I would like to share a link to a great processing method for deep sky photos.

I tried out the workflow of a guy names Scott Rosen I found in the internet when I searched for methods to apply the basics of LRGB composits to DSLR photos.

It was 2 hours work - watching the Video and applying his steps to my image. But the result is - in my eyes and compared to the low quality of my original image - spectacular! The image was made with my K3 II and my old Pentax-A 400 mm F5.6 from my balcony last December:



I never managed to get these faint things visible without drowning in noise in my normal workflow.

The method of Scott Rosen is based on a separate treatment and later combination of the luminance and the color data of the image. You can find him here:Astronomers Do It In The Dark - astrophotography, astronomical photos, astronomical photography, astro photos, astro photography, Dark Nebulae, IC, Sh, B, Vdb, and Abell Nebulae, Reflection Nebulae, Open Clusters, Abell Galaxies, Spiral Galaxies, Gal.

It is a bit of work to follow him through his workflow for the first time - but it is worth it....!

P.S. The Photoshop actions of Noel Carboni that Rosen uses uses are also worth the money......

WOW - spectacular!!

Wow! I'll listen to this video for sure, thanks for sharing.

Nice way to bring out the Trapezium stars. But it leaves the bulk of the nebula colourless.

I perhaps could have preserved the faint blueish tint that is present in the outer parts of the nebulae. As I said - it was my first try with that workflow. And outside the cam was shooting new lights in frosty airand I frequently had to care for it so that I was not fully concentrated. I started the PP from this point (out of DSS):

Indeed, the pp'ed version is much superior!

Last night I tried for the first time on the Rosette Nebula withe the K3 II and the 400/5.6 without any filter.
For the postproduction I tried Scott Rosen's method once more. I works extremely good for nebulas I think. Only the colors were not as red in the end as in all the other images of that nebula. They remained magenta whatever I tried. At last I had to help myself doing several colortemperature shifts into the red direction in several consecutive layer masks in the fínal Image.

Nice, Pete. Not much to improve with the RGB capture. The rage these days seems to be merging narrowband and wideband shots.

very nice pete

Thank you both. Yes, maybe it is like you say. But I do not want to invest into, use more technology and spend more time at the moment. But compared to what I was able to produce a year ago I still improve and have a lot of space above me thrashing out conventional dslr photography with lenses and without spending thousands of dollars for technical equipment and spending all nights on that "balcony". If life is very kind to me and I have time and money some day when I have retired perhaps I will have a pro-observatory on that balcony and another remote controlled one in the Brittany . Perhaps I will buy some decent travelling scope in this year - let's see.

P.S. For the "Scott Rosen Method" I do the sharpening and other procedures he mentions not with Images Plus but with comparable Photoshop functions. But I downloaded "HLVG" (Hasta la vista, green ) which is Freeware and a nice tool. I also invested into the "GradientXterminator" and the "Carboni Actions" which are affordable and very effective.

Beautiful capture! That old Pentax glass is amazing!

Hi Pete, you really see me impressed with your shot of the Rosette nebula. It is a much harder target than the Orion nebula. Your focus is spot on and the amount of detail is just amazing especially considering the equipment you use. I had a go at both these targets recently and found the rosette to require about 4 hours worth of data (5min exposure) to become presentable. Having said this, I think your M42 shot is somewhat out of focus and worth revisiting. Having seen what you did on the Rosette you could improve M42 significantly. Search up "Bhatinov mask" on Google - it will help you enormously with the focus. I've cut mine out of cardboard and it works a treat.
Anyway keep at it and clear skies!
HJ

Hi, thanks for your comment on the Rosette nebula and sure you are right with what you say about M42 . But the M42 picture was just my first exercise on the "Rosen Method" and an example to show what is possible with my (bad) DSLR data. I already have a selfmade and a professional Bahtinov mask since a while but sometimes I still suffer from "milk glass Images". I think this time the freezing, falling temperatures had influence on the focus and I should have controlled and adjusted it during the session.

The effect I wanted to show in this thread refers to the circumstance that -"before Rosen" the faint structures and the backgrounds differ typically about 2-3 bit in luminance in a 16 bit Image. This small offset is in my case not enough to work out the structures without catching lots of noise that spoils the result if I execute normal stretching with levels and curves etc. The Rosen method I cited here leads to a dramatically improved ratio of faint structures and background without boosting the noise. Another thing is that I often lost the star colors in my former workflow and ended up with white overexposed stars. Working along the Rosen's way I learned using just the lower part of the curves tool and star colors are preserved much better

I will practise on more examples and introduce them here later.

Greetings and clear skies!
Pete

I just finished watching Mr Rosen's M45 processing example. Pretty impressive result but I doubt many people would have the patience to fiddle with an image for two hours. Probably doesn't take him very long when he is doing it for himself but he had to drag it out for the tutorial. And of course, every image is "done to individual taste" as far as colour rendering, saturation, etc. I also noticed that on the left side of his image, the stars show glaring chromatic aberration. A lens fault, not his but he didn't even seem to notice. His method is definitely in the "work with the non-linear image" camp rather than with those mathematical purists who stress that most of the processing should be done while the image is still in a linear state, i.e., before stretching. Thanks for the link.

I agree with you, the "acclimatisation" to the method is a bit labourious . But it offers me a new way to more DSO objects to image at my location with my equipment. As I am shooting in suburban skies the difference in luminance between the fainter DSO objects and the backgrund is mostly very very small and my exposure time is quite limited by the light pollution. Besides much better distinction of the DSO from the background one of the main differences to my older results is that stars do not white out but stay colored. I tried to develop the Rosette Nebula image with my normal workflow (mainly cautious conventional stretching with PS CC in 32 and 16 bit, noise reduction and sharpening, then fine tuning in LR CC) and did not come to a presentable result in 3 trials. OK, the video is long and somehow pernickety/forensic (right word?). But having understood the main principles of his approach after processing with Rosens video in parallel on the second screen 3 times I now need about 1/2 an hour for the processing. After having invested 2 hours outside for one hour light on the sensor I consider this effort as reasonable .