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Posts Made By: Jon Isaacs

January 18, 2013 04:09 PM Forum: Off Topic Discussions

She Got Her $250,000

Posted By Jon Isaacs
Rod Kaufman said:

A woman, driving on a suspended license, takes off on the CHP, gets taken down, sues and wins. Geez...
http://latimesblogs.latimes.com/lanow/2013/01/chp.html

Did you actually read the story? I saw it in the LA Times this morning. The lady was pregnant and she was talking on the cell phone. Did you see the video? That was the video of the event which the prosecutor and the CHP tried to hide. When the judge saw the video, the case against the lady was tossed.

The CHP settled the case before the officers could be disposed. In your mind, were the officers actions a proper and warranted response considering the misdemeanor crimes that were involved ? They certainly were over the top as far as I am concerned.

Jon

Jon

January 23, 2013 12:43 AM Forum: Equipment Talk

Pronto Vs Televue 60

Posted By Jon Isaacs
Margaret Stratton said:

Which is the better scope? Is the Pronto as good? Is $650 a good price for a used Pronto?

Thanks, I'm new and very excited to get started.

Margaret:

First let me say hello and welcome to Astromart... smile

Second, I owned a Pronto for several years, it was a nice scope and I had a lot of fun with it but it is a scope that time has passed by. Today, $650 will buy a significantly more capable refractor. The Pronto is essentially an achromat so that at higher magnifications, there will be false color that interferes with the view. Modern ED scopes have much less false color.

In terms of the TeleVue 60 versus the Pronto, maybe you could tell me more about what you are hoping to look at, what is your dream??? Both these scopes are quite small in terms of aperture and it is the limited aperture rather than the quality of the optics that limits what you will see.

Jon

January 26, 2013 11:21 AM Forum: Telescope Making

using a prism in a diagonal for a refractor

Posted By Jon Isaacs
Joe:

Prism diagonals are commonly used in slower refractors with 1.25 inch focusers. Most of the classic refractors from the 1960's and 1970s used prism diagonals as do many SCTs. In faster telescopes a prism will result in some chromatic aberration.

For 2 inch focusers, they are quite uncommon.

What is the focal length of your 4 inch scope?

Jon

January 28, 2013 11:44 AM Forum: Reflectors

reaching focus with focal reducer and external foc

Posted By Jon Isaacs
John:


Where are you positioning the focal reducer? If you placed the focal reducer after the focuser, between the diagonal and the focuser, at least you would have the approximate 100mm of spacing.

Otherwise, the problem you are facing is that the effective focal ratio of a focal reducer depends on the distance between the actual focal plane without the reducer and the reducer. When you increase that distance by adding the Crayford focuser, you are decreasing the effective focal ratio which positions the focal plane even further inward. It is a losing battle.

Jon



January 28, 2013 06:29 PM Forum: Pictures of Me and My Telescope and........

I don't like to brag....but.

Posted By Jon Isaacs
Scott:

Like you, I have my own personal dome that goes with me everywhere I go. 8O

We have a place out where the skies are about as dark as they get in Southern California. I frequently am asked why I haven't built an observatory. I have never wanted an observatory, just a place to observe where I can feel as if I am camped out in the Valley of the Gods with nothing but the sky above me.

Jon

February 2, 2013 06:50 AM Forum: ASTRONOMY

Shuttle Flight Director on Columbia Disaster

Posted By Jon Isaacs
Russ:

Interesting... Thanks for finding that and posting the links.

Jon

February 15, 2013 11:29 PM Forum: Refractors

Schott or Ohara currently offering fluorite?

Posted By Jon Isaacs

I'm interested in smallish ones in the 4" and under size, in particular. I remember when William Optics used to advertise small ED-glass optics as "fluorite", and have a feeling another vendor may be doing the same now.

Jim:

I have an 80mm William Optics Megrez II FD. The objective clearly states Fluorite Doublet.

However, several years ago it was made clear that these objectives as well others that William Optics termed Fluorite were not Fluorite, in my case it was actually FPL-53. I believe the LOMO triplets were also called Fluorite but were not. I confirmed this in a recent Email conversation with William Optics.

Jon

February 20, 2013 04:33 PM Forum: Equipment Talk

Weather Stations

Posted By Jon Isaacs
Louis:

I really can't help you, I am hoping to benefit from your inquiry. We have a second home up in the mountains, I am most interested in the wind, it's a rare day when the maximum wind speed in under 20mph. Currently we have a $100 Accurite Unit, a similar unit without rain is $50. It's actually pretty good but a better unit would be nice.

I think wireless is important, we have our sensing unit on top of a unused Telephone pole about a 100 feet from the house. It's an ideal location cable but it would be impractical if it were not wireless.

An important feature for us is the ability to store information, that's the one thing I dislike about our current unit. It stores the information for the day but at the end of the day, it starts over. After that, it only stores the maximum value ever reached. It looked to me like the Ultimeter did not have build in recording, wasn't so sure about the Davis either. They are setup of using an external data acquisition system, integrated would be better.

Running off of internal batteries is nice too, if one were trying to use a computer for data logging, a power outage could mess everything up.

Jon

February 27, 2013 12:17 PM Forum: Telescope Making

aluminizing chamber

Posted By Jon Isaacs
Joseph Babendreier said:

I'm starting to wonder what the possibilities are for convincing some business man here in Kenya to buy and operate a unit that could aluminize small mirrors.

I would like to introduce some kids to the idea of ATM, but the big obstacle for us here would be having to send a mirror outside the country for the service.

Can anybody direct me to some company that sells units that do aluminizing?

Clears,
Joe

Joe:

I know nothing about it, maybe someone here does. You might contact Bob Fies at Alcoat, he's been doing it for a long time and is somehow connected with John Dobson and the Sidewalk Astronomers.

http://alcoat.net/

Jon

March 3, 2013 11:56 AM Forum: AstroMart FAQ

Uploading photos

Posted By Jon Isaacs
Carl Weber said:

Hello all,

I'm new to AstroMart and wanted to place some classified ads with photos. Can't figure out how to upload the pics. Can it be done from my iPad ?

Can anybody advise?

Thanks

Carl:

It's a probably not so easy from the Ipad. Have you tried a desktop?

JOn

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