By far the best photograph I have seen in the early days after the storm is this 10 minutes exposure by Iyad Mustafa with 24 mm f/2.8 on Ektapress 800 ASA that he took at the Al Azraq desert camp in Jordan's Eastern Desert, right around the maximum - it was quickly published on the JAS Leo'99 results website. The original negative shows up to 100 meteor trails, but most are faint and often just above the background noise from the film grain.
I had received a good print from the original negative (sharp but with rather low contrast) which I have scanned and which I've tried out some image processing techniques, all with standard Photoshop functions. As I had dealt so far only with planets and the solar corona, bringing out meteor trails was a new challenge.
The main problem with Iyad's spectacular image are the gradients in the sky background, caused by vignetting effects of the camera lens, transparency variations and the zodiacal light around Venus in the lower left. If you just cranked up the contrast (the 'gamma') of the image, you would merely enhance these background fluctuations, but the meteor trails wouldn't get any more pronounced.
For this first attempt I used unsharp masking, with a pixel radius of about 10: That kept the star and meteor trails sharp and dampened the background gradient locally. Now the contrast could be enhanced, and the trails became more prominent; also the increase in the noise was tolerable, while some artifacts were unavoidable (the dark haloes of the brighter trails, a Gibson's phenomenon).
Another approach I came up with uses the scratch removal function of Photoshop: For the algorithm star as well as meteor trails are the same as scratches. After removing them I had a pure picture of the dreaded sky background of Iyad's image (with only Venus' strong glow faintly visible).
After subtracting that background from the original (at an 80% level), the star and meteor trails came out beautifully, wile some of the impression of the sky remained (because I didn't subtract 100%). Doesn't that look cool (I've even manually removed some obvious dust specks)?
And here I have taken out the sky background completely (and cranked up the gamma to the max): While the trails come out even clearer, the sky looks definitely unnatural now. Anyone with more ideas what to do to Iyad's picture...?
Daniel Fischer, Nov. 25, 1999