July 2012: the Dumbbell

Encouraged with the pay-off of my primitive flat-frames technique, I now target one of the brightest deep sky object: M27, the Dumbbell, a magnificent planetary nebula in Vulpecula.

Due to its brightness, the 600-second exposures, and the extraordinary sensibility of the QSI, the central part of the nebula got over exposed, so the fine detail inside was burned. Fortunately, Pixinsight tools recover all this information which is hidden “below”.

The final image is the result of stacking and processing almost three hours total through RGB and H-alpha filters, in 600-second exposures.

Go to this object description and this image technical detail.

June 2012: Trifid and NGC4565… now with FLATS

After some months with bad weather and/or other priorities, I’m back again with my QSI. Now aiming at two great targets, and testing, FINALLY, my first flats! I consider this my first attempt, to be largely imporved (I hope). I used the T-shirt method. As I couldn’t wait till the dawn, I imaged my flats at dusk. And, as the focus was not exactly teh same as used during the night, these flats were not 100% correct. Anyway, I think they did a good job. More to explore and improve.

First target is the famed Trifid Nebula. And I must say that I’m not totally happy with my results, as I think I can improve focus. Although tha nebulosity has been perfectly captured, the overall look of the image, with it’s rich star field, is a bit fuzy. Now that I have experience enough with my setup, and comparing with previous targets, I am sure this imaging session can be improved. Maybe I slightly missed the focus, maybe it slightly shifted during the session.

For this image, I didn’t use the H-alfa filter. It’s a composite of  15 minutes through clear Luminance, and 30 minutes each through R, G and B filters, for 1:45 hours of total exposure.

Go to this object description and this image technical detail.

The second target is NGC4565, one of the most spectacular edge-on galaxies. I must say that thanks to my much-to-be-improved flats I had little difficulties processing this baby. One thing is to image big ans bright objects, which fill the frame, and the other is aiming at little objects, in poorly iluminated fields. In this case, severe vignetting appears in my frames, as you must stretch the histogram to pull out the most of it.And flats come into rescue! Having processed this kind of images before without them, I tell you, flats make the difference.

Probably due to the focus issue I said before, and due to a poor guiding session, the galaxy details are not wery well defined. But being this object much more demanding than the Trifid, I consider myself satisfied with it.

For this image, I didn’t use the H-alfa filter. It’s a composite of  15 minutes through clear Luminance, and 30 minutes each through R, G and B filters, for 1:45 hours of total exposure.

 Go to this object description and this image technical detail.