Digital SLR Astroimaging

Digital SLR Astroimaging
DSLR: Digital Single-Lens Reflex Camera
Effective observing tool
Oregon Star Party 2005
Affordable: less than $1,000
Lower noise compared to fix lens cameras
Long exposures 4 to 8 minutes
Wide range of optical configurations
Lens & telescopes
12-bit raw image files
Lots of pixels: greater than 6,000,000
David Haworth
http://www.stargazing.net/david
Copyright 2005
Fun to use
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Canon
Nikon
Entry Digital Single Lens Reflex Cameras
Entry Digital Single Lens Reflex Cameras
EOS Digital Rebel
300D
6.3 MP
3072x2048
$660
D50
6.1 MP
3008x2000
$750
EOS Digital Rebel XT
350D
8 MP
3456x2304
$800
D70 out of
production
6.1 MP
3008x2000
$780
EOS 20D
8.2 MP
3504x2336
$1330
D70s
6.1 MP
3008x2000
$900
EOS 20Da
Astronomy Version
8.2 MP
3504x2336
$2200
D100
6.1 MP
3008x2000
$1000
Body Prices: B&H Photo 7/22/2005; OPT 20Da
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Body Prices: B&H Photo 7/22/2005
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DSLR Less Noise than Digitals
DSLR Less Noise than Digitals
1 minute exposure
1 minute exposure, top left corner cropped
6.7x
Nikon D70: ISO 200
3.8x
Nikon 990: ISO 100
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Nikon 4500: ISO 100
Nikon D70: ISO 200
Nikon 4500: ISO 100
Nikon 990: ISO 100
Nikon 995: ISO 100
7.9x
Nikon 995: ISO 100
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DSLR Less Noise than Digitals
4 minute exposure
DSLR: Digital Single-Lens Reflex Camera
Interchangeable lens & prime focus imaging
66.3x
Nikon D70: ISO 200
Nikon 4500: ISO 100
180mmED lens
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T-ring & eye piece
adapter
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DSLR
Fun to Use
Easy to mount on telescope
D70 fast & quick setup
Monitor
Tele Vue TV-60: 60mm, 360mm focal length at f/6
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IR Remote
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DSLR
DSLR
Focusing through the lens
Focusing through the lens
Mirror is down when
focusing
Mirror swings up when
taking an image
Mirror
Light hits the mirror
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Light hits the CCD
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Nikon D70 CCD
Nikon D70 CCD
6.1 million 7 µm square pixels
Charge Coupled Device
CCD converts light into
electrical signals
Hybrid Nikon-Sony CCD Design
2000 pixels high
15.6 mm high
CCD is at the focal plane
Filters
Bayer
Anti-aliasing
Infrared
Camera converts the electrical
signals into image data
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3008 pixels wide
23.7 mm wide
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D70 versus 35 mm Film
D70 CCD
D70 versus 35 mm Film
F3HP 35 mm
D70 CCD DX-Format
F3HP 35 mm
Smaller field-of-view
35 mm is 1.5x larger
Both 2:3 aspect ratio
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D70 versus 35 mm Film
DSLR versus Astro CCD
D70 larger CCD, larger FOV
CCD
Feedback at the telescope
Nikon D70 CCD
Film
Need to develop film
3008 x 2000
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SBIG ST-237 CCD
640 x 480
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DSLR versus Astro CCD
DSLR versus Astro CCD
D70 single image for color
Nikon D70 CCD
ST-237 better color resolution
SBIG ST-237 + color filters
Nikon D70 CCD
1 image with Bayer array
that interpolates pixels
SBIG ST-237 CCD
3 images with 3 filters
red, green & blue
ST-237 three images (red, green & blue) for color
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DSLR versus Astro CCD
DSLR versus Astro CCD
ST-237 lower noise
Nikon D70
D70 less electrical power
SBIG ST-237
No cooling
Electronic & fan cooled
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D70 & Monitor
Small batteries
120 Vac or 12 Vdc car battery
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Spectral Response of DSLR Cameras
DSLR versus Astro CCD
http://www.pbase.com/terrylovejoy/image/29755088
D70 faster setup
D70 & Monitor
Monitor attaches
to telescope mount
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SBIG ST-237
SBIG ST-237 & Laptop
Need laptop table
Graph by Dennis diCicco
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Hutech/Canon Enhance DSLR
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Canon Astronomy version EOS 20Da
First introduced in Japan this year
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Canon Astronomy version EOS 20Da
www.canon.co.jp/Imaging/eos20da/index.html
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Deep-space Imaging with the Canon EOS 20Da
www.lrgb.com/20da.html
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Mega Pixels versus $
Canon Astrophotography
web.canon.jp/Imaging/astro/index-e.html
8MP
7MP
6MP
5MP
4MP
20D
350D
300D
20Da
Cannon
D50, D70, D70s & D100
Nikon
STL-4020M
SBIG
3MP
2MP
1MP
ST-402ME
$1K
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ST-10XE
ST-2000XM
ST-1603ME
ST-8XME
ST-7XME ST-9XE
$2K
$3K
$4K
$5K
$6K
$7K
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Jerry Lodriguss: Canon vs. Nikon
Christian Buil: Canon vs. Nikon
http://www.astropix.com/HTML/I_ASTROP/TOC_AP.HTM
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http://astrosurf.com/buil/d70v10d/eval.htm
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Why I Picked the D70
Why I Picked the D70
Nikon Lens
Nikon F bayonet lens mount
Used Nikkor manual lens
1977 Automatic Indexing (AI) lens
High quality & low cost
Many lens work with D70 in manual mode
Have a Nikon F3HP SLR
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Manual 300 mmED lens
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Imaging Challenges
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Tracking
Seeing
Polar alignment
Wind
Diffraction
Dew
Vignetting
Light pollution
Coma
Mirror bounce
Chromatic aberration
Camera noise
Spherical aberration
Internal reflections
Finding object
Clouds
New 2005 Astroimaging Books
To solve imaging challenges
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