At our recent Practical Sessions we have covered the basics of capturing video images of the Moon, the Sun and Planets and using software to process good quality images. Now it was time for the Masterclass!
Pete Lawrence has been a presenter on the long running BBC Sky at Night television programme since 2005 and is highly regarded in the world of astrophotography. And it’s fitting that Wycombe Astronomical Society can attract such an eminent speaker to help us refine our skills.
Of course one could resort to “lucky imaging” – taking that single shot of Jupiter where the seeing is perfect. But in real life we face that enemy of astro-imaging – our atmosphere and its effects on seeing. To overcome this we need to take hundreds or thousands of images and these days high frame rate video cameras are available which make this relatively easy. Coupled with (usually free) image processing software, planetary imaging is now well within the capability of amateur astronomers and Mr Lawrence gave us valuable detail on how to get the best results.
Collimation, cooling and focus of one’s scope are all critical – so, too, being able to understand the basics of meteorology! We also learned about the pros and cons of mono –v– colour cameras, appropriate focal ratios to employ depending on seeing, the use or otherwise of IR Pass and IR Blocking filters. Finally the ins and outs of frame rates and the number of frames to capture.
And then on to image processing. Mr Lawrence favours Autostakkert!2 for analysing, ranking and stacking just the very best frames, then Registax’s Wavelets for image enhancement. He gave a live demonstration of the use of these tools on a Moon video he’d captured, and showed in detail how to bring the best out of the image. He also emphasised there is still a place for Photoshop in the final stages of image processing.
Judging by the questions which emerged from our Practical Sessions, answers to which Mr Lawrence ably provided during his talk, there is considerable enthusiasm amongst the members of our Society to improve our imaging techniques. So much so that at least one of our members raced straight home to put them into practice!