Dear Loopers,
I, Piet Martens, and Meredith Wills-Davey have just uploaded to the ArXiV a recently-accepted APJ paper on stray light in the TRACE telescope. We find, based on the Venus occultation data, that 43% of incident 171A light is scattered, so that the instrument-scattered "halo" around bright features is expected to contain 75% as much brightness as the features themselves.
This has a not inconsiderable effect on the inferred degree of localization of plasma in active region loops, and on the feasibility of DEM analysis with TRACE and similar instruments.
Interested folks can find the preprint at "http://arxiv.org/abs/0808.3980v1 ".
Cheers, Craig DeForest