Cyril CAVADORE Home page

Welcome to Cyril Cavadore home page, a web site mostly dedicated to CCD ASTRONOMY, Telescope making and Photography. To know more about me !

This page is no longer updated (as Dec 2018). Nevertheless kept here.

For new events and achievements, please go here:

·         ALCOR SYSTEM company (I've founded)
· PRISM Software web site
· My Facebook page
· Video #1 here and Video #2 there (in French)
·         Youtube channel about PRISM


Last posts (till Dec 2013) :

·         All Sky camera
· Direct-drive mount prototype
·         Some site testing
· Some fisheye tests
· My Observation page

PISES observatory remotlye operated (RCE 2008 talk)


Cloud sensor system


DIMM seeing monitor software


An automated dome control


  I'm fond of astronomical observations. I have built my own telescope (250mm), running CCD camera. I am observing at IAU A86 site various kind of objects. I try to find ideas to overcome the problem of life family, professional life and light pollution that are non compliant to overnight observations. Sometimes, I am using telescopes belonging to other people/associations (Pises Observatory,….)

The full index of my nice images is available here


1999 Total Solar Eclipse
This link relates all the result we got with a CCD camera and a 200mm telescope during the famous August 99 Total solar eclipse in France. English version here.

Observing with 60cm VALMECA Telescope
It describes observing runs achieved with the Valmeca 60 cm telescope troughout the years, at Puimichel, France. This is the report presented thru these pages.
2006 Libya Jalu total solar Eclipse
This is the story of the fabulous trip I did to observe the total solar eclipse in Libya. I was plunged into the deep desert to watch this great event !


Observing under Chilian Skies
This is a run I did while I was in Chile in 2005, using the facilities provided by A.Maury (spaceobs) , under one of the best skies in the Earth. Here is my results.

Engarouines observations
Here are the observing runs I did using the observatory of my friend (L.Bernasconi). This later has produced gorgeous images of the sky using his 500mm F3 telescope.
Observing at PISES Observatory
I like to observe in this place, the nature is really impressive and the place is full of charm.I use the 500mm F/4.5 telescope, as well as photo lenses. I knew this place since 1987 and fell in love of it !


Image gallery (other telescopes)
Image gallery of observed object with other telescope than the T250 can be found following this link. You'll find here images from the VLT, for instance...

V916 variable observations
This pages provides information for those who wants to observe a variable star and contribute to a research lead by profesionnal astronomers.

Observations at Pic du MIDI
This is a magic place, above the clouds, located at 2870 m of elevation. I spent there lot of time during the early 90s. I report here my observations in this place.


Spectrography observation run
This was the first time in my life that I carried out spectrography observations ! I used the Lihres spectrograph and my F/10 Intes telescope. This was an experience to remember !!

Asteroid 9811 Cavadore
It was discovered by the Schmidt telescope located at OCA, and by A.Maury int he late 90s.




My papers Articles on Astronomy, related to technical matters

These are paper, notes that I have written during the course of my life about Astronomy and technical matters related to it. this can be on various topics


Limiting mag. reference fields
These pages is related to the limiting magnitude you can reach with your telescope. Selected fields that show stars up to magnitude 26 can be used to figure out whether a star is actual or not in your image and test your telescope capabilities. Currently a single field have been calibrated, more to come...

DIMM seeing monitor software
The DIMM aims at measuring the seeing (or turbulence) condition in a given observation site. The following page presents a DIMM dedicated software that uses a Webcam (or any directshow camera) and performs measurement 20 times per second.
Turbulence effects and high speed imaging
The turbulence effects are now well known, this paper explains the Fried radius, and all the parameters that counts for evaluating the turbulence effects with respect to a telescope aperture and atmosphere conditions.


CCD observations in suburb site
This is a 4Mb PDF file demonstrating that CCD imaging is possible even under a mediocre suburb light polluted site (In french).

Light pollution and sky background
This page discuss about the light pollution from human activities and how it increases the Sky background in CCD images. Discussion undertaken to optimize the amount of images per exposures versus Signal to Noise Ratio.
Units and systems employed in Astronomy
This is useful to know all the units employed in professional Astronomy, their meanings and their scope is explained in this pages. Page always updated ...


Star coverage for AO application
This is a not about star that can be used for AO. Bright star are not well spread on the sky to catch one for Adaptive Optics wavefront sensing. This page discusses about probability to catch a bright one in a given distance from the target.

How to enable Pises Observatory for remote observations ?
This is a pdf file that explains how Pises Observatory was upgraded to be able to be driven from thousant of kilometers appart, remotely. It aims at improving the telescope usage rate.


  Telescope making and Hardware designs Telescope making is a very nice hobby when the weather is not suitable for observing. It allows you to build your telescope for a real cheap price and to control the whole system. I have been making telescopes for 16 years, like Schmidt Cameras up to 300mm, Newton telescope up to 400mm. This involve the knowledge of mechanics, optics, electronic and computer programming.. a real challenge where improvement is always possible due to technology changes.


A 250 mm computerized telescope
This page is the index to many pages that are describing all the constructions phases of a 250 mm telescope. This telescope has to fulfill the requirement of being able to observe alone over the whole night. Currently, this is the telescope I am employing mostly.

Intes M703 180 mm tests
I have purchased in nov 2003 an Intes Alter M703 telescope. This is the main entrance to get all the pages related to it : test and use with CCD camera and webcams.
500mm telescope tracking mechanics redesign
This is basically the Pises Observatory 500 and 400 mm tracking systems that I have completely redesigned by myself. This lead to significant improvement in terms of tracking performance. but also convince me that Torque Motor are the future...


G11 Mount tests
G11 have mount have been tested here. Installed drives are MCMT II system. The mount is performing very well and tracks very well the stars. Periodic error is minimized.

Focusing system for Alter Intes M703
I have installed a focused to my M703 Intes. This focuser has a reset position achieved by a magnetic sensor.
Alt-AZ telescopes
Some plots and discussions about ALT-AZ telescope trajectories. this might be in the future a project for me ;-)


  Telescope optics Telescope optics is a very attractive field, as well as designing optical systems using ray tracing software like Zemax, manufacturing the parts and makes the sky test. I have been involved in this field since 1985. Schmidt plates, correctors, main mirror are fields that I used to enjoy to polish. I have also worked on Shack Hartmann devices.


Shack-Hartmann principle
Shack Hartmann is a powerful setup to test and tune accurately telescope optics. This page explains the principle and a shows a setup that has been assembled and tested

Shack-Hartmann talk
This is a talk given in 2003 during AUDE Seminar in Paris about basic princples of Shack Hartmann.
Schmidt Cameras
In 1992, I wrote a book to explain how to achieve a complete Schmidt camera. This book describes how to cut the Schmidt plate and all other details. This is scanned files that have been compressed down to 3.7Mo


Optic and turbulence
Turbulence affects high resolution imaging, this link explains how. Also relation with the use of webcams in astronomy is discussed as well as optical mirror quality versus turbulence trade-offs

Shack-Hartmann software
I have written a Shack Hartmann real time software that allowed me to carry out measurements and to compute wavefronts in a real time" fashion.Very funny project.
Shack-Hartmann sytem
Shack Hartmann system has been built and is used on the Sky to characterize turbulence and optical systems performance.


16383 spot (128x128) Shack Hartmann system
This is a crazy Shack Hartmann I have designed




  Detectors and CCD systems This is a fascinating field: the CCD detectors used for Astronomy. Say that, 20 years ago, a film had quantum efficiency of 2%, whereas the CCD has now up to 80%. CCD has revolutionized the way of doing Astronomy, allowing amateurs using a 20cm telescope to compete with 4m telescopes when they were using photographic plates in the late 60s. This is a field where I've being working professionally for.


Kaf1602E and Marconi E2V 47-10
This section provides a comparison between the Kodak Kaf1602E and Marconi47-10 CCD for deep sky imaging in Astronomy. This link gives hints to make you mind up about these two great CCD devices.

The Chungara CCD controller
The Chungara CCD controller is a low noise system able to read out many kid of CCD. It uses the Ethernet interface to transfer the data to the computer. In 2001, it was an UNIQUE feature !
CANON EOS 20D CMOS detector tests
This is a page that deals with 20D CMOS sensor measurements (read out noise and dark current)


Sony XCD-V50 camera tests
A test with a Sony firewire camera mounted into a long focal length telescope. An expensive but capable camera.

Backside illuminated CCDs
This is an old, but still valuable paper about backthinned devices and their benefits for color imaging.
Interline shutter
The use of interline CCD can avoid the use of an expensive mechanical shutter. This electronic shutter can leak a bit... see how much.
  DMK QHY5 and QSI comparison
Have a look here how performs a DMK with a sony CCD compared to a QHY5 with a micro CCD and a QSI with a KAF1603 CCD.
KAF-6303 blooming
Old KAF sensors does not have blooming protection, see how this is impacting image quality with bright stars.


PRISM software   Prism is an Astronomical image processing and sky Atlas software that I have been writing since 1992. It's been used worldwide.
It is made of 880.000 Delphi line code, and features hundred of functions to prepare and to take the best benefits of your astronomical observations. The current release is V8, first released in March, 17th 2011

These page intend to provide some application note regarding PRISM


Users FORUM (French)
This is the link where you can register to the forum to share information. Thiscan help you to overcome problems related to PRISM and share your experience.

Here is a trick to setup Prism v6 for Windows VISTA. Prism v7 is not affected by those issues and runs with no user specific setup changes from OS.
Ascom drivers are used widely and can support a lot of hardware (filter-wheels, dome, telescopes, focusers and CCD cameras). This links explain how to setup Prism to use ASCOM interface.


Script editor
his page recommends the nicest script editor that can be used to edit PRiSM script. Color syntax is supported.

PisesAtlas-Prism said PAP98
PAP98 is an old version of PRISM that can be loaded here. It comes with all the features for free. Just download and install!

PRISM CPA file handling
This page explains how to read CPA images format (source code and DLL included).


Blooming cleaning
Cleaning a CCD image from the bright star blooming can be a nightmare... This is presenting how PRISM can deal with that and perform image cleaning from blooming.

Process images from digital SLR camera
A kind of tutorial that guides you to preprocess images from digital cameras and obtain nice deep sky images, from Raw images from SLR cameras such as Nikon, CANON EOS 10D or 20D.
PRISM Courses and training


Additional help pages related to PRISM
This provides additional help to Prism software use.

Prism pages (2009)



Electronics Designs Electronic design is part of telescope making, it starts by driving RA/DEC axis of telescopes, proceed to assistance to focusing, to drive a dome, to drive a CCD camera, etc etc.. Electronic is nowadays unavoidable to point the telescope towards an invisible target, achieve automated telescope. This section will provide general purpose designs, as well design related to telescope driving.


This is an electronic system that allows to synchronize a Dome with a Telescope. It takes into account that the telescope Pier is not at the center of the dome. This has been deployed at Pises Observatory and Valmeca. It works very well with PRISM also.

Embedded Ethernet interface
This section provides all the information related to a custom- made Embedded Ethernet Interface that can be used with a CCD camera to transfer data to a WINNT based OS PC. This design can be used for all application requiring high speed data transfer to a PC.
Switches driven by Ethernet
This shows how a set of general purpose high power switches can be driven by the Embedded Ethernet interface. The goal of such a design is to enable the PC to switch on/off devices remotely. This is a basic brick for an automated remote observatory. This design can open-close a dome, switch on the telescope drives, telescope CCD, etc etc...


MCMT II is system that turns your telescope into a GOTO telescope. Based only on step motors. Telescope up to 600mm can to point everywhere in the sky. Have a look, it worth to be seeing.

Cloud Sensor system
This is a design based on an infrared sensor to measure the cloud coverage. It does as well magnitude per arsec square measurments, wind, temperature humidity.. A lot of work !
EOS Digital camera Remote Control System
The current EOS remote control system provided for performing astronomical images is insufficient. This page shows a system developed for the purpose of achieving long exposures images allowing total control from a PC.


Weather, climate and all SKY systems What could be Astronomy without any basic knowledge of weather forecast and climate ? Since weather is an important component of astronomical observation, it disserved its whole section.
Also, additionnal information is put here about cloud sensors, all sky camera, that are now common use in Astronomy.


EUROPE Sunniness
Whole Europe “Sunniness” data is quite impossible to find. So based on satellite images I have made my own statistics for year 2001. This pages explain also the method to achieve these results.
New : Better statistics here

FRANCE Climate and sun
This sections shows a whole set of charts related to France climate and its sunniness. This is the data compiled by Meteo France for many years.

Link to best satellite images site
This is the link to DRSD UK meteorology; this is the web site that shows the nicest satellite images and compute your own statistics. Also this is one is not so bad : meteosurf


Lacrosse Weather Station 3600
Free software for handling data created by Lacrosse 3600 Weather Station .

Peleng 8mm Fisheye review
A test of this fisheye, not so bad, not so good.. I would love to carried out the same test with SIGMA lenses...


Cloud Sensor system
This is a design based on an infrared sensor to measure the cloud coverage. It does as well magnitude per arsec square measurments, wind, temperature humidity.. A lot of work !


My Weather web page
[real time updated
This section points to a web page that summarizes the weather conditions in the place I live. Also measure the cloud coverage with a cloud sensor with an IR sensor.

Starway S1 as a all Sky camera
I was wondering if the camera could perform well to be used as an all Sky camera. You get the reply if you click on the link above.


Photography That's a real hobby...Photography section will show pictures from the trips I have made around the world. If you want to use the picture, please, be kind to ask permissions and credits to use it for your own purpose...


Link to my pictures (General)
By clicking here, you will access the index web page to all other sections related to my pictures.

Paranal Obs from Plane
On the way back to Santiago ... :-)


Updated by Cyril Cavadore, all right reserved. Ask for authorization to use images and documents.

To know more about me and my professional path, have a look here.