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Lawrence Parchman

Sculptor Galaxy (NGC 253)

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Posts Made By: Mark Holden

February 21, 2006 09:30 PM Forum: Politics

UAE to replace Secret Service!

Posted By Mark Holden
I'm not thrilled with the deal, but President Bush does have a point.

The contracts are already with a foreign company.

The reality is we never should have allowed that to happen - even though the company was owned by our good friends in GB.


February 22, 2006 04:44 AM Forum: Beginning Astronomy?

What do you look for in an observing site?

Posted By Mark Holden
Lee Spain said:

Living in an urban setting, I don't have a backyard to use for observing. Instead, I use an unlighted tennis court. I chose it because it is inside our communities gates and does not have a direct line of sight into anyone's home. The site itself is quite light polluted. In the summer, I can use foliage to screen myself from some nearby street lights. However, in the winter, when the leaves are down there are lots of nearby streetlights.

If you don't observe in your own backyard, what kind of characteristics do you look for in an observing site?

A large open field, without nearby street lights.

A site some friends and I often use is a cemetery, built on a site that used to be a private airport.

We can set up right on the pavement at a traffic circle.

February 24, 2006 08:02 PM Forum: Eyepieces

Any difference between a 2" and 1 1/4" eyepiece?

Posted By Mark Holden
Steve Stainbrook said:

I just bought a 35mm Panoptic and 22mm Panoptic and can't wait to use them tonight. On the 22mm it has the 1 1/4" built in and I am wondering if I should sell it, buy a 27mm and switch to a true 2" barrel. Am I losing light collection, sharpness or FOV by using a 2" eyepiece? If not, why use a 2" anyway? My equipment - Celestron 8" GPS XLT at 10,000 feet in the Rockies!

The Meade series 4000 14mm and 8.8mm UWA eyepieces are also set up for either 1.25 or 2".

Personally, I prefer to use them as 2" ones because I have a 2" focuser and I feel the larger diameter barrel will give a better grip.

March 3, 2006 04:11 PM Forum: Equipment Talk

GM8 for a 25lb 6" F8 refractor?

Posted By Mark Holden
Bill Barrett said:

I have have a 6" F8 refractor and have been using an old Mead6 826 mount on a home made pier. The Meade is plenty solid and it tracks well with the scope. I would like to upgrade & have been looking at the Losmandy GM8.
I am strictly a visual observer, and was wondering if the GM8 would have the capacity to handle the 6" scope? The OTA is about 20lbs, and is nearly 25 lbs. with a 35mm panoptic, diagonal, and chromacor.

My primarty interest in the GM8 is the setting RA circle design which (if I understand correctly) does not have to be reset moving from object to object.

I use a GM8 with a G11 tripod, and it handles my TMB 115 CNC for imaging - the weight is roughly the same as your setup - but my tube is probably easier to swing because it's shorter, and will catch less wind.

I have the Gemini system, mostly because the cost difference between Gemini and digital setting circles wasn't that much when buying a new mount.

But IIRC the RA setting circle that comes with the mount won't be accurate if you slew with the motors, and they'll lose some accuracy if you use the RA motor to center objects in the field.

March 3, 2006 09:20 PM Forum: Telescope Making

Tube Material

Posted By Mark Holden
Public Missiles has phenolic tubes that are 6.007" in diameter.

These are intended for large scale model rockets. A 4 foot one will cost little over $36.25 plus shipping.

https://secure.consumersinterest.com/pml/

(look under airframes)

March 7, 2006 04:26 AM Forum: Politics

It Does Not Seem Right !!!

Posted By Mark Holden
Tom Rodstrom said:

I'm leaving California for New Mexico and it's none too soon. On the way to work today I saw a full sized Hummer with a HANDICAPPED STICKER. It just doesn't seem right. How handicapped can you be if you can climb into and drive one of those beasts? If you are handicapped and keel over while driving whose family are you going to run over with that monster?

Perhaps it was issued to a physically fit driver who was environmentally handicapped.


A higher vehicle can be good for people with lower back injuries.

With a typical car you need to lower yourself and twist to get in. With a "truck" you can use an "up and over" motion - and this requires much less flexing of your lower back.

I was stuck driving trucks for a few years because of back injuries, and one of these days I may have to go back to them.


March 7, 2006 01:05 PM Forum: Film Astrophotography - Imaging and Processing

The Solar Eclipse

Posted By Mark Holden
John Sellers said:

Hi everyone, I have the good fortune of going to the Mediterrean to view the solar eclipse coming up at the end of this month. My question: Will my Cannon EOS Rebel film camera be able to capture this event just pointing to the sun while completely covered by the moon ???

John

It'll be a bugger to aim safely.

And you'll want a long telephoto lens. Something in the general range of 1000mm would probably be a good compromise.

You can get a good feel for what size image you'll get with a given lens by using the full Moon as a target.

March 7, 2006 10:25 PM Forum: APM

TMB80/480 vs TMB80/600

Posted By Mark Holden
Steve Vaughn said:

Anyone have any views on 80/480 vs 80/600. I am leaning toward a carbon fiber 80/480 for two uses: quality view finder on my TMB-152 and as a grab and go to use on an alt/az. Seems to fit the requirement of light and compact as well as wide field.

A friend got an 80/480 as a finder for his 175 and 229. It's quite nice.

As for the carbon fiber - I doubt it has any advantage over the normal tubes unless you like the look.

March 8, 2006 02:23 AM Forum: Astro-Physics

A-P pier questions

Posted By Mark Holden
Ivan Ong said:

Hi, I have not seen a A-P pier in real life, but I heard it is extremely stable. My questions are
(a) how portable is this (48" height version)
(b) what is the setup and tear down time and effort involved(c) how many pieces does it disassemble to and finally
(d) rust resistance? Is it aluminum or steel?

Thanks very much, Ivan

The folks I know with AP mounts have been buying the ATS or Particle Wave piers.

Both are very easy to set up and adjust.


March 9, 2006 04:47 AM Forum: Politics

House votes to poison America

Posted By Mark Holden
Tom Rodstrom said:

Now those jokers in Washington are taking away the ability for the states to protect their citizens.

House Moves to Strip Food Warning Labels
By LIBBY QUAID, Associated Press Writer
Wed Mar 8, 7:39 PM ET

"This bill is going to overturn 200 state laws that protect our food supply," said Rep. Henry Waxman, D-Calif. "Why are we doing that? What's wrong with our system of federalism?"

http://news.yahoo.com/s/ap/20060309/ap_on_he_me/food_warnings


From the article:

The bill's supporters argue that consumers deserve the same warnings on supermarket shelves across the country. The bill would allow a state to seek a nationwide warning from FDA.

"We ought to do it in all 50 states," said Rep. Mike Rogers, R-Mich. "Chicken grown in Louisiana is going to end up on a plate in Michigan."

Rogers mentioned a warning his own state about allergy-causing sulfites: "If they're bad for Michigan citizens, I think they're bad in all of the other 49 states," he said.

It seems reasonable to me.

I can also understand food companies wanting to be able to use uniform labels nationwide.


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