Posts Made By: Brad Cottingham

June 12, 2003 04:17 AM Forum: CCD Imaging and Processing/Solar System

Newbie Help Needed

Posted By Brad Cottingham

I'd like to try my hand at imaging without breaking my savings account. I was thinking about maybe a Phillips webcam. Is this a waste of time and effort? I'll be using a Dob on an equitorial platform.

If the Phillips is worth the effort, which model would be best?

Brad

August 5, 2003 06:35 PM Forum: CCD Imaging and Processing/Solar System

IR Filter with WebCam

Posted By Brad Cottingham

I have a webcam and adapter on order, and have been reading about IR filters. Several sources indicate they are only needed with refractor type telescopes. I'm not sure that is accurate. I will be be using reflectors, and would appreciate brand names of IR filter if needed.

Thanks,

Brad

August 5, 2003 11:25 PM Forum: CCD Imaging and Processing/Solar System

Another Webcam Question

Posted By Brad Cottingham

How big a factor is computer speed and how much free harddrive is needed for successful webcam astrophotography?

Brad

August 9, 2003 01:34 PM Forum: CCD Imaging and Processing/Solar System

Eyepiece Projection with Webcam?

Posted By Brad Cottingham

Anyone have any success with eyepiece projection with a webcam? I just received my ToUcam, but my Moog adapter is several weeks away, and I haven't found a IR filter yet. So, thought I'd try eyepiece projection if I can rig it up.

Brad

August 10, 2003 03:53 PM Forum: CCD Imaging and Processing/Solar System

K3CCD Help Needed

Posted By Brad Cottingham

Anyone who knows K3CCD pretty good available to answer some questions from a newbie? I started out with the tutorial but ran into problems about half way through.

I'll start from the beginning today and try to determine where I messed up. But may need a little help if I get hung up again.

First of all, the tutorial uses images obtained using a SC modified webcam, and has quite a few hot spots and also needed flat screen correction. Is that a factor when doing imaging of bright objects with a unmodified camera?

Thanks,

Brad

August 10, 2003 06:04 PM Forum: CCD Imaging and Processing/Solar System

Re: MARS: CAVE ASTROLA 12.5" F/6

Posted By Brad Cottingham

Hey, that looks good. Answers my question about using eyepiece projection with the ToUcam. How did you process it?

Brad

August 10, 2003 06:12 PM Forum: CCD Imaging and Processing/Solar System

Re: MARS: CAVE ASTROLA 12.5" F/6

Posted By Brad Cottingham

Another question to help me understand exactly what you used. Did you use direct eyepiece projection by removing the webcam lens system, or did you couple the stock webcam with it's built in lens system to the ortho?

Brad

September 4, 2003 06:08 PM Forum: CCD Imaging and Processing/Solar System

Mirror Quality and Size for Astrophotography

Posted By Brad Cottingham

Would you guys comment on the optimal quality and size for a Newt type photo setup? I currently have all dob mounts, but want to try some photo (ccd) work after moving to a dark sky area (retirement). So, looking at building up equitorial mount of some kind using either a 8" or 10" mirror.

I have a 8" f/5 mirror with good rating, and will soon have a 10" f/5 that should be good (better than the consumer type mirrors).

Somehow I got the impression that quality isn't a big of issue with astrophotography as with visual viewing. Maybe because we usually use higher power visually?

Would a f/5 be an optimal f/ratio or would you look for something else?

Thanks,

Brad

December 30, 2003 04:19 AM Forum: Telescope Making

Dual Sling Primary Mirror Suspension

Posted By Brad Cottingham

I'm sure I saw a link or picture in this forum for a dual sling mirror mount, but I can't locate it. Anyone help me find drawings, explainations, pictures?

Brad

January 14, 2004 05:12 AM Forum: Telescope Making

Re: 18" starstructure solid edge cell part 2

Posted By Brad Cottingham

Michael, Your research is much appreciated. I'd like to mention something I found that might be of interest. In your message, you say of a solid mirror lateral support:

Cons, All the weight of the optic and solid cell frame are on the 3 collimation bolts. Bottom line folks we are dealing with weight and gravity.

I ran across an article by Nils Olof Carlin in the BigDob Yahoogroup forum. In message #8551, he mentions using ball bearings for edge support, and posted a picture in the Photo section. The name of the picture is "Ball Bearing Edge Support".

What interest me is that using this method, the weight of the mirror would not have to be on mirror mount, and be transferred to the collimation bolts. The ball bearings could mount direct to the frame assembly.

The positioning of the bearing might need to be adjusted to the center of the mirror after the initial collimation takes place. The bearings would then allow the minimal adjustments necessary for final collimation.

Has anyone else other than Nils tried this arrangment? I'm wondering if there would be any mirror distortion with the weight of the mirror resting on only two small points on the edge of the mirror.

Comments appreciated.

Brad Cottingham