Image of the day

Captured by
Gerald Elkin

Roseate Spoonbill

About Astromart

My Account

New to Astromart?

Register an account...

Need Help?

Posts Made By: Jarad Schiffer

December 18, 2003 09:05 PM Forum: TeleVue

Nagler zoom or 2.5x Powermate?

Posted By Jarad Schiffer
I have a 13mm, 9mm, and 7mm Type 6 Naglers. I am looking to get some higher power eyepieces for my Orion ED80 (f7). Anyone have any recommendations between getting a 3-6mm Nagler zoom vs. getting a 2.5x powermate (which will give equivalent to a 5.2mm with the 13, and 3.6mm with the 9mm)? The main advantage I can think of for the powermate is that I keep the eye relief and larger FOV of the T6's, but I lose the ability to tune the power to the highest the seeing can handle. Anyone ever compare sharpness and contrast with the powermate + nagler combo vs. the zoom?

Thanks,

Jarad

February 5, 2004 03:22 AM Forum: Telescope Making

Dewshield Experiment part 1

Posted By Jarad Schiffer
Okay Vladimir, I performed the experiment you suggested. I set up my ED-80 with a temperature probe inside the dewshield, as close to the objective as I was willing to go without risking scratching it (I estimate about 1/4" from the objective). The inside temperature is measured at the probe, the outside temperature at the metal fins at the bottom of the display. The top number is the inside temp, the bottom number is the outside temp. Note that at the beginning (inside my heated house, with everything at equilibrium) the temperature inside is showing slightly higher than outside. I can think of no reason for this, and the difference may indicate the limit of sensitivity of the instrument. Here is a picture of the setup:


April 2, 2004 01:44 PM Forum: Refractors

Orion ED-80 - Next batch?

Posted By Jarad Schiffer
Markus -

You said you should be getting the next batch of ED-80's a few weeks ago. Did they arrive? I am still curious how their QC is holding up.....

Jarad

July 7, 2005 08:42 PM Forum: Politics

Re: Just for the record

Posted By Jarad Schiffer
"Freedom fighters" attack military targets. Further, to be defined as "freedom fighters", they must in fact be fighting for freedom (i.e. the military they are attacking must be restricting their freedom in some way, and their stated goals must be to restore freedom to those being oppressed).

Neither Bin Laden, the 9/11 terrorists, the Iraqi insurgents, nor the ones who attacked today qualify for that label.

The ones responsible for this attack deserve to be hunted down, caught, and punished.

However, this attack does not justify a counterattack on anyone you want, only on those responsible.

And yes, the original question was definitely a troll.

Jarad

September 28, 2005 01:55 PM Forum: Refractors

Re: Wow! 100mm Nikon

Posted By Jarad Schiffer
Yeah, saw it in refractors, too.

As an antique and collectible, maybe. As a scope, I find it a bit much. You could get a 6" Tak for considerably less, or an 18" GOTO Starmaster.....

Jarad

November 1, 2005 09:38 PM Forum: Reflectors

Re: Ed Stevens Optics

Posted By Jarad Schiffer
This is not surprising, since Ed used to work with Zambuto. Carl also speaks highly of him. Hopefully he will continue to produce the same high quality - having more "Zambuto-class" mirror makers out there is good for all of us.

Jarad

June 10, 2009 12:28 PM Forum: Politics

Re: Use of nukes for offense

Posted By Jarad Schiffer
Jim -

I find it interesting that you consistently complain that "the left" called Bush an idiot, or the press was unfair, etc. First, you use this complaint to smear anyone who you disagree with (you repeatedly include Obama in this group, but I don't beleive that he ever said anything personally derogatory about Bush). Then you proceed to go on a tantrum of name-calling ("the idiot", "the even stupider VP", "socialist commies", etc.).

After posting a long rant filled with personal invectives, and implying subversive motives to every action or statement (real or imagined) that "the left" has done, you then complain that you don't get a nice, intellectual debate in response.

Gee, I wonder why.

Jarad

September 10, 2003 01:32 PM Forum: Equipment Talk

Big AOP or Dob help pick!

Posted By Jarad Schiffer
Well, Chas, if you decide to go the Starmaster route, I have an 18" with GOTO and a Zambuto Stabilite mirror (hollow cell mirror, wuick cool down, no longer available)that I will be looking to sell soon. Depending on how tall you are, you will either need a 1-step or no ladder for it. I live in Atlanta, and would be willing to drive to meet you for an observing session if you are interested. I will be posting it on Astromart in a few weeks, unless I get a local seller first (giving the Atlanta Astro Club members first shot....).

Jarad

September 18, 2003 01:10 PM Forum: Equipment Talk

Coating Services comparison

Posted By Jarad Schiffer
I used Precision Applied Products a few years ago to coat a 10" mirror. They did a nice job - quick turnaround too. They are located in Placentia, CA, just south of LA. Their website is:
http://www.precisionapplied.com/

Hope this helps,

Jarad


September 18, 2003 03:28 PM Forum: Telescope Making

Two plate primary dob mirror?

Posted By Jarad Schiffer
This looks like a Stabilite mirror. You can check them out at http://www.stabilite.com. I have an 18" mirror from them, although mine is the radial design (look at the pictures of various blanks on their website - mine looks like the 30" pictured). It does work well, is lighter, cools down fast and stays at ambient. I added a fan to mine tht blows into the space between the plates for even faster cooldown. Also, you can put the mirror retention clips over the back plate so nothing is in front of the mirror. The downside is that they are harder to figure - mine was done by Zambuto, but he apparently only made 1 or 2 before deciding they took too much extra effort to figure properly for him to make money on them. The one in the picture looks like a blank (uncoated and unpolished) - not clear if that is a picture of the actual one being sold (since the ad lists a Strehl ratio....).

Hope this helps,

Jarad

Funding Member

Telescopes, Astronomy, Binoculars

Sponsors


View all sponsors

Search