This is really a different image of the Orion. Fantastic resolution Peter. Your image shows very nicely that even the most popular targets are beautiful, mystical and breathtaking and definitely never ever boring. If a DSO image is boring, the reasons are somewhere else, but the DSO itself is never to blame.
This is really a different image of the Orion. Fantastic resolution Peter. Your image shows very nicely that even the most popular targets are beautiful, mystical and breathtaking and definitely never ever boring. If a DSO image is boring, the reasons lie somewhere else, but the DSO itself is never to blame.
Ta...and very kind of you. I'll go with those sentiments about DSO's.
Sometimes you need to get up super-close to make the ordinary extraordinary.....which is why I suspect the Hubble imagery is so awesome...
I'd also comment imaging at +3000 mm focal length is hard....so much conspires to ruin your efforts, but I'd invite all astro imagers to move away from the cosy sub 1000mm zone and push the envelope...you may be surprised at the results
I'd also comment imaging at +3000 mm focal length is hard....so much conspires to ruin your efforts, but I'd invite all astro imagers to move away from the cosy sub 1000mm zone and push the envelope...you may be surprised at the results
I’m sure imaging at such long focal length is not an easy task. I’m also sure that nearly every amateur would love to move away for cosy shortish focal lengths, but unfortunately quality DSO imaging at 3000mm+ requires an investment in excess of $50k, which for most is a bit too much to take sharper but still just pretty images.
I’m sure imaging at such long focal length is not an easy task. I’m also sure that nearly every amateur would love to move away for cosy shortish focal lengths, but unfortunately quality DSO imaging at 3000mm+ requires an investment in excess of $50k, which for most is a bit too much to take sharper but still just pretty images.
Thank you for the invite nonetheless
I take your point, but there are some excellent focal extenders on the market that get you there and don't require anything like a $50k budget. Most larger SCT's, while optically a little slow ( not a biggie with linear response CCD's, just expose for longer) are also a great workhorse. I used a C11 for many years.. the key to success is a rigid and accurate mount IMHO....but that's a topic for another conversation.
I take your point, but there are some excellent focal extenders on the market that get you there and don't require anything like a $50k budget. Most larger SCT's, while optically a little slow ( not a biggie with linear response CCD's, just expose for longer) are also a great workhorse. I used a C11 for many years.. the key to success is a rigid and accurate mount IMHO....but that's a topic for another conversation.
Thank you Peter - sounds like an interesting idea as I have been looking at options for a second scope for higher resolution imaging.
I'd also comment imaging at +3000 mm focal length is hard....so much conspires to ruin your efforts, but I'd invite all astro imagers to move away from the cosy sub 1000mm zone and push the envelope...you may be surprised at the results
I'd personally argue that focal length is only part of the picture and it's the image scale that counts. For example, my piddly little 8" F4.5 works out to a mere 989mm when combined with the Paracorr... but that's still 0.5"/px with my 2.4 micron pixels. I believe a 16" Alluna combined with the 16803 works out to 0.56"/px while being in excess of 3m.
I'd personally argue that focal length is only part of the picture and it's the image scale that counts. For example, my piddly little 8" F4.5 works out to a mere 989mm when combined with the Paracorr... but that's still 0.5"/px with my 2.4 micron pixels. I believe a 16" Alluna combined with the 16803 works out to 0.56"/px while being in excess of 3m.
Many thanks. You know, I've long struggled with this and wondered why I get better resolution with when the numbers should pan out in a similar manner.
I suspect it is purely how the seeing affects the image at the focal plane. With a large aperture, the image is stable, but suffers from a high frequency, localised "ripple". Smaller apertures have less "ripple" but are also less stable. Both smear the image..but I have no idea how to determine what is the best FL+sampling rate for conditions on the night.
But another aspect is, at the same sampling rate, I get 4x the flux with a 16 than I would do with an 8 inch aperture. Signal certainly helps!
I have tried smaller, decidedly faster optics, but all they seem to give me is a wider field...which can be great....but the details are lost for reasons I frankly don't fully understand, given the seeing ultimately is the limiting factor.
I'd be very happy to receive some insight here...any takers?
Quote:
Originally Posted by gregbradley
I agree a spectacular M42. Makes me want to image it again.
Greg.
Yes! You have some amazing gear (and a dark site..you bugger! ) Image as much as you can, as tomorrow is not promised.
Quote:
Originally Posted by Derek Klepp
Peter a truly spectacular image .I do hope you print this and hang it up somewhere.
Derek
Thanks Derek, a good idea...if only we had more wall space
Quote:
Originally Posted by keller60
An amazing Messier 42! So many fine details.
Thanks for sharing!
I have tried smaller, decidedly faster optics, but all they seem to give me is a wider field...which can be great....but the details are lost for reasons I frankly don't fully understand, given the seeing ultimately is the limiting factor.
I'd be very happy to receive some insight here...any takers?
In my limited understanding, this image says it all.
Small aperture quality optics is almost always diffraction limited (right) no matter how good the seeing is. A larger aperture is affected by a mixture of seeing and diffraction effects (middle), while largest apertures confidently resolve fine structures being always affected by the seeing only (left), and diffraction becomes negligible for our purposes. Even with seeing blurring the detail, DSO information is still of higher resolution.
I do understand this is a simplified approach but makes sense to me why large aperture resolves finer detail.
Incredible image Peter. The detail is certainly extreme. Almost like you have an airless vacuum around your scope. I think though I have noticed a shift in your processing over the last few years. Are you using a sharpening technique which is different? It looks remarkably similar to the one Ted uses on his solar images. The only thing is the stars look a little off circular and jagged (only a minor point though and the detail of the nebula over powers this anyway, I have become obsessed with star shapes with in the last year and see defects every where now; a product of a stressed experience with the AG12).
In any event an amazing image of this oft imaged target.
Incredible image Peter. The detail is certainly extreme. Almost like you have an airless vacuum around your scope. I think though I have noticed a shift in your processing over the last few years. Are you using a sharpening technique which is different? It looks remarkably similar to the one Ted uses on his solar images. The only thing is the stars look a little off circular and jagged (only a minor point though and the detail of the nebula over powers this anyway, I have become obsessed with star shapes with in the last year and see defects every where now; a product of a stressed experience with the AG12).
In any event an amazing image of this oft imaged target.
Thanks Paul. Believe it or not I did not de-convolve the data, though I do employ localised contrast enhancement to give low contrast features more snap.
The stars in the original .fits files are symmetrical
but, I did have to mask the h-alpha star data which was problematic....it was too sharp
The h-alpha data had stars about 2x smaller than the RGB.
I don't think the "select highlights" tool I used to fix the mis-match did a perfect job, but without doing so the HaRGB blend had dark rings around the stars.
...hence I'm guessing the slight distortions you have picked up on are from that.
Last edited by Peter Ward; 09-06-2019 at 07:08 PM.
Reason: typo
