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Posts Made By: Andrew Riehl

August 16, 2003 05:50 PM Forum: Insects - Flowers and Other Small Stuff - Photos

lens tests...

Posted By Andrew Riehl
Cat
Sigma 15mm f/2.8 diagonal fisheye on canon 10d

August 16, 2003 05:54 PM Forum: Insects - Flowers and Other Small Stuff - Photos

lens tests...

Posted By Andrew Riehl
hibiscus
Sigma 15mm Diagonal fishey on canon 10d

August 16, 2003 05:59 PM Forum: Insects - Flowers and Other Small Stuff - Photos

lens tests...

Posted By Andrew Riehl
shows the level of fisheye distortion with the 15mm fisheye and canon 10d...

August 26, 2003 06:33 AM Forum: Insects - Flowers and Other Small Stuff - Photos

Psychadelic Scarab

Posted By Andrew Riehl
groovy, man...

August 28, 2003 06:38 PM Forum: CCD Imaging and Processing/Solar System

A break from Mars, M33

Posted By Andrew Riehl
Thank god, I needed that break!

October 5, 2003 02:06 PM Forum: CCD Imaging and Processing/Solar System

Off axis guider question

Posted By Andrew Riehl
only option is a lumicon Newtonian easy guider, and that may still leave you with not enough in travel. you will most likely have to get a lower profile focuser (my guess is that if you can focus a camera already, your focuser profile is probably as low as it can go); or you will have to move the primary cell forward in the tube. This of course will require a larger secondary, if you don't want more vignetting.

http://www.lumicon.com/egnewt2.htm

October 24, 2003 04:59 PM Forum: CCD Imaging and Processing/Solar System

Mystery spot on Jupiter ?

Posted By Andrew Riehl
look closely, the spot is really a growing number of little 1:4:9 black monoliths...

October 27, 2003 01:48 PM Forum: CCD Imaging and Processing/Solar System

Old Moon

Posted By Andrew Riehl
You need noise reduction algorithms which photoshop type programs won't give you...you should take dark frames, subtracting them will give you much better results than noise filtering. Most of your noise here is from dark current, which is highly repetative image to image. Stacking multiple images will only reduce the random factor of the noise--the constant dark current and read noise won't be touched that much. You need to get rid of this noise before combining multiple images. That's what dark frames are for.

Andy R.
www.broadscopeimaging.com

November 12, 2003 04:40 PM Forum: CCD Imaging and Processing/Solar System

H-alpha filter costs

Posted By Andrew Riehl
you were right the second time--the photo filters are just deep red photographic filters, not true narrowband interference filters.

December 25, 2003 12:43 PM Forum: CCD Imaging and Processing/Solar System

Which is a better reducer for a C14?

Posted By Andrew Riehl
between the two, use the f/6.3. The GEG, while the better choice on film, will leave you scratching your head trying to figure out why your stars look so poor. The extra element in the 6.3 r/c will give you much better results; and it's shortcomings will be hardly visible on the tiny st-8 chip. May want to look into AP's ccd reducer as well...

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