Posts Made By: James Brown

Hi all:

In response to all of your help, I have adjusted my monitor at home and learned to embed the sRGB color space in images for web posting. This version of Cederblad 214 looks pretty much the same at home and on my work monitors now! I am happy, and grateful for all of your input. I do notice that the image is noisy in full resolution. Time to take more subs of this faint object!

Full resolution is here:

http://home.comcast.net/~jameslbrown/pwpimages/Ceberblad%208bit.jpg

Thanks, Jim

Hi all:

I took the LRGB data for this M33 image in September and October. As you know if you have read the Cederblad thread and another before it, I have had a heck of a time processing this data to preserve the subtle outer regions of the galaxy.

With your help I have adjusted my computer at home, embedded a sRGB profile in this image and tried InfanView for jpeg conversion. I am pleased with the results and very grateful for all of the help from this forum!

This image is LRGB with (20) 15 minute L subs binned 1x1 and (20) each 5 minute RGB subs binned 2x2. I de-saturated the colors a bit in final processing to achieve a more subtle look that I like.

The full res image is here, I really have enjoyed spotting tiny galaxies in the background. South is up in this image, I guess I like the way it looks better that way.

http://home.comcast.net/~jameslbrown/pwpimages/m33LRGB%20cropped%208bit.jpg

TEC APO 140
TEC Field Flattener
Astro-Physics Mach 1 Mount
Finger Lakes Microline 11002 M, 2” Filter Wheel and PDF
Starlight Xpress Lodestar with Borg 50mm f5 Achro guide lens.
Astrodon LRGB Filters, Baader Narrow Band Filters
Maxim DL 5, CCD Commander, The Sky 6, Photoshop CS2, Focusmax

Jim

Thanks!

Jim

Floyd:

I'm not sure I understand the rail/support ring idea. If the support ring clamps to the camera side of the draw tube, (as shown with your guide scope), then each time you focus don't you have to loosen the clamp screws, focus and then re-tighten the screws? Otherwise you would have to implement the support ring on your main scope with a very good sliding bearing so the drawtube and camera can move fore and aft relative to the support plate when you focus. I suppose this is no big deal on the guide refractor, because if you are like me you seldom have re-focus the guiding system.

On your main camera, if you must loosen the ring, focus, tighten the ring, image, etc. that seems like a real pain, and it would eliminate the possibility of an automated periodic focusing software routine if you decided to do that later.

Let me know if I am missing a key conceptual point.

Jim

Tyler Allred said:

Hi all. I finally got a chance to get the scope into the new observatory and try everything out. So far, it looks like everything is working perfectly. The roof rolls off easily despite being 12'x16' is size. The pier seems solid and is nicely isolated, which allows me to move around at will. It was really cold and there were loads of ice crystals in the air, so the seeing was pretty lousy, but I bundled up in a king-sized electric blanket and stayed warm and cozy. This image is just a few shots of the "Running Man" that I took to see if everything was working.

AP130 Starfire F/6
Losmandy G11
Starlight H16

Hi Tyler:

Congratulations, I'm sure that you will have a ton of fun with the new observatory!

Jim

Very nice!

Jim

Alex McConahay said:

So, I'm thinking of doing some narrow band imaging with my ST-7.

Step 1 is to get some narrow band filters.

I see one level is like the Orion at 7 nm bandpass, another is Astrodon at 5 nm, and a third at 3 nm bandpass. I know what that would mean optically, but what does it mean practically?

I mean, I'm sitting in my light polluted back yard. If it is going to cost me $900 or $1000 or more to get into narrow band imaging, I wonder if I want to go there. If it is only going to cost $350, sure, its worth a try. If I spend the $350 how close will I be to what I would have gotten with the $900? How long before I decide that I need to get the $900 to "do it right?" Will I be getting haloes, and lots of IR light leak, and parfocal problems, and whatever?

I have the pier mounted Gemini G-11, an off axis guider, ST-7, CFW, and whatever tube is needed to pull this off, I should think. It's just the filters I don't yet have. I don't want to get "entry level" and then find out they don't make it at all and have to spend more. On the other hand, I mean, I'm working an ST-7 here. I'm obviously not into premium performance--just want to take some pretty pictures.

Alex

Hi Alex:

With an ST-7 you use 1.25" filters right? Assuming that is correct, If I were you I would either get the Baader 1.25" Ha at $164.00, or if I was living large I'd get the 1.25" Baader Ha, OIII, SII narrow band set for $395.00.

The price for the Baaders is great. Lots of folks on the web speak very highly of the quality. I have a set of the 2" Baaders and they perform well.

Certainly, I have not personally A/B compared lots of narrow band filters. I have compared the Baader Ha to a 5nm Astrodon with my own system, and I can not see any difference.

Jim

Beautiful work Dean, thanks for posting those.

Jim

That's a really cool image Jim! I've spent the last several minutes trying to find this object in my resources. Based upon the coordinates you gave, I can pick out the 5 or 6 brightest stars of your image in my copy of Uranometria 2000, but the dark nebula must have been deemed too "insignificant" to include. It sure is pretty!

Jim

Hi all:

This 36 degree by 24 degree image of Orion and part of Monoceros is my first light for a 55mm Pentax 67 camera lens at f5.4. The lens is coupled to a FLI Microline 11002M, CFW-7 filter wheel and PDF focuser.

I was inspired to try the Pentax 67 medium format lenses by Richard Crisp who has imaged extensively with this lens family and FLI products. Thanks Richard!

The Pentax 67 family of lenses makes a lot of sense for me, because the field flattener of my primary refractor requires 85 mm between the back of the flattener and the image plane. 85mm was selected by the lens designer so that the refractor/field flattener could be used with a Pentax 67 medium format film camera body, which requires 85 mm of back focus.

85 mm is a lot more than the back focus of a 35mm format lens. With a 35mm lens it would be difficult or maybe impossible to use a ccd camera, filter wheel and PDF type focuser after the lens, there just isn’t enough back focus room. However, the Finger Lakes Instruments focuser and wheel, plus the distance from the front of the chip to the front of the camera are less than 85mm. So, to make a long story short, I have made one adapter that attaches my camera/wheel/focuser system to the refractor/field flattener and another adapter that attaches the same imaging gear to any Pentax 67 lens. Now, I can keep the camera, filter wheel and focuser more or less permanently hooked together and easily select a camera lens or the telescope. I made a simple platform that holds the camera and mini-Borg guide scope when imaging with a camera lens.

This particular image is only 20 minutes of L, in 2 minute subs and 120 minutes of Ha; 30 minute subs. The moon, plus the moon reflecting off of snow, plus Denver's light dome made for some very dramatic gradients! I am very pleased with this for first light given that I have so few subs. The full resolution version is here:

http://home.comcast.net/~jameslbrown/pwpimages/new%20final.jpg

Take a look around and you will see that the well known objects in this field (M42, The Rosette, The Horsehead/Flame) are reasonably well rendered, given the extremely wide image scale.

The Pentax 67 lenses are quite affordable on the used market; I'm looking forward to using this versatile system with a few different focal lengths.

Thanks for looking!

Jim