4 ms·
Honest question: Is the lens flare at the center to be expected or more corrections are underway?
by srvmshr 5y ago
Honest question: Is the lens flare at the center to be expected or more corrections are underway?
- Sharlin 5y agoIt’s an inevitable result of diffraction caused by the three arms holding the secondary mirror.
- willis936 5y agoCan this not be mathed out if we know the distance of the target? I know it wouldn't generate the missing information in the occluded regions, but it might look neater.
- Sharlin 5y agoDistance to the target doesn’t matter because to an astronomical telescope every object of interest is at optical infinity, but yes, if you know (an approximation) of the optical system’s point spread function, you can compensate for the effects of aberrations including diffraction. The JWST team knows the PSF from having designed, simulated, and now actually testing the telescope, and likely it will come useful in getting the last bits of scientifically valuable information out of the data, but in normal use those diffraction spikes in particular are unlikely to be any problem. They basically only show up because the star in the test image is highly overexposed.
- _xerces_ 5y agoI believe most of the diffraction is due to the edges of the hexagonal mirrors, not the spider holding the mirror. The lens flare though I think is due to the spider.