Sensor troubles with my D800????

Hey, I recently was able to afford to upgrade from a D300 to a D800. The camera I have I paid $661 for thru an eBay auction. The camera is in dynamite condition and had only 9,557 firings of the shutter.

 

It had been a while since I had been able to shoot a real camera again so I went to town in the Azaleas, and Primroses that have recently bloomed out front of my apartment. I have had a 100mm f2.8 micro and 4x life size converter so yeah, bug heaven too. Damn, this thing can digitally zoom in so I've been in heaven going from a 12mp D300 to the Beast! Then I started noticing a common anomoly in all the photos. These two sometimes three black dots to the upper right quadrant in all of my photos. At firsti could aware I could see some dust on the back side of the focus screen. Now I can't see them but still the dots remain in every photo. So is it possible that I have some dead pixels in my sensor?

Hey, I recently was able to afford to upgrade from a D300 to a D800. The camera I have I paid $661 for thru an eBay auction. The camera is in dynamite condition and had only 9,557 firings of the shutter.

 

It had been a while since I had been able to shoot a real camera again so I went to town in the Azaleas, and Primroses that have recently bloomed out front of my apartment. I have had a 100mm f2.8 micro and 4x life size converter so yeah, bug heaven too. Damn, this thing can digitally zoom in so I've been in heaven going from a 12mp D300 to the Beast! Then I started noticing a common anomoly in all the photos. These two sometimes three black dots to the upper right quadrant in all of my photos. At firsti could aware I could see some dust on the back side of the focus screen. Now I can't see them but still the dots remain in every photo. So is it possible that I have some dead pixels in my sensor?

 

Or you can have dust on the sensor?

Hey, I recently was able to afford to upgrade from a D300 to a D800. The camera I have I paid $661 for thru an eBay auction. The camera is in dynamite condition and had only 9,557 firings of the shutter.

 

It had been a while since I had been able to shoot a real camera again so I went to town in the Azaleas, and Primroses that have recently bloomed out front of my apartment. I have had a 100mm f2.8 micro and 4x life size converter so yeah, bug heaven too. Damn, this thing can digitally zoom in so I've been in heaven going from a 12mp D300 to the Beast! Then I started noticing a common anomoly in all the photos. These two sometimes three black dots to the upper right quadrant in all of my photos. At firsti could aware I could see some dust on the back side of the focus screen. Now I can't see them but still the dots remain in every photo. So is it possible that I have some dead pixels in my sensor?

My guess too would be dust on the sensor. Fortunately easy to clean off with sensor swabs.

These two sometimes three black dots to the upper right quadrant in all of my photos.

Sensor dust is the first thing I would check also. Since the black dots are in the upper right of the images, check lower left on the sensor when the photographer is behind the camera. If you look at the sensor from the front, it'll be the lower right of the sensor. I sure hope I got my orientation right.

I will definitely check into this, the only other camera I want to buy right now is a second D300. I want to have a couple converted to IR.

 

It's been a while since I messed around this in depth with equipment is there a setting on the camera that opens the shutter to expose the sensor after ive orders the swabs ofcourse

Yeah. It's in the Setup menu: Lock mirror up for cleaning. The battery must be at least half-charged for this item to be enabled.

 

By the way, you can try blowing the dust off with a rocket blower before swabbing. It probably won't work, but it's worth a shot.

Edited May 1, 2020 by chulster

I've never used swabs on a sensor, just a rocket blower.

The sensor cover glass isn't infinitely thin. If there's dust on it, it'll be blurry (and sometimes invisible if it's small enough) at large apertures and sharp at smaller ones. I usually shoot at relatively large apertures, partly to avoid diffraction, and on the occasions that I shoot at f/16 or f/22 I tend to get shocked by the amount of crud that I've allowed to accumulate on the sensor; there's nothing visible at f/4. If you want to see whether it's a sensor issue or just dust (which I agree is more likely), see whether you still have the same three dots at f/2 or faster. There's also a "dust off ref photo" option in the setup menu which affects at least Capture NX 2 (which means I've never tried it) - although it might work better if the dots aren't completely opaque.

 

One other thing if you don't already know: the sensor captures an inverted image, so if you have black spots in the top right of the image, they'll be in the bottom left of the sensor - or the bottom right as you look through the mount if you're holding the camera the normal way up. Just so you don't spend a load of time banging a blower against your mirror when in fact you should be aiming at the other corner of the sensor.

 

I've used a blower (I tilt the camera forward so that anything dislodged falls out), but only ever got Nikon to do the sensor clean - partly because I don't trust my own competence, partly because most of my photographic existence has coincided with the house being full of cat hair. Not currently (right now it's more dust from rearranging my study so I can work), but soon again, I imagine. A lot of camera shops offer a sensor clean service if you'd rather make it some else's problem. I don't believe a swab clean is particularly difficult, but since I couldn't varnish a table without getting bubble and streaks in it and I have a bad track record with leaving smudges on windows, and since Nikon once reported to me that my D700 had an (invisible) sensor scratch even though they had been the only people ever to clean it, it's one of those things I'm prepared to leave to others. If I shot a lot more I might have a different opinion.

 

Good luck! The D800 is a lovely camera. Buy fast cards if you don't want to be annoyed waiting in live view, and don't forget that the 1.2x crop gets you to 5fps if you find yourself shooting action. :-)

Many thanks, I just ordered a cleaning kit. I saw the specks right where you said they'd be and all my rocket blowrs are long gone. I waited to too long to be able to get a D800 to go messing around without the proper tools. This thing maybe what keeps me afloat!

 

Good luck! The D800 is a lovely camera. Buy fast cards if you don't want to be annoyed waiting in live view, and don't forget that the 1.2x crop gets you to 5fps if you find yourself shooting action. :)

 

 

I use the Lexar 1066x cards for all my cameras. I shoot more macro so for now haven't been using continuous mode. But that is also why the dust has been such a big deal because at life size and x2, x4 have been such a big deal because my aperture has been set to f22, f32.

Is it possible to upload a sample picture showing the "Dots" ?

Use an air blower first! It's much less risky than poking at the sensor with swabs and suchlike.

 

If you can remove the muck without physically touching the sensor - great! If not, all you'll have lost is the price of a rocket-blower. But you might otherwise gain a scratch on the sensor cover glass that you can't clean away. Those things are delicate, and shouldn't be poked at if you can shift the dust in another way.

Kinda wondering why nobody is advising this guy to do the simplest of tests...

 

Capture 2 sample photos of a bright wall or the sky, focused at infinity: one at f/22 and the other wide-open. *Adjust the shutter speed to match the exposure.

In the stopped-down sample those "dots" should look very distinct while in the wide-open sample they shouldn't be as pronounced (or even non-existent). If that's what you're getting - it's dust. So, yeah, you will have to clean the sensor.

 

If in both samples those dots look about the same then you've got yourself some dead pixels. No need to rush out and buy any rocket blowers, cleaning products won't do you any good.

 

BTW: Dead pixels look almost nothing like sensor dirt at 100%.... If the OP provided a photo of the culprit I'd be able to tell what it is just by looking at it.

Kinda wondering why nobody is advising this guy to do the simplest of tests...

 

Capture 2 sample photos of a bright wall or the sky, focused at infinity: one at f/22 and the other wide-open. *Adjust the shutter speed to match the exposure.

In the stopped-down sample those "dots" should look very distinct while in the wide-open sample they shouldn't be as pronounced (or even non-existent). If that's what you're getting - it's dust. So, yeah, you will have to clean the sensor.

 

If in both samples those dots look about the same then you've got yourself some dead pixels. No need to rush out and buy any rocket blowers, cleaning products won't do you any good.

 

BTW: Dead pixels look almost nothing like sensor dirt at 100%.... If the OP provided a photo of the culprit I'd be able to tell what it is just by looking at it.

 

I did, but perhaps not that clearly. :-)

To be fair, Andrew, I skimmed over your post. Yes, all the pieces are there. However, I felt that the OP needed clear instruction on this DSLR 101 stuff. That's why I didn't "catch" what you were saying.

 

Also, I myself agree that fast CF memory cards go nicely with a D800, and they're not expensive as they used to be. However, a word of caution. Back in the day when I was shopping around for an upgrade to my then-current CF cards, I read up that large-capacity (and "fast") memory cards can actually slow down a D800. So, I settled on a 64-GB one, because of that claim which was also backed up by several other parties (and also because it made sense). I ended up buying the Lexar Professional UDMA 7, 1066x, 160 MB/s which I am using to this day with my D800 (but only because I gave it a new life as an infrared camera). With the 77 MB/s, tested, sustained, in-camera write speed, it frees up the buffer really fast, compared to my other two, older 32-GB cards. However, at times I do feel that it makes the camera a little more sluggish at other tasks. Like, for example, it takes the Live View a little longer to come on. Browsing through photos feels a little more laggy (which is not a word, apparently). But let me tell you, I would not want to find out just how much this camera lags with a 256-GB CF card, for example. The number of photos stored on a card is a factor but it is not the only bottle neck with such huge capacities.

Nevertheless, not all CF cards are made equal. Actually, to the point that compatibility issues are commonplace. But even when two similar memory cards interface with the camera just fine, the inner workings of such 'compatible' cards can be quite different between all the different brands and makes. I have not researched the subject in several years, yet I remain fairly convinced that in a Nikon D800 the write speed is maxed out at around 80 MB/s but perhaps someone can shed some new, brighter light on the current state of this dying technology. *In this context it would have to be specific to performance of the Nikon D800 camera with a CompactFlash memory card. Also, I (and I assume others too) am interested in the camera's functioning abilities besides photo capture.

 

To make a long story short, large-capacity CF cards are affordable and the fast ones are great on paper but in the actual reality it may be better to buy multiple cards of smaller capacities. It's a jungle out there and without research one risks purchasing a new memory card which will not work at all with an older camera like the D800.

Unless you have a whole group of dead pixels together, you're not going to notice them unless you scrutinise the entire frame at 100%. Therefore I think we can rule out dead pixels.

 

Dust, OTOH, is much more noticeable.

Unless you have a whole group of dead pixels together, you're not going to notice them unless you scrutinise the entire frame at 100%. Therefore I think we can rule out dead pixels.

 

Dust, OTOH, is much more noticeable.

 

I agree. Especially, with a pixel-packed sensor like the one on D800, a defective pixel will produce an artifact which is smaller in size than your typical dust spec. However, there is a chance that that defective pixel will be very pronounced, despite its small 'physical' size. A white (hot) pixel in the night sky, a black dot (dead pixel) in a clear sky... Dust specs are almost never 'black'. Typically they range from bright gray to dark gray and with the right skill set one stands a good chance of physically getting rid of the ones that are currently bugging you, for good. But if those black dots really are dead pixels, you may have to keep living/dealing with them for as long as you're processing the photos out of that camera, unless you decide to immediately replace the sensor, which is unrealistic, or to replace the whole camera. Having a few dead pixels in your sensor is not the end of the world, even if you're stuck with them for good. And, fortunately, more and more "dead pixels" are becoming a thing of the past (and I'll explain), plus, not all dead pixels are actually "dead pixels". There are "stuck pixels", "hot pixels" and who knows what else. Sometimes, stuck pixels can be easily fixed (like, for real) and I remember reading an interesting article or a discussion (can't remember that) where they were talking about a camera's ability to "self-repair" (but, actually - conceal) defective pixels. It works on a similar principle as the Long Exposure Noise Reduction, however, the approach is not quite the same. Bad pixels are permanently mapped and cloned out in every subsequent picture that you take. This approach is also of particular use when it comes to shooting at high ISOs.

As the gain is increased, a whole bunch of pixels (and quite shockingly, many more than you know and would like to have) begin 'acting out' by becoming 'hot'. There is no practical way of fixing them, so they're just 'replaced' on the spot. Any pixel has the potential of becoming 'hot' during a long exposure and the way to 'fix' those is to shoot a dark frame and take care of it in post, or let the camera do just that right there and then. However, I am talking about short exposures at very high ISO's, which is something else. Some pixels are just recognized as 'problematic' and get mapped (permanently) by whichever IC that's tasked with doing it. The bottom line is that this is done behind the scenes and we, the users have no way of knowing whether or how many bad pixels each of us actually has in our sensors. *A special test, conducted in a lab setting can reveal any and all 'misbehaving' photosites but it's not something you can do at home.

 

I couldn't tell you how many camera models are concealing bad pixels this way at present, but by now, I would guess that pretty much all of the newer ones. But perhaps someone here knows more about it.

At any rate, something like this has next to zero impact on the real-world applications of photography, especially considering the ever-growing pixel count and the ever-diminishing significance of each individual pixel in the frame. But I'll tell you this:

 

I had just remembered something. When I bought my D800 in 2012 I immediately put it through a bunch of tests. In the very first photos that I've captured with that camera I noticed 4 or 5 'colorful' dots (pixels): A few red, green and blue ones. They were just 'normal' exposures, probably around 1/8" or 1/15", on a tripod, at the base ISO, so, naturally, I became concerned. I remember looking it up on Google and at one place it said that the camera should be able to take care of those faulty pixels on its own. I can't remember if it said there that I should let the camera do a sensor cleaning or even if I actually did anything about it. The next thing I knew, those 'dots' were gone, not to return ever again.

What I suspected had happened was that the camera came with a few defective photosites in the sensor, and as we know, each pixel is comprised of several of those. So, if at least one photosite is out of commission, the affected pixel will really stick out from the crowd. At the time, it was obvious to me but because I never had to deal with anything like that again I had forgotten all about it and just went on to learn about and enjoy my new camera.

Edited May 10, 2020 by david_r._edan