Here's my impressions of the 600/5.6 ED-IF AIS (new) thus far:
Flare/ghosting: Excellent. Made a couple of shots aimed right at or just off to the sides of the setting sun and it didn't seem to have any problems. Much better than my 400/5.6 ED AI or 300/4.5 ED AI
Sharpness: Very very good. I shot mostly wide open and did not notice any obvious sharpness fall-off out to the edges, which is very important for me. Wide open it appears to be sharp enough for the D800, BUT you have to focus extremely carefully as just a very slight movement of the focus ring makes a huge difference, especially for CA. I should have expected this, but there is a difference in optimal focus position for a 2 mile subject and a 10 mile subject!!!!
CA: Well, it's an old ED Nikkor. At very high contrast areas there is some PF that cleans up pretty well in PS and there is the usual red/green CA if not focused just right, but it's very well controlled for the most part.
Contrast: I would say it was very good. Not quite up to my 400/5.6 ED-AI or 135/3.4 Telyt or 180/4 APO Voigt, but it's pretty good. Obviously even on a perfect day atmospherics take its toll on contrast, but it seemed to do well.
Handling: Well, it's a 3KG tele that's weighted towards the front, so deal with it. Put into a backpack of sufficient size it's not a problem.
- On my copy the focus ring is way too under-damped (typical of older MF IF lenses in my experience) - needs to be re-lubed with some thicker grease for sure and the aperture ring needs a re-lube due to being too tight (typical of many older MF lenses!). Focus ring goes way past infinity as most ED lenses do, but this one goes way way past infinity.
- Love the combination of the short detachable hood and the short built-in hood. This allows one to either leave the detachable hood at home and just use the built-in hood or use them both to get a much longer hood.
Other:
- Point light stars when stopped down: Looks like that 7 non-curved blade aperture does the trick and gives cool spikes when stopped down just a bit. I'm sure the bokeh isn't the greatest stopped down, but I don't care for my uses. It's up there with the 400/5.6 ED AI which is excellent. by comparison the excellent 300/4.5 ED AI has the "Ninja Star" aperture blades and it does not do well
- Light fall-off wide open: It's there, it corrects pretty well using the standard manual correction tools in photoshop and overall it's pretty good. It's definitely better than my 400/5.6 ED AI.
- Sensor Hygiene: Even wide open these long focal lengths show every microscopic speck of dust on your sensor ;>(. and boy does my D800 need a cleaning!