Posts Made By: Jared Willson

I have been playing around with my DSLR and my scope/mount for a while now and always got mediocre results. Finally this Saturday I took something I am pleased with! I've seen better images of M42, but at least this one isn't embarassing any more.

Date/Time: January 7, 2007, 04:00 UT
Location: Oakland, California
Conditions: Seeing--6 out of 10; Transparency--Magnitude 3 skies; waning gibbous moon
Subject: M42, M43, and NGC 1977
Equipment: Losmandy GM-8 mount unguided; WO FLT-110 w/ TEC optics @ f/6.5; Nikon D50 DSLR w/ IR filter removed
Exposure: x11 30s subs @ 30s each, ISO 1600; x5 30s subs @ 30s each, ISO 200
Technique: All images loaded into Photoshop CS3 using ACR; Dark subtracted and median combined in Photoshop CS3; White balance, curves, levels, and sharpening

Thanks for looking - Jared

Last Saturday I captured an image of the Triangulum Galaxy and am pretty pleased with the results...

Losmandy GM-8 Mount
FLT-110 APO @ f/6.5 (TEC)
SBIG ST-2000XCM
Mill Valley, CA (seeing 7/10, NELM 4.5)

x6 Ten minute subexposures
Captured in Equinox Image
Calibrated and combined in Maxim DL
Post Processed in Photoshop CS2



What do you think?

I picked up an STL-11000 at the AIC conference the other week, and here is a test exposure--just to see if I can figure out how to make it run. I actually had a problem with the combination of MaximDL (running on a MacBook Pro under Parallels) and the camera--the computer kept locking up part way through the exposure. As a result, I ended up shortening my subexposure time to three minutes, and even so only managed to capture three luminance frames and one each of RG&B in about three hours of work... I think I'll go back to using Equinox Image for capture--it's native to the Mac.

Excuses aside, I am quite pleased with the result. The image has a much wider field of view than my old ST-2000XCM (obviously), and it also has more resolution since it is a monochrome camera. I was expecting the resolution with the 9 micron pixels to be about the same as on my old one-shot-color camera with 7.4 microns, but that wasn't the case. The new camera has nearly twice the resolution!

Here is M31 captured from Oakland, CA using the STL-110000M, an FLT-110 APO @ f/6.5 (TEC), and a Losmandy GM-8 mount. Seeing conditions were average--5/10--and NELM was around 4.0 (lots of haze).

I managed to capture a nice shot of Bode's Nebula and the Cigar Galaxy last weekend (with a nearly full moon from Oakland, CA). Thought I would share it.

40 minutes of luminosity (five minute subexposures) and 15 minutes each of RG&B (five minute subs).
Losmandy GM-8 mount, FLT-110 APO (TEC), and SBIG STL-11000M camera with Astrodon "I" series filters
Image was self-guided. Seeing conditions were good--7/10, and transparency was poor (despite the clear skies--it's pretty light polluted!) with a NELM of around 3.8. Image was captured using Equinox Image. Calibration was in Maxim DL, and post processing was in Photoshop CS2. I was pleased to be able to see Holmberg IX in the image! What do you guys and gals think?

After roughly an 18 month wait, I finally received my Astro-Physics Mach1 GTO mount last month, and it is WONDERFUL. Now I can finally image at the longer focal lengths I have always wanted to... So, naturally, I went out and bought a longer focal length optical tube--a Vixen VC200L modified classical Cassegrain--to take advantage of the new mount. My checking account may never recover, but what the heck.

Here is first light with the VC200L from June 8th.

Eastern Veil
Fremont Peak, San Juan Bautista, CA
Seeing 6/10; NELM of 5.8.
Image captured in Equinox Image, calibrated in Maxim DL, and post processed in Photoshop CS3
One hour of luminosity, thirty minutes each of RGB.
SBIG STL-11000 camera, Vixen VC200L @ f/9, Mach1 mount

I was in Yosemite Park last weekend. Unfortunately, due to wild fires the transparency was really horrible--quite literally I have had better transparency at home in Oakland. The gibbous moon didn't help either. On the other hand, the seeing was really outstanding. I decided to pick an object that (I hoped) would benefit from the good seeing and wouldn't be bothered too much by the poor transparency. M13 was the obvious choice!

Vixen VC200L @ f/9
Astro-Physics Mach1 GTO
SBIG STL-11000M w/ Astrodon filters
x2 five minute exposures for luminance; x1 each five minute RG&B exposures
Captured in Equinox Image
Calibrated, DDP, and Lucy Richardson Deconvolution in MaximDL
Synthetic flat, color combine and balance, curves, levels, noise reduction, and contrast enhance in Photoshop CS3

Not much exposure time, I know, but it was all I could manage with passing clouds, a dead battery (don't ask how that happened with a week to prep for this trip), and a really annoying Moon.

In any event, I was pleased with the final result.

- Jared Willson

Went to Chabot Space and Science Center last night as a volunteer expecting to spend my timing showing people some of the "showcase" objects through the eyepiece. But when I realized that the fog was hiding the city lights--to the point that the Milky Way was actually visible in Cygnus (NELM approximately 4.5)--I decided to try my hand at imaging for a while. I managed to get fifty minutes of luminosity and twenty minutes each of RG&B while explaining to visitors exactly what I was trying to do. Tracking on the Mach1 GTO was just fantastic. Equinox Image was reporting typical RMS tracking errors of 0.08 pixels (0.24 arc seconds) which is essentially seeing limited. The result was far better than I expected within Oakland city limits.

NGC 7000/North America Nebula
LRGB (50:20:20:20) image with ten minute subexposures binned 1x1
FLT-110 APO @ f/6.5 (TEC); Astro-Physics Mach1 GTO; SBIG STL-11000M w/ Astrodon series I filters
Image was self guided.
Calibration (darks and flats) in Maxim DL; post processing in Photoshop CS3

Constructive criticism is welcome!

- Jared Willson

Here is my first successful (at least moderately) attempt at merging H-alpha data into an LRGB image--the Soul nebula. Captured in Oakland, CA this past weekend with an FLT-110 apo @ f/6.5 and an SBIG STL-11000 mounted on an Astro-Physics Mach1 GTO. 90 minutes H-alpha (through Astrodon 3nm filter), 30 minutes luminosity, and ten minutes each RG&B. Obviously, I could have used more time in all subexposures, but particularly in the RG&B. Still, I was pleased with the results and particularly pleased that I was able to keep most of the contrast and detail in the H-alpha layer without losing the stars in the luminance layer or creating a salmon colored nebula. Boy, what a difference H-alpha makes on an object like this. Under Oakland's magnitude 3.8 skies I couldn't even detect the nebula in the unprocessed luminance layer--even when stretched. Then add in the H-alpha and suddenly you've got an image!

I frequently hear various amateur astronomers referring to certain telescopes as being, "well corrected achromats." That always made me curious...

I know that the designer of an achromatic doublet can decide where the color error is going to be--split equally between red and blue or less on the red side at the cost of larger errors in the blue, etc., but I had always thought that for a given focal length and aperture virtually all achromats had fundamentally the same color error. Am I wrong? Do differences in quality affect the amount of chromatic error? Are there variations in commonly used glass that would matter? Without resorting to special dispersion glasses?

Just as an example, I heard someone claiming that one model of 6" f/8 achromatic refractor had substantially less CA than another model of the same size and focal ratio. Is this likely to be true? Or is it just that the color error may be in a different part of the spectrum?

Thanks - Jared

Finally captured a couple images with my new (to me) TMB-152. Would love your feedback.

Captured on 5/26/2009 from Oakland, CA
Limiting magnitude of 4.9, seeing 7 out of 10
Astro-Physics Mach1 mount; TMB-152 @ f/7.9; SBIG STL-11000M w/ Astrodon TrueBalance LRGB
Captured in Equinox Image; Calibrated and stacked in Nebulosity; Post processing in Photoshop CS3
Thirty minutes lominosity; fifteen minutes each RG&B; five minute subexposures
FWHM prior to processing was 1.9 arc seconds
Darks and flats applied

Thanks - Jared Willson