nimbushopper Loc: Tampa, FL

sb Loc: Florida's East Coast

Awesome - well done! Thanks for sharing all your hard work to get such images.

BboH Loc: s of 2/21, Ellicott City, MD

What you have captured, described and presented is rather, to use a trite phrase, "mind-boggling". I read media reports about what you have presented and said "OK, so what!". Now, your presentation has changed my perspective to one of interest in just what is presented - thank you.

I have read the textbook on filtering but have never sought an occasion to use any. What I recall seems in error in that my recollection is use, for example - the red filter to cancel out red light waves, but what it seems to me that you have done has emphasized rather than canceled the particular light wave. This also has evoked my interest. Again - thank you

Question - what does it look like without any filtering?

nervous2 Loc: Provo, Utah

These are absolutely fascinating shots and composites. If I were your neighbor, I would pester you to take me along to broaden my education. Really very nice.

Nalu Loc: Southern Arizona

What a great series of images. Your description of how you made the images with various filters just reminds me of why I would never get into Astro-photography. My brain is just not capable of grasping the complexity. Thank you for allowing me to be the viewer and not the photographer. Again, wonderful images!

Ballard Loc: Grass Valley, California

Hi J-SPEIGHT
Thanks for checking out images of the Crescent Nebula and for the comment.

Ballard Loc: Grass Valley, California

Hi Manglesphoto
Thanks for viewing the images of the Crescent Nebula and for all the Thumbs up.

Ballard Loc: Grass Valley, California

Hi nimbushopper

Thanks for checking out the images of the Crescent Nebula and for the Thumbs up.

Arizona Art Loc: SE Florida

Amazingly beautiful! Thanks for sharing.

tony85629 Loc: Sahuarita, Az

Nice work. Narrow Band is truly an artists pallette.

Curmudgeon Loc: SE Arizona

What wonderful images

Ballard Loc: Grass Valley, California

Hi BboH
Thanks for viewing the images of the Crescent Nebula and for the comment. I also enjoy hearing that you found the information interesting. Since the camera I use has no bayer pattern on the sensor it generates a monochrome image for each filter used (of course all electronic sensors are underneath it all just monochrome and the color comes from the integration of images with Red, Green and Blue filters over the individual pixels in the camera. The filters used for this type of photography are band pass transmission filters not blocking filters, so the Red refers to a range of Red light (620 nanometers to 700 nanometers) it allows through, ditto for Green and Blue filters for there respective ranges and the Luminance covers the entire range from 390nm to 720nm. However with many nebula they emit strongly in very specific ranges of light and to get the most detail/contrast out of these objects it is useful to use very narrow band filters. In my case I used 5 nano meter wide Hydrogen Alpha (656.3nm), Sulphur 2 (671.6nm) and Oxygen 3 (500.7nm) filters. (Note the terms 2 for Sulphur and 3 for oxygen refer to ionization state, 1 is neutral, 2 is singly ionized and 3 is doubly ionized (i.e. how many electrons have been ripped on the atoms)). The color in the images is determined by how one assigns the colors to a given frequency. The fourth image using the Hubble pallet would be considered a false color image since Ha was assigned to green but our eyes would see it as red, but since our eyes would also see S2 as red, this technique allows use to differentiate the different elements in the single image more easily.

When you say no filters, I assume you mean what would a standard DSLR show and in this case the second image would be the answer as this uses the same type of filtering that a bayer pattern on a standard DSLR sees. However the images below shows what comes out of the monochrome sensor just a Luminance filter (i.e. clear but it blocks UV and IR). The second image shows the effect of just the HA filter as it comes out from the monochrome sensor and shows how much better the contrast and detail gets with a narrow band filter on this type of image.

Luminance filter image

(Download)

Ha filter image

(Download)

Ballard Loc: Grass Valley, California

Hi sb
Thanks for checking out the photos of the Crescent Nebula and for the comment. It does take some time and effort, but it is a lot of fun.

Ballard Loc: Grass Valley, California

Hi nervous2
Thanks for checking out the images of the Crescent Nebula and for the comment. I enjoy sharing the images and what I have learned with others.

Ballard Loc: Grass Valley, California

Hi Nalu
Thanks for viewing the images of the Crescent Nebula and for the comment. It does take some time to learn how to do this stuff but it is a lot of fun. I started with just using a DLSR camera where you don't need to use all the filters and filter wheels and just went one step at a time from there.