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Lion Nebula SH2-132 - RC71

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Posts Made By: dan hilts

March 18, 2007 08:15 PM Forum: Beginning Astronomy?

Just how big are those Deep Sky Objects?

Posted By dan hilts
Peter,

A nice piece of work and really shows the relative sizes of these objects. I don't think I've ever seen a collage quite like it. Nice job!

dan

March 23, 2007 01:30 AM Forum: Telescope Making

8in f6 Comet sweeper

Posted By dan hilts
I like it.

There was a similar lens in the ads last week and though I was tempted I let it pass. (Too many projects on the go now.) The idea of seeing clumps of galaxies is appealling. I may have to rethink my decision.

have fun,
dan


April 3, 2007 03:15 PM Forum: Refractors

Need new objective

Posted By dan hilts
Terry,

Unless your glass is damaged, you only need to replace the cell, not the lens. You may be able to obtain one at Hands-on-Optics in the US or at Island Eyepiece in Canada.

good luck,
dan

April 12, 2007 09:59 PM Forum: Ask rating questions here

backing out of a deal

Posted By dan hilts
Let it slide and mark it up to experience gained. It's really not worth the long term grief to start off ratings with an exchange of bad ones.

FWIW I recently had a deal for some goods here and we discussed shipping, costs and delivery dates. The seller sent a note stating that if I sent payment on the weekend he would ship my goods on Monday. I thought we had a firm committment. I sent payment Sunday around noon and by 1:00 I had a refund sent with a separate email saying since he hadn't heard from me he sold the goods to next in line. I was a little ticked especially since it was an expensive item and I lost 3% to paypal on the deal. As it turned out, I now don't think the deal was a good one and I wouldn't have been happy in the end. I got lucky.

Don't worry about a missed deal. If you play by the rules, there will always be another deal, another time. And one thing you can be very sure of; there will always be a great deal you just missed.

clear skies,
dan

April 13, 2007 12:53 AM Forum: Refractors

Baffle Question

Posted By dan hilts
This OTA uses a 100mm tube. It makes the first baffle look incorrect.

clear skies,
dan

April 17, 2007 06:34 PM Forum: Telescope Making

want to make a telescope with my 6th grade son

Posted By dan hilts
Hi Mark,

You're going to have to define "inexpensive".

For $25 or so, you can get a decent lens and eyepiece to make a simple but very useable refractor. Typically assembled using mailing tubes and plastic plumbing fittings. Surplus Shed has a good selection of usuable lenses and basic eyepieces.

For a little more money you can assemble a quick and dirty small refelector that will work just as good as Newton's first scope did.

For $100 you can put together a really nice 4" reflector DOB with a real focuser and a couple of eyepieces that will work really good on the moon and brighter planets. This will give some pretty good views of the stars clusters as well. The trouble is, you can often buy a finished scope this size for a lot less.

Sorry, but I don't have any plans at my finger tips. If you spent a hour or two surfing you can find lots. Perhaps someone else will have some goods directions or know of a good kit.

have fun,
dan

April 19, 2007 01:37 AM Forum: Telescope Making

making a binoscope

Posted By dan hilts
Itz,

The prisms will need to be fairly large to work well. Why cannibalize a large pair of quality binos to make a pair of binos?

More to the point, in good binos, the objectives will be made to correct for the spherical abberations created by the large blocks of glass that are the prisms. If this correction is not made then the final images will not be as good as they should be. If you want to use well corrected telescope objectives to make a bino, you need to use mirrors to shift the images to the eye point. Mirrors won't mess up the fine figure of the objectives.

hope this helps,
dan


May 1, 2007 07:05 PM Forum: Equipment Talk

Baffle bafflement

Posted By dan hilts
The site Dave has referred to shows how to layout the baffles. I have found this is a practical way to install them and position them.

I string a fishing line from the objective cell to the eyepiece opening and pull it good and tight so that it defines the outer limits of the light cone as in the first drawing in the article. The baffles can then be placed so that they just come up to the line. If any of the baffles are too far forward the line clearly shows where. Once all baffles are in place, remove the line.

have fun,
dan


May 23, 2007 05:46 PM Forum: Beginning Astronomy?

Which spiral?

Posted By dan hilts
Paul,

Check out M104 at the southern edge of Virgo. Galaxies don't come much brighter than this one.

Here's a link to a page for the constellation Virgo with maps, photos, and descriptions of DSOs.

http://www.hawastsoc.org/deepsky/vir/index.html#ngc4472

clear skies,
dan

June 5, 2007 10:54 PM Forum: Telescope Making

what kind of refractor is this?

Posted By dan hilts
Hi Todd,

Welcome aboard.

The scope you are describing could be anything at this point. Maybe a gem, maybe not. Maybe an old rich field refractor like Jaegers used to produce. Also maybe an old aerial photography lens home-mounted in a tube. Maybe a less useful TV projection lens mounted. Pictures may help someone to recognize it.

You can find the glass in the objective by shining a laser into it. Even a cheap laser pen from the dollar store will help. You may even be able to tell whether an element is thicker in the centre or not. It is possible with careful examination to get enough info to sketch the lens assembly without opening it up. Cemented elements may or may not show up with the laser.

have fun,
dan

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