Lou Jost wrote: ↑Mon Jan 24, 2022 6:00 pm
So imaging will include light at wavelengths as short as 0.6 microns, or 600 nanometers--so orange and red portions of the visible spectrum, by my read.
Chris, those numbers refer to center wavelength, and the spectral width of the passband for the visual filters is very wide. See the graph that started this thread. The telescope can see down to 500nm.
Lou, if you see something that says 500nm, I would like to know an exact pointer to that information.
The graph that I see at top of this thread is for the Mid-Infrared Instrument, for which the shortest wavelength filter is the F560W, which is described at
https://jwst-docs.stsci.edu/jwst-mid-in ... ingfilters as λ0 (μm) 5.6 and Δλ (μm) 1.2, meaning that it covers the band from 5.0μm to 6.2μm, same as what is shown in the graph.
The instrument that gets into visual is the Near Infrared Camera, described at
https://jwst-docs.stsci.edu/jwst-near-infrared-camera . That is described in text as "observes from 0.6 to 5.0 μm" and the shortest filter as shown at
https://jwst-docs.stsci.edu/jwst-near-i ... ra-Filters is the F070W which covers roughly 0.6-0.8 microns as shown in the graph on that page (which is
not the one shown at top of this thread).
Everything I read is the same as Chris S., that the scope only sees down to 600 nm. I also see only one band in the visual, for the F070W in the Near Infrared Camera. The next band would be the F090W, which is graphed as starting at 0.8 microns.
--Rik