The Lhires spectrography micrometer was adjusted in increments of 0.50 while taking spectrum images of the Sun. There is about 50% overlap of the images when using micrometer increments of 0.50.

The short wavelengths are on the left side of the spectrum image and the longer wavelengths are on the right side of the spectrum image.

Sony NEX-6 camera sensitivity decreases in the blue short wavelengths and in the red short wavelengths.

The below images are vertically cropped and they are resized 25% of the full image size of 4912 x 2760.

YouTube Videos

• Sun Spectrum with Shelyak Instruments Lhires III & Sony NEX-6 camera showing the Sun spectrum from the blue wavelength to the red wavelength.
• Blue Sky Spectrum with Shelyak Instruments Lhires III & Sony NEX-6 camera showing the blue sky spectrum from the red wavelength to the blue wavelength.

Lhires Micrometer Setting 13.0: DSC02190.JPG

Sony NEX-6 sensitivity limit in the blue short wavelengths.

Lhires Micrometer Setting 13.5: DSC02191.JPG

Lhires Micrometer Setting 14.0: DSC02192.JPG

Lhires Micrometer Setting 14.5: DSC02193.JPG

Lhires Micrometer Setting 15.0: DSC02194.JPG

Hydrogen beta Fraunhofer F absorption line at the center-left of the spectrum.

Lhires Micrometer Setting 15.5: DSC02195.JPG

Hydrogen beta Fraunhofer F absorption line at the left part of the spectrum.

Magnesium triplet Fraunhofer b₄, b₃, b₂ and b₁ absorption lines at the right edge of the spectrum.

• 5150 to 5200 Angstroms Magnesium triplet

Lhires Micrometer Setting 16.0: DSC02196.JPG

Magnesium triplet Fraunhofer b₄, b₃, b₂ and b₁ absorption lines at the center of the spectrum.

• 5150 to 5200 Angstroms Magnesium triplet

Lhires Micrometer Setting 16.5: DSC02197.JPG

Magnesium triplet Fraunhofer b₄, b₃, b₂ and b₁ absorption lines at the left edge of the spectrum.

• 5150 to 5200 Angstroms Magnesium triplet

Lhires Micrometer Setting 17.0: DSC02198.JPG

Lhires Micrometer Setting 17.5: DSC02199.JPG

Lhires Micrometer Setting 18.0: DSC02200.JPG

Sodium doublet Fraunhofer D₁ and D₂ absorption lines at the right side of the spectrum.

Lhires Micrometer Setting 18.5: DSC02201.JPG

Sodium doublet Fraunhofer D₁ and D₂ absorption lines at the left side of the spectrum.

Lhires Micrometer Setting 19.0: DSC02202.JPG

Lhires Micrometer Setting 19.5: DSC02203.JPG

Lhires Micrometer Setting 20.0: DSC02204.JPG

Hydrogen alpha Fraunhofer C absorption line at the right edge of the spectrum.

Lhires Micrometer Setting 20.5: DSC02205.JPG

Hydrogen alpha Fraunhofer C absorption line at the center-left of the spectrum.

Sony NEX-6 sensitivity decreases in the red long wavelengths caused by the camera's infrared filter.

Equipment

• YouTube Video: Mg Triplet Solar Spectrum - Lhires III, NEX-6 showing the equipment used to take images of the Sun's spectrum.
• Shelyak Instruments Lhires III
  • Grating module 2400 gr/mm
  • Model#: SE0082 CCD adapter for Lhires III to mount a QSI ccd camera ('ws' front plate) on a Lhires III. Thread: M42x0.75 backfocus: 34.9 mm
  • Celestron 25mm eyepiece and 2X Barlow in the guider port
    • NOT USED FOR SOLAR IMAGING
    • Used for Moon imaging
  • Model#: PU0024 Photographic Tripod Adapter
• Optics attached to the Lhires III
  • Baader T2 Extension Tube - 40mm for lens shade
  • Edmund Optics T-Mount Iris Diaphragm Barrel Stock #52-299 to reduce the Sun light.
  • Edmund Optics Achromatic Doublet Lens 40mm Dia. x 160mm FL, MgF₂ Coating Stock #32-923
    • I happen to have this lens, so I used it. The lens f/4 is too fast for the Lhires III which is designed for f/10 telescope. When the the iris is closed down to 16 mm diameter (f/10) then the optics is a good match for the Lhires III f/10 design. When the iris is less than 16 mm diameter the spectrum resolution will decrease because the grating is not fully illuminated.
  • Edmund Optics 10mm T-Mount Extension Tube Stock #52-294
  • Baader Varilock T-2 Extension 20-29 mm
  • SCT male to T-mount adapter
  • Agena AstroProducts Blue Fireball # S-SB SCT Thread Spacer Ring with 1" Extension modified to fit on the Lhires III
• Sony Alpha NEX-6 mirrorless digital camera
  • Imaging Sensor : 16.1MP Exmor APS-C HD CMOS sensor (23.5 X 15.6mm)
  • Still Image Size 16:9 : L: 4912 x 2760
  • Still Image Size 3:2 :4912 x 3264
  • Interchangeable Lens Mount Type: Sony E-mount
  • Sony E-mount to T adapter
  • 5mm T-Mount Extension Tube
• Astro-Physics Mach1 GoTo mount

Image Processing Software

• Adobe Photo Shop CS5 to crop and resize JPG spectrum images

Sony NEX-6 Camera Image Information

• Image exposure: 1/4000 second
• Image size: 4912 x 2760
• ISO: 100
• White balance: Daylight
• Creative Style: Standard
• Contrast: Normal
• Saturation: Normal
• Sharpness: Normal
• DRO / Auto HDR: Off
• Manual Focus Assist: On
• Color space: sRGB
• Release without lens: Enable
• Long Exposure NR: On
• High ISO NR: Normal
• Custom Key Settings: Soft key B Setting: MF assist

Sun Spectroscopy Images

• High resolution solar spectrum by NOAO

Sun Spectroscopy

• Spectroscopic Atlas 5.0 (English), Chapter 17 Spectral Class G, by Richard Walker

Sun Spectroscopy Atlases

• The Interactive Database of Spectral Standard Star Atlases
• High resolution solar spectrum by BASS2000
• Liege Solar Spectral Atlas
• Spectroscopic Atlas for Amateur Astronomers by Richard Walker

Sun Fraunhofer Lines

• Fraunhofer Lines by Wikipedia

Spectroscopy

• Analysis and Interpretation of Astronomical Spectra Version 9.2 12/2013, by Richard Walker