My Equipment

Equipment Page: this is a work in progress

Telescopes:

Meade 2080 OTA* — This is an 8" F/10 Schmidt Cassegrain Telescope. I mostly use this for narrow-field and planetary work.

Meade DS2000 OTA — this is a 90mm F/11.1 Doublet refractor. Mostly used for guiding.

Orion ST-80 — this is an 80mm F/5 doublet refractor. Used for guiding and wide-field work.

Brandon Vernonscope 80mm 11x — this is an 80mm F/3.75 doublet refractor. It was sold by Brandon but actually a Lumicon Superfinder. It was originally sold with a 27mm eyepiece to yield a magnification of 11x. I use it for wide-field and have tried using it for guiding (simply too wide a field for guiding). It also makes a good finder scope. The optics on this baby are great.

In addition to the above scopes, I have access to a C14 (14", F/11 SCT) , a 12.5" F/7 Cave Newtonian, and a 12.5" F/5 Newtonian made by members of the astronomy club I'm part of. These are permanently mounted at our observatory in Columbus, Texas.

I also do a fair amount of work (so far my best work) via robotic telescopes. The two services I use are the Bradford Robotic Telescope (telescope.org) and iTelescope.net. You can check out their equipment on their sites.

Cameras and Imaging Equipment:

I use several different cameras and imaging devices:

SBIG SGF-8300C — this is an 8.3 megapixel single-shot color cooled CCD imaging system. This is my highest quality device right now, but I'd prefer a monochrome with filter wheel. More info can be found here: https://www.sbig.com/products/cameras/stf-series/stf/stf-8300c/

Canon 350D — this is a good quality 8 megapixel DSLR, but a few years old. It's modified for astrophotography† , so it does get H-alpha light. But it's old enough that it won't work with anything later than Windows XP. To use it I have to use a Virtual XP partition on my hard drive — which is a complete pain in the rear. Still, the camera does great work. Here's some more info: http://en.wikipedia.org/wiki/Canon_EOS_350D

Nikon D5000 — this is a great 12.3 megapixel Nikon DSLR for daylight photography, but not suited well for astronomical work. I've used it. But it's really not best suited for it. It's also not astrophotography modified Still, it does great planetary work. More info here: http://en.wikipedia.org/wiki/Nikon_D5000

Nikon D3000 — this 10.2 megapixel DSLR was my first DSLR, and I bought it primarily with AP in mind. However, it was really not suited for it. This camera was not modded.

Atik 16C — This is another single-shot color CCD, but only does 640x480 resolution. It's also USB 1.1, which is exceedingly slow. Even though the images are only 1/3 of a megapixel, they take 1.3 seconds each to download from the camera. I intended this to be a camera for guiding, but it really isn't great for it. It's not a bad camera though, just not a great one. I may end up using it for wide-field work.

Meade DSI II — I have two of these, one color, one monochrome. They're not bad imagers, pretty good for planetary work. But they're low resolution and they're so old that the quality is pretty bad. Neither even have the resolution of the ATIK, but they're USB 2.0 so they're faster. Lately these are my guiding cameras.

I have another Meade camera that was originally bundled with a cheap refractor. It's higher resolution, but lower quality. It's not bad for planetary, lunar, and guiding. It's really not much different from the LPI camera they sold.

Mounts:

Most people who don't do astrophotography mistakenly think that the most important pieces of equipment are the telescope or camera. But the truth is that the most important piece of equipment is the mount. Most people would probably refer to this as the tripod — but not all have tripods and they are far more than just a tripod.

You see, the stars move across the sky — exactly like the sun and moon do. This movement is not a straight line — it's an arc. This motion is entirely caused by the rotation of the earth. If you point a camera at a star and take a picture, that star is moving across the sky and if you don't have a fast shutter speed, it will be blurred. But stars are relatively dim objects, and the interesting things — galaxies, nebulae, and star clusters, are even dimmer. To take pictures of these objects you need to use long, sometimes very long, shutter speeds. My best nebula pictures are about 5 minutes of exposure — and even that's fairly short. I know people who do twenty minutes and more. Some hubble images are DAYS long.

Because the stars move, and because you need long exposure, you need the telescope and camera mounted on something that can accurately follow the stars across the sky. Enter the Equatorial Mount.

Most astrophotographers use German Equatorial Mounts. These mounts have two axes of motion — right ascension (RA) and Declination (Dec). When the main shaft of the mount is properly aligned with the north celestial pole, the RA axis sweeps an arc across the sky from east to west. The Dec axis then sweeps north to south. If properly aligned, once an object is located in the field of view, you need only move in one axis — RA — to follow an object across the sky. This simplifies the problem. But then you still need to do so at a very precise speed.

A good mount for astrophotography can cost several thousand dollars. They are extremely precise and reliable and designed to hold a sufficient weight of equipment. Electronic controls are additional and can be extremely important for better alignment, tracking, and finding of objects.

I have two such mounts.

My first mount was a Celestron CG-5-ASGT. This mount is actually quite good for visual observing. Fairly small and light, easy to set up and use, fairly easy to align… I used this mount for four years before I realized it just wasn't good enough for photography.

I now use an iOptron iEQ-45. This mount is great. It's NOT ideal, but it's good. It does what I need it to and I have no complaints.

Other Bits and Pieces:

For optical observing I have a good array of eyepieces. Most are 1.25", but I have a handful of 2". They include, but are not limited to:

Meade 5000 series

2" eyepieces: 40mm, 30mm

1.25" eyepieces: 26mm, 20mm, 5.5mm

Celestron Ultima Series (all 1.25")

35mm, 32mm, 30mm (two of these), 18mm

Meade 4000 Series 26mm eyepiece

Brandon Vernonscope 27mm(1.25") eyepiece (I'm not 100% sure on the measurement on this one, it's unlabeled).

Celestron Omni 40mm (1.25") eyepiece —huge field of view.

I have a few other random eyepieces, but these are the ones I use most.

Meade and Celestron 6.3 focal reducers — these are designed for use with an F/10 SCT. They are most useful for creating a wider field of view for photography. They do, however, increase vignetting. I have one each from Celestron and Meade. They appear to be identical — probably created by the same Chinese factory. I've actually used them double-stacked to effectively move my F/10 SCT down to F/4. Extreme vignetting and some coma, but it works.

Eyepiece adapter for photography — this doodad from ScopeStuff (great company!) makes it possible to add an eyepiece (if it's physically small enough) to the optical train‡. This is particularly useful for planetary work.

Typical Configurations:

I have a few different commonly used configurations of equipment I use. Here's the most common.

Meade 2080, f/6.3 focal reducer, SBIG STF-8300C mounted on iEQ-45 with DS-2000 refractor and ATIK 16c camera for guiding.

Same as above but using the Canon 350D instead of the 8300C

Same as above but using a different camera for guiding (usually the DSI II)

I also often use the STF-8300C or 350D through the Vernonscope. Often these are un-guided.

I have a rig, yet to be used, that allows me to use any of the 3 refractors, one for guiding, one for shooting. I can use any of the cameras through any of the refractors. I have yet to implement this, but it's ready to go.

I'm sure I could put down more info, but I think this is enough for now.

*For those of you who aren't familiar with telescope equipment, OTA stands for Optical Tube Assembly and refers to the telescope itself, the lenses or mirrors and the structure holding them all together. It does not include the mounting equipment, tracking equipment, eyepieces, cameras, and other doodads.

†Nearly all digital camera imaging chips are sensitive to a wider range of light frequencies than the human eye, particularly in the infra-red and near-infra-red area of the spectrum. Those devices that are not specifically designed for scientific work typically include an IR cutoff filter to block these frequencies. If you don't do so, you often end up with weird pictures that are deeply reddened. The filter balances things out just fine. However, for astronomy, this is bad. There is a lot of visual data to be captured in the near infra-red range, particularly the glow of the H-alpha hydrogen spectral line at around 656 nm. Emission nebulae glow bright with Ha light and blocking it makes for less interesting pictures.

To fix this, many astrophotographers replace the IR filter that's mounted right over the sensor chip with a piece of plastic that is optically clear to Ha light. However, such cameras are really no longer good for taking regular daylight pictures any longer unless another Ha filter is attached.

‡The Optical Train is the equipment that light flows through. For example, a very simple optical train would be my ST-80 with a diagonal and single 4-element plössl eyepiece. In such a case my optical train would include about 7 pieces of glass: the two elements of the 80mm objective lens, the 4 of the eyepiece, and the prism of the diagonal. If I used my 2080 OTA it would add another piece of glass: the OTA includes the primary mirror, secondary mirror, and corrector plate. If I added a focal reducer, a couple more pieces of glass (not sure how many elements are in the reducer). The more glass, the more room there is for imperfection to be added (dust, scratches, distortions). The “Optical Train" for a given configuration is all of the surfaces that have the ability to modify the light passing through them or bouncing off of them.