photo pages, I recognized dust in several photos that were shot against the sky already in September 2014 (during vacation):

 
f/16, 70 mm equiv.
    
f/7.1, 70 mm equiv.
 
f/16, 70 mm equiv.
 
f/16, 46 mm equiv.    
 
f/16, 59 mm equiv.    
 
f/16, 70 mm equiv.
 
f/16, 70 mm equiv.

Photos: Overview photos and 50% section photos from September 2014, showing already the dust issue (click images to see the original photos).

After that , I looked at my photos backwards in time and found further, mostly weaker, indications of the dust particle on some photos, with the latest incidents dating back to the end of March 2014. Thus, it looks as if the issue appeared between mid and end of March 2014. But admittedly, I never had realized the dust, I did so only after I had found dust on some photos from February 2015...