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View Full Version : Which focal length for saturn ?


yb98
10th of March 2009 (Tue), 16:27
I'm new in astronomy pics.
I have a 5D + 70-200 4L. Is this enough to take a shot of saturn or do I need a longer focal length ?
If yes, in which direction of the sky is Saturn ?
Thanks.

MidnightSun
10th of March 2009 (Tue), 18:27
Well, Saturn is in Leo right now. In USA it rises about 6 PM. The longer f.l., the better for planets.

Celestron
10th of March 2009 (Tue), 18:34
If you want to get a nice shot of saturn then use a scope of at least 80mm (480mmFL) . This will give you a very small image of Saturn . I use a 8" SCT for my images of Saturn (2032mmFL) . You can find my image of Saturn on my website in my signature .

Dusty
10th of March 2009 (Tue), 18:43
Yes you'll need longer FL to get a decent image of Saturn, 200mm on a 5D is not enough.
A telescope is a much better option. But the best images you'll see are from long FL scopes and a web camera which takes a short avi and then stacks hundreds of inividual frames to bring out the detail into a single comosite image.

To find Saturn from Paris, look to the east around 9pm and it will be to the left of the moon, see attached image.

chris.bailey
11th of March 2009 (Wed), 02:59
Yeah 2m plus for Saturn ideally. As mentioned above a lot of people use a webcam which has a VERY small chip so images only a small part of the image circle. The resultant avi is then stacked to take only the best frames.

Adrena1in
11th of March 2009 (Wed), 06:11
I got acceptable images at 1200mm, but tried longer FLs by adding Barlows and stuff, but it just made the image quality rather poor. I captured Saturn at around 25mm last night...just can't *tell* it's Saturn! ;)

http://img11.imageshack.us/img11/456/moonsaturn.jpg

yb98
11th of March 2009 (Wed), 16:56
Thanks !

markjpcs
11th of March 2009 (Wed), 17:04
I use a 3100mm 8" f15.5 MakCass for planets.

Adrena1in
23rd of March 2009 (Mon), 09:14
As an example, I shot a single pic of Saturn last night, at 1200mm, and here's how big it looks on a 12Mp image.

http://img15.imageshack.us/img15/3705/iss2233009.png

About 45 pixels wide on an image that's 3888 pixels wide. i.e. very small. You can capture Saturn at pretty much any focal length, but being able to zoom in and *recognise* the dot as Saturn takes a pretty decent FL. I've managed at 400mm, but wouldn't really want to go much smaller to be honest.

Did you manage to get it with your 200mm?