Widefield Orion and Taurus

[sumangeek]

I've been trying to get a pretty good widefield shot of Orion and Taurus for a long time. Here are some of the recent images I took

Above is the Orion shot taken on a fixed tripod using Canon 550D unmodded 55mm lens @ ISO 800 & aperture 2 secs. Image was stacked using 30 lights and 25 darks. Am not too happy with the post processing. Could any of you comment on this.

I have some queries while taking photos on a fixed tripod. How does the shutter speed change with latitude, longitude and sensor size for avoiding star trails. 2 secs for the orion shot gives star trails extending to 2 pixels on the sensor. Also do I have to apply a proper White Balance to each image in the lights and do a stacking.

Here is a shot of taurus + orion

canon eos 550 D unmodded, 18mm, 20 sec, ISO 800. Stacked using 12 lights and 9 darks. I am unable to remove the greenish tinge in the bottom of the image. Original raw file has a reddish-orange background colour. Could you tell me a way to remove the greenish tinge and also to make the image sharper?

Cheers

Suman

(www.slickr.com/sushant_vk/)