After 5-6 years of problem free shooting; firstly with a Nikon D40 and then a Canon 50D, I’m at a loss to explain the rash of sensor related issues I’ve been experiencing for the last 6 months with my Nikon D600. No dust problem at all with the Nikon D40, a little dust (that required only a few rounds of cleaning) with my Canon 50D (and that was due to me regularly rotating zone plates, pinhole caps and Diana lenses) and certainly no issue with oil on the sensor with either camera. But with the D600 only the first 20-30 or so shots were usable. After the last clean and inspection with Nikon in Sydney I got a handful of usable shots (20th June) but nothing since that hasn’t required a big overhaul in Photoshop.
I picked the D600 up from Nikon’s new service center over at Rhodes on 20/6/13. The guy on the service desk said the repair team mentioned cleaning dust from the sensor and from the mirror box (my request). However they were apparently of the opinion that the dust on the sensor was environmental. Now…. unless there is a trans-dimensional vacuum inside the camera body that specifically targets and sucks in dust through some huge gap in the body, there is no way that dust from the environment could enter the camera. The camera is kept in a sealed case when not in use, I don’t shoot at construction sites in India and the lens has not been off the camera since I picked it up. According to Nikon the D600 has the same degree of effective weather-sealing as the D800. So I don’t buy the environmental dust story from the repair team. One of the weird parts of the story (the other is currently withheld from publication) is that when I took the camera in for the second time (after the first repair) the technician there said that only dust spots were visible via the software connected to the camera that displayed the sensor surface on a monitor. I was curious, since the reference images I have by the bucket load clearly indicated that the sensor had a healthy covering of some other translucent substance. In relation to the agreed dust marks I mentioned that I suspected that the mirror box might require cleaning, since this had been a recurring theme appearing across a number of Forums as a suspected source for internal dust. I asked if they wouldn’t mind checking that out and cleaning it. I didn’t mention all the other marks on that visit but just decided to lay low and see what the prognosis was. Since they couldn’t detect oil on the sensor I doubted that the people at DigiCam would be able to either. So I kept my cards and asked them to clean it and I would wait and see if anything else developed after I picked it up.
Now to backtrack, the reason I had taken it in to Nikon for the second time was that I had initiated a claim against the warranty with Harvey Norman and the people at the claims dept wanted me to ship the camera off to DigiCam in Adelaide to have it inspected / and or repaired prior to any further action being recommended. I thought that this was a little suspect and odd, since the camera had been sold to me in the first instance with a faulty component which Nikon had replaced/repaired despite prior remonstrations from the people at Harvey Norman in Penrith that the problem with the camera was either in my imagination or due to my usage and that if such an issue actually existed; Nikon would have issued a recall and they hadn’t so… (this is documented in earlier posts). I also wanted a second opinion and statement ready to go in case the guys at the other end (DigiCam) fudged the findings or the camera went missing in transit. By the way DigiCam ‘s preferred courier TOLL PRIORITY only provide minimal insurance to the value of $500 as an optional buy in.
After I got the call to say the camera was ready I returned to Nikon with a reference image loaded on my laptop and a small case to carry the camera body (the rest of the camera was packed and ready to go to Adelaide if necessary). There was no one at the service desk so I booted up the laptop and had it ready to go. When the service guy came back I mentioned that I had something I wanted him to look at in relation to marks on a particular image. I said that I suspected that the larger dark marks were dust and then asked him to look at a whole swag of other marks that I thought were oil. He agreed there was something worth checking out. The camera was retrieved and further checks were done on the sensor to ensure that the sensor was clear of debris. He asked for a copy of the reference file and passed that on to their tech people. I took the camera home and put the original 24-85mm lens back on and took some test shots that returned zero contamination.
I thought we were now back on the road to a peaceful co-existence. However……..visible evidence of sensor contamination began to surface relatively quickly and once it appeared it was literally a matter of less than 100 shots before the sensor had a healthy covering of either oil and or dust.
Since nothing had changed in terms of the cameras exposure to the environment it’s impossible to attribute this increase to external causes. The contamination, whatever it is, is internally generated.
The image below was one of the first where I detected some contamination of the sensor.
This following image demonstrates an increase in sensor contamination. Only about 10 shots separate these images.
The image below again demonstrates a significant increase in contamination of the sensor. The UV filter had been cleaned prior to this shot. Only about 20 frames separate these two images. I’ve used a number of contrast based processes to push the visibility of the marks.
The reference image below (taken a day after the image above) demonstrates a moderate increase in contamination of the sensor.
I took these just shooting for some open sky so that whatever was on the sensor would be easier to ID on the file.
This shot below was taken today (1-7-13) after cleaning the UV filter (front and back), cleaning the lens (front and back) and running multiple sensor cleans to remove dust if any was present. As you can see not much has changed, there are some new marks (due to either being able to push better contrast or an increase in contamination) and the previous still remain, despite some on the upper right side loosing visibility due to lack of adequate contrast. Some may even argue that on closer examination it’s obvious that there are more that I haven’t identified.
Frustrating? Sure is…….(to the tune of ‘Trust British Paints’)
…and it’s back to Nikon tomorrow for Round 3.