The Andromeda Galaxy

crashmaster

Hi everyone. I'm new to dgrin and learning my way around a Canon 40D, my first real daylight camera. I dont have any shots worthy of posting yet. Although I am quite new to daylight photography, my interest is mainly astrophotography and thought I would share this image I took that was recently published in Sky and Telescope. I realize there are many dedicated astro forums but thought you might like to have a look at this shot to see some of what is possible with a small telescope and an astronomy dedicated CCD camera. I stumbled on this site at the recommendation of fellow inmates over at advrider. Man there is a wealth of knowledge here and some awesome photographers! I look forward to developing my daylight skill with the help of all of you, thanks.

This image was shot with an STL-11000M CCD camera, Astrophysics 105 EDF refractor riding on an Astrophysics 900 GTO mount. An RGB shot of 120 minutes per channel, 6 minute subexposures. Calibrated in MaxIm DL, aligned in registar, combined in Sigma, and processed in PS CS. This is the closest large spiral galaxy to our own Milky Way and at 2.2 million light years distant, is visible tothe naked eye under dark skies in the constellation Andromeda.

Richard

crashmaster wrote:

It was shot with an STL-11000M CCD camera, Astrophysics 105 EDF refractor riding on an Astrophysics 900 GTO mount. An RGB shot of 120 minutes per channel, 6 minute subexposures. Calibrated in MaxIm DL, aligned in registar, combined in Sigma, and processed in PS CS.

Hi crashmaster and welcome to Dgrin. I confess that I don't understand the first thing about astrophotography, but that sure sounds complicated and expensive. As for the pic, it is simply awesome. :ivar Looking forward to seeing more.

Cheers,

Tango

:lurk 1 star, 2 star, 3 star, 4.....

amazing, and mind blowing

Cuong

I can see how expensive astrophotography can get knowing it takes a lot of dough for lenses just to catch terrestrial subjects like birds. When you deal with galaxies light years away, we're talking about serious glasses and equipment.

That's a terrific image.

Cuong

DaddyO

I believe that Crashmaster would also like you to know that M31 has
two companion galaxies seen in this most excellent shot. bow

Wowzer Work.

They would be M31, the smallish bright white fuzzy orb seen at about
the 9 o'clock position next to Andromedas outer rim and then M110,
the elliptical bright fuzzy just below Andromedas lower approx.
5 o'clock position.
Both of these galaxies are beautifully imaged here.

Welcome to Dgrin Crashmaster. Hope we get to see more of your
astro work plus other shots you'll be working on and getting. Michael

DavidTO

stromhammer

Well Toto, I don't think we're in Kansas anymore!

Amazing!

Vycor

"This image was shot with an STL-11000M CCD camera, Astrophysics 105 EDF refractor riding on an Astrophysics 900 GTO mount. An RGB shot of 120 minutes per channel, 6 minute subexposures. Calibrated in MaxIm DL, aligned in registar, combined in Sigma, and processed in PS CS. This is the closest large spiral galaxy to our own Milky Way and at 2.2 million light years distant, is visible tothe naked eye under dark skies in the constellation Andromeda."

The only word outta that I understood was "Sigma"

crashmaster

Thanks for the kind words folks, now I gotta get off my butt and shoot in the daylight with the 40D!

Astrophotography really isnt all that complicated once you get good equipment and learn how use it. Well, OK, its complex, but not difficult. The better the equipment, the easier it gets, espcially having a good mount that autoguides well. Alot of software has to work in unison to control the mount, the autoguider, the robotic focus motor, the camera etc. and it takes quite a few sleepless nights to get everything dialed in the first time out with new equipment. Everything is controlled via the laptop. Once its up and running though, data capture is totally automated, thanks to the CCD and computer age.

The STL-11000M camera uses a 35mm format interline ABG chip with a peak QE of about 40%, internal filter wheel and onboard TEC cooling. I keep the chip at around -20 C to control the noise for long exposure. There is no Bayer matrix, sub-exposures are taken though individual red, green, and blue filters. It is not uncommon to spend two or three nights gathering data on just one object for the best results.

The telescope itself is a triplet apochomatic refractor of 105 mm aperature, 660 mm FL operating at a fixed F6. The glass is ED Flourite, so its not cheap, but its the good stuff, like an L lens, though far less complex.

The mount is probably the most important piece of gear as it has to track the stars over long exposures and be aligned to the pole well enough that you dont get any field rotation. The onboard guide chip in the camera takes short exposures of a guide star (1 to 5 sec typically), calculates any movement, then sends the corrections back to mount. This compensates for any error in the mounts tracking ability and gives you nice round stars.

Now back in the film days we would use gas hypered tech pan and shoot though RGB filters and use very long exposures, 60 to 90 minutes typically. So, it was really painful when you lost one of those due to an aircraft, or some idiot turning on his headlights as he was leaving the observing site, effectively fogging you 1 hour+ of tedious hand guiding. Also the guiding was done by hand with your eye stuck to the eyepiece of a separate guidescope for hours on end, looking at a guide star though illuminated crosshairs and making small adjustments with a joystick controller for the mount. Man, I dont miss those days.

Anway, during digital processing, each sub exposure is subtracted with a master dark frame to eliminate noise and hot/dark pixels (same chip temp and exposure time as the light frames), then master flat frame to correct for optical tube and filter nuances. Then the each subexposure must be aligned then stacked into individual R, G and B channels. The channels are then color combined into an RGB stack. Then the stretching starts in Photoshop as the stacked image is mostly black, so extensive use of curves and levels is used to bring out the data lurking in the file. Then the daunting task of color correction, sharpening, and eliminating boogers like cosmic ray hits begins. Color ratios are roughly calibrated using a G2V star (white, just like our sun) akin to shooting a white card to find proper white balance on your DSLR/lens combo. However, there is alot of artistic license used in displaying colors on these images, its not science, its really art. So what you see in the images is not how the object would look if you were in a spaceship, the CCD is much more sensitive than the eyes.

Here's a pic of my widefield setup, lots of cables running everywhere, welcome to the digital age.:D

Thanks again for the comments, hope some of you find my long winded dissertation informative.

As far as being expensive, its all relative. I have less wrapped up in my astro gear than most folks spend on a modest ski boat, so about $25K. But it can be done with much more modest equipment. You can spend as little as $3000, use a modded DSLR instead of a cooled CCD camera, and still get very, very good images. Just like daylight photography, the skill of the imager is what really makes the image.

Vince

Vycor

Cheater! You have a computer moving the camera so you don't get blurs. Blah!

But in all seriousness that is some really cool stuff right there. Can you share more photos of the gear, looks really neat.

dlplumer

Incredible

and yes the people here at Digital Grin are not only talented, but generous. I have only been here a few weeks and I have learned so much......and it's fun. :ivar :ivar

TristanP

Great pic - thanks for posting. Before I bought my 20D, I was actually saving up for a telescope for both viewing and astrophotography, but after seeing the work, time, and money involved in getting great captures like this, I figured I might as well put the $ to use now, rather than waiting years to save for the right equipment. Boy am I glad I did (saved me much time and $), but kudos to you for having the patience to do it right. Congrats on getting published, too. That's a great feeling.

crashmaster

Actually, you can do it right for not alot of money. I went through many iterations of equipment before I saved enough pennies to get the top notch stuff. Buy used on astromart.com, and sell when youre ready to upgrade, you will lose very little when you buy and sell used equipment. The better stuff holds its value rather well, and in the case of the top notch optical tubes, they appreciate in value as the glass is hand figured in very small quantities and not readily availible on the new or used market.

The learning curve is quite steep, and you will need an accomplished AP'er to walk you though things the first time around if you want get the hang of it rather quickly. But first you would need to familiarize yourself with the night sky, and general telescope/mount use, after that its all software, technique and processing skill.

I cant empahsize processing enough, I generally spent from 8 to 20 hours processing a single RGB image, sometimes longer once I get input from other AP'ers on the image. You know how you stare at the screen so long, you dont know what looks good anymore, thats where the outside input is very useful.

Critiques on the astro forums usually seem a bit harsh and blunt, but meant as helpful. Afterall, when you ask for opinions, you will get them. Much is left up to personal preference, but there is an established standard of whats pleasing and what is not, not to mention all the technical critiques which can be harsh and frustrating, but helpful.

Its an extremely satisfying hobby for me. Its my boat, my sports car, etc, but quite a bit less expensive actually, even with the top end equipment.

FWIW I am selling the STL-11000 for just about what I paid for it, and am getting an Alta U16M. It has a larger chip than the 35mm format, which is quite taxing for any optics to produce a flat field, but it has a KAF-16803 full frame architecture chip with anti-blooming gates, 60% QE and much better noise characteristics than the KAI-11000, not to mention USB 2, frame buffer and triple TEC cooling which can cool the chip to 50 degrees C below ambient. Should arrive in a couple of weeks. Of course, then I have to get it dialed in for my system which will take several nights of tweaking before its up and running for image capture.

black mamba

Hi Vince...

Welcome to our family. There's a great bunch of folks involved here that will make you feel right at home.

Your picture was fantastic. I have a proclivity toward things technical so I enjoy very much you taking the time to give us a peek at the jargon and facts of what you do. I look forward to more fascinating stuff from you.

Tom

eL eSs Vee

That is one fantastic image, Vince!

Welcome to Dgrin.

Serrator

Wow...M31 never looked so good coming from a non-Hubble image!

Welcome to the site.

I always enjoy good astronomical images such as yours, thanks for sharing your image and setup information.

Karrie McD

Sure is something to stare at! Beautiful and mind blowing!!