Astropics with digital camera/ Remodeled Nikon D70

TEST REPORT
		Astropics with Digital Camera Remodeled Nikon D70---

In recent years, it's getting familiar to use low-priced digital SLR cameras for astro-photographing. Digital SLR cameras have various merits compared with past film-cameras, but it has a major demerit that we cannot capture reddish diffused nebulae, which radiate H-alpha spectrum, because its low-pass filter installed in front of CCD unit obstructs the nebula's light. Accordingly we can raise sensitivity for H-alpha band by replacing the filter and capture clear digital images of reddish nebulae.
In this section I have displayed some sample images taken by a "remodeled" digital SLR camera of Nikon D70 purchased in Feb 2005.

  This D70 camera has a feature that long-exposed images are fogged by amplifier heat and I have to reduce the noise. I'm using a noise-erasing software of "RAP" that has been developed by a Japanese amateur astro-photographer.
  And this camera has been replaced its low-pass filter so the sensitivity for red color has been very raised, it's indispensable to readjust the white-balance in process of image retouching.
  By remodeling I can get very satisfied astro-images, but as displayed in bottom of this page, it's needed to preset the white-balance when I take normal pictures. It can be said that this camera is of poor practical use for general photographing. In case of remodel, you have to consent this demerit with a good grace.

D70 camera body with its filter replaced.
In lower left shows you a removed original one.

1. Example images with photo lenses

	A star field image around Orion captured with 4min. exposure time. You can detect some H-alpha nebulae like the Barnard's Loop, around Horse-head Nebula and so on. Taken at Hokuto city, Yamanashi pref. Feb 11, 2005, 22:24 JST, 4min. exp., AF Zoom-Nikkor 24-85mm, f=35mm, stop: F3.5, Auto-guided with TAKAHASHI JP Equatorial CCD sensitivity: ISO800 Noise erased with RAP, WB & level adjusted with Nikon Capture 4 Recording format: 12bit CCD-RAW, converted to 8bit TIFF(3008 x 2000)

	A star field image around the Rosette Nebula captured with a telephoto lens. You can see complicated structures of nebula. Taken at Hokuto city, Yamanashi pref. Feb 11, 2005, from 21:52 to 22:06 JST, 4 shots composed with 4min. exp., TAMURON SP f=300mmF2.8, stop: F4.0, Auto-guided with TAKAHASHI JP Equatorial CCD sensitivity: ISO800 Noise erased with RAP, WB & level adjusted with Nikon Capture 4, composed with Photoshop 5.5 Recording format: 12bit CCD-RAW, converted to 8bit TIFF(3008 x 2000)

	A star field image around the Milky Way in summer with a wide-field lens. You can detect some H-alpha reddish nebulae. Taken at Koumi town, Nagano pref. Apr 16, 2005, from 25:48 to 26:01 JST, 4 shots composed with 4min. exp., AF Zoom-Nikkor 24-85mm, f=35mm, stop: F3.5, Auto-guided with TAKAHASHI EM-200 Equatorial CCD sensitivity: ISO800 Noise erased with RAP, WB & level adjusted with Nikon Capture 4, composed with Photoshop 5.5 Recording format: 12bit CCD-RAW, converted to 8bit TIFF(3008 x 2000)

	Around star field of the North-American Nebula taken with zoom telephoto lens. Taken at Hitachi-Oota city, Ibaraki pref. May 3, 2005, from 24:28 to 24:45 JST, 4 shots composed with 5min. exp., AF Zoom-Nikkor ED 80-200mm, f=200mm, stop: F2.8, with IDAS LPS-P1 filter, Auto-guided with TAKAHASHI EM-200 Equatorial CCD sensitivity: ISO800 Noise erased with RAP, WB & level adjusted with Nikon Capture 4, composed with Photoshop 5.5 Recording format: 12bit CCD-RAW, converted to 8bit TIFF(3008 x 2000)

2. Example images with TAKAHASHI 16cm epsilon

	Around the Horse Head Nebula in Orion. This camera can capture more detailed structures than that with normal films. Taken at Hokuto city, Yamanashi pref. Feb 11, 2005, from 20:05 to 20:18 JST, 4 shots composed with 4min. exp., TAKAHASHI 16cm(6.3") epsilon, Auto-guided with TAKAHASHI JP Equatorial CCD sensitivity: ISO800 Noise erased with RAP, WB & level adjusted with Nikon Capture 4, composed with Photoshop 5.5 Recording format: 12bit CCD-RAW, converted to 8bit TIFF(3008 x 2000)

	A supernova remnant of IC443 in Gemini. You can see dimmed H-alpha region in eastern part of the nebula. Taken at Hokuto city, Yamanashi pref. Feb 11, 2005, from 22:37 to 22:50 JST, 4 shots composed with 4min. exp., TAKAHASHI 16cm(6.3") epsilon, Auto-guided with TAKAHASHI JP Equatorial CCD sensitivity: ISO800 Noise erased with RAP, WB & level adjusted with Nikon Capture 4, composed with Photoshop 5.5 Recording format: 12bit CCD-RAW, converted to 8bit TIFF(3008 x 2000)

	A close-up image of the California Nebula in Perseus. Taken at Hokuto city, Yamanashi pref. Feb 11, 2005, from 19:31 to 19:45 JST, 4 shots composed with 4min. exp., TAKAHASHI 16cm(6.3") epsilon, Auto-guided with TAKAHASHI JP Equatorial CCD sensitivity: ISO800 Noise erased with RAP, WB & level adjusted with Nikon Capture 4, composed with Photoshop 5.5 Recording format: 12bit CCD-RAW, converted to 8bit TIFF(3008 x 2000)

3. Example image with Meade 10" Schmidt-Cassegrain

This image shows you the Pinwheel Galaxy M101 captured on prime focus of f=1600mm. Some H-alpha region along its arms have been recorded as reddish figures. Taken at Hokuto city, Yamanashi pref.

Feb 11, 2005, from 25:05 to 25:40 JST, 4 shots composed with 10min. exp.,
Meade 25cm(10") Schmidt-Cassegrain with reducer, Auto-guided with Meade LX200 Equatorial & Pictor 201XT
CCD sensitivity: ISO1600
Noise erased with RAP, WB & level adjusted with Nikon Capture 4, composed with Photoshop 5.5
Recording format: 12bit CCD-RAW, converted to 8bit TIFF(3008 x 2000)

4. Change of color-balance in general photographing

	An upper image has been captured with a white balance of "Auto", and lower one has been taken with manual-preset of white balance. Images with auto WB show you very reddish color but we can see normal colored images by presetting the white balance. Both images taken with ISO200 and program auto mode with f=85mm lens.

	Copyright(c) 2005 by Naoyuki Kurita, All rights reserved.
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