Sadr (γ Cygni) Region

11 10 2010

Sadr (γ Cygni) Region

Originally uploaded by Eriza

Fresh from the oven.

North America Nebula

9 10 2010

North America Nebula

Originally uploaded by Eriza

Weekend, no moon, clear sky, returning mood to drift align, target object high near zenith… a very extremely rare combination. But it happened nonetheless…

Why Astrophotography?

17 10 2009

It’s the question I sometimes ask myself. A bit of reflection gives the answer: it’s its multi-disciplinary nature that attracts me to it. It’s not sheer photography, neither it’s sheer astronomy. There’s just a bit of everything. Just to mention some:

– Astronomy: from understanding the movement of the heavenly bodies, celestial sphere coordinate system, to astrophysics, the formation, evolution, and death of stars and galaxies.

– Photography: mastering the camera. How to do focusing. How to select the appropriate exposure. How to post-process. How to make a nice composition. What is light frame, dark frame, offset frame, bias frame. What to do with noise and hot pixels.

– Optics: one needs to be able to a certain degree assess the quality of the telescopes and the issues around it. Should it be a reflector or a refractor or a catadioptric. What is the good focal-to-aperture ratio. How important is magnification. What is chromatic aberration, spherical aberration, astigmatism.

– Mechanics: should it be alt-azimuth or equatorial mounting. What is the principle of tracking. How to balance an equatorial mount. How to polar align. How to guide.

– Computer and software: from automating the image acquisition, autoguiding, and image processing.

This for sure will keep me busy for years to come.

My first deep-sky astrophoto!

3 10 2009

The Orion nebula:


With the stuck mount problem removed, the long nights of deep-sky imaging begin…

UPDATE: A new picture of the same object here.

Notes from near the Equator

9 01 2009

One of the “missions” of the recent visit to Indonesia was to get acquainted with the sky of the southern hemisphere, when possible also to capture some photographs. Now, carrying a 6-inch Schmidt-Cassegrain, along with the tripod and the equatorial mount, is cumbersome, if not impossible. So the idea was to bring along some simpler equipments: a binocular for observing, and a small tripod for photographing, so that I could create a star trail or something like that. But darn it! As I was sitting in the aircraft before departure I realized that neither of them was in my luggage. And so observation must then be limited to naked-eye visual only. It was not so bad, it turns out, as it was pretty exciting to see Orion up high near zenith, with different orientation from the one one would be seeing in Europe. It also looks interestingly smaller. My immediate speculation was this might be another form of the Moon illusion; well, it’s just a guess, I would like to further investigate this later. The Crux was another impressive discovery. It was actually my visual cue, sort of, to really understand after-midnight sky. Once I identified the Crux, other stars were much easier to find, comparing the sky map picture to the real night sky.

The idea of creating a decent star photograph was simply forgotten. Until the 31st of December. I had no idea that Venus and the Moon would be very close together that day. I simply went outside, and behold! Two heavenly bodies were on the show, right in front of our house. So here’s the scenic, something that was unthinkable to make a few weeks earlier.