I rather like the softness; it fits well with fuzzy undefined halo. If it get's too crisp I think it might start to look "processed."
Bravo,
Peter
Thanks Peter for encouragement and a refreshing view. One worries in particular that if one makes it too crisp, detail starts to appear that is not in the sky.
Scylla on one side and Charybdis on the other, the devil behind and the deep sea below.
Quote:
Originally Posted by topheart
Excellent ! Very very beautiful colours.
Hat's off to you!
Cheers,
Tim
It's georgeous, wonderful star colours and dynamic range, lots of amazing little galaxies in the background, classy image processing indeed
One compositional niggle though, the hero seems just plonked in the centre of the frame. There have been other published versions of this subject that use the supporting stars to balance the image as well.
It's georgeous, wonderful star colours and dynamic range, lots of amazing little galaxies in the background, classy image processing indeed
One compositional niggle though, the hero seems just plonked in the centre of the frame. There have been other published versions of this subject that use the supporting stars to balance the image as well.
Just a thought.
Again though, a top shelf image
Thanks for the kind comments and taking the time to take an artist's view too. We ache because there are some exquisite, very bright, and intensely colourful stars just out of field. If we live long enough, we might have to consider a mosaic.
Quote:
Originally Posted by multiweb
Good stuff Mike. Lovely colours. Heaps of faint fuzzies too.
Thanks Marc, and lovely to hear from you to, friend!
- - - - -
Oh, good news with the replacement Honda EU30iS generator. It has both two-wire and wireless key-fob remote start/stop. We carefully measured the power consumption of the gear last night. We were very surprised. The whole observatory (two big screens on, cameras cooling, 160 Kg dome rotating, shutters opening, lights on, etc) uses about 250 watts, but once all is set up, it only uses 190. A 600AH battery would see us through the longest winter night and be only 40% discharged. So we're going to see the solar power folk at Lucknow about a system where it recharges in the daytime, but the generator will kick in automatically if it's too cloudy and not recharged by say 4pm. It will pay for itself in about 4 years in saved fuel. But the big thing is it means we could contemplate remote operation from the house when we're a few years older and greyer.
Congrats on a truly superb image.
I like the way the stars are evenly coloured and no colour rings which tends to plague filtered imaging.
As far as sharpness goes you probably left a bit on the table but I also agree its a fine line between sharpened and an overly processed look.
The big halo looks great and the galaxy colour looks spot on to me.
One if your very best images.
Everyone likes a good Sombrero!
Greg
Congrats on a truly superb image.
I like the way the stars are evenly coloured and no colour rings which tends to plague filtered imaging.
As far as sharpness goes you probably left a bit on the table but I also agree its a fine line between sharpened and an overly processed look.
The big halo looks great and the galaxy colour looks spot on to me.
One if your very best images.
Everyone likes a good Sombrero!
Greg
Thanks so much, Greg. We've seen a few really beautiful Sombreros in the last week or so. Technology has come a long way. Oh to have access to a machine at high altitude!
Quote:
Originally Posted by Camelopardalis
Beautiful M&T love the little spirals too!
Thanks, Dunk!
Quote:
Originally Posted by John K
Mike and Trish,
congrats on your image! Really like the colours you have achieved.
I counted almost 20 galaxies in your field which really puts things in perspective.
I've had a go at some further wavelet sharpening. Despite best efforts with automatic masks and even PhotoShop finger painting on masks, either the core blows or it starts to look totally weird. My best effort is here. Not sure that I like it.
Excellent M&T! Beautifully deep and rich colour. To split hairs, I would have expected it to be a teensy bit sharper.
Thanks muchly Marcus.
Quote:
Originally Posted by SimmoW
Wow that really does look concave, and great edge detail, great work MnT
Cheers, Simon.
Quote:
Originally Posted by willik
Very nice image but it looks slightly out of focus or needs to be
a bit sharper on detail.
Martin
A number of people have commented that the image seems a little soft, or even out of focus. The raw FWHM was about 2 sec arc, which is reasonable for our altitude (660m) at this time of year. We refocus every 3 subs.
As for local contrast, I suspect that folks missed our previous reply, in which we pushed the wavelet sharpening a bit past where we felt truly comfortable.
A good test of true sharpness is the ability to resolve a close double. In the attached, we bravely compare with seven other utterly superb images by leaders in the field using excellent (but widely differing) technology under similar circumstances.
Please in particular observe the very tight double, roughly central or just above central in the image, and at the extreme left of the galactic disc. These stars are approximately 2 seconds of arc apart, easy to see visually but hard to photograph under 2 sec arc seeing.
Clearly Peter Ward's Alluna with adaptive optics wins, hands down. Ours is pretty much in the middle, neither better nor worse than average, and therefore definitely not blurry.
Please also observe the very faintest background galaxies in each image, and the grittiness of the background.
Folks are right that there are sharper images out there, but I very much doubt if we, with our gear, in our situation, could do hugely better for sharpness. At our altitude of 660 meters, a scope larger than about 8 inches is very much limited by the seeing, not the aperture.
In conclusion, while our gear and our techniques aim for depth rather than sharpness, we think we are middling sharp for our altitude without the use of adaptive optics.
That's a fascinating comparison. To my eyes you certainly "win" in terms of depth. On a side note are you ever tempted to add AO to your gear?
Peter
Thanks, Peter.
We've seen some amazingly sharp images with AO, so yes, it is very tempting. I've always put it in the too-hard basket. I suppose what I would do physically is remove our off-axis guider, which uses up about 25 mm of the back-focus, and replace it with an off-axis guider. But the thing that worries me is how often we'd get a guide star that would give us 8 frames a second. Perhaps it's time to start talking to people who've used one on a similar scope to ours.
Thanks for the kind words Rob, but while it's deep, and middling sharp, it isn't so razor sharp.
Perhaps we should stick to photographing great big ridiculously faint things like the outer chevrons of the Helix, rather than tiny but super-bright things. Or perhaps we should consider throwing out tens of thousands of dollars worth of Aspen camera, home-made off-axis guider, and 50 mm square ten position filter wheel, and go to
something along the lines that Tim Caruthers uses (SBIG self-guiding camera controlling an AO-X) is the way to go.
Apart from the money, there's the emotional investment. I've written every last line of software that controls our observatory, cameras, cooling, acquisition on main and dual guide cameras, filter control, mapping, catalogues, synch and goto, tracking, guiding, focusing, the lot, so it is all fully automated, even working the dome and shutters, and turning off the generator in the morning. To go back to SBIG again would mean either scrapping all that, years of work and the whole way of operating, or to learn how to use their current DLL to do the camera control myself. (I am familiar with a much older version). The Aspen camera also has superior cooling which is very important for faint targets in summer.
On the positive side, the Aspen camera has a couple nasty habits: it has very bad after-images, and the brighter stars "drip" a little. Although the SBIG camera has exactly the same chip, perhaps they do it better.
Nah. Do the new living room and the conservatory first. There goes the budget for the next 5 years. We'll stick to big faint things.
I just projected your photo on the big screen TV. Had a ball finding the galaxies captured in your photo and zooming in on the dust lanes and the stars on the right in the spiral arms. Great capture.
With your brains I think you could "easily" build your own AO along the lines of the SX-AO. It's just a thick clear window with 4 motors controlling tilt. It can be placed just about anywhere in the system...even quite far away from the CCD and it can use any guide camera.
Hi Mike,
Interesting discussion and comparison. I think you are doing great as you are and it is so much work and expense to swap everything out....so assessing the benefit would need to be done very carefully....maybe I can formally assess the difference with and without the AO-X for you on a few typical nights, perhaps when the full moon is interfering with serious imaging....let's see if I can setup a scientific comparison. Also, I forgot to mention I have a 0.6 reducer in the light path to the off axis guider, so the FOV of the guider is a bit bigger and the stars a bit brighter....so the OAG sees 0.6 of the 4.7M focal length of the main scope.
