1. Blythe Guvenen Kitt Peak Visitor Center

2.  Astrophotography is a specialized type of photography that involves making photographs of astronomical objects in the night sky such as planets, stars, and deep sky objects such as star clusters and galaxies. photographyplanetsstarsdeep sky objects

3.  Astrophotography is used to reveal objects that are too faint to observe with the naked eye.  Digital cameras  Can accumulate and sum photons over long periods of time.  Astrophotography poses challenges that are distinct from normal photography.  Subjects are usually quite faint, and are often small in angular size.

4.  First photographic plate, thin film of polished silver on a copper base.  Invented by Louis Daguerre in 1838

6.  First to photograph the Orion Nebula; September 30 th, 1880  50 minute exposure!

7.  No permanent record of images.  No way to change exposure time.  No good way to measure quantitatively.

8.  Pros:  Well-established  Archival quality (black and white)  Cons:  Finicky to temperature, humidity, processing conditions  Fragile; brittle  Low efficiency: 1-10%  Non-linear (reciprocity failure)  Difficult to get quantitative information  Nearly extinct!

9.  Semi-conductor based solid state detectors  Incoming photons generate electrons that are added up to form an image  Excellent quantum efficiency: 60-90+%!  Available for a wide range of wavelengths:  300 - 1100 nm (Si)  1 - 5 µm (InSb)  1 - 25 µm (HgCdTe)

10.  Good quality, wide-angle photographs of the night sky can be made by almost anyone using a single lens reflex digital cameras.  Should travel far away from the bright, light- polluted skies.  Prevent the photograph from being completely washed out and ruined by bright urban light pollution.

11.  Equipment needed  Camera capable of long (>30 sec) exposures  Sturdy tripod  Techniques  Amount of trailing depends on exposure time and declination  Digital stacking  Time-lapse

13.  Equipment  >30 second exposures  Tracking mount  Piggybacked camera w/ lens  Techniques  Digital stacking  Foreground will trail (unless you use a flash to freeze it)

15.  Use CCD with “Hyperstar” or modified webcam  Short exposures = less expensive mount  Align and stack  Exact polar alignment is less important  Larger periodic error is tolerable  Unguided

16.  Good mounting is critical  Exact polar alignment is necessary  Solid connections (rings, plates, etc.)  Must be guided  Manual or auto  Need reticle EP or autoguider

21.  Guiding  Piggyback  Need adjustable rings  Need larger mount  Differential flexure  Off axis guider  Can be hard to acquire guide star  Built in autoguider  Guides through filter  less sensitivity

22.  Afocal  “Prime” focus  Eyepiece projection  “Piggyback”

23.  Simplest telescope coupling (unguided) - Skylight filter recommended (protect camera lens)  Difficult alignment and focussing  Variable results - lots of patience!  Good telescope method to start with - Digital cameras  Requires good quality eyepiece

27.  Camera directly coupled to telescope  Telescope objective acts as very long focus lens  Camera replaces telescope eyepiece  Focusing easier than afocal method  Telescope guiding desirable!

28. Focus on chip Cassegrain telescope Camera Off-axis guider Detector