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Posts Made By: Philip Blanda

April 19, 2005 12:20 AM Forum: Astro-Physics

Here it is - 160EDF

Posted By Philip Blanda
I posted just a few moe pics in the yahoo AP group. let Yahoo pay for the storage & bandwidth rather than Astromart!

April 21, 2005 11:54 AM Forum: Equipment Talk

TeleVue FocusMate or Feathertouch Micro?

Posted By Philip Blanda
I played with the TV fine focuser at NEAF, and it felt very nice and smooth. I can't see anyone being dissapointed with it.

I just got a scope with a feathertouch focuser and it is awsome. Is it better? Mine isn't comparable as the feather touch is on a 4" focuser, but if I had to call it, I would say that the feathertouch looks better!

However, if I had a TV scope, I think I would go with the TV solution because:
a)it's just about as nice to use as the FT
b)Easier to install on a TV scope
c)Modestly cheaper

April 29, 2005 12:34 PM Forum: Equipment Talk

Atmospheric Dispersion Corrector?

Posted By Philip Blanda
It's purpose is not to correct for bad seeing (only adaptive optical systems can begin to do that), but to correct for the prismatic dispersion that the atmosphere imparts at a noticable level to objects at lower elevations.

Look at Jupiter as it's rising any evening and you will notice a blueish fringe on one side, and an orangish/yellowish fringe on the other. This is the effect that the corrector mitigates. As the planet rises higher, the effect is diminished.

The problem is the Earth's atmoshere isn't built to APO standards :0

Bill Barrett said:
Does this corrector actually produce a stable, clear image in unsteady conditions?

May 4, 2005 05:36 PM Forum: Eyepieces

Criterion AR eyepieces

Posted By Philip Blanda
I have a RV-6 that my father bought for me in 1976. The eyepieces are Achromatic Ramsden. They consist of two cemented doublets. They work quite well in the f/8 RV-6.

Jon Isaacs said:

I recently acquired a Criterion RV-6, it came with 2 eyepieces, an AR-9 mm and an AR-18mm. Measuring the field stops, the AFOV should be 38 and 35 degrees.

jon

May 7, 2005 12:24 PM Forum: Binoviewers

disassembling Pentax XW series

Posted By Philip Blanda
Good for you. I, however, gave up on using my Pentax 14mm XW's with my Baader binoviewer. Having a working eyecup is a must for me as I observe often in suburbia and stray light is an issue. I bought a pair of 14mm Radians instead. Are the Radians as nice optically? No, but the work physically. Too bad, the Pentax XW's are fantastic eyepieces.

I still have my 5.2mm XL for mono use.

George Blahun, Jr. said:
I am determined to use the Pentax XW14 in a binoviewer, but in the event the eyecup is too wide I want to be familiar with its disassembly.
George

May 12, 2005 02:20 PM Forum: Star Parties

Jersey Starquest 2005 in June

Posted By Philip Blanda
I'll be there with my two kids & wife. This is the 1st time anyone is coming with me to a star party - we bought a tent to sleep in and it should be a blast!

My son will have his Orion XT4.5, I'll have my new scope and everyone has red flashlights.

May 24, 2005 12:02 AM Forum: Equipment Talk

Laser collimator - safe for eyes?

Posted By Philip Blanda
No danger of permanent damage. See this study: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11115266&dopt=Abstract

Short version: Three people who were going to have an eye removed agreed to allowed the doctors to shine a class 3A laser into the eye for 1 minute, 5 minutes and 15 minutes at different regions in the eye. No permanent damage found. "The risk to the human eye from transient exposure to light from commercially available class 3A laser pointers having powers of 1, 2, and 5 mW seems negligible."


Dave Adams said:

I would like to get a laser collimator but am wondering if they are eye safe?

June 17, 2005 02:42 PM Forum: Astro-Physics

AP160...delayed...*%#!

Posted By Philip Blanda
Bummer. Hang in there, the scope is worth the wait. My 160EDF has been giving me some great views (not recently due to clouds).

I hope you ordered the feathertouch focuser, it's really nice. The rotating focuser assembly is also pretty nifty!

I know it's frustrating to wait so long, but I turned down one of the 10" Maks when they came out - I just moved into a new house from an apartment and all cash was going into the house. Still, I regret not pulling the trigger on that one.

Eventually you will get it, and it is worth the wait.

Timothy McDougall said:

Well, it would figure! After a five plus year wait, my delivery date has been moved from this month until JAN 2006!!! Anyone else get the same letter on this run? The explanation was vague at best citing "other" projects :S . That will bring the total time to over 6 years??? Ridiculous...Very disappointed... sad

June 19, 2005 01:44 AM Forum: Equipment Talk

Can diagonal cause chromatic aberrations?

Posted By Philip Blanda
A mirror diagonal cannot impart any chromatic abberation. A prism diagonal will act as a weak lens in a converging light beam, and as a simple lens it will introduce colour error. The steeper the light cone, the larger the effect. A good rule of thumb is that at f/10 or above the effect is negligible.

Philip

June 27, 2005 01:18 AM Forum: Astro-Physics

Moderator Checks In

Posted By Philip Blanda
I like it! I received one AP shirt gratis, back when I got my 130EDF (or was it with the Traveler?). I assumed that I would get one along with the 160EDF, but all I got was the scope. Which is much better than a shirt. Never mind.

Joe Bergeron said:
By the way, I designed the artwork on all your AP shirts and hats.

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