Tumbleweed Observatory's

Astronomy Hints


HOME

LINUX
SCI FI
ASTRO
BLOG

MENU

Images Taken Through an ETX-90 with a Webcam

Shop Amazon Telescopes

Astrophotos Taken Through A Meade ETX 90



Survey of Amateur Astronomers Who Take Photographs

The above survey results, obtained from over 250 amateur astronomer participants, shows that over half amateur astronomers surveyed at one time or another took their own moon pics, and nearly as many have taken planetary pics. Another survey result showed that while film cameras are still used some by amateur astronomers, digital photography is now by far the most popular choice for astrophotography. In addition to showing pics of the moon that I've taken, this web page gives some hints on how to take photographs of the moon and planets.

This collection of lunar and planetary images were taken with my Meade ETX90, and older version of the Meade ETX-90 MAK with 884 Tripod and SP 26mm Eyepiece 3514-04-15. I used a modified Quickcam Express Webcam and a 2x Edmund Barlow for some images. I've recently added some additional images taken using a Celestron NexImage web cam conversion. Most of the images are movie captures (avi files) whose frames have been combined with a Yorick program I wrote. If you can still find a Celestron NexImage, I can recommend it, but it has been replaced with the even better Orion StarShoot Solar System Color Imaging Camera IV.

Meade has apparently dropped their once popular ETX 125 Maksutov telescope, though for the time being seem to be still making a version of the ETX 90. A similar telescope from the Celestron lineup is the Celestron NexStar 90SLT Mak Computerized Telescope (Black). If you want to do some solar system photography on a budget, then the Orion camera and Celestron MCT would give comparable instruments to what I used to get these images.

These moon pics and planet pics give some illustration of what can be accomplished with the compact Maksutov and SCT telescope designs. With their short tube and built in tracking motors and computers, setting up for solar system photography is relatively easy. Not all of the moon images are representative of the best the telescope can do, but some are very close to that. The Jupiter photographs are not as good as I hoped, but again, near the best this scope can do, at least with a digital camera of web cam design. I think to get better Jupiter photos I need to move to a 3X Barlow to magnify the planet to a greater extent.

These images were obtained by first aligning the equatorial mounted telescope with Polaris. This helped the clock drive do a better job, keeping image drift to a minimum. I found that with the digital web cam camera, the moon was an easy target. Even if considerably out of focus initially, when the moon swept through the camera field of view it was noticeable. I could then adjust the focus to get the best image to show on my laptop, which was running the web cam program and presenting the real-time display.

For the Jupiter pics, Mars pics, and Saturn pics, I found that it was best to focus the telescope-camera combination first on something before trying to get the planets into view. I used the moon if it was up, otherwise a streetlamp or something similar at least a block or two away. In this way, when I swept across a planet, it would be at least be noticeable on the computer screen, letting me complete fine focus and take my photographs. If I didn't pre-focus on anything, I found I could sweep past a planet and not even tell that it had passed through the field of view.

I first adjust the parameters of the web cam to give an optimal image in terms of brightness and contrast. If I had the contrast or brightness too high, some parts of the images would be saturated, and nothing I could do in post processing would recover that. So be sure if you do this you set your camera parameters for an image that has good contrast, but nothing besides the empty space is totally black, and nothing is completely white.

Next, and perhaps most difficult, I'd try to get the finest focus. This is difficult when looking at an image on a computer screen. The update is a bit slow, and touching a focus knob can cause motion. When the motion subsided, often I couldn't tell if I'd improved the focus or not. Don't rush this step. Unfocused images, like poorly exposed ones, can't be recovered in post processing.

Best results were obtained by taking movies through the web cam, rather than taking individual pictures. This allowed image stacking, which gives far superior results. But on some of my earlier outings I didn't get enough images to do that.

The first Saturn photo was taken at prime focus because of the dimness of the planet. The result after processing was then enlarged. To learn more about how stacking images can give better results, check out the Celestron NexImage review.

Some of these photos turned out very well, including Copernicus, Tycho, and Eratosthenes as examples. I've compared these to about every similar photograph on the web, and have concluded that for the size instrument used, they are top notch. The only images I've managed to find that put some of these to shame are a few taken by 8 inch and larger instruments, and sometimes even these don't shame the ETX 90 efforts. It just shows what a remarkable instrument the ETX 90 is.



Click On Any Of The Following Images For A Larger View

The Equipment: Meade ETX 90 Maksutov telescope on pipe tripod with wedge. Attached to the fork mount base with Velcro is a hand controller for the RA motor. It is a simple modification to the controller circuit card, and is indispensable for doing digital photography of solar system targets. The newer computer controlled ETX 90 models already have the necessary controls.
Aristarchus crater with ETX 90 Moon, Aristarchus region. Meade ETX 90 with Celestron NexImage camera and 2x Barlow. Stack of 76 frames. The brightness of the floor of Aristarchus hides details of the crater floor, but Schroter's Valley shows up well.
Copernicus crater with ETX 90 Moon Image, Copernicus, Meade ETX90 With Celestron NexImage Webcam, 2x Barlow, stack of 50 frames. The mountain peaks are well resolved, and some of the roughness of the crater floor to the upper left of the peaks is discernible.
Lunar Alpine Valley with ETX 90 Moon Image, Alpine Valley, Meade ETX90 with Celestron NexImage, 2x Barlow, stack of about 60 frames. The fascinating Alpine Valley, near the crater Plato, was well displayed by the position of the terminator in this view.
Plato crater with ETX 90 Moon Image, Plato region, Meade ETX90 With Celestron NexImage Webcam, using 2x Barlow, stack of 60 frames. This is one of my favorite lunar regions, and the terminator was just about perfect for a nice view of Plato. Just above Plato is the pitchfork shaped Tenerife Mountain Range
Lunar Straight Range with ETX 90 Moon Image, Straight Range, Meade ETX90 With Celestron NexImage Webcam, using 2x Barlow, stack of about 50 frames. Near Plato, this enigmatic small mountain range is unusually linear.
Clavius crater with ETX 90 Moon Image, Clavius, Meade ETX90 With Celestron NexImage Webcam and 2x Barlow, stack of 50 frames. This big majestic feature is always a treat, with many smaller craters on the floor of the big crater.
Tycho crater with ETX 90 Moon Image, Tycho, Meade ETX90 with Celestron NexImage Webcam, 2x Barlow. In this closeup view, the resolution of the amazing ETX 90 is evident. Too close for the magnificent system of rays to be seen, this image shows clearly the crater floor and rim, as well as the heavily cratered region surrounding Tycho.
Albategnius crater with ETX 90 Moon Image, Albategnius region, Meade ETX90 with Celestron NexImage, 2x Barlow, stack of about 60 frames. The nearby large crater of Ptolemaeus is also well displayed.
Eratosthenes crater with ETX 90 Moon Image, Eratosthenes, Meade ETX90 With Celestron NexImage Webcam, 2x Barlow. I've oft strained to see the three mountain peaks on the floor of Eratosthenes, and this image shows them well.
Purbach crater with ETX 90 Moon Image, Purbach region, Meade ETX90 With Celestron NexImage, 2x Barlow, stack of about 60 frames. Purbach is the large crater at the bottom of the image.
Lunar Bay of Rainbows with ETX 90 Moon Image, Bay Of Rainbows, Meade ETX90 With Quickcam Express Webcam, 2x Barlow, stack of 50 Images. This large feature, near the Plato region, gives testimony to a large impact in a distant past, largely filled in with lava.
Lunar Pallas region with ETX 90 Moon Image, Pallas region, ETX90 With Celestron NexImage, 2x Barlow, stack of about 60 frames. Pallas is the crater near the upper left of the image. It overlays the rim of the larger crater Murchison
Lunar Apennine Mountains with ETX 90 Moon Image, Apennine Mountains Region, ETX90 With Celestron NexImage, 2x Barlow, stack of about 60 frames. This mountain range forms the southeastern border of Mare Imbrium
Gassendi crater with ETX 90 Moon, Gassendi Crater. ETX90 With Celestron NexImage and 2x Barlow. While not a region I view often, Gassendi presented itself well on this evening. Seeing, however, was only moderate, allowing me only a so-so image.
Lunar Hyginus Rille with ETX 90 Moon Image, Hyginus Region, ETX90 With Celestron NexImage, 2x Barlow, stack of about 60 frames. In this view, the small crater is seen split by the Hyginus rill.
Stofler crater with ETX 90 Moon, Stofler Region. ETX90 With Celestron NexImage and 2x Barlow, stack of about 60 frames. Stofler is the large crater to the lower left, with part of its rim destroyed by a series of later impacts.
Jupiter with ETX 90 Jupiter Image, Nov 4, 2010, ETX90 With Celestron NexImage, 2x Barlow, stack of 22 frames. In 2010, the SEB did its famous but infrequent disappearing act. This image shows clearly that the SEB is missing.
Jupiter Great Red Spot with ETX 90 Jupiter Image, Nov 5, 2010, ETX90 With Celestron NexImage Webcam, 2x Barlow, stack of 82 frames. The Great Red Spot shows up well in this image. Normally the GRS is seen on the border of the SEB, which happened to temporally disappear in 2010.
Io transit of Jupiter with ETX 90 Jupiter Image, Nov 03, 2001. ETX90 With Quickcam Express Webcam, 2x Barlow. Above Center And Left of each image is Io's Shadow, Shown Moving In The Successive Images. Note in these older, non-stacked images the SEB is clearly visible.
Saturn with ETX 90 Saturn Image, Oct 14, 2001, ETX90 With QuickCam Express Webcam. This was an early attempt, and with the limited gain of the QuickCam Express, I was forced to shoot Saturn at prime focus. This left me with a small image, and only limited detail was thus available.
Saturn with ETX 90 Saturn Image, Apr 4, 2012, ETX90 With Celestron NexImage Webcam, 2.5x Barlow, stack of 141 frames. With the added sensitivity and resolution of the Celestron NexImage camera, I was able to use a Barlow to boost up the image size for this image. Note that between the 2001 and 2012 images, Saturn had gone through a ring transition.
Mars 2003 opposition with ETX 90 Mars Image, 2003 Opposition. ETX90 with Quickcam Express Webcam and 2x Barlow, stack of 48 frames. This image turned out better than I ever expected, aided in large part with an opposition that presented Mars at its closest approach in decades. Mars was at an apparent size of 25 arc-seconds.
Mars Image, 2003 Opposition, colorized to Mars typical photograph color.
Mars 2012 opposition with ETX 90 Mars Image, 2012 Opposition, ETX90 with Celestron NexImage and 2.5x Barlow, stack of about 60 frames. In 2012, the Mars opposition wasn't nearly as favorable as in 2003. In this image, Mars was only at an apparent size of about 12.5 arc-seconds.
Mars Image, 2012 Opposition, colorized to Mars typical photograph color.
Mars 2016 opposition with ETX 90 Mars Image, 2016 Opposition, ETX90 with Celestron NexImage and 3x Barlow, stack of about 80 frames. In 2016, the Mars opposition presented an image with an apparent size of about 18 arc-seconds.

Personal Notes

Though the pictures on this web page were taken with a modified web cam, they could have also been obtained with a digital camera mounted behind the eyepiece. With a digital camera, you don't need to haul a computer out to the telescope to control the camera. I've constructed a simple mount to hold my Fuji behind the eyepiece, and will soon be adding photographs taken with that method.