Posts Made By: Mike Ratcliff

Hi Roger,

Welcome back! The 10" dob will be a huge improvement over your previous telescope.

I would not buy any of the eyepiece kits. The 4mm and 6mm plossls are almost unusable because you have to get your eye so close to the eyepiece (the "eye relief" is too small). In the Meade kit, they have both a 32mm and 40mm plossl, and these are too similar to each other and a waste. The moon filter you really don't need, just use a higher magnification and that will darken the moon enough. The color filters I haven't used before. I'd recommend posting on the solar system forum and finding out which color filters are really useful and which are a waste of money.

If you might like to look at nebula (deep sky objects), then a narrow band nebula filter like a UHC (ultra high contrast) is really good. The broad band light pollution filters are generally not useful, which is too bad because light pollution is a big problem.

Plossl eyepieces are not a bad way to start. One possible line up is 32mm, 20mm, and 15mm (doesn't have to be exactly these sizes), plus a 2x barlow. Barlowing a 32mm plossl has issues with a too long of an eye relief, but you can barlow the 20mm and the 15mm to effectively give you 10mm and 7.5mm. (Barlows double the magnification which is the same as dividing the focal length by 2).

So, 32mm 20mm, 15mm, 2x barlow, (32, 20, 15, 10, 7.5mm effective sizes) + UHC filter is my recommendation.

Mike

Yes, the Cocoon has a lot of H-beta wavelength emissions, so it makes sense that the UHC is better than the O-III filter. The O-III cuts out the H-beta. The H-beta filter is even better; the nebula is pretty obvious then, but not so pretty. Not an easy object though so congratulations on getting it.

I see that Mt Pinos has some of the same characters that Joshua Tree has. The price to pay for having people around for security, I guess.

Mike

There are no "collector" web sites that I know of. Astromart is the best around for selling. Cloudy Nights has a very active forum, but not as much stuff for sale.

In years past, only the 11mm Type 1 Nagler has been a real collector's item because it was discontinued the earliest of the Type 1's. I owned a used 13mm T1 smooth side about 5 years ago, in decent but not like-new condition. I bought it for around $180. I think the prices have actually dropped since then.

A like-new eyepiece of that era could definitely sell for more. Maybe $300? That's a guess. I recall seeing some 11mm T1's asking for $400+.

You could try the Astromart auction with a high reserve price.

Good luck!

Mike

Very interesting idea. Me being (ahem) vertically challenged, that would be helpful. Plus my feet hurt after a while of standing too.

I've had that happen too. That person would a day later give a glowing rating to someone else!

What am I, chopped liver? Did I say something wrong? Or was he mad because I offered a lower price? Oh well, maybe just forgot. I've got enough anyway.

Mike

I didn't look for 288 when I just had a 6", but like a lot of medium brightness globular clusters, based on my experience 6" aperature and dark skies would be plenty to detect and recognize it as a deep sky object. Guessing you could go down to 3" to 4" and still detect it without much trouble.

In a 16" in dark skies it is a nice object with lots of resolution. Several good galaxies in the area too, especially 253.

Mike

Generally speaking, both have similar performance and will work well with your telescope, being the focal ratios are somewhere between f/6 and f/10. (ratio of FL to aperature). They both have 4 lens elements. The plossl will have a wider field of view, 50 degrees, versus 42 degrees or so for the ortho.

The ortho will have a slightly larger eye relief (i.e. more comfort) for a given focal length. Both orthos and plossls have small eye relief for the smaller focal lengths. For me, I don't like plossls at 11mm and below, orthos 9mm and below. Though I can stand them for a little while.

For astronomy I can state from personal experience that the Televue plossl and University Optics ortho brands are good. There are other brands of plossls around too that have good reputations. Televue is having a 20% sale right now.

There are some very premium brands of orthos around on the used market, some going to $800 each! Haven't tried those.



Mike

I saw this the other day at a Home Depot. Was surprised and first thought there was a local power outage.
Mike

I enjoyed my Pentax 10.5 XL. (16" f/4.9 dob). Sold it for financial reasons only. $157 is a good price.

Mike

The Obsession Telescope web site has a rough comparison of images of M13 in various size scopes.

http://obsessiontelescopes.com/m13/index.php

I would say the difference between 10 and 14 is noticeable but mostly not shocking or WOW worthy. I went from 6 to 16, and that was a WOW. As always, try to view through some other scopes if you can.

Mike