3D Field Curvature Gallery - Topic Powered by eve community

That looks pretty good, Bob. The curvature shows actual difference in FWHM between the center and the edge. At lower FWHM values, the curvature will appear to be more flat than at really large FWHM values.

The Curvature % is the important number, as it is indpendent of the actual FWHM values.

Regards,

-Paul

Posts: 981 | Location: Cloudy NJ | Registered: 15 February 2005

Ignored post by Paul Kanevsky posted

Good Seeing

Posted

Note--ST8XE on C11 A

Posts: 100 | Registered: 15 February 2005

Ignored post by Bob Benamati posted

Richard A. Bennion

CCDWare Publishing
Orbiting around Earth

Posted

Bob, the fact that your curvature maps show an oval pattern and not a round pattern indicates to me that you may have tube currents that are effecting the images.

When my mirror is not stabilized, I see the oval pattern as well. Do you have any other images taken with the SCT that show a round pattern?

rb

Richard A. Bennion
CCDWare Publishing
http://www.ccdware.com

Posts: 555 | Registered: 14 February 2005

Ignored post by Richard A. Bennion posted

Good Seeing

Posted

Thanks, Paul.

Very nice job, guys!!! Worked like a charm!

Here's a neat little comparison--I also uploaded results from my old C11 Aluminum tube (circa 2002), and the curvature definitely is greater! While I always SUSPECTED such (as compared to my old LX's), and when compared visually to my CF's performance, it appeared to be the case. Now some hard data! Thanks, Paul!!!!

Take care,
Bob

quote:
Originally posted by Paul Kanevsky:
That looks pretty good, Bob. The curvature shows actual difference in FWHM between the center and the edge. At lower FWHM values, the curvature will appear to be more flat than at really large FWHM values.

The Curvature % is the important number, as it is indpendent of the actual FWHM values.

Regards,

-Paul

Posts: 100 | Registered: 15 February 2005

Ignored post by Bob Benamati posted

Good Seeing

Posted

Ah! I'll have to take a look at my times. These were earlier evening images--so that is probably it!

NEAT!

quote:
Originally posted by Richard A. Bennion:
Bob, the fact that your curvature maps show an oval pattern and not a round pattern indicates to me that you may have tube currents that are effecting the images.

When my mirror is not stabilized, I see the oval pattern as well. Do you have any other images taken with the SCT that show a round pattern?

rb

Posts: 100 | Registered: 15 February 2005

Ignored post by Bob Benamati posted

Good Seeing

Posted

OK--uploaded a run from the same night, but from the early AM (about 4 hours later)

Thoughts??

quote:
Originally posted by Richard A. Bennion:
Bob, the fact that your curvature maps show an oval pattern and not a round pattern indicates to me that you may have tube currents that are effecting the images.

When my mirror is not stabilized, I see the oval pattern as well. Do you have any other images taken with the SCT that show a round pattern?

rb

[/QUOTE]

Posts: 100 | Registered: 15 February 2005

Ignored post by Bob Benamati posted

Richard A. Bennion

CCDWare Publishing
Orbiting around Earth

Posted

You can now clearly see that the shape is circular. This means the tube has cooled down. Also notice how much lower your FWHM is.

You are still out of collimation slightly. I like to be less than 1 arc-second collimated. You need to zoom in to be able to see this clearly.

Right click on the curvature plot and zoom in.

Also, right click on the curvature plot and select range...play with these values to adjust the color range to show the exact collimation mis-alignment.

rb

Richard A. Bennion
CCDWare Publishing
http://www.ccdware.com

Posts: 555 | Registered: 14 February 2005

Ignored post by Richard A. Bennion posted

Good Seeing

Posted

Thanks for the tips, Rich! Still getting the feel of things, but overall, I'm impressed!

Can't wait to test it out in a 'live' session! Collimation in real-time has always been challenging--and this really fits the bill.

Thanks,

quote:
Originally posted by Richard A. Bennion:
You can now clearly see that the shape is circular. This means the tube has cooled down. Also notice how much lower your FWHM is.

You are still out of collimation slightly. I like to be less than 1 arc-second collimated. You need to zoom in to be able to see this clearly.

Right click on the curvature plot and zoom in.

Also, right click on the curvature plot and select range...play with these values to adjust the color range to show the exact collimation mis-alignment.

rb

Posts: 100 | Registered: 15 February 2005

Ignored post by Bob Benamati posted

Richard A. Bennion

CCDWare Publishing
Orbiting around Earth

Posted

Once you do real-time collimation with a CCD, you will throw away your eyepices. Just point your scope at the zenith and start turning those knobs till the targets line up.

It was this experience that convinced me that CCDWare *needed* to publish this product.

Thanks Paul!!!

rb

Richard A. Bennion
CCDWare Publishing
http://www.ccdware.com

Posts: 555 | Registered: 14 February 2005

Ignored post by Richard A. Bennion posted

Bill Patterson

Average Seeing

Posted

Richard,
Could you post an image on your RCOS? I'm working on collimnating a new unit and would love a reference point. Thanks.

Bill

Bill Patterson
www.laastro.com

Posts: 30 | Location: Los Angeles, CA | Registered: 20 February 2005

Ignored post by Bill Patterson posted

Paul Kanevsky

Orbiting around Earth
Picture of Paul Kanevsky

Posted

Hi Ben,

That's very cool! As an owner of another TEC scope (TEC140), I was very curious to see the performance of the TEC Maks. Thanks for posting it!

I see the curvature is reasonably large, but better than a similar-sized SCT scope.

Also, from the looks of the map, you had it focused best on the outside of the FOV, and not in the center.

Collimation, on the other hand, looks perfect!

Regards,

-Paul

Posts: 981 | Location: Cloudy NJ | Registered: 15 February 2005

Ignored post by Paul Kanevsky posted

GeorgeH

Average Seeing
Picture of GeorgeH

Posted

Hap,

Excellent results! What is your pixel size? What is the resolution in "/pixel?

Posts: 92 | Location: Dallas, Tx | Registered: 21 February 2005

Ignored post by GeorgeH posted

Stardoctor

Average Seeing

Posted

I can't see the screen shots after the first 10 or so....my computer stops the display. Any suggestions?
Thanks, Ruben

Posts: 12 | Registered: 07 July 2006

Ignored post by Stardoctor posted

Paul Kanevsky

Orbiting around Earth
Picture of Paul Kanevsky

Posted

quote:
Originally posted by Stardoctor:
I can't see the screen shots after the first 10 or so....my computer stops the display. Any suggestions?
Thanks, Ruben

Ruben, you should see about 10 small versions of all the images and left and right arrows that allow you to scroll through the rest of them:

Regards,

-Paul

scroll.jpg (94 Kb, 52 downloads)

Posts: 981 | Location: Cloudy NJ | Registered: 15 February 2005

Ignored post by Paul Kanevsky posted