Focus Errors and Corrections

Update 2018: At one point the Tamron 70-200mm fell from a car seat onto a paved parking lot, and the lens never performed well again. Despite liking its handling and look, I ended up selling it.

The new Tamron 70-200mm on my D100 in the front yard this afternoon
The new Tamron 70-200mm on my D100 in the front yard this afternoon

For a couple of years, I’ve had the excellent AF-Nikkor 180mm f/2.8 in my bag here at home, but seldom shot with it.

When I did, it was usually in plentiful light, stopped down a little bit. As a result, when I shot with it wide open at Bryce Canyon last summer, I was surprised to discover that everything was front-focused, meaning the point of focus was between me and the subject. I didn’t really want to accept that the 180 was broken, so I sort of blamed it on one of the D100s. More recently, I put it on another D100, then a D70, and found the same problem, that everything was front-focused, quite noticeably. However, when I took it to the office and shot it on my cameras there, the D1h, the 720x and the 760 (the latter two built on Nikon F5 bodies), everything was perfectly sharp. Hmmm. How could this be? Well, a bit of internet research showed that I wasn’t the only one who got this focussing error with the 180mm. The best I could figure is that the CAM-900 focus module in the D100/D70 family wasn’t compatible with the optics of the 180mm, but that the CAM-1300 module in my pro cameras got along fine with it.

I decided last week that the 180mm had found a new home: in my bag at work. But now I felt a little naked not having a decent longish f/2.8 in my bag here at the house and while I was teaching, so when I was in Oklahoma City yesterday, I picked up a Tamron AF70-200mm F/2.8 Di LD (IF) Macro. It’s smaller and lighter than the 80-200mm f/2.8 Nikkor I use at work, and has the extra bonus of being a macro, adding close-up photography to my tool box. So far I’ve only made a few test frames with it, but early frames appear quite sharp, it handles smoothly, and appears to focus perfectly on my D100s. I am excited to have it on board.

Raindrops on leaves in the front yard, shot with the Tamron at 200mm, f/2.8, about a 250th of a second. Very sharp.
Raindrops on photinia leaves in the front yard, shot with the Tamron at 200mm, f/2.8, about a 250th of a second. Very sharp, nice bokeh.

1 Comment

  1. I’m kind of kicking myself. I had a chance last summer to buy an old Minolta (Sony) 300mm prime f/2.8 and a 2x for under $1500 locally. As much as I like to shoot wildlife I’m not sure why I talked myself out of it.

Comments are closed.