I don't want to send mixed messages or confuse anybody by starting off this discussion in saying that I'm very happy with the images I am seeing with my Nikon D5100. Recently I upgraded to this camera from the previous Nikon D 5000. Prior to this my digital cameras have been progressively point-and-shoot graduating to high end bridge cameras (similar with a fixed lens, but generally a wide to super telephoto lens). These limited me to JPEG only, although things are moving on and I believe some bridge cameras are offering Camera Raw as the file format option.
When I got my original Nikon D 5000, it came with a mid-range wide to telephoto zoom. During 18 months of ownership I bought a longer reach telephoto, which I then sold for a slightly more powerful alternative, plus the super wide-angle zoom, 10 to 20 mm from Sigma.
I got on superbly with this camera, taking all kinds of photography, including close-up, landscape, sports and architecture. These images frequently included large areas of sky or light plain backgrounds. Not once ever, when reviewing images on a very large computer monitor, using photo shop, and Adobe camera raw, did I see any sign of trouble. Then I changed my camera! I kept all lenses to use with it.
For the first five weeks everything was great. Images were sharper due to higher resolution at a given magnification, and exposure, colour balance, and everything else associated with the image produced superior results, although the larger file sizes did slow things down on the computer. Nevertheless I was very happy.
The Nikon D 5100 is undoubtedly a good camera. So what is the problem?
If you have, like me, come from a 35 mm single lens reflex camera, then you will know the importance of keeping your lenses clean. That's fair enough. However DSLR cameras don't have film, what they do have is a rectangular sensor inside the back of the camera, facing the rear of the lens. When you take an exposure, there is a mirror in front of it directing the image from the lens up into the prism situated behind the "Nikon" legend, and then back into the viewfinder. This mirror, just as in traditional film SLR cameras, flicks up out of the way, the shutter opens exposing light onto the sensor (instead of 35mm film), and then the shutter closes, the mirror comes down, and the camera electronically records that image to the memory card of the camera.
All perfectly understandable, and you would think it is just a matter of occasionally changing the lens to suit the subject you are shooting -- which is HOW IT SHOULD BE!
However, after five weeks, and despite having no such problems on the previous DSLR, I noticed a small out of focus spot on one of my images. It happened to be a landscape shot taken at a small aperture, F 19. I checked images taken at the same time, and over previous days, and then I took a test photograph out of the window. All of these images possessed the same spot!
I took the camera to my dealer, who seemed amused by the fact I was unaware that dust could accumulate on the sensor surface inside the camera, and provide evidence of its presence on all your images!
As I had travelled abroad to take many of these shots, finding that the dust spot appeared approximately halfway through the batch of photographs, I was very disappointed. It seems an easy problem to solve. I was told that Nikon technicians do not recommend that you use anything to physically touch the sensor. This leaves you only with the option of blowing air at the sensor, which "will usually remove anything" -- Yeah! Right!
Whatever is stuck on my sensor has been described as "welded dust". Apparently, in use, taking photographs, the sensor becomes warm then hot. Any dust which may have settled on the surface will then fry, and bond itself firmly to the surface. This means the camera has to go back to Nikon to have the dust professionally removed. Although I haven't checked this myself, I have read several forum posts elsewhere which indicate the cost of this is approximately 60 Great British Pounds.
I have also read cases where professional photographic dealers offer the service, and have inadvertently damaged sensors by attempting to clean them with a recognised "swab" method, where a thin plastic paddle, square ended and coated with factory sealed cleaning material, is impregnated with a few drops of chemical, and then wiped across the sensor in one action, just like a windscreen wiper on a car. Reports I have read, indicate that two kinds of damage can occur. Physical damage to the surface of the sensor, where dust particles are actually slightly on the gritty side, and wiping them across the surface of the entire sensor from one side to the other has produced a lovely scratch right across the sensor, in the same way a gritty stone dragged across a varnished coffeetable would leave a mark. This would leave a terrible mark on all images, and would also cause diffraction, if you like, a slight rainbow effect along both edges of the scratch, one edge red, the other edge green, especially in bright light, which, on enlargement would render the image unusable without cropping it out completely.
The second problem I've seen reported related to some of the cleaning fluid getting past the edge of the sensor being cleaned, and filling up the tiny space between the actual sensor surface, and a very thin anti-aliasing filter which is fitted onto the surface of DSLR sensors. This cannot be resolved easily, therefore an expensive trip to the factory for the camera would be required, to remove the anti-aliasing filter, clean the sensor properly, and replace the anti-aliasing filter again, in clean room conditions.
Although I have read countless forum postings elsewhere, where contributors have cleaned their own sensors many times, with great success, you have to ask yourself why, so many years after we were putting men on the moon, responsible camera manufacturers are putting products out there with such inherent vulnerabilities, or if you like, defects.
I can't explain why, in 18 months of ownership of the D 5000, I never saw the slightest problem, but in just five weeks using the D 5100 I am in this situation. If anything, I "learned my craft" on the D 5000, which would have made that camera far more susceptible to these problems. I have been far more careful with the new camera because firstly I've become more aware of the problem, through careful reading, and secondly my regime whenever changing lenses is always very strict. The new lens is prepared resting on its endcap which is unscrewed so that it can be lifted vertically from the desk. The camera lens release button is pressed and the lens rotated a fraction to unlock it, then the camera is pointed towards the ground, the lens fully removed, and the lens on the desk fitted as quickly as possible. The lens which was just removed gets a blast of air from a Giottos rocket blower, before the small end cap is fitted.
Therefore, if you are still shooting 35mm film using an SLR camera, thinking about the inevitable change to a DSLR, be prepared for this very serious problem. There is, if you are professional, a very good argument to choose your lenses first, and then purchase a camera body for each of the lenses, so that you never have to switch them round. Expensive? Very! but if you end up with a damaged sensor on your main camera body, it's a total disaster.
I don't mean to put you off completely. But this is serious design problem, and there is no excuse for it. This fault is potential in every DSLR camera, so don't go away thinking that the D 5100 is particularly vulnerable, they all are!
Good luck, I hope I've given you something to think about. If anyone out there has had "disasters" with dirty sensors, I'd like to hear your story if you'd be kind enough to post.
Recent discussions in the photography discussion forum (778 discussions)
|Film Corner - JUST film, not digital.||2833||4 days ago|
|Amusing photographic adverts and comments.....||143||22 days ago|
|The Cumbria Photography Show - Exhibitors wanted||1||12 Jun 2016|
|canon cashback problem||47||11 Apr 2016|
|Japan trip with Sony A7||1||19 Feb 2016|
|Canon FD accessories||3||29 Jan 2016|
|Vivitar 100mm f3.5 macro 1:2||6||26 Dec 2015|
|Grey imports on Amazon||66||11 Dec 2015|
|Telephoto lens for wildlife photography||2||26 Jul 2015|
|Wireless storage||3||8 Jul 2015|
|Upgrade from Adobe Elements 7 to.......?||4||18 Jun 2015|
|Telephoto lens||1||17 Jun 2015|