I should have done it sooner - I knew both my main cameras were acting up a little and had focus problems. Over the last few years I have sent in every camera I've owned except the Fuji S5 (D200 with different guts/sensor)- probably because I don't have a lot of wear on it.
My D300s is a year old (I think) and was doing ok but then started to focus hunt and then stop - and had trouble being "Accurate". Having had trouble in the past, I tried the same lens on my D300 and had somewhat better luck (but a different problem). So I began to use my D300 for action / birds in flight. I sent in the D300s to be tuned, cleaned, and calibrated - and they did just that and it works much better now. Nikon service fixed it for free, doing the work under warranty.
The D300s was still functional but didn't perform well. So I found myself juggling bodies for action and then video - because the D300s does video and the D300 doesn't. That finally got old, and with the summer wrapping up, and fall just around the corner I got the D300s fixed. It has about 48,000 shots on it now.
Now the D300.
This camera has been in for service now 3 times. It has over 120,000 shots on it and I've used it for around 3 years. The first time I sent it in was for the same type of focus trouble that the D300s had - hunting, bad performance, and giving up trying to focus without having gained focus. The second time was when a sensor for the mirror went bad - the mirror would bounce during the shutter/exposure, and would then stay UP, not down. The camera was a couple years old and I think I had to pay for the repair. But when I got it back the focus points didn't line up with the actual focus.
It was strange, if you selected the center focus point it would often appear to be ok, but in fact it was getting focus from just to the left and down about a sensor's width and height over. There were two very specific hints that something was very wrong with the camera when I got it back. The screen cover for the back of the camera was cracked.
Then about 2 weeks later I noticed that the hotshoe wouldn't accept a flash - it was bent a bit and the flash didn't fit. It was then I knew the camera had been dropped. I didn't drop it, and I doubt HIGHLY that Nikon Service would drop it and wrap it up and send it back. So, since it was boxed and in bubble wrap, the only way it could have happened during the repair process - was if the store I sent it back via had done it. They must have got the camera back, and during the unboxing processes dropped it, it bounced, cracked the screen, bent the hot shoe, and what took the most time to discover - WHACKED the focus alignments/calibration.
I won't name the store, but they've got a history of being jerks in my local community - and they won't be getting any of my business any more.
So, when I sent it in asking for cleaning and adjustments, and calibration to fix focus, and the misaligned focus points, nearly a year later, I expected Nikon Service to charge me. But THEY are good. Unlike the store that broke stuff and pretended nothing happened - Nikon Service just fixed it under the old repair warranty. Now that's nice, not to have to complain, or beg, or pay for it to be made right.
I shot this with the repaired D300s - it's at 400mm and 1/160th of a second.
One big thing to consider is that focus is a fickle thing - and it impacts how VR performs. VR uses focus as part of its math (from what I've heard) - so having a poorly performing focus system may make VR less effective. Before I had the camera recently repaired getting a good infocus, sharp shot like the above was very hard. They all seemed to just be off a little.
I don't know if it will be very noticeable in this osprey photo taken with the broken camera months ago - because it is one of the better ones, but the focus is just behind the head, more towards the body. What I found, probably the hardest case for a camera to focus well in, is that for birds in flight, where the distance is changing, ie toward the camera, a poorly performing camera will not do well. I think it lags behind, and might seem to be "back-focus" but it is more likely "lag-focus" where the camera is just behind in its calculations, and can't get it right / or perfect, and the movement makes it visible.
This spring and summer I literally took thousands of birds in flight shots that left me wanting more, better focus, sharper detail... Having been out shooting now just a couple weeks with the repaired D300s - I found it much better at doing a good job. And even in the hardest cases - like seeing a flying bird and wipping up the camera/lens and trying to get focus before it vanishes from view - it did ok, fast, and accurately. The repaired D300s even did ok on far off moving birds in FOG! Fog is rough, and it did ok.
~4 years ago I broke my D70s with about 45,000 shots on it - breaking the shutter! Nikon fixed it for free. Since then the card reader/writer died, and it randomly takes a shot and turns the card in to jibberish and writes random stuff to it. I haven't had it fixed, but I still have it. The electronic shutter (aka strobist hackable) makes it worth it - some day I will pursue getting that repaired.
~1 year ago I had my D200 refurbished - cleaned, tuned, adjusted, and had the rubber-grip replaced so it looked like new! And they only charged me around ~240 if I recall correctly. That camera had around 160,000 shots on it at the time.
I am pretty ready for fall now. The D300 will be back in my hands probably in a week. All I need to get tuned up is my 80-400mm which probably needs gears replaced because I have really beaten it up over the years and it doesn't focus well, and no where near as cleanly as a new 80-400mm (I've borrowed a friends).
The Take Away - get your gear (mainly body) tuned, cleaned, and focus-adjusted every year if you shoot a lot, and every couple years if you shoot some. And if you think your camera isn't performing, focus, metering, etc, properly, SEND IT IN right away.
Sending stuff to Nikon now - I use UPS and insure for the replacement cost, and Nikon Service in Melville NY is very fair and does a great job.
Original content posted at http://natureandwildlifephotography.blogspot.com/Nikographer.com / Jon