19 replies to this topic

[Bill Grass]

Okay, I should be able to figure this out, but I can't. How in the heck do you use the transparent overlay to figure out precise coordinates?? :o I just got my new Sky Atlas 2000.0 laminated desk version, and I played around with the overlay a little. But I just can't seem to figure out how to align it or whatever it is I need to do.

Any help is appreciated!

[Blues]

Bill,

Aside from the Telrad overlay, the other grids are map specific, so you have to use the appropriate one for the specific map. (Circumpolar, equatorial etc.) You'll see that each one has a particular range when you look at the scale. Once you have the right grid for the particular map, you can overlay the object in question and measure to specific points on the map. I hope that is somewhat clear and that I've actually addressed what you were asking.

[Vince Tramazzo]

Bill,I'll try my best. The sky atlas comes with three overlays. One for the polar charts, one for the mid- latitude charts and one for equatorial charts. For practice, go to chart 1. Place the long pointed overlay touching Polaris. Move the overlay left to right, until the numbers on the overlay match the declination numbers at the top of the chart. Ex. 80 on the overlay = +80 at the top of the chart. Now you can read off the charts RA. and Dec. from the overlay. Hope that helped.

Vince

[Bill Grass]

Thanks, Vince & Elliott! I think I tried what you said, Vince, but I never could get the declination numbers on the chart & on the overlay to match. It seems like the scale is different, even on the grids that correspond to the proper charts. I'll try again this afternoon when I get home; I may have done something wrong the first time. I'll let y'all know if I do it correctly.

[Blues]

Bill,

You're welcome and please give a shout if you still need any help. I remember staring at it myself until it clicked.

You'll notice on the transparencies that the declination scale is along one side and the RA scale along the other. Each scale on the transparency works only with particular maps. It will be obvious to you when you do the overlay whether it "fits" or not.

As an example, (I picked the following number at random) when you look at a map in the atlas, make sure that you line up the 20 degree line on the transparency with the corresponding 20 degree line on the appropriate map (or whatever particular declination you happen to be looking at, remember, this is just by way of example).

You'll notice that the transparency fits perfectly over the grid of the actual map AND that it lays out the RA in 5 degree increments between the hourly RA lines on the map. Thus, if you are looking at a particular DSO you can measure the difference in degrees of declination and RA to a known object on the map. (Or, conversely, you can measure from a known DSO to a point on the map, you get the idea.)

Hope this is clear, if not send me a pm and I'll provide a cell number so we can discuss it in English. LOL!

[Bill Grass]

Thanks, Elliott! I'll check it out this afternoon & see what happens.

[desertstars]

Good stuff, guys! This is one of those things, I think, that just about every owner of this atlas bumps into and figures out, without ever think to pass it along. Should save some others a bit of trouble.

[Bill Grass]

Nope, still not working! I think I know what's supposed to be happening, but the overlay's grid just seems to not be at the same scale as the main charts. Here's a photo showing what I mean. The chart's declination numbers are circled in red and the overlay's declination numbers are circled in green. As you can see, the scales aren't the same, even though I'm using the right grid. (Correct?) It's the same problem with RA; 60m on the overlay isn't equal to 1h of RA on the chart.

Is this how the overlay is supposed to go over the chart, or am I doing it very wrong?

Attached Thumbnails

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[Jim Shaffer]

Are the different editions of the Atlas on different sizes of paper? If so, someone put the wrong overlay in yours. I put the overlay of my deluxe non-laminated edition in the exact position you photographed, and it aligns perfectly with the chart.

I don't see anything on the overlay identifying which version it pertains to, but I could've sworn that when I was shopping for mine the laminated and non-laminated versions were different sizes. The non-laminated one has fold-out pages -- does yours?

[Blues]

Edited in light of post below.

[Blues]

Bill,

I take it back. I went back and set it up exactly as you have it above and now I'm pretty sure that you do in fact have the grid from one of the other editions. The deluxe version is on a slightly different scale than the other editions and you must've received the wrong transparency by accident.

I apologize for not seeing it earlier.

Edited to add that upon posting this I see that Jim has just mentioned the same thing. Seems like they mixed up the grids.

[Bill Grass]

Aha!! That's kinda what I was thinking. Yeah, mine's the laminated desk version (non-foldouts). I guess I should contact Sky Publishing about this (I bought it directly from them). Thanks for all the help, folks! I appreciate it.

[Vince Tramazzo]

Right Bill,
The Deluxe Desk version has a larger scale than the regular
desk and field edition. But we're glad you solved the problem. Good observing!

[Bill Grass]

Thanks, Vince! I sent an e-mail to Sky Publishing last night. Hopefully I'll hear from them today. I'll let y'all know!

[DenisY]

This is very interesting post... Can't wait to read there answer!

[Bill Grass]

I just got an e-mail from 'em. They're going to send me the correct overlay. They said I don't have to send back the wrong one. Cool! I'll let y'all know when I get it.

Thanks again for the help!

[Blues]

Good to hear. Let us know how it works out.

[Bill Grass]

I got the correct overlay today! Other than a nice crinkle in it, courtesy of the Post Office , it arrived safe & sound; the grids align perfectly to the main charts.

I like stories with happy endings!

[Blues]

Great news. (Given the holiday season, sounds like the overlay was delivered by Kris "Krinkle". I know, I know, go ahead and groan. )

[Bill Grass]