Posts Made By: James Brown

One of many things I like a lot about the TEC 140 for imaging is the dedicated field flattener. Other vendors make dedicated flatteners too of course, but I only have experience with TEC's offering. The TEC flattener is very large, with about a 3.5" aperture, so vignetting is a non-issue. The flattener housing is threaded to screw onto the drawtube of the Feather Touch 3545 focuser; it is very secure. I use Astro-Physics part A-1261 to couple the flattener to the camera, wheel and focuser assembly I use.

If you scroll through the attached, you will see that I am getting a very flat field and minimal tilt with this set up, across the entire surface of a 35mm chip. This attachment also demonstrates that it is important to get the specified field flattener to chip distance right, within a mm or so.

http://home.comcast.net/~jameslbrown/flatteneranalysis.pdf

Jim

Hi Guys:

I linked to this Stephen J. Gould essay this morning, but it was buried deep in a deep thread. Sleeping with the fishes so to speak. I read the entire essay at lunch. Like all Gould essays it is shockingly well written and provocative. As I'm sure you know, Gould was a paleontologist and evolutionary biologist professionally, but he is perhaps best known as an essayist who brought evolution to the masses. He was a humanist. Sadly, Gould died at the too young age of 60 a few years back. Gould testified as an expert for the plaintiffs in the landmark McLean v. Arkansas creationism trial. He even voiced himself in an episode of The Simpsons.

http://www.inf.fu-berlin.de/lehre/SS05/efs/materials/FlatEarth.pdf

This essay was published in 1995. I think that Gould's summation of the complimentary and non-exclusive relationship between the institutions of science and religion, which may be found near the end of the essay, is both insightful and important.

Read the whole thing, it's really quite good.

Jim

We were treated to a massive herd of cow elk and spring calves this evening. There were at least 30 cows and 30 calves coming and going in little groups as the sun set. It had rained some today, and the calves ate fresh grass, drank some elk-milk, napped and played. It was truly spectacular.

All of these photographs were taken with a Canon T1i at the prime focus of my 980mm f7 TEC APO 140. Hand-held of course. (Just kidding, I was using a reinforced Takahashi Teegul mounted on a fairly sturdy generic tripod. The elk wandered all over the open space behind our home. These were taken at a range of between 20 and maybe 200 yards.

I hope you enjoy these photos, we sure enjoyed watching the baby elk.

Jim

Hi all:

Here is an M13 I have been working on this spring and summer, (imaging nights have been few and far between). My goal was to go much deeper than I have in the past. I have always been dissatisfied with the appearance of the fainter stars in the outer regions of the cluster in my globular images, these stars have looked more like noise than stars. So for this image I used (18) fifteen minute subs for the luminance channel and about (20) 5 minute subs each for the R, G and B channels. It turned out better than my previous efforts, which involved much shorter total imaging time.

This first image is a medium crop. I personally find this to be most aesthetically pleasing view. The next image is a wide field, pretty much full frame, but with the edges cropped to get rid of alignment variations. The final image is an extreme crop of the cluster alone. These are all the same image, just cropped quite differently.

The full frame image (unfortunately a jpeg, it’s not nearly as rich as the 60M tiff) is here, before any cropping. There are dozens of tiny galaxies in the background including a nifty edge-on barred spiral at the right edge that I’ve not noticed before.

http://home.comcast.net/~jameslbrown/pwpimages/M13%20LRGB%20Uncropped%281%29.jpg

Thanks for any comments, Jim

TEC APO 140 with TEC field flattener
Astro-Physics Mach 1 Mount
Finger Lakes Instruments ML 11002M Camera
Finger Lakes Instruments PDF focuser
Finger Lakes Instruments CFW 2-7 Filter Wheel with Baader Filters
Starlight Xpress Lodestar guider with mini-Borg guide lens.
Maxim DL
Photoshop CS2
CCD Commander.

Doug:

Earlier I posted this summary of Calvinism by Eric:

Eric Gage said:

By way of information, for those whose curiosity may have been piqued by an earlier reference to Calvinism, the 5 core doctrines are:

1. Total depravity: see other thread
2. Unconditional election: God's offer of salvation is not based on any merit on the part of the individual.
3. Limited Atonement: God does not make this offer to all. "I will show mercy on whom I will show mercy."
4. Irresistable Grace: The elect cannot refuse the offer--God's will trumps human will.
5. Perseverence of the Saints: Once saved, always saved.

Enjoy,

Eric

I've read most of your posts in the previous thread, and it seems to me that you would agree with Eric's summary. So here is a question that I've been puzzling over. You and I (and others) have gone round and round over the years about salvation through works or salvation through faith alone. I thought that you were firmly and entirely in the salvation by faith camp. If I understand the ULIP parts of Eric's TULIP acronym however, even faith is not necessary. Either God picks you and you are saved or God skips you and you are not, and there is not a dang thing (faith, works, etc.) that you can do about it. So the whole works v. faith argument becomes moot if this is entirely in God’s hands.

So, am I missing something?

Or are you not a Calvinist after all, since in the past I believe that you have argued salvation through faith alone?

Thanks, Jim

Hi all:

This is the full moon rising through some wispy clouds earlier this week. It was quite beautiful, and changed by the moment.

Canon T1i with a Tamron 28-300mm lens.

Jim

Herb has just split the Religion forum into two groups, believers and atheists. Where is the fun in that? Will I be banned if I debate the atheists down in their own forum?

This is basically censorship. Imagine splitting politics into two forums; “liberal” and “conservative .” Can you say boring?

In my no-holds barred view, the evisceration of "Religion" is a bad move Herb. Maybe this new forum will make up for it. We'll see.

Jim

I'm probably violating the 1st Commandment, but my prayers have been answered. This has been a long several weeks coming.

http://cleardarksky.com/c/EvrgrnCOkey.html


Jim

Interesting results in Colorado yesterday, on the Republican primary for Goveronor side. Scott McInnis was leading the primary race by a lot just a few weeks ago when a plagiarism scandal broke. It turns out that McInnis was paid about $300k to prepare a series of studies on water rights. Most unfortunately, he got caught plagiarising some of the content. Then he tried to blame an 82 year old research assistant for the plagiarism.

I'm seriously bummed that this scandal has decresed the Republicans chances in the CO Goveronor's race this November. I am exceptionally pleased however that the Republican voters gave McInnis the cold shoulder when this scandal broke. It seems that voters in Colorado have integrity after all.

Jim

Hi all:

This is the often photographed, but hopefully never boring central portion of the Milky Way as viewed from 40 degrees north latitude. The frame includes parts of Sagittarius, Scutum, Ophiuchus and Scorpius. I centered on M8. Messier objects M 6, 8, 9, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 28, 54, 62, 69 and 70 are all included, but as you will see from the full resolution version, all of the globulars except M 22 appear pretty much stellar.

Full Res:

http://home.comcast.net/~jameslbrown/pwpimages/Saggitarius%20RGB.jpg

This image is a 1x1 binned RGB composite with 8 subs of 5 minutes each per color channel. The lens is a 55mm Pentax 67 medium format camera lens stopped down to f 5.6 (one click). The Pentax 67 lenses have 85 mm of back focus which accommodates my regular imaging train of a Finger Lakes Instruments Microline camera, filter wheel and PDF focuser. Richard Crisp pioneered the use of Pentax lenses with FLI gear. It certainly makes lens changes and focusing easy. I did not use an L channel and probably will not, since the non-APO nature of the camera lens seems to cause a noticeable star bloat in the L channel when compared to the RGB channels.

The 55mm lens gives about a 24x36 degree field with a 35mm diagonal chip. This particular image is cropped down to 22 x 32 degrees to avoid dramatic color weirdness at the bottom where I was picking up the horizon. The image scale is 33 arc seconds per pixel. As usual, my Astro-Physics Mach 1 mount made imaging control relatively easy.

Thanks for any comments!

Jim

Pentax 55mm 67 Lens
FLI PDF focuser
FLI Microline 11002 M Camera
FLI CFW7 Filter wheel
Astro-Physics Mach 1 Mount
Starlight Xpress Lodestar guider camera
Borg 50mm achro guide scope
Maxim DL, Focus Max and The Sky 6, all controlled by CCD Commander