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Posts Made By: John Anderson

April 16, 2006 07:44 PM Forum: Equipment Talk

how to: stiffen a tripod

Posted By John Anderson


Several quick and dirty tricks used by photographers to stablize tripods when using long lenses:

1. Do not extend the legs, particularly the lowest/thinest legs, or use the least extension possible - sit down to observe.
2. Drill a hole in the cental column, spreader triangle/deck, bottom of head, or whatever, and put an "S" hook through the hole. Then hang a heavy weight from the "S" hook. The camera bag, a car battery, rocks in a mesh shopping bag, milk jug(s) full of water, etc. all work - just do not get the weight swinging like a pendulum.

Good luck, John

April 14, 2007 08:54 PM Forum: Eyepieces

Permanently marking eyepieces

Posted By John Anderson

Hi Ron,

Take a look at . This is an electric arc etching pen that has very little vibration - certainly not the intense action of the diamond point engraving pens. I have one that I picked up at a hamfest a while back that you are welcome to use, when I get a new point for it.

An alternative is a jeweler. They engrave with hand tools and some have laser engravers; I suspect the price is not too bad for simple jobs.

73, John wd4muo/0

April 20, 2007 08:10 AM Forum: Equipment Talk

Particle Wave Technologies (PWT) DDCAP

Posted By John Anderson

Astro-Physics web site price list says they have the DDCAPs in stock; part # PWDDC2 - $50. Of course it will have "AP" on it instead of "PWT."


March 16, 2009 07:52 PM Forum: Camping and Outdoors

Good telescope spots in Zion National Park?

Posted By John Anderson


Your query about observing locations in Zion NP has only drawn one response and very few hits so let me try to get the ball rolling with some comments and a few possible sites. I am sure someone down there has better information and hope they will chime in.

The caveats on my comments are that while I live near Denver I have been to Zion (and other parks in the area) several times in the past 10 years or so and have traveled through the area a number of times. I have stayed over night at Zion and in the area, but have not done any star gazing there.

If you have been to Zion I apologize for the following idiot lesson. The main area of the park, accessed from the south or east entrance, is a narrow, deep canyon running from the south-southwest to the north-northeast. While the road, Zion Canyon Scenic Drive, has some pull offs and picnic areas it is on the floor of the canyon and your horizon will be zenith down to maybe 45 degrees. The overlooks shown on maps are a 1,000 or more foot climb by foot from the road. So unless you are into transit viewing the main area is probably out. BTW: several years ago the Park Service closed the road in high season to private automobiles and took people into the canyon by bus, I assume that is still the policy, but not sure it will apply in April.

I have stayed in one of the three camp grounds at the south entrance/Springdale, but do not remember which one. The camp was good, but many old, large cottonwood trees formed a thick canopy. Some areas at the edges were exposed, but trees to the north and Watchman Mountain to the south and east limited the horizon. There are several amphitheaters near the camp grounds which might provide good views if the idiot light bombs have been removed.

I believe that an ideal location to observe from if it is open at night would be the Kolob Canyons Viewpoint, which is in the northwest section of the park, accessed from I-15. It is a fair drive from Springdale. The overlook is high with excellent views to the east and good to the west and north as I remember. There is a hill/part of the mountain to the south or southwest which should block light from that direction (important). I think there were a table and a vault toilet/porta-potty at the overlook. The road up the mountain twists a lot, but is good. This is a ‘lost’ part of the park with many fewer visitors than the main canyon.

The east entrance to the park had a pull off/parking area that might be an option. It is a good bit closer to Springdale than Kolob, but a winding mountain road through a long tunnel. Further to the east on route 9 toward Mt. Carmel there might also be some good spots, but the area is hilly/mountainous.

Outside the park the area is sparsely populated and quite dark except in the several very small towns. The big problem will be to the southwest where sprawling St. George and its environs put up a large light dome. I would think that any areas west and south of Virgin would have this problem.

North from Virgin is the Kolob road. The southern portion of the road is paved, but then turns to dirt and continues north to meet route 14, the Cedar City-Cedar Breaks road. There are probably a number of observing spots along the road, but lacking facilities. Notable locations are Lava Point, which is in the park and may have some facilities. As I remember the location it had sparse tree cover to the northwest and west and good views south and east. There is also a fire tower near here shown on the map; we did not go to it. Further north there are two reservoirs, Kolob Reservoir had a number of camp sites and some facilities. It was populated by a lot of fishermen when we drove through. The area was a wooded valley, but there were a number of side roads to barren hills.

As I remember the areas south of route 9 between Rockville and Virgin, there were a number of roads leading off to barren mesas/hills, there might be some good areas if you can block out St. George. North of rout 9 was a mountain(s).

Maps I have of the area say not to take dirt roads when wet.

The few years old Park Service map I have of Zion says ‘for information write: Superintendent, Zion National Park, Springdale, UT 84767-1099; call 345-772-3456; or visit on the internet.’

I hope this gives you some ideas to explore.

Clear skies with low horizons,

April 7, 2011 11:12 AM Forum: Solar System Observing

Solar Projecting Viewer

Posted By John Anderson

"Is there any problem just ... with a nice eyepiece?"

Apparently yes:
from "Solar Astronomy Handbook," Beck, Hilbrecht,, Willmann-Bell, Inc., Richmond, Va, 1995. pg 15:
"A.2.1 Solar Projection Screen
A solar projection screen enables the observers to see sunspots and faculae (see A.1and Fig. A.1.1) in absolute safety. It is also the simplest method of observation. Heat can build up in a telescope that projects the sun and therefore cemented eyepieces should never be used - use only Huygens, Mittenzwey, or Ramsden eyepieces. The owner of a telescope having a cemented objective mounted in a black cell should cover the black areas with reflecting aluminum coated Mylar to dissipate the heat. Even with these precautions prolonged observations of the sun can cause the cement between lens elements to melt, thereby damaging the objective."


October 24, 2011 07:24 PM Forum: Solar System Observing

Baader Solar Continuum Filter

Posted By John Anderson

Steve Stonehill said:

I'm interested in some opinions and advice regarding this filter. I would be using it with a 102mm ED refractor and a Lunt Herschel Wedge. Does it provide a significant increase in contrast? Does it help with fine detail?



Yes and yes. The Baader or a polarizing filter is recommended to increase contrast and detail (see the Company 7 and Baader web sites). I have tried both in the Baader wedge and the 1 1/4, APM wedge (which I believe is the same as the Lunt). I prefer the the Baader filter. To me it seems slightly sharper and there is no need to rotate the filter. The disadvantage of the Baader is having to explain to the uninitiated that unlike the moon, the sun is not made of green cheese.

FYI: One possible annoyance with the Lunt wedge is threads. The filter is placed between the wedge and eyepiece. You can unscrew the eyepiece holder from the wedge body, screw the ND3 (don't forget that this filter is necessary!) and the high contrast/polarizing filter into the bottom of the holder and reassemble. This works for the Baader wedge and a recent 2 inch Lunt wedge I tested. It does not work on my year+ old, 1 1/4 APM wedge, the apparent threads are either wrong or baffles instead of threads. Thus, the two filters must be screwed into the eyepiece, a pain if you change eyepieces often.

Enjoy the sun, it is fascinating. John

May 1, 2012 10:57 AM Forum: Equipment Talk

Telescope system in a four-wheel-drive

Posted By John Anderson


I hope this will give you a lead.

Some years ago (5?) at Riverside there was a large SUV (Caddy?) on display with a scope (I think I remember a fairly large Meade) mounted in the rear area. As I remember it the scope was mounted on rails and slid out of the rear compartment and them a leg(s) dropped down to the ground to stabilize the platform, there was quite a bit of bracing associated with the rig. It drew a pretty good crowd, but I was not interested and moved on quickly so I do not remember the manufacturer. Latter I saw an ad and picture of the set-up in one of the astronomy magazines, S&T or Astronomy for the item; believe that the ad was one of the small ones in the back of the mag.

Good luck with your project.


June 7, 2012 12:18 PM Forum: After Dark

Anyone Tried This Park For Observing?

Posted By John Anderson


I have visited GB NP and Lehman Caves several times, the last time 4-5 years ago. I have not camped or observed there nor participated in their astronomy program.

The park is a couple of miles south of Rt 6/50 on the west side of a broad desert valley. The entry road climbs steadily from the small town of Baker across desert to enter trees at Lehman Caves and camping areas. Then the road climbs very steeply to the Wheeler Peak area. Views of the sky to the west become increasingly limited as you climb; the Wheeler Peak parking area is in a circque with only easterly views (as I remember).

Camping facilities at the Lehman area appeared good. The cave tour was interesting. The entry road had funky statues on fence posts - worthy of pictures. Baker had a couple of stores, food, etc. Nearest town with major facilities is Ely.

There was an exhibit shelter in the road triangle between 6/50 and Baker that would provide better views to the west, but more light from the highway. A dirt road from 6/50 enters the park from the north and climbs to a mining area; southern views blocked and limited westerly. No facilities when I visited. Southeast of Baker toward Black Rock is very desolet, gravel road, better horizons, no lights or facilities. (Black Rock had oasis pond with lots of birds, mostly various ducks - if they interest you).

Hope this helps a little.

John Anderson

May 20, 2013 05:04 PM Forum: Equipment Talk

replacing cross hairs

Posted By John Anderson

See Porter's article and diagram in "A Filar Micrometer" in Scientific American "Amateur Telecope Making" book two, pg 456 (original editions).
Refers to spider web x-hairs, but I have used similar technique with very fine copper wire and hair.
Good luck, John

May 19, 2004 05:51 PM Forum: Polls

Do you like the new design?

Posted By John Anderson

Herb, et. al.,
Transition to new format appeared seamless, much less of a problem than I thought would occur (re-registering, new pass words, etc.). Like the side boxes and ability to customize format, options, etc. Thanks.
One suggested improvement is to increase the contrast/color between an item that has been viewed and one not viewed. As it now stands the change is minimal, making it difficult to keep track of what I have looked at and where post of new items starts.