My first photo of Mars
December 16th, 2007 by Maxim · 2 Comments · 4,671 Views
This weekend I tried to photograph Mars. This is a perfect time to make pictures because Mars is in the opposition and closest to Earth as it’s ever been in the past 130 years or so. Around midnight it’s roughly overhead and the Moon sets by that time – it’s light won’t interfere and when the Mars is directly above you you are looking . I set up my Meade ETX-125AT telescope with 26mm eyepiece and pointed it to the planet. Adjusted focus, and Mars appeared like a little orange dot, or more like a tiny orange circle. Still to small to see any features. I tried to add Barlow 2-3x lens. This should have boosted magnification from 94x to three times that: 288 times. Since focal length changes too, I had to readjust the focus. Now the problems began. First of all I was not using the GOTO function or tracing feature of the telescope. The Earth rotates so fast, and Mars would move out of the within 30-40 seconds. But the biggest problem is that at almost 300x magnification everything is so shaky it’s practically impossible to see anything – the image is bouncing around in the view.
What about taking picture? Well, the camera attaches through t-mount adapter to the accessory port of the ETX telescope. Since Mars is overhead, it’s impossible to get to the port. My solution? Instead of mounting telescope in standard Alt-Az mode I flipped the telescope mount into equatorial mode, so the telescope sort of hangs on a side of the tripod. Granted, the tripod had to be extended to full length of its legs so keep it from tipping over by the weight of the telescope. Equatorial mounting is a bit awkward to use because horizontal and vertical axis are interchanged. Now I could attach the camera to the accessory port, which now was accessible and unobstructed via t-mount. Third problem is that Canon EOS 20D SLR camera is very heavy, and it’s dragging the telescope down. So much so that Mars is moving out of the view – again had to manually adjust the scope. Forth problem: I can only adjust focus on the Canon EOS by looking at the picture through the viewfinder: a really tiny picture, smaller then what I can see through the eyepiece.
I took some pictures. First picture is what camera sees through the scope: Photo of Mars through Meade ETX-125AT using Canon EOS 20D. Second is really the same picture enlarged and cropped: you can see the part of Mars illuminated by the Sun.
Today we’ve set up the telescope with the computer and looked at the Moon – it was fantastically sharp and beautiful, and at the moment it was also overhead so taking pictures was inconvenient. We’ve also took a guided tour of the sky – brightest objects of the day were Moon and Mars again, as well as Vega, Aldebaran and Betelgeuse. Some star clusters were also fun to look at. The GOTO function with panning is brilliant.
I have better idea now about the technical problems with photographing Moon and planets. I will probably still shoot the Moon with Canon EOS 20D through T-mount and accessory port – maybe even later today when the Moon is lower and closer to horizon; I also got some experience photographing in equatorial mode. It’s still not as easy as I would like it to be. So today I’ve got the idea to begin to use a small mount that I can attach my Canon A620 digital camera directly to the eyepiece. This method, I expect, will have several advantages:
- No need to flip the mirror and maybe even no need to readjust the focus
- I can use zoom on the Canon A620 camera without changing magnification so drastically with Barlow lens
- A620 weighs less then 20D so hopefully the telescope won’t shift under its weight as much (if at all)
- No need to view the stars through the camera’s tiny viewfinder – I can use A620’s LCD display to compose and preview the image
Potential problem could be the absence of manual mode on A620 and it’s poor ability to auto-focus in low light conditions. My life can also be a little easier if I got another 26mm or wider eyepiece so I can interchange this eyepiece with the one attached to the camera. It would also be interesting to see how much of the image will be black because, unlike shooting through t-mount, which is technically a prime-focus adapter turning the telescope into a very powerful zoom lens, the camera sees what the eyepiece can see, with a tiny image formed at the center of the lens.
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astrophotography | astrophotography with Canon EOS | Canon A620 | eyepiece | Mars | Moon | photo of th Mars | photo of the Moon | t-adapter | t-mount | telescope