Colours of the Night Sky The Amateur Digital Astrophotography Piotr Fita Warsaw University, Faculty of Physics, The Optics Lab The Astronomical Club ALMUCANTARAT.

Colours of the Night Sky

The Amateur Digital Astrophotography

Piotr Fita

Warsaw University, Faculty of Physics, The Optics Lab

The Astronomical Club ALMUCANTARAT

Logo designed by Armella Leung, www.armella.fr.to translated by Robert M. Sadowski

This project has been funded with support from the European Commission.This publication reflects the views only of the author, and theCommission cannot be held responsible for any use which may be made of theinformation contained therein

http://www.armella.fr.to/





Festiwal Nauki 2005 Barwy nocnego nieba

What Do We Make Photos of the Night Sky for?

• To see more

• To see in colours

• To record the rare events


What Can We Make the Photos of the Sky with?

With anything we have at hand!

•The digital compact photocamera

•The SLR photocamera (either digital or standard)

•The webcamera


Digital Compact PhotocameraSpecifications The simplest

modelThe best

modelMaximal exposure time ½ s 10 min

Maximal sensitivity (film speed) ISO 100 ISO 400

Maximal aperture size 4 1,5

Focal length (equivalent to the 36mm picture format)

35 mm 28-200 mm

38-350 mm

PRICE ~ € 125 ~ € 500


Digital Compact Photocamera

• Photography of the constellations

Applications

Olympus C-5060 WZ

Phot. Piotr FitaThe Astronomical Club Almucantarat



• Photography of the Moon and planets

Applications


Canon Powershot A20 with telescope of F = 900 mm



• Photography of the rare events

Applications


Venus in transit across the solar disc, June 8, 2004 r

Canon Powershot A20 with telescope of author’s own design



• Photography of the big star clusters

Applications

And many other…


The open star cluster Praesepe

Olympus C-5060 WZ


The SLR Photocamera (either digital or standard)

Maximal exposure time Anyone

Maximal sensitivity (film speed) 1600 ASA

It may have attached lens of any typeor be directly attached to the telescope

PRICES:

Standard SLR camera : € 12-50 film 1600 ASA: € 10

Digital SLR camera: > € 600 ,

But this is the best tool for astrophotography!


The SLR Photocamera (either digital or standard)

Applicable to photography of all objects, even the nebulae

Phot. Piotr Fita, Andrzej RzepeckiThe Astronomical Club Almucantarat

The nebulae in Orion

Standard SLR camera EXA Ib

The „North America” nebulosity

Digital SLR camera Canon EOS 300D

The Zenit 135 mm telephoto lens


The WebcameraIn connection with a telescope or photo lens allows

to take pictures of the Sun, the Moon, and the planets

Phot. M. Marszałek, E. Chludziński, A. Dwornik, R. Konieczny, G. Mikołajczyk, A. Rzepecki, M. Tokarski, A. Urbańska, W. Warkocki, R. Zięba,

The Astronomical Club ALMUCANTARAT


The WebcameraAfter modification allowing for the long exposures it is also

suitable to take pictures of the nebular objects

Phot. M. Marszałek, P. Fita, N. Domińczak A. Majcher, M. Nowakowski, W. Rutkowski, A. Urbańska, R. Zięba

The Astronomical Club Almucantarat


The Webcamera

Total cost:Camera: ~ € 25

Modification: ~ € 12 (the Philips cameras only)

Adapters: € 10 PLN

Lens: up from € 9

Very economical method!

but

the laptop is recommended!

http://ccd.astronet.pl


How to Make a Photo of the Sky? Method 1 – the simplest

In the main focus of the fixed camera

Advantages:

•Simplicity

•Saving time

•Minimal efforts and expenses

Shortcomings:

•The blurred star-tracks at the long exposures

•Weak objects may remain unrecorded

Or „just so…”


How to Make a Photo of the Sky?

Method 1 – the simplest Let’s go:

1. Mount the camera on a tripod

2. Set up manually distance scale to infinity (in the simple digital

cameras use the „landscape” mode)

3. Set up the lowest aperture number, the exposure time for a few or

even for some tens of seconds, and high sensitivity (film speed)

of ISO 200-400

4. In order to avoid vibrations release the shutter by a remote control

cablean electronic pilot, or by a mean of a self-shutter

The results?



Method 1– the simplest

Disappointed?

The stars are too small?

No colours?

Let’s make the stars blurred!


Olympus C-5060 WZ, focused for the wide range (f = 28 mm) exposure 15 s


How to make a Photo of the Sky?

Method 1 – the simplest

Cygnus

Lyra

Sagitta

Delphinus Aquila

fot. Piotr FitaKlub Astronomiczny Almukantarat

Olympus C-5060 WZ, focused for the wide range, f = 28 mm, ekspozycja 15 s



Method 1 – the simplestHow to choose the focal length?

To make pictures of the constellations f = 28-200 mm is sufficient

While

To obtain photos of the Moon, the Sun (with filter only!),

and planets The focal length above is required 500 mm

Hence the reflex (SLR) camera is indispensable!



Method 2- more difficultWin the so-called afocal projection,

i.e. with camera directly touching the eye-piece lens (of a telescope, psy-glass, binocular…)

Advantages:

•Big magnification with compact camera

•Low expenses

Shortcomings:

•Worse picture quality than in the main focal plane

•Method more complicated than photography in the main focus



Method 2 - more difficult Let’ go:

1. Set up manually distance scale to infinity (in the simple digital

cameras use the „landscape” mode);

2. Aim the telescope (a spy-glass or binocular on tripod) at the chosen

object;

3. Apply (attach) a camera to telescope’s eye-piece;

4. Focus the image carefully with the telescope’s eye-piece control screw

while observing it at the camera display (or in the viewfinder of the

SLR camera);

5. Release the shutter;

6. The focal length, aperture size, and exposure time have to be found

experimentally. Results?


How to make a Photo of the Sky?

Method 2 – more difficult

Partial Solar eclipse, May 31, 2003Canon Powershot A20 + spy-glass with magnification 12x




Method 2 – more difficult

Canon Powershot A20 + telescope of 27 cm diametre and focal length 4.5 m

Phot. Piotr Fita, Agata KarskaThe Astronomical Club Almucantarat



Method 2 – more difficultHelpful advices:• To attach a camera to any telescope it is useful to buy

(to do it yourself) the special sleeve (F-adapter);

• In compact cameras with zoom lens the longest focal lengths (tele) should be set up;

• The camera’s lens has to touch the eye-piece of a telescope.


With, or Without Tracking?

Taking pictures of the weak objects requires tracking the camera along the diurnal movement of the sky

fot. Piotr FitaKlub Astronomiczny Almukantarat

Exposure time 13 min Exposure time 15 s

The Earth’s rotation

Apparent diurnal movement of the celestial sphere

The blurred traces of stars on the pictures with long exposure time

Only bright objects cab be seen on the pictures

with short exposure time


With or Without Tracking?

Without tracking With tracking



The mount with tracking can be:

• Done by yourselfVademecum of the Amateur Astronomer,

Internet – the „barn door” type mount

• PurchasedMeade, Celestron, Orion, Uniwersał



Drive

Hand Electric

Mechanic(Orion, Uniwersał)

Digital(Meade, Celestron)

For the astrophotography purposes the mount has to be equatorial (paralactic), and not azimuthal!


The Computer Picture Processing

The computer picture processing makes up to 70% of the digital astrophotography!



Golden rule of the digital astrophotography:

Take as many as possible identical photos and add them all together

20 photos by 15 secs each

=

one photo exposed by 5 minuts!



Golden rule of the digital astrophotography:

Take as many as possible identical photos and add them all together

Advantages:

• Noise reduction• Increasing sensitivity• Pictures with long effective exposure time with no

tracking!

IRIS

C:\iris\iris.exe


Visualization

Adding

Superposing

× 23

Phot. Piotr Fita, Andrzej RzepeckiThe Astronomical Club Almucantarat


Visualization• Blurring the star images

• Removing the background

• Lowering the contrast

• Sharpening the pictures of the Moon and planets


CorrectionRemoving the dark frame

=

-

dark framesingle exposure



CorrectionRemoving the dark frame

Galaxies M81 and M82

Webcamera with F = 50 mm lensPhot. Piotr FitaThe Astronomical Club Almucantarat


CorrectionThe blurred pictures

The Little Dipper (Ursa Minor)

The standard SLR camera with F = 135 mm lens Phot. Piotr FitaThe Astronomical Club Almucantarat

Richardson – Lucy’s algorithm


CorrectionRemoving the regular structures

M31 Galaxy

The webcamera with F = 135 mm lens, photo made in the B band Phot. Piotr FitaThe Astronomical Club Almucantarat

Filtering with help of the Fourier transform


How To Do It?

SuperposingAdding

VisualizationCorrection

and many other options…

The IRIS programhttp://www.astrosurf.org/buil/us/iris/iris.htm

IRIS is freeware!


Other programs

• Astrostack

http://www.astrostack.com/

• TeleAuto

http://www.teleauto.org/indexEn.php


Knowledge

• A webpage dedicated for the digital astrophotography:http://ccd.astronet.pl

• „The CCD Observatory at School”(incl. A practical manual of IRIS program)http://www.cft.edu.pl/~tomsow/ccd/ccd_pl.pdf

• Homepage of the EU-HOU Projecthttp://www.cft.edu.pl/astro/


Shopping

• Delta Optical

http://www.deltaoptical.com.pl

• Astrokrak

http://www.astrokrak.pl

• Uniwersał

http://www.universe.com.pl

• Website i-sales Allegro

http://www.allegro.pl


You can take nice photos of the sky almost with any camera!

Good Luck!

Colours of the Night Sky The Amateur Digital Astrophotography Piotr Fita Warsaw University, Faculty of Physics, The Optics Lab The Astronomical Club ALMUCANTARAT.

Documents

festiwal nauki

slr photocamera

wz slide

design slide

telephoto lens slide

standardthe webcamera

standard maximal exposure

planets applications