Monday, September 12, 2011

D7000 and 18-200VR – AF test

I tested the 70-300VR with the D7000 recently and this time I turned my attention to the 18-200VR, a lens that is difficult to fine tune because of its remarkable 11x zoom range. Yet it is worth the effort to get the lens as sharp as possible as it is my go to lens for walking around.

It is important to set the lens to its sharpest aperture for tests such as these. I use f/8, which is generally its best aperture. But frankly, this lens is decent from wide open through f/11 for typical snap shooting.

I also mount on tripod and release with the infrared remote in mirror up mode. In this way, I can click once to raise the mirror, wait 5 seconds or so for everything to settle, and then click again to expose the image. Works very well.

So here are the crops from my experiment. I started with the AF fine tune set to –10, a figure I arrived at by just fooling around with the camera for a few minutes. Then I shot a second long zoom image at –13 and found this to be tack sharp (or as close to that as this lens is able to do.)

These images are all processed in tandem in ACR, so there is no difference in processing to blur the results.

At –10 AF fine tune, the contrast detect was slightly sharper at 18mm and slightly less sharp at 200mm. This must, however, have been a statistical thing as I did forget to turn off VR.

No matter … I then slightly tweaked AF fine tune to –13 and found the image tack sharp. Wow ….

So I am satisfied that my 18-200VR is again the perfect travel companion. I can drag along my primes if I want even better results. Especially my MF 105mm 2.5 Ai (Afghan Girl lens.)

For those who are really worried about shooting the D7000 because of all the noise on the forums, you should consider whether you are willing to invest a bit of time in tweaking your skills and your camera. If you are, then I say jump at this thing … it is certainly good enough for me to sell off both the D300 and the D700 …

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