Archive for no tracking

Moon scratched by the claw of a bear

Posted in Astrophotography with tags , , , , , , , , , , , , on 2011/08/31 by computerphysicslab

Near Bullialdus crater (at top-right side of the picture) there is a quite interesting region called Rimae Hippalus. Hippalus crater is the big one (left-center side of the picture). It is a big crater. In this image, shadows in this crater due to a low altitude sunlight creates a visual effect, as if a great creature had stamped his bare footprint in lunar soil. Do you see it?

Polaris A & Polaris B

Posted in Astrophotography with tags , , , , , , , , , , on 2009/10/18 by computerphysicslab

Polaris has a close neighbor at 18 arcseconds that can be spotted easily through a telescope.


This is a 15 seconds exposure through a Meade Lightbridge 16-inch, a Dobson with no tracking, but fortunately Polaris moves very slowly through its small circumpolar path, due to its proximity to north pole in the sky. The camera used was a Canon EOS 450d, also known as Rebel XTi. The method employed was an eyepiece projection using a 14mm Meade Series 5000.

Auriga and Moonlight

Posted in Astrophotography with tags , , , , , , , , on 2009/10/10 by computerphysicslab

This is a set of 71 single shots of 10 seconds each one to the Auriga constellation on 2009-10-08. The Moon was located at its south and its brightness is visible on the edge of the image and on the background gradient. The single frames were recorded using a Canon Rebel XTi (EOS 450d) and a conventional EF 18mm lens. The Kids is a triangle of stars on the upper side of Auriga constellation.


Reaching Binocular focus

Posted in Astrophotography with tags , , , , , , on 2009/09/29 by computerphysicslab

Someone asked me for help recently using this comment:

“Hello, I have 16×50 binoculars and a 7.1 mega pixel camera with 4x zoom and I’ve done what you said and looked at the Moon and the images are no where near as close as yours. The image blurs once the picture is taken of the moon and doesn’t seem no where near as close to the moon as yours. Please help.”

I would like to share the answer just in case someone is also interested.


16x and 4x should mean a final 64x optical zoom. That is as much as when seeing through a telescope. If you are capturing frames at 7 MegaPixels this is to say they are around 3,000×2,500 pixels in size. When creating a video you need a final image size of 1,000×700 as much, so if you crop a frame of 3,000×2,500 into a final frame of 1,000×700, it would be equivalent to apply a 3x additional zoom to the image, because (1,000×700) * 3 is more o less equal to 3,000×2,500.

Bottom line: do a crop to your 7 Mpx image and you will get an effective 182x magnification.

Respecting the blur, don’t panic. The blur may be a product of the weather conditions, or a thermal issue in your binoculars.

Try to avoid make photos of the Moon when it is located directly over the roof of a neighbour. This is a very frequent source of blurring problems.

Try also to cool down your binoculars before the observation, trying to get a thermal equilibrium with the outdoor temperature.

Be sure that your digicam is functioning with a infinite focus mode. The focus must be achieved manually using the binocular focuser.

If you have the option of taking continuous shots, use it. The majority of the images recorded may be blurred, but sometimes you may get one more clear and sharp.

Well. I hope this helps you to get sharper images.

Good luck.

Jupiter, Io & Wesley impact scar

Posted in Astrophotography with tags , , , , , , , , , , , , , on 2009/08/28 by computerphysicslab

Good seeing yesterday too (2009-08-27 23h05m UT). Wesley impact scar is fading day after day, but it is still there. I made an animation that shows Io approaching Jupiter’s limb:


Big Jupo

Posted in Astrophotography with tags , , , , , , , , , , , , , , , , , on 2009/08/27 by computerphysicslab

I have a good seeing last night. So I got my best Jupiter yet. Here it is:

Jupiter 2009-08-26 Sharp

It is 4x resampled via Registax Mitchell and PS. After resampled I can spot more details in bands and polar zones.

As always I used the 6-inch no-EQ mounted newtonian reflector, the 14mm eyepiece doing afocal projection over the Canon EOS 450d (Rebel XTi) body and recording video using “EOS Camera Movie Record” free software. Three times Jupiter crossed over the field of view. Registax and VirtualDub added and stacked the footage properly.

M42 with point & shoot digicam

Posted in Astrophotography with tags , , , , , , , , , , on 2009/08/26 by computerphysicslab

It is interesting to explore the possibilities of some common devices such as digicams and binoculars. I have been reprocessing some old stuff from March. I took 474 single exposures of M42 in Orion through the binoculars with my Exilim digicam. Using a stacking software, all these subframes may become aligned and added accurately, resulting into a 4 minutes long exposure single shot with a perfect star-tracking. I reckon I didn’t use any kind of equatorial mount or motorized tracking. Just an steady tripod. Orion belt passed accros the field of view of the binoculars 3 times. In every gap, I corrected manually the FOV to get M42 inside it as longest as possible.

Orion M42 binoculars-exilim


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