This page is an introduction to the whole site
Canon EOS 5D 100-400mm @ 400mm
1/1000s f/11 ISO400 2007:04:27 17:56:17
This web site is about both creative and technical aspects of photography.
It may be of interest to anyone with a camera. Find out how to take interesting photos of all kinds of things.
Have a go at photographing the night sky. It's surprising what simple cameras can reveal, even from our light-polluted towns and cities. There is a real chance you could spot something new - a nova or a comet.
There are more advanced techniques on these pages for those who are already hooked on astrophotography. Measure your images and do some real science.
Canon EOS5D Meade ETX-125 37x20s f/15
ISO3200 2008:01:16 20:22:54 - 20:39:51
GR's Image Processor (GRIP) is free to download from here and will run on just about any computer. It's not limited to Windows and it can do many things that standard digital photo applications cannot.
And if you are a programmer you can find here all the information needed to extend GRIP to do whatever you want. It's a comprehensive starting basis for very creative or highly technical image processing and analysis.
A question: if you have a camera, what is the greatest distance from which you have photographed anything?
You might say 30km (20 miles) or so, that being the distance of the horizon in a landscape.
Think again. Have you ever included the moon in any of your shots? If so you have to multiply your answer by more than 10,000. The moon is 384,000 km (240,000 miles) away.
Canon EOS5D 100-400mm lens at 285mm 1/1000s
f/5.6 ISO400 2008:2:11 17:52:05
Have you photographed the sun at sunrise or sunset, or inadvertently included it in a daylight shot? If so, multiply by another 400. The sun is so far away that its light takes 8.3 minutes to reach us. So we can say the sun is just over 8 light-minutes away.
Have you tried putting your camera on the ground facing upwards at night and taking a long exposure to see star trails? you don't need a fancy camera to do that. (More on that idea is described here.) Most of the brightest stars are around 10 to 100 light years away - their light takes 10 - 100 years to reach us. That's 6 hundred thousand to 6 million times further away than the sun.
Still using nothing more than a cheap camera, though it would help to put it on a simple tripod, if you aim it in a certain direction in the constellation of Andromeda you can photograph the nearest galaxy outside our Milky Way. The Andromeda Galaxy (known to astronomers as M31) is about 2 million light years away. It is just visible to the naked eye as a faint patch of light provided you know where to look and your local street lights are not too bright. It is the furthest object that can be seen without optical aid.
Cameras, even cheap ones, can do better than the naked eye by taking long exposures. The main difficulty then is the rotation of the earth, causing objects in the sky to trail and blur. On these pages you can see how software such as GRIP can remove that problem. (Start at the same reference as the previous one: here.)
Adding more equipment helps of course. A motorised tripod, compensating for the earth's rotation, is the first thing to get. Mount the camera on it directly, as shown here. Then of course a telescope. And in due course a bigger telescope. With my 254mm Newtonian I have photographed a group of galaxies called Stephan's quintet. Alright, it is only a faint blur. The staggering thing is that most of that blur is caused by light emitted 300 million years ago! And yet I can catch it in my camera in my own back garden.
But you really don't need either a motorised tripod or a telescope to see some amazing things. Have you photographed the craters and mountains on the moon? You probably can, especially if your camera is recent and therefore has at least 6 megapixels. The moon photo above was taken without tripod or telescope. I have a page that explains why first results usually seem disappointing but that you only have to enlarge the picture to do better than Galileo could.
Galileo was the first to see the 4 principal moons orbiting Jupiter. Today it is possible to photograph them without a telescope. [Example to be added here soon.]
I have developed GRIP over several years to solve a particular problem in astrophotography but along the way it has grown into a flexible general-purpose tool that I use in various ways to assist my own photography. Not only is the complete working software of GRIP available but also its workings are discussed, along with many aspects of digital photography. This is not commercial. I am simply making it available for others to use.
Scientific uses of the software are possible because GRIP includes many facilities for measuring photographs. There is even a printable scale for calibrating photographs.
Canon EOS5D 24-105mm lens @ 47mm 3 x 1/20s f/22 ISO800 2006:06:27 17:49:37
Creative, fun and artistic uses abound too and examples will be shown in these pages. Further possibilities in that direction are limited only by your imagination. Here is an example created with GRIP from 3 successive images:
Canon EOS10D Sigma 70-300mm @ 300mm
2 x 1/750s f/9.5 ISO200 2004:08:28
The photo of heron and curlews shown here is another example, created by subtracting 2 photos. Both of those examples required the camera to be on a tripod to provide a fixed background in successive shots of some moving subjects.
GRIP is written in Java. Some will be quite surprised at the idea of processing photographic-sized images with Java. So one aim of this site is to demonstrate that in fact this is very feasible with today's readily available computing power. Only quite ordinary PC's are required. However, these pages delve into certain quirks of the Java programming environment and how they have to be dealt with in order to achieve satisfactory performance.
If you only want to improve your photographic technique, there are pages about that kind of thing too, so please explore from here. See the contents and index pages.
I have been using Canon EOS digital SLR cameras since the beginning of 2001, starting with the 3 megapixel D30. I have traded up 4 times since then so I am now using a 5D MkII. That has over 21 megapixels. One of its RAW images loaded into memory occupies 124 megabytes. I almost always photograph in raw mode and the significance of that is also explained in these pages. I will show how such images can be processed in only a second or two by GRIP running on a typical PC under Windows.
The third-party library jrawio, used by GRIP for reading raw images, is not yet fully working for the 5D MkII camera, so I first have to convert my raw images to TIFF format. I am hoping that will only be a temporary problem.
I have received user feedback that GRIP does also work fine under Linux. It should work on any platform for which Java (Standard Edition) is available.
Graham Relf is a keen amateur photographer who has dabbled in astrophotography for many years. So long in fact that during that time he has progressed from a Kodak Brownie box camera (which he now wishes he had not dismantled) to a Canon EOS digital SLR. He has worked in software design and development for almost as long. He started programming in FORTRAN using punched cards but was until recently a technical architect for a major commercial web site. He has now retired. In the 1980s and 90s he worked for a pioneering company in the field of image analysis, mainly for biological and medical applications. He has a degree in physics and is fascinated by both scientific and creative uses of digital imaging.