Posts Made By: Enrico Africa

Hi all,

I've been battling with this image for a while now, and perhaps it's time to take a step back and let everyone take a look at this and see what could be improved.

I finally got around to adding color data to my Rosette Nebula H-alpha image. I've added 3 hours of RGB (12 x 5 minutes each channel, binned 2x2) to my original 4 hours of H-alpha.

I don't know if I'll ever bin my color data again. What an adventure it was, to say the least!

All data was captured last November, 2006.

Takahashi FSQ-106
Takahashi EM200 Temma 2
SBIG STL-6303
Astrodon HaRGB filters

My biggest challenge was aligning the stars so they don't end up with uneven haloes. A few tricks helped along the way. I'm still not 100% satisfied, but I thought I'd share for feedback.

Eric

Hot off the chip!

Here is my attempt at capturing the February 23 conjunction of the Moon and the Pleiades over Ohio. A 1/250 second exposure was digitally overlaid in Photoshop with a 10-second exposure for this digital composite. I used a Canon Digital Rebel Xti on a Borg 76ED at f/6.6 riding on a Takahashi EM200 mount. The mount was not polar aligned, and focus with no focus aide at all was something else: at full resolution, the stars are painfully bloated, so I’m presenting this at 25%. I definitely want some better focusing technique – software-aided for astroimaging, though I’d still want some form of manual focusing technique as well.

This is my first attempt with this DSLR (not counting a Moon quickie a few weeks ago). With no focus aide, I wonder how I'll do with this combo for next week's lunar eclipse? Ah well, worst case I'll keep my images small

Eric

Hello,

I've been working on an imaging project since last month. This isn't it

Last weekend we had an unexpected string of clear skies, and an invitation from a friend of mine to join him at his dark site could not be ignored.

In a quest for better focal length for higher-resolution imaging, I bought a Mewlon 210 a couple of years ago. To tame its focal length, I also bought an AP 0.67 telecompressor. Which did not come to focus with the scope. Adding insult to injury, last year I messed up the collimation of that scope and relegated it to the bench for a while.

This year, I made it a project to collimate this beast once and for all. Visually, it was very promising: I got to see the E and F components of the Trapezium the night I tweaked its collimation, something I've never seen with my 8" SCT's (well, the E on occasion, but never the F). I also got a lower-profile, sturdier focuser for the Mewlon: a Moonlite Crayford with a Robofocus-compatible stepper motor. To my delight, the Mewlon came to focus with the AP telecompressor and that focuser!

So here is my first shot with that combination. It's relatively shallow compared to my multi-night uber-sessions, but it was taken at a dark site, so I can't complain. It still needs some collimation tweaking, and the stars aren't perfect - either coma, collimation, tracking errors, or a combination of all. Stuff for me to work out over time.

NGC 4565
Takahashi Mewlon 210 with stepper-equipped Moonlite focuser
AP 0.67 Telecompressor
SBIG ST-8XE with Astrodon LRGB filters
Takahashi EM200 Temma 2

L: 14 x 10 minutes binned 1x1
RGB: 10 x 5 minutes each binned 2x2

I count myself lucky on a couple of additional points: I found a guide star with the camera's default position, and I was actually able to rotate the camera almost perfectly 180 degrees after the meridian flip!

Dawn cut my session short.
Enjoy, and comments and suggestions always welcome.

Eric

Congratulations to our own Dietmar Hager, who just made it to that "other APOD", Astronomy Picture of the Day, with his wonderful NGC 4449 image! Way to go, Diets!

Eric

Hi all,

This has been a rocky year for me. I have quite a few unfinished projects in the works. I either have images with less exposure time than I'd like, and/or images that I consider incomplete for one reason or another, or images that I just can't seem to get right. Maybe it's the perfectionist in me.

Anyways, here's an RGB that I shot of the Lagoon/Trifid nebulae. This was shot last June 9-10 at a local park/dark sky site. This data is part of a collaboration I am having with John Noble: I shot most of the RGB data, and he shot H-alpha data. The RGB data alone looks pretty good, so I decided to share it anyway (I hope you don't mind, John

This is an RGB of 45 minutes each channel with 5 minute subs.

Camera: SBIG STL-6303
Scope: Takahashi FSQ-106
Mount: Takahashi EM200 Temma 2
MaximDL used for acquisition, calibration, alignment and stacking
Photoshop CS used for final processing

I averaged the aligned and stacked RGB data to create an artificial luminance for this image; that seemed to smooth the data out a bit.

I've hemmed and hawed about the color balance. One big hint is that the cloud of stars between M8 and M20 in the image had a green cast
to it, which I processed out but maybe at a cost of real data? I'm not 100% sure I have it right. What do you think?

1/3 sized image attached.

50% sized image here:
http://members.nuvox.net/~on.aunt/DSO/M8-20Medium.jpg

Thanks,
Eric

H-alpha data only.

Seven hours of H-alpha data (14 x 30 minutes).

Takahashi FSQ-106 @ f/5
Takahashi EM200 Temma 2 Mount
SBIG STL 6303 Class 1 camera
Astrodon Narrow-band Filters

Big picture here:
http://tinyurl.com/27cftd

Hi all,

If Warren's late, what am I? 8O

Here's my one and only attempt at Holmes so far, taken this past Monday, Oct. 29.

I shot an LRGB sequence with 30-second subs, only to discover during processing that 30 seconds was way too long to preserve details in the comet's nucleus. Details were better preserved in the RGB data, so I went with that.

SBIG STL-6303
Takahashi FSQ-106N
Takahashi EM200 Temma 2

RGB: 12x30 seconds for each filter, all binned 1x1

Enjoy,
Eric

Hello,

On December 19, 2007 I was driving home from work. At around 5:50pm EST,while I was stuck in traffic on I-75 just north of Cincinnati, I saw what I initially presumed to be a plane - the brilliance was similar to a plane's running lights (Mag -2 maybe?). Then it dawned on me that the object was moving faster than a typical plane. This was one time that I was glad I was stuck in gridlock, because it allowed me time to watch the object. It was moving faster than a plane but slower than a typical meteor. It was heading more or less due west. And it persisted for a bit: I'm estimating at least five seconds from when I first spotted it. Long enough for me to have this train of thought: "Hmmm... that's too fast to be a plane. Fireball? Maybe. No blinking lights. Wow, that's quite a fireball. Hmmm.. it's lasting pretty long. Could it hit? What if it hits? There it goes..." The fadeout clinched my guess that it was some sort of fireball.

Has anyone else seen it? I thought it had a bright green tint to it, but then again I might have been viewing it through the tint of my windshield. Could it have been reentering space debris? An atmospheric skipper?

Eric

Hello all,

I tentatively present my latest "finished" work: Cederblad 214 and NGC 7822. I say "finished" because I am at a point where I'm probably sufferring more from processing fatigue than fully satisfied with these images. What hurts a bit is:

1) Just when I think I have a pleasing image, I look at my histograms and see severely-clipped data. Even with these versions, I see that I am in danger of having some data clipped after performing my TIF-to-JPG conversions.

2) Some of my final processing was done on an uncalibrated laptop with a really bright screen; I'm hoping that some of the noise I'm seeing is more a result of this laptop (it's not as jarring on my calibrated monitor, the last time I checked), so I'm leaving it alone for now. If you hear a scream later on coming from my general direction it means I looked at these JPG's on my calibrated monitor and don't like what I see

This image represents 20 hours and 18 minutes of total usable exposure time taken over September and October 2007 (6 hours of H-alpha, 7 hours of SII, 7 hours of OIII, and 6 minutes each RGB for natural star colors).

Here is the nebula in the Hubble Palette:
Small: http://tinyurl.com/33s82h
Large: http://tinyurl.com/2urff4

Here it is with a pseudo-RGB look:
Small: http://tinyurl.com/2jcw6m
Large: http://tinyurl.com/354674


And here is a look that I am dubbing the SkyFactory palette, named after Davide De Martin's website (http://www.skyfactory.org/index.htm) of fabulous pseudo-RGB images taken from red and blue data from professional observatories. I don't presume that my image even comes close to his, I'm just inspired to create this image as he did his:

Small: http://tinyurl.com/364xfy
Large: http://tinyurl.com/2ooslq

To all, I wish a Merry Christmas and here's to a Fantastic New Year!
Eric

PS I've attached a small Hubble Palette version to whet your appetite.

Hello,

Here are a couple of composites of the eclipse that I shot from my back yard:

a big one:
http://www.buytelescopes.com/gallery/view_photo.asp?pid=15822

and a little one:
http://www.buytelescopes.com/gallery/view_photo.asp?pid=15816

Enjoy,
Eric