Nikon D90 problem - is it terminal (and if so what next)

[Rodwsmith]

Hello, and in advance thank you.

I love my D90 and have taken some good pictures with it, but recently it developed a fault.
Every so often (I shoot mainly in automatic 'P') it would take a very dark image, underexposed to the point occasionally of almost black. Sometimes it would take a dramatically over-exposed picture.
I sometimes got the 'err' message

Here is what I have tried, after exhaustive searching here and elsewhere on the internet:

Changed battery.
Removed lens (usual is Nikkor AF-S 18 - 200). Cleaned contacts on both lens and body.
(This, or something, appears to have cleared the 'err' issue - so far at least)
Checked firmware is up to date (in fact there was an update [L2.013] so I installed that)
Tried two other lenses - same problem, so it cannot be the lens
Restored all settings (with and without lens attached - someone suggested the latter might make a difference)
Set the ISO to 200, and turned off ISO sensitivity control
Tried every permutation of completely automatic (with and without built-in flash), S, A, & M
It appears that the issue is the automatic selection of shutter speed (i.e. in automatic looking at the same subject it repeatedly selects the same aperture, but will select a shutter speed that is alright most of the time, but occasionally far too fast, resulting in the dark image)

The above all seems to have helped but has not cured the problem (I have not have anything over-exposed, or the 'err' message, since)

So I'm perplexed. The problem appears to be with something operating too fast, and therefore not 'sticking'.
I can, of course still use the camera. I either select the shutter speed all the time and have it set to 'S' - perfectly good discipline, but nevertheless irritating, Or just review and delete the bad images, again not the end of the world, but might mean me missing some of those point-and-click opportunities.

So my questions are these:
- Is it a known problem (light meter?), and if so what (there are lots of results in a google search for 'D90 dark pictures, but the only 'cures' suggested were those above)?
- Is it likely that it can be economically fixed?
- Should I just accept it and look at buying a new body, and if so, which, D7100(?) (Has to be Nikon because of the lenses) replacement D90?

I live in France, and although my French is good, I'm not sure how well I could explain all the above! Repairs in France (of most things) tend towards the very expensive. I can see secondhand D90 bodies costing less, or not much more.

The two images below shot immediately after each other. No 'bright spots' for the camera to meter (focus points identical). "Automatically" picked 1/250 s and then 1/500 s

Thanks in advance for any guidance.

Cheers

Rod

 

[goooner]

It does seem like a metering 'problem'. What metering preset are you using? The 1st seems to be exposed for the table, the next is exposed for the window. Do you have bracketing on?

 

[Rodwsmith]

Thanks Gooner.
Appreciate your time and help
For metering (and this is now going beyond my comprehension), here are the settings (all the factory/reset)
b1 EV steps for exposure cntrl. 1/3
b2 Easy exposure compensation ON
b3 Center-weighted area (·)10
b4 Fine tune optimal exposure - Matrix metering +3/6, Center weighted metering 0, spot metering 0
e4 Auto bracketing set AE.
e6 Bracketing order N
Do you recommend I alter any of these settings?

But perhaps these two images show the problem best, taken of the display on the back of the camera:

Everything (it seems to me) is identical: speed, shutter, ISO. The camera was focussing on the same point each time, one second apart. And yet the pictures are very different. What could possible explain this

 

[jaomul]

Id try a different lens, the lens may be not opening or closing enough (sticky apertutre blades) for some shots causing diff exposures at same settings, its worth a go

 

[goooner]

Can you display the focus point as well. I'm quite new to Nikon myself, but the focus point and the light metering are often 2 different 'points'. The best test would probably be to set your camera on a tripod/table. Don't focus on a bright/dark spot (away from the window towards the 'darker' room). Set it to A mode (f7 or 8), set iso to 200 or 400. And take 5 shots with the self timer (2s). The shutter speed should stay the same for all 5 shots, unless the lighting conditions change.

I'm sure one of the pro's will be along soon to explain this in much more detail.

 

[goooner]

Just saw that little thing at the bottom right (the people with the 'auto' next to it). Is that a night mode? Switch it off if you can.

 

[pixmedic]

set the camera in full manual.
then take a shot using settings that gets the exposure right based on what the meter is saying. see what it looks like.

 

[jaomul]

It of course could be the meter but the two shots above have same settings and different exposures

 

[Rodwsmith]

Thanks again all

Jamoul - tried several lenses - same problem.

Gooner. No idea what the little logo in the bottom right is. Seems to be that same with P, flash, and A selected.
So I tried as you and pixmedic suggested:
Completely manual. Set to 1/8s, f7.1, 200 iSO. Blank wall, no changing light. Taken with the remote control
Different "exposures" still happened, and I started to get the dreaded 'err' message again.









As far as I can make out the 'err' message is likely due to a miscommunication between camera and lens (although I don't know how it explains this). Removing and replacing the battery helps, but cleaning the contacts on both lens and body hasn't sorted it.

I have ordered a brand new battery. Those that I have are at least three years old, but they show as fully charged and in fine conditions. This seems to be my last hope that it is something other than a complete-meltdown.

Once again I appreciate your time and help greatly

Rod

 

[Rodwsmith]

Of course, I'm aware that taking a picture of the camera's screen with my phone compromises this somewhat (in fact in one of them you can see my shadow), but if anything the differences between the photos themselves is even greater. And the graphs should surely be exactly the same? There are no other variables...Or are there?

 

[goooner]

No, it does look strange. Are you recording in jpeg? Maybe try a few RAWs, I guess the camera will convert them for display, but maybe it is doing something with the jpegs.

 

[Dave442]

What are the 6/7, 7/7 in the first two and 5/5, 4/5, 3/5 in the last three.

It looks like the classic Bracking is active.

 

[Rodwsmith]

Nope, RAW makes no difference (worse if anything, but the light is going). These three all shot as rapidly in succession as possible with the remote, on a tripod (gorilla pod) with all manual settings. Everything identical, but three massively different 'exposures'.

So, it seems my original thought that I could continue to use the camera manually was misplaced optimism.

Any ideas?

 

[Rodwsmith]

What are the 6/7, 7/7 in the first two and 5/5, 4/5, 3/5 in the last three.

It looks like the classic Bracking is active.

Just the number of the picture in the memory on the card. I have been copying them to a folder on my computer and then deleting them from the card as I go. In the last trio I have twelve pictures left on the card, and these are the 9th, 10th, and 12th. (the 11th was the same as the 10th)

What is "classic Bracking"?

 

[KmH]

See page 92 of your D90 User's Manual.
Bracketing is under and over exposing a series of shots on purpose to ensure getting a good exposure. Nikon calls it AEB - Automatic Exposure Bracketing.
Your D90 has a setting that does that with each shutter release. Shooting/Display Menu e4, pg 191 of your user manual.
The top LCD shows if bracketing is set.

If AEB isn't set, I think the 'ERR' code is because the image sensor in your D90 is dying.