Posts Made By: Steve Lathrop

Today's Astromart photo is a shot of Saturn showing a zillion atmospheric bands, and the Encke division in the rings--all brought to you by an 8-inch LX-90!

I had not realized that such views were possible with only 8 inches of aperture.

Steve

A few months ago several posters to this forum were awaiting delivery. I was looking forward to first-light reports and follow-ups. Got any?

Steve

Any good downloadable planetarium programs which can run on Mac System 10 or higher?

Do planetarium programs suffer from display on LCD screens vs. CRTs? I worry that my square LCD pixels may give me the appearance of square stars, all the same size.

Before upgrading my Mac I had an older copy of Starry Night Deluxe (about 5 years old). It won't run on the new machine. I liked it a lot.

Are there any Mac users who have new Starry Night versions, especially Enthusiast and Pro, who can comment, compare, contrast?

Thanks for the help,

Steve

John,

I can't give you much help on the comparative views through the scopes you named. I have never looked through a dob, although I plan to take the first chance I get to try out a Starmaster. Based on what I read, the Starmaster will probably at least match the refractors, no matter where you set up. Under dark skies, the Starmaster should blow the refractors away, they say.

I can say from experience, as a person who chose a TV102 for a first scope, that I doubt you would regret making the same decision. I have never bought anything that gave me as much satisfaction. Someday, if I can afford it, I plan to buy a 14.5 Starmaster. However, I can't imagine ever selling the TV102. The views on clusters, planets, the moon, and other bright stuff are just so beautiful. Under darks skies, the double cluster through a 22 Nagler provokes an exclamation every time I show it to someone for the first time. You have never seen a picture of the double cluster that looks even remotely as good.

So yeah, you're probably doomed if you buy the refractor first. On that basis, avoiding doom, you might want to try the Starmaster first.

However, one thing that either of the refractors will do that might help you get going is they will make it somewhat easier to find stuff. They give wider fields. It has been a great pleasure to me to discover that by using a red dot finder I can quickly find pretty much everything I set out to look for.

What a great dilemma. You can't go wrong!

Steve

I have the 22 Nagler and it's my favorite ep for my TV 102, ...at least today. Some other days it might be the 7mm Nagler type 6, or the 35mm Panoptic.

Couple of thoughts: since it's apparently a close choice, ask yourself if you prefer to see the field stop, or not. When sweeping around looking for stuff I find it a little reassuring if I can easily see all the way to the edge of the field, which is a point for the Panoptic. Also, the eye-relief on the 22 Nagler is somewhat longer than on any of the comparable Panoptics, maybe just long enough to be slightly uncomfortable for some people. Or maybe just perfect if you wear glasses when you observe. So maybe you could make the decision on the basis of the eye relief that's comfortable for you.

Steve

I think the Terrafly website might solve your problem. It provides aerial photography of the entire U.S., and as I recall a latitude and longitude readout follows the cursor. You should be able to see your house in the pictures.

I forget the address, but entering Terrafly in Google should bring it up.

Steve

I bought the Funjinon 10 x 70s before I bought a telescope, and I still love them and use them, but I think it might be a shame to sacrifice the incredible versatility which you get with a small apo. (I now have the TV-102, and when it is set up, nobody is looking through the Fujinons.)

With the TV-76 you would get the chance to use powers from 9x to 160x without resorting to a Barlow, with the corresponding selection of fields. Think about it... with a Panoptic 24 you would get about 3.2 degree views of the Milky Way at 20x, with incredible rendering of star colors. The view I get with my Panoptic 35 and TV-102 is about 2.5 degrees, and when you look at the Cygnus Milky Way, it's really almost too much to take in in every field you look at.

For daytime use, you have maybe the best lightweight spotter scope around. Given that the reviews of the TV-76 say it produces images of a quality similar to the TV-102, how can you go wrong?

Get the TV-76 and invite me over.

Steve

How about large dobsonians clustered and aligned on a single mount, with images dynamically collimated in one eyepiece?

Three 24s would provide more light than a 40-inch, they would offer a much wider field for equivalent aperture, they would cost a tiny fraction what the 40-inch would cost, and you might even be able to figure out a way to make the whole thing portable. Probably have to arrive early to start your setup, though.

Steve

I did a side-by-side comparison of these two in daylight at the Meischner store in Boston, before it closed.

Both produce a huge optical bang in a TV-102, terrific sense of wide-field wow with either EP.

A few differences: the Nagler 31, in daylight, has a LOT of color at the field stop. So much that the entire field is suffused with a warm color as a result. This is absent in the Panoptic, and my guess is that it would not affect night viewing with the Nagler at all, except perhaps to color stars at the edge of the field.

Another issue to pay attention to is eye relief. With the Nagler it is a touch shorter than with the Panoptic, which may be an advantage. If the eye relief on the Panoptic creates a problem, it is a problem with being too long. This is something you should probably try to experience before deciding.

My recollection is that the Panoptic showed somewhat more pincushion distortion than the Nagler, but this was evident in both EPs. For me, neither EP would be a first choice for terrestrial viewing as a result.

I bought the Panoptic, and I have been delighted with it. In my TV-102 it gives me 2.5 degrees of Milky Way in a 25x field. The views are staggering.

Steve

What EPs are you comparing?

The key question is what is the size of the field stop in each EP, data that not all manufacturers supply, but you can find it for Televue EPs on their website.

For instance, you can check out the new 7mm T6 Nagler and see that it's field stop is a bit larger than the older version. Both are the same focal length, both have apparent fields of 82 degrees (which is probably just a nominal value) but the old version will probably show a bit less sky than the newer one.

One point is that apparent field is not that good a datum, since it depends on assumptions about eye-relief and where the observer's eye is located. Apparent fields get wider as your eye gets closer, and this gives manufacturers room to fudge their claims about apparent field a little.

I think it's certain that there could be differences in true field between the two EPs you mention, but unlikely that they would be huge differences.

Check out the field stop sizes. If you can't get the info, maybe you could compare the EPs for true field by looking out the window. That's the one advantage of buying at a store, you can get your hands on the stuff you are thinking about buying.

Steve