Category: All Objects

Trial shooting to evaluate the performance of semi-narrow band filter, utilizing IDAS LPF-P2 and Lumicon H-alpha filters. ———————————————– The cutoff wave length of the Lumicon filter is 635 nm while the cutoff of the infra-red region by LPF-P2 occurs at 685~690 nm. Thus these two filters passes the spectrum of 35nm width. ーーーーーーーーーーーーーーーーーーーーーーーーーーーー IDAS LPF-P2 and Lumicon H-alphaを利用したＨアルファフィルターの性能テスト　 ーーーーーーーーーーーーーーーーーーーーーーーーーーーー Kit Zoom lens (35-80mm for film EOS REBEL) at 80mm FL Session 1: 20 frames with IDAS LPF-P2 at ISO1600, 60 seconds of EOS REBEL T3 Session 2: 10 frames with Lumicon H-alpha filter and LPF-P2 filter at ISO3200, 180 seconds of EOS REBEL T3 20 darks and 20 flats for each session ————————————- It appears these two filters combined together can filter out the city lights to a certain extent, enhancing the contrast of the image.

The Trapezium is seen at the center of M42. Gadgets: Sigma Telephoto lens 150-500mm at 500mm FL, with two EOSs, EOS Rebel XSI and T3, both modded, 0.5,2,4,8 minute exposures (4~8 frames each) at ISO1600 with XSI and Orion SkyGlow filter and, 2 min. x 25 frames at ISO3200 with EOS Rebel T3 with IDAS LPF P2 Note 8 minutes frames were discarded due to drift. The processing was not easy due to the difference in the transmission spectra between the Orion and the IDAS filters.

The shots were made just for testing purpose! 3 min. x 8 frames at ISO3200 for H-alpha (poorman’s H-alpha — Lumicon H-alpha + IDAS LPF P2) 2 min. x 3 frames (IDAS only) same Sigma zomm (150-500mm) at 500mm. Regardng H-alpha and RGB composite, please refer to the method of 80/20/20 by Neil Heacock. http://tinyurl.com/7jqxzly

Shooting this reflection/emission nebula was quite challenging. Dark clouds surround the nebula. VC200L+Vixen Reducer Canon EOS T3(KISS X50), self-modded ISO3200, 2 minutes exposure 59 light frames, 20 dark and flat frames each

光害カットフィルターと　ルミコンＨ−アルファフィルターの併用 Sigma Telephoto Zoom Lens of 150-500mm FL at 500mm, Canon EOS Rebel T3, self modded, ISO3200, Exposure time 2 minutes, 27 lighs, and 20 darks and flats each, Lumicon H-Alpha filter with IDAS IPS P2 filter, combined together, being used as a semi-narrow band filter. The transmission wave length is between 635 nm and 680nm , roughly 45nm band width at the half peak. Note the H-Alpha peak is 656 nm. Refer to http://www.sciencecenter.net/hutech/idas/filtplt.htm for LPS P2 and http://www.astrosurf.com/buil/filters/curves.htm for Lumicon H-Alpha pass filter (this filter is a low pass filter, not a band pass filter). The star images were superimposed with the shots (45 seconds exposure frames) taken without the Lumicon filter

光害カットフィルターのみ　（ルミコンＨ−アルファーフィルターは除去） without the Lumicon H-Alpha filter