How about a scratch on the protective glass over the filter? -- Best regards, Bruce
Wednesday, February 11, 2004, 2:39:15 PM, you wrote: MC> For the last few month I've been using my *ist-D to take snow crystal MC> photos. The basic rig has a 50mm macro lens (SMC M 50 f4) reverse mounted MC> on a set of bellows and tubes, to get to 4 - 8 x lifesized MC> magnification. I then blast a flash straight up through the snow crystal MC> and into the camera. I'm usually shooting at f22 - 32. This setup seems to MC> result in surface flaws in the *ist-D sensor coming into focus. For MC> example, a while back I had a dust speck on the sensor. It got past me MC> because instead of looking like a blurred blob, it was really sharp with MC> well defined edges. It looked like a bit of dirt on the glass next to the MC> snow crystal, but was really a speck of dust on the sensor. MC> So - take a look at this: MC> http://www.markcassino.com/temp/line.jpg MC> Note the faint horizontal line running from the lower left corner to the MC> upper right. MC> It's been on all of the snow crystal shots I've done since late MC> February. I've cleaned the sensor with a blower several times in that MC> period, it does not move. It does not appear in shots taken with more MC> normal setups, and really is not a problem with even these snow crystal MC> shots (it's pretty close to the edge of the frame.) MC> Perhaps a tiny microscopic scratch in the sensor? MC> - MCC MC> ----- MC> Mark Cassino Photography MC> Kalamazoo, MI MC> http://www.markcassino.com MC> -----
