Image of the day

Captured by
Craig Bobchin

Coathanger CR 399

About Astromart

My Account

New to Astromart?

Register an account...

Need Help?

Posts Made By: Daniel McConaughy

September 16, 2005 01:56 PM Forum: Celestron

Optimal Back Focus for C14

Posted By Daniel McConaughy
I've heard from Celestron that the optimal back focus is 4" behind the mirror cell. This makes it inaccessible using a rack and pinion focuser and a 2" star diagonal (which itself takes up about 4" of back focus).

How sensitive is the system to changing the back focus?

Has any one experimented to see if there is a change in the quality of the image with changes in back focus?

My thought is to fix the mirror and use a Feathertouch focuser.

Dan McConaughy

November 13, 2006 03:32 PM Forum: TeleVue

Widefield vs. Panoptic

Posted By Daniel McConaughy
Is there much difference between the Widefield and the Panoptic eyepieces? I've had some Widefields for over 15 years but haven't had the chance to compare them with Panoptics.
Dan McConaughy

January 6, 2007 02:35 PM Forum: Celestron

C14 Mirror Coatings

Posted By Daniel McConaughy
Is there much difference between the newer mirror coatings and the older ones? Clearly, the corrector plates have been improved, but it's not so clear to me from reading Celestron's website that the mirror coatings have been improved. Actually, I'm considering getting 98% reflective coatings on the mirrors of my old C14 (optics are so good that I'd hate to risk getting a newer one with poorer optics even if it got greater throughput.)

February 24, 2007 11:00 PM Forum: Celestron

Effective F-ratio with star diagonal and focuser

Posted By Daniel McConaughy
I heard that the effective F-ratio of the C14 with a focuser and star diagonal is actually F/12 because the focus is moved back (because of the primary being put closer to the secondary).

Can anyone confirm?

March 8, 2007 01:49 AM Forum: Celestron

removing a mirror and recoating

Posted By Daniel McConaughy
I have heard two different things regarding what to do when removing a mirror from a C14 (or any Celestron SCT)for coating and then replacing it.

One school seems to indicate that you just put it back the way it came out, add some adhesive, and recollimate like usual.

Another school indicates that its a really tough thing to realign the primary and reglue it to the mirror mount before recollimating the secondary.

Can anyone comment on your experiences?




March 17, 2007 07:27 PM Forum: Celestron

Is the C14 the best planetary scope?

Posted By Daniel McConaughy
The best pictures I have seen by amateurs are from Celestrons. Does that make them the best planetary scope?

April 11, 2007 01:28 AM Forum: Deep Sky Observing

What is the latest word on Galaxy Filters?

Posted By Daniel McConaughy
I haven't heard anything about the DGM Galaxy Filter. Does this help? Do you have any filters you think help galaxy observing from light polluted areas?

September 17, 2007 02:30 AM Forum: AstroMart FAQ

How do I 'shrink' pictures to upload

Posted By Daniel McConaughy
I get an error message telling me my picture is too large. Someone told me to email the pictures to myself and that would shrink them, but it didn't work.

I take pics with a digital camera and they are jpg files.

Please help.

Thanks,

Dan McConaughy

October 1, 2007 02:22 PM Forum: Deep Sky Observing

Planetary Nebulae catalogue

Posted By Daniel McConaughy
How do I translate the PK- numbers into the Gemini catalogue? I think it's "GPN" but I'm not sure of this and if it is, I don't know how to enter the number. Thanks for your help.
Dan McConaughy

October 1, 2007 11:48 PM Forum: AstroMart FAQ

Is there a way to have 2 email addresses?

Posted By Daniel McConaughy
Is there a way to have AM responses sent to 2 email addresses (like home and work) from one account?

Funding Member

Sponsors


View all sponsors

Search