How do you shoot a galaxy from your backyard?
While many of us have been amazed in the recent years by the images from Hubble & JWST space telescopes, not many are aware how much can be captured with much humbler equipment even from a city. I have imaged Deep Space Objects (DSO) like galaxies & nebulae millions of light years away right from my backyard in suburban Auckland.
Many DSO are not visible at all to the naked eye or even with a visual telescope, but the modern camera sensors and astrograph lenses are capable to capturing very faint light using extremely long exposures and processing techniques. Each image can take many weeks or even months of work to produce, as I repeatedly photograph the same target at night whenever weather permits, using a tracking mount that follows the target at the correct speed i.e. matching the earth rotation. Each exposure is about 30 seconds to 2 minutes long. Once I have about 15-30 hours of quality exposures, the thousands are photos are ‘stacked’ using specialist software to combine all the information into a single image. It is then further ‘polished’ to bring out the faint colours and features using other software.
And finally, if all goes well, the image reveals itself on my computer screen after weeks of work! The light that has been travelling for millions of years through space and then landed on my camera’s sensor is now made visible to the human eye.
