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Posts Made By: Mike Ratcliff

January 27, 2004 07:05 PM Forum: Eyepieces

TV Plossls/Powermates: Poor Man's EP Set?

Posted By Mike Ratcliff

I thought of getting 3 TV plossls (32mm, 25mm, and 20mm) plus the 2.5x and 5x TV Powermates and using this setup exclusively as a "poor man's" set. Has anyone else done anything like this?

Got to thinking about this after reading R. F. Royce's website (premier mirror maker) where he said he only used a few plossls and barlows.

For a common 1200mm focal length (10" f/5, 8" f/6, 6" f/8) this would give 38x, 48x, 60x, 94x, 120x, 150x, 188x, 240x, 300x.

Advantages:
Optical excellence, comfortable eye relief (12.5mm UO ortho bothered me even though I don't wear glasses), good magnification coverage, much cheaper than say 5 Naglers.

Disadvantages: 50 degree field of view, awkward swapping of equipment

I look at both planets and DSO's. Undriven dob.

Any thoughts?

Mike Ratcliff

May 24, 2004 09:33 AM Forum: Equipment Talk

wide field eyepiece for 16" f/4.9?

Posted By Mike Ratcliff

I'm wondering what eyepiece to get for wide field viewing. I don't want to spend $500 or so for the big 26mm or 31mm Naglers. But I tried the inexpensive BW Optik 30mm 80 degree widefield, and the aberations were too much for f4.9. So yeah I want it both ways, good views and reasonable price.

I've got a 17mm Nagler Type4 for medium magnification but that only covers a 0.7 deg field. Telescope is 16" f4.9 dob Newt with a 3.1 inch secondary.

I know that an exit pupil greater than 5 to 6 mm will be too big for my 49 year old eyes and some light is lost. Is it OK to go beyond 6 mm exit pupil anyway for the field of view? If so, how far beyond 6mm before the secondary shadow is a problem? What is your recommendation?


Thanks much,
Mike Ratcliff

June 1, 2004 10:15 PM Forum: Equipment Talk

focuser travel problem with Paracorr

Posted By Mike Ratcliff

Drats. cwy

I bought a used 2" Paracorr with tunable top. Unfortunately, I couldn't get anywhere near close to focusing. Need a lot more in-focus distance toward the secondary, I'm guessing at least another 1/2 inch. Up until now I have had no problems focusing with a variety of eyepieces.

Anybody else with this experience using a Paracorr? Did I do something wrong in using it?

My current focuser is the JMI DX3, relatively inexpensive and single speed. Is there a better brand that would allow more travel?

I'll try moving the primary mirror up too with the collimation bolts, but I've got a long way to go.

Thanks,

Mike Ratcliff

July 19, 2004 11:43 AM Forum: Deep Sky Observing

Fun with O-III filter - 3 great nebulas and one dud

Posted By Mike Ratcliff

A brief note on some nebula seen Saturday night. Second time with an O-III filter and a 16" dob. Previous telescope 6" dob have had for 7 years.

Site was in S. California desert about 15 miles east of Lucerne Valley. Observed with the San Bernardino Valley Astronomy Association. Sky was clear and pretty dark overhead. Light domes from LA to the south and southwest.

First one Veil Nebula was great. No struggling with dimness or averted imagination this time! Both main arcs of Veil had many details. Plus many areas between the two arcs were easily visible too.

North American nebula, have seen many times in my old 6" but the view was dim. This time, the Gulf of Mexico area was really nice and obvious, and many parts of the nearby Pelican nebula as well.

Crescent Nebula. Seen before with 6" but just barely. This time, very obvious and nice delicate details. Not as bright as Veil. I'd like to rename this one the "Ear" nebula. Also saw on friends 10" Meade LX200, dimmer as expected but details still seen.

Bubble Nebula. This one is the dud. Still just can see some faint nebulosity around one star. Could be fooled into thinking there was some dew on an eyepiece and the star had some glare on it. Of course no dew in this place. In photos the bubble is beautiful. But visually - - how could anyone put this on a "must see" list like the Caldwell or the RASC Best 110?

I did see the nearby nebulas Sh2-157 and NGC 7538. The Sh2-157 looked nice like a smaller dimmer Crescent nebula. NGC 7538 a small blob of nebulosity, reminds me of M78 in my small scope. Both of these much nicer than the Bubble!

Mike Ratcliff

August 28, 2004 11:52 AM Forum: Eyepieces

Re: Eyepieces that are absolutely NOT worth the bu

Posted By Mike Ratcliff

Great question.

My one disappointment was a Meade 6.4mm Super Plossl. I didn't know anything about eye relief at the time(how close you have to stick your eye to to the glass). It was a very uncomfortable eyepiece. And I felt guilty selling it on Astromart, but the buyer reported that he liked it. I did sell it for a very low price, about 1/5 of what I paid.

The view was good, but not "super". I suspect the super is now just marketing hype. I also bought it retail sad , and the Meade Super plossls go for deep discounts here.

A Siebert 24mm Ultra Plus I bought in 2003 didn't have nearly the AFOV advertised, so I returned it within Harry's 30 day money back guarantee period and did get a refund.

Mike Ratcliff

November 8, 2004 07:44 PM Forum: Equipment Talk

Re: Your Thoughts:

Posted By Mike Ratcliff

Maybe the Teleport telescope? All fits together in a nice box and telescopes out for use.

September 1, 2005 02:49 PM Forum: Binoviewers

Will I have difficulty merging views?

Posted By Mike Ratcliff

I'm thinking of trying the Denk Big Easy binoviewers (maybe not a good name right now), but I've never had success in merging views when I've tried other people's binoviewers for a minute or two. Including the recent Burgess ones. I was successful in merging the views with the JMI 6" binocular telescope at the RTMC show. But that costs $3000.

Will it just take more time or is this a bad sign? I noticed the Denks had self-centering eyepiece holders that make the eyepieces better aligned.

Any suggestions? Especially what would be a good eyepiece selection to start out.

Thanks,

Mike Ratcliff
16" f/5 dob
51 year old eyes

August 7, 2006 03:53 PM Forum: Deep Sky Observing

A recent observing session, Walker Pass California

Posted By Mike Ratcliff

Warren Bitters mentioned a lack of reports. Here is one during a recent heat wave a few weeks ago.

Walker Pass campground is north of Mojave at about 5000 ft elevation. It is a small campground. Only 2 spots for full size campers to park, several other tight parking spots as well. While traveling up there I was worried about not having any room, but turns out I was the only one there! I wouldn't recommend it for photography because there is a highway nearby and traffic lights sometimes intrude into the area.

It is pretty hot in the daytime. Was 91F at 7:30pm at arrival. (106F in the desert below).

This was going to be a short night with twighlight ending about 9:00 pm and moonlight starting around 11:30.

The place is Dark, showing as dark gray on the light pollution maps, (Clear Dark Sky web site). Not quite the darkest possible but close. I didn't bother looking for the limiting magnitude. Every time I do that it is always less than other peoples' estimates. I could see a slight light dome toward Ridgeway (edit: that should be Ridgecrest), otherwise no light whatsoever. There were a few smoke clouds in the area from some fires about 100 miles away, but evidently were not a serious problem in most parts of the sky. Very dry skies. The seeing was not good though.

With so little time and skies so dark, this was a Kid-in-the-candystore type of night, trying to see favorite objects in a new light, and some challenges as best as possible.

I'll just describe some highlights. It was a memorable night with some "personal best" views of M4, M24, the Veil Nebula, North American Nebula, Cocoon Nebula.

M4 is usually on the dim side but not tonight. Has an unusual bar structure that I had not seen before, plus a partial loop of stars along the outer edges that joined at one end of the bar.

M24, I've seen the dark nebula in the area before but not as well as tonight. Plus there were so many stars visible. You can also tell that there are a lot of uncharted dark nebula intermixed with the stars besides the 2 or 3 larger ones on SA2000. This was where the well-corrected wide field eyepieces (Nagler 20mm T2 in this case) really shine compared to my less expensive plossls.

Realizing this was a great night for transparency, I went for the nebulas in Cygnus.

Well, the first view of the Veil near the star 52 Cygnus with an OIII filter just about knocked me to the ground. I've seen this a dozen times but not this well. The rest of Veil was great too. Other sections had been my previous favorite, but this area with the double strands and nebulosity between was great. Think of a DNA molecule that has been untwisted. Again I had seen this structure before but not as cleanly.

North American nebula, again seen numerous times but this was the best and brightest. Pelican nebula too.

Remembering some recent cursing by me of the Cocoon Nebula and the Caldwell Catalog, I tried for the Cocoon again, and Success! There was no doubt this time and no doubt that this is a dim object! Circular in shape, not that small. I used no filters. Supposedly the H-beta helps but I don't have one. I memorized some of the foreground stars and confirmed against pictures this morning, there is no doubt. The nearby dark nebula lane was actually best seen in the finder scope.

A first-time view was Planetary Nebula 6781 in Aquila. Pretty large with a circular shape, reminded me of the Owl Nebula. Some mottling or darker areas within. Brightness was good, but being large this one may need dark skies to see well. Also found for the first time nearby Planetary 6804 but with seeing bad didn't look long. Looked for Planetary 6803 also but did not see, it is small. I saw some suspiciously bloated stars but did not pursue farther with the bad seeing. (PS one week later still did not fine 6803).

Another highlight, the Pipe Nebula in the Milky Way above Scorpio and Sagittarius was visible naked eye. As was the dimmer sections of the Milky Way going down towards the center of Scorpio.

A funny observation, when the moonlight was increasing before actual moonrise, I considered the sky "ruined" for the night. But actually the Milky Way was still very evident. It occurred to me that if I were home I would be ecstatic with these conditions, but here I was giving up and putting my stuff away. Dark skies will spoil you!

Mike Ratcliff

--------------------
16" f/4.9 dob
6" f/8 dob

March 13, 2007 08:36 AM Forum: Ask rating questions here

Erased an Unused Rating by Mistake

Posted By Mike Ratcliff

I was clearing out some unused ratings of other people for transactions that I was too late for. I accidently erased someone that I did have a tranaction ongoing, and now I can't leave a rating.

Any ideas?

Can the other guy respond again to the "SOLD" ad? I couldn't figure out a way to undo the SOLD.

Create a new fake ad and hope noone else responds? (Eh, I know, a set of Meade 4000 Super plossls for $4000. That should keep everyone away. smile )

Thanks,

Mike

October 27, 2009 07:52 AM Forum: Global Warming - REAL or NOT

We must now convert to vegetarianism

Posted By Mike Ratcliff

No way!

http://www.timesonline.co.uk/tol/news/environment/article6891362.ece

Key sentence:
"He predicted that people’s attitudes would evolve until meat eating became unacceptable."

Mike