Retiring the A900 for astrophoto

A few days ago I got a new camera for my astrophotography -- a termic cooled CCD camera with a 8.3 Mp sensor. Just a box with a sensor and some electronics. This spacial camera has way higher Hydrogen-alpha response than the A900 (areas colored red in these pictures). Such cameras has now become affordable for most amateur astronomers, so I simply could not resist.

A bit sad to say: I think my A900 has been outperformed for this kind of photography by a Kodak CCD sensor. Also, the astro camera has much wider dynamic range, which is very helpful for contrasty astronomical objects.

My A900 wil stil be heavily used for down-to-the-Earth photography, and for some astrophoto.

Here are a few examples, taken under less than ideal conditions recently. First two pictures showing the same subject, one made with the Sony A900 (below), the other with the Kodak chip (on top). The Sony picture has a bluish cast, and was exposed for about 3 hours. The Kodak sensor photo is exposed for nearly 1,5 hours, still it carries much more detail:



The Orion nebula exposed for one hour with the Kodak CCD sensor:



Finally, the Horsehead nebula and Flame nebula exposed for about one hour with the Kodak CCD sensor:

wow, great pics. what camera did you get and how much are they these days?

--
the second mouse gets the cheese

Like comparing apples to oranges. Your new astro camera is designed for a specific task and should excel at it. CCD sensors are more sensitive in general and are better suited for long exposures, especially when cooled. Congratulations on your new toy. Enjoy.
--
Tom

Look at the picture, not the pixels

http://www.flickr.com/photos/25301400@N00/

You can get decent 6.1 Mp astro cameras for about US $ 1200, and 8.3 Mp cameras for less than US $ 2000 -- we have to pay more for an A850 body here in Norway.

A lot of people use DSLR cameras for astrophoto. Many also customize the IR cut filter to get better H-a response. But then you can't use the camera for ordinary photography. I know it is like comparing apples and oranges, istill makes sense to find out how they compete.

Oh, I forgot the second part of your answer - I got a SBIG camera, the one with Bayer filters in front of the sensor.

Those are some great nebula shots.

I really enjoy the possibilities of astrophotography.

It looks like you have found a good CCD to capture these photos.

What telescope are you using?

Thanks for posting.

--
Rick

Veni, Vidi, Velcro!
'I came; I saw; I stuck around.'

I am using a 106 mm Takahashi refractor with 530 mm focal length (f:5). This small telescope is my window to the universe!

Nordstjernen said:

A lot of people use DSLR cameras for astrophoto. Many also customize the IR cut filter to get better H-a response. But then you can't use the camera for ordinary photography. I know it is like comparing apples and oranges, still makes sense to find out how they compete.

Click to expand...

If your comparing the two try your astrocam for landscape photography and compare that.

--
Tom

Look at the picture, not the pixels

http://www.flickr.com/photos/25301400@N00/

Great pictures!

I am a fan of your astro photography. I wish I could go into this in the near future, but man.... those pictures.... really make me feel so small.

Enjoy your new gear!

Lol!

With a minimum shutter speed of 0.1 sec, no viewfinder, no memory card slot, no in-camera firmware, not balanced colors or WB settings, the need of an external laptop or computer, camera lenses via clumpsy adapter systems, no auto mode, no MLU (actually no mirror ) and no video etc etc. Oh yes, there is a tripod mount 1/4-20 threaded side plate!

I don't think such a camera could compete with any Sony DSRL for ordinary photography! Not even the 3xx series!

Nice shots. The CCD sensor really shows off the colors nicely.

Question: The red dots or stars in the first shot, are they actually red stars, or hot pixels?
--
FEM2008

I wonder if you could try an old A100, cooled somehow, at ISO 100.

I still find A100 to easily beat my A700 and A900 at detail and colour response.

Nordstjernen said:

You can get decent 6.1 Mp astro cameras for about US $ 1200, and 8.3 Mp cameras for less than US $ 2000 -- we have to pay more for an A850 body here in Norway.

Click to expand...

--
http://www.supernovak.com
http://www.flickr.com/photos/rogic

FED-S (my father's) > Canon AE1 (my brother's) > Minolta Maxxum 3xi (my first precious) > Minolta Dynax 400si (hello Canada) > Minolta Dimage 7i (darling) > Konica Minolta 5D (first DSLR) > Sony Alpha A100 (killer baby) > Sony Alpha A700 (serious tool) > Canon 5DMkII (weird computer with average lenses) > Back to A700 (reassured about the greatness) + A900 (depth of colours and pixels)

These are very nice! Thanks for sharing.

I thought those colors were added for better demonstration in space related TV shows. Thanks for showing me that space is truely colorful!

The red dots are hot pixels. There also are blue and green dots. The frames that made up this image was not calibrated. With astro cameras you need to calibrate all frames to subtract digital noise, hot pixels included. There is no in-camera NR processes going on. The red dots are no more mysterious that that. When the frames are calibrated, all the hot pixels are gone. The result is clean and smooth images.

Also, I was a bit confused when I inspected the first uncalibrated frames. So noisy! But after calibration I realized how they deal with digital noise.

Lovely pics - the 3rd and 4th are just beautiful!

--
-Andy

Flickr: http://www.flickr.com/photos/andydrake

I used an A100 for professional photography and for astrophoto until the A700 was launched. The A100 resolution is very high. The camera worked very well for galaxies, but the A100 is almost completely H-a blind (near-infrared at 656.3 nm). This makes it less useable for general astrophoto unless you get it modified, I think.

The colors are close to the real colors, at least measured from the spectrum. The intensity of the light from these objects is too weak to trigger color vision. Even with very big telescopes they mostly look gray-greenish to the eye.

What a beautiful picture that Orion nebula makes! Fantastic, awesome!
Thanks for sharing Nordstjernen.

How does one even find these things in the sky? is there anything like this visible
simpley with binoculars or a spotting scope?