by Chris Peterson » Tue Sep 13, 2011 1:26 pm
Boomer12k wrote:AWESOME PICTURE, of one of my favorite nebula!!!!!
I had been getting my 10" Meade LX200 GPS out in the early morning and taking pics of objects...this just blows my efforts clean out of the water!!!!! We have been having forest fires and the smoke is thick enough to block Jupiter and some bright stars, but not the Moon. I can barely make out the Big Dipper!!!
I use the Deep Sky Imager 2 ccd camera for my pictures. I do not get wide angle shots, I get just a small area, like The Trapezium area. Still an interesting area. I also get M43, and here is my BEST, MOST PROUD OF EFFORT TO DATE.....M43, AND the middle rift, with the (in this picture), the "left" of M42... This is about 32 or so pictures, with DRIZZLE MODE, for derotation, at about 2.8sec exposure. I had NEAR perfect focus as indicated in the software....decent for what it is....
The APOD image was taken with very modest equipment. Your SCT will allow shorter exposures (or more signal per exposure) than the much smaller scope used for today's image. So what's the trick? First, focus. Despite what your software was reporting, your focus could be better. If you have a motorized focuser, autofocus software is best. Otherwise, you might want to look at making a focusing mask. Second, tracking. Your stars are slightly out-of-round, which indicates a tracking problem. You need perfect tracking for your exposures, which with this object could be up to around ten minutes. Perfect tracking requires that your scope mount be properly balanced, and it generally requires a separate guiding camera. Third, collimation. Yours may be fine (the tracking and focus issues could be hiding problems), but look at this. SCTs are frequently not collimated as well as they could be.
Once these mechanical issues are under control, the key to a good image is getting enough signal. That means lots of exposure time- an hour or more for sure with this object. And make no mistake: despite its brightness (which is one reason beginning imagers often gravitate towards it), M42 is one of the most difficult objects to image. That's because of the huge dynamic range required. There are parts of this object that will saturate in less than a minute, and other parts that require hours of exposure to get good S/N. So the best images of M42 are collected using a wide range of subexposure durations, which are then cleverly combined using fairly advanced image processing techniques.
My advice? Ignore M42 for a while. Turn your attention to smaller, less dynamic objects (M51, M57, M104, M16, IC434). Develop your skills with these much easier (but no less pleasing) objects, and come back to M42 later.
Also, while imaging can allow you to do some amazing things under relatively bright skies, the best images are still made when the sky is dark. If you can't get to a darker site, make sure that you at least collect your deepest subexposures when there is no Moon interference. In areas with light pollution, the skies are often darkest in the hours before dawn, since that's when more of the lighting is turned off.
[quote="Boomer12k"]AWESOME PICTURE, of one of my favorite nebula!!!!!
I had been getting my 10" Meade LX200 GPS out in the early morning and taking pics of objects...this just blows my efforts clean out of the water!!!!! We have been having forest fires and the smoke is thick enough to block Jupiter and some bright stars, but not the Moon. I can barely make out the Big Dipper!!!
I use the Deep Sky Imager 2 ccd camera for my pictures. I do not get wide angle shots, I get just a small area, like The Trapezium area. Still an interesting area. I also get M43, and here is my BEST, MOST PROUD OF EFFORT TO DATE.....M43, AND the middle rift, with the (in this picture), the "left" of M42... This is about 32 or so pictures, with DRIZZLE MODE, for derotation, at about 2.8sec exposure. I had NEAR perfect focus as indicated in the software....decent for what it is....[/quote]
The APOD image was taken with very modest equipment. Your SCT will allow shorter exposures (or more signal per exposure) than the much smaller scope used for today's image. So what's the trick? First, focus. Despite what your software was reporting, your focus could be better. If you have a motorized focuser, autofocus software is best. Otherwise, you might want to look at making a focusing mask. Second, tracking. Your stars are slightly out-of-round, which indicates a tracking problem. You need perfect tracking for your exposures, which with this object could be up to around ten minutes. Perfect tracking requires that your scope mount be properly balanced, and it generally requires a separate guiding camera. Third, collimation. Yours may be fine (the tracking and focus issues could be hiding problems), but look at this. SCTs are frequently not collimated as well as they could be.
Once these mechanical issues are under control, the key to a good image is getting enough signal. That means lots of exposure time- an hour or more for sure with this object. And make no mistake: despite its brightness (which is one reason beginning imagers often gravitate towards it), M42 is one of the most difficult objects to image. That's because of the huge dynamic range required. There are parts of this object that will saturate in less than a minute, and other parts that require hours of exposure to get good S/N. So the best images of M42 are collected using a wide range of subexposure durations, which are then cleverly combined using fairly advanced image processing techniques.
My advice? Ignore M42 for a while. Turn your attention to smaller, less dynamic objects (M51, M57, M104, M16, IC434). Develop your skills with these much easier (but no less pleasing) objects, and come back to M42 later.
Also, while imaging can allow you to do some amazing things under relatively bright skies, the best images are still made when the sky is dark. If you can't get to a darker site, make sure that you at least collect your deepest subexposures when there is no Moon interference. In areas with light pollution, the skies are often darkest in the hours before dawn, since that's when more of the lighting is turned off.