I’ve been doing an equipment shake down to investigate trailed stars at focal lengths of over 1500mm which begin to become noticeable at exposures of over 3 minutes, and I appear to be having some success.
Last night, I was managing 5 minute sub frames at 1760mm and here is the result of 5 x 5 minute exposures of NGC6369 through the Mewlon 180 with 0.8 FR, giving an efl of 1760mm. ST7E CCD camera, aligned and stacked in MIRA AP with final processing in CS3.
I’m not sure if the apparent “detail” in the ring is a processing artefact or not? At capture, the raw images on screen looked awful; loads of noise and horrible sky glow from Brisbane. The “detail” popped out when I ran the Noel Carboni “Remove Light Pollution” Action in CS3.
Brilliant Dennis. You've obtain great resolution on this target. I'm wondering if a little deconvolution would bring out more (assuming you can find the optimal PSF value so you don't over do it). Well done.
Thanks Jase. I’ve got Images Plus and Maxim DL and I think both have various deconvolution routines, so I may have a read up on these techniques and see how the image responds.
The image was a test run so I didn’t take as many subs as this target warrants, nor did I use the colour filter wheel to bring it to life!
Actually, Dennis, I think doing the neb in B&W has done it a lot of justice. Sometimes I feel colour can be a bit overrated, it swamps the details in some shots and targets. Great shot.
