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chicagoastronomer
21st of December 2006 (Thu), 10:15
Fellow S3 owners,

I ask all of you digital enthusiasts a question about an observation I have on the S3 that is really bothering me. I did not desire to go to a full DSLR, as the S3 has features that the full fledged DSLR does not, but I hope I can work around this.

http://img.photobucket.com/albums/v209/josephguzman/PowerShot%20S3/practice/Plaides4.jpg

Overall, the camera is fine and I enjoy all of it's features, but I think there is a problem on focusing. As an astronomer, I desire to take astrophotos with the S3, and in my tests, it seems that I cannot focus stars to pin points. I am using manual focus to infinity, but on the LCD screen and resulting images, the stars are not pin points as they should be.

Is this an inherent problem with all Digital cameras in this type of exposures...or could it be my camera?

Here is a link to my begining stellar astrophotography exposures:

http://astronomer.proboards23.com/index.cgi?board=ps3&action=display&thread=1166148281

I have not yet attached it to a telescope yet, but using only it's on-board lenses and zoom, (12x).

Thanks.

Respectfully,

Aray_Of_Art
21st of December 2006 (Thu), 10:30
I looked at the shots from your other forum posts, and it seems the advice you got there is pretty sound. I'd try some of their suggestions.
By the way your shot near the Adler Planetarium is awesome!!!!

Jon
21st of December 2006 (Thu), 12:18
What shutter speed and lens zoom setting were you using? This could simply be normal star trails.

BigDBronco
22nd of December 2006 (Fri), 15:31
They do look a little like star trails becuase the stars look slightly oblong. also focusing to infinity maynot produce the shapest images, try focusing to infinity the backing off just slightly.

chicagoastronomer
22nd of December 2006 (Fri), 18:18
Thank you all for the replies.

I have tried to back off a bit from focusing to infinity, but on the LCD screen but the star images seem even more out of focus.

Now, there is some star trailing going on there, and I used ISO 200, F-3.5 and a 5 second exposure. I could be getting some pixel oversaturation, but I think it's just not reaching that infinity focus sweetspot by a millimeter or two.

And thanks for the kudos on the Planetarium skyline shot. It was an impromptu effort after taking some astro images over the lake. I do like it myself!