Nikon 18-200mm VR IR Pollution? (Continued)

Started Feb 17, 2008 | Discussions thread
ForumParentFirstPrevious
Flat view
SteveL54 Senior Member • Posts: 2,709
Nikon 18-200mm VR IR Pollution? (Continued)

The other thread reached its limit. Here's the link:

http://forums.dpreview.com/forums/read.asp?forum=1039&message=26783756

I felt it's more appropriate for the lens forum so I've continued it here.

One of the hypotheses floated in that thread is the VR (or other electronic components) actively emits IR -- not just BB radiation.

I tried the 18-200mm VR on my D70. Its sensor's filter does not cut IR as much as the D300. (I often use an IR cut filter on the D70 to avoid IR turning blacks magenta and greens becoming somewhat yellowish.)

Here's a 30 minute exposure ISO 200 with VR On. (lens AF Off)

Same but with VR Off

Notice what looks like may be a lens flare pattern in the first photo.

I cooled the camera in the refrigerator well before and during the 30 minute exposures.

You can see in both photos what looks like amp glow to me in the upper left. The "IR" pollution is a more pure red.

When I performed the same at room temperature the camera had really warmed up, especially with the VR turned on. After the exposure the metal L-bracket was noticeably warm to the touch.

This is what that exposure looked like:

Now, I'd do the same with my D300, but I don't have the equipment to make a long bulb exposure without holding open the shutter release. And I'm not gonna crawl in the frig for thirty minutes at a time to do the test

Steve

ForumParentFirstPrevious
Flat view
ForumParentFirstPrevious
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow