Friday, November 6, 2015

So, You Want To Learn About Nebula Filters?


Just when I thought I'd already read everything there was to read about nebula filters...I just came across this Site today - For all intents and purposes, and as far as I can tell, this is "The Granddaddy" of all Web pages on nebular filters!

And, I just wanted to share it, right away.
Wow! Amazing stuff! I have no idea why I never came across it before?
I strongly suggest you check-out all of the (extremely informative!) Links.

Also, I've always been a huge Fan of the light pollution filters made by Omega Optical (I usually order them from DGM Optics). If interested, check-out This great PDF document (found via the "Mega-Nebula Filter Site" linked to above).

----- I'd like to take this opportunity, to just briefly mention a new must-have book!
I'll write a full Review of it here, for the blog, in the near future. -----
So, just the bare minimum for now:

I'm very happy to report, that Rony De Laet, an amatuer Astronomer who's work I've greatly admired for many years - Has written a book! 'The Casual Sky Observer's Guide'
I bought (the electronic version of) it immediately! And, I simply love it!
I highly recommend it! (Hopefully, Santa Claus will bring me a paper version of the book for Christmas?)

I have been following his impressive, and very inspiring Website for many years...
Besides the fact, that the Author is obviously a binocular fanatic (like me!) -- He also produces amazing and inspiring pencil sketches! Using Binocs, of course!

In a nutshell: What impresses me most, is his minimalist approach in regards to equipment.
He has been able to do all of this, mainly with just two pairs of binoculars. Two pairs, of what many amateur Astronomers might consider modest binocular models. In other words, not "Alpha" model or super-expensive units.
A pair of 8x56's and a pair of 15x70's (along with a SkyWindow mirror mount).
Very inspiring.

It is basically something that I would love to be able to do: Choose just two pairs of binoculars, to be used for any and all observing (and sketching).
In fact, I'm working on doing just that...
I've always seemed to be spending too much time comparing the performance of various binoculars -- Instead of simply investing in two good pairs, and using them (instead of always scrutinizing their optical abilities).

To be continued...

Incidentally, I've noticed that The SkyWindow looks like it's available for order
once again - The Website was undergoing renovations for a while there... 

Clear skies!

Friday, October 30, 2015

VHT Nebula Filters From DGM Optics

The VHT Nebula Filters from DGM Optics - First impressions

Just a short Post, for now.

You can see the full line of (1.25") nebula filters available, from DGM Optics Here Of course, they are also available for 2" eyepieces.

As I mentioned in my previous Post: The pair of Garrett Optical 100mm binoculars were in need of some nebula filters...More specifically, the pair of (stock) 1.25" eyepieces needed filters. And, I wasn't 100% sure which types I would go with, this time around. These binoculars are much larger than any pair I've used before.

I was originally thinking: A pair of (1.25") GCE's (again)... Unless, (I thought to myself) after consulting Dan: He might suggest something different this time? Perhaps NPB's? I was anxious to find out.
Well, I did ask Dan (of DGM Optics [via e-mail]) and he recommended The VHT's. And it made a lot of sense to me. Here's a Link to the Info page, for the various filters.

Here is the transmission curve, from Omega Optical, the manufacturer: 



Also, from Omega Optical's Site regarding The VHT's:

"An excellent Nebula filter for smaller scopes (4-6 inches aperture) where light gathering and throughput are at a premium. It is also quite effective with larger scopes."

I have been very intrigued, with the measured spectral information shown here on DGM's page. The white graph on the lower right is of GCE Filter.
I also can't help wondering exactly what the measured spectral results would be, for my actual filters. That would be neat.

I haven't had many nights of good seeing, in which to thoroughly test them - But so far, the VHT's have been able to boost the contrast, on the few nebulae that I've tried them on.

And, finally, for astrophotographers - Here are some examples of how these filters help when imaging.
You'll see links to some Reviews of DGM nebula filters Here.

I plan to post a short Review of these filters here, in the near future.

Clear skies!

Tuesday, September 22, 2015

The Bortle Scale - Route 6 In Cortlandt NY -

The Bortle Scale - Bright suburban skies, and Route 6 In Cortlandt NY -

   Image credit: created with the free software Stellarium, retrieved from Sky & Telescope.

I'm happy to report a short, but successful "mini-field-trip" to Cortlandt New York, courtesy of my BIL, Nelson. It was the first outing for my recently acquired Binocs:

The Garrett Optical 100mm binocular telescope
-and-
The New 12x60 handhelds, from Oberwerk.

Nelson enjoyed, and remarked about the abundant FOV in the 12x60's (compared to the narrow FOV of the big Garrett's). 

Among the objects observed, were: 
M31 - The Andromeda Galaxy
M33 - The Pinwheel Galaxy
The Double Cluster in Perseus -
(NGC 869 [h Persei] and NGC 884 [Chi Persei])

And, The Milky Way looked great!

I went ahead, and set-up Google Earth, as was described on the very interesting (if somewhat eclectic Page) Here

According to this neat new map - My local skies, here at home, are:

Bortle 6   Bright suburban sky 5.1-5.5
  • the zodiacal light is invisible
  • light pollution makes the sky within 35° of the horizon glows grayish white
  • clouds anywhere in the sky appear fairly bright
  • surroundings are easily visible
  • the Milky Way is only visible near the zenith
  • M33 is not visible, M31 is modestly apparent
  • limiting magnitude with 12.5" reflector is 14.5

If this overlay technique is accurate, then my local light pollution is just about as "good" (maybe even half a magnitude better) than I had originally guesstimated. And I'm really happy about that...

If this is in fact, the case - Then I'll take it! I can work with 'Bright suburban sky'

What this all actually translates into now, for me...Is that I will (eventually) have to confirm this map's accuracy. By "manually" checking the naked-eye visibility of several different constellations / stars, etc.

According to this map, the skies (which I thought were awesome) during a recent Astro-outing, in Cortlandt New York, are:


Bortle 5   Suburban sky 5.6–6.0
  • only hints of zodiacal light are seen on the best nights in autumn and spring
  • light pollution is visible in most, if not all, directions
  • clouds are noticeably brighter than the sky
  • the Milky Way is very weak or invisible near the horizon, and looks washed out overhead
  • limiting magnitude with 12.5" reflector is 15
 Clear skies!

Saturday, September 19, 2015

Finally: A Binocular Telescope!

I'm very happy to have "picked up" visual Astronomy observing again.

F/5.3 100mm Garrett Optical

I finally managed to get a nice pair of (early model) Garrett 100mm Binocs. And, I'm going to need a new pair of nebula filters for them.
I was shopping around, just looking, etc. 
But, it didn't take long for me to realize, that I'd be best off with a pair from DGM Optics! Duh!

So, my next Post, will be about the selection and use of nebula filters for this instrument...
Along with a short review.

Clear skies!

Sunday, September 13, 2015

Visual Observing Has Commenced Once Again!

I'm very happy to be posting on this blog once again...

Thanks to the generosity (and Herculean effort) of two very dear Friends - I'm now the proud owner, of my very own 8" Cat (SCT Telescope).
A rare, Bausch & Lomb 8001 Schmidt-Cassegrain, with (sidereal) motor drive.

The complete restoration, and collimation of the optics, is still a work in progress...
The first few phases have been completed -

Below is a quick Pic of the telescope.


In the meantime, I've started observing/sketching again (using my Barska 15x70's); and having a lot of fun!
 
 Clear Skies!

Saturday, December 15, 2012

Star Atlases: The Good, The Bad, And The Not-So-Good...

Just a quick heads-up: I recently purchased some "printed Astronomy materials" - A few books and...Star Atlases, etc. Including the 'Bright Star Atlas' 2000.0 by Wil Tirion: I bought it, because I read a recommendation for it, on some binocular Astronomy site (I believe).
From what I read, it was supposed to be great...Well, the fact is, I don't happen to like it very much... It seems as though there are many Deep Sky Objects missing/not shown.

I'm not sure "what happened" when this atlas/book was produced; because other publications that Wil Tirion has worked on are excellent! So, I don't get it..

Luckily, it was only ~ $14 (shipped) from Amazon. So, first & foremost, I just wanted to start with this one: It's on my "Not-So-Good List" 


On the other hand, 'The Pocket Sky Atlas', from Sky&Telescope - Is awesome! Excellent images, useful Legends and measuring scales. One of them, represents a Telrad sight. The atlas is spiral-bound, and conveniently sized. I use it all the time, as my main sky chart. Nice, accurate, and detailed:

...Beautiful cover too! :)

And, another really good publication -
Binocular Highlights: 99 Celestial Sights for Binocular Users (Sky & Telescope Stargazing) [Spiral-bound]

Being a die-hard binocular Astronomer, I really love this book! Highly recommended...I can't say enough good things about it. It is a delight. For example: I really love how Gary Seronik simply comes right out and states, that 10x50 binoculars are, in fact the best size to get (and why). Outstanding!

I recently noticed, that another favorite Author of mine (Stephen Tonkin) also recommends 10x50's as the best size overall... And, one of his most awesome books, is now in it's Second Edition - It is simply a must-have!

 

Clear skies!

Sunday, November 25, 2012

The Best Kept Secret In Nebula Filters! DGM Optics!

Just a quick post, to let you know, that I've ordered a pair of innovative new "nebula" filters from a company called DGM Optics. http://www.dgmoptics.com/ Not only are these filters priced lower than many other companies' offerings - But, according to the excellent reviews (on Astronomy forums, etc.) they perform better than filters from the other well-known companies! (It's true - I've seen it myself now, using my 8" Dob). You can check out this Link , to order filters. OIII filters are currently on sale!
I have ordered a pair of their GCE filters for use on a couple of pairs of binoculars, for spotting DSO's.
CGE stands for Galaxy Contrast Enhancement! Neat, huh? These are the only filters currently in existence, that are actually indicated for the image improvement of Galaxies! I think this is great, and I'm really looking forward to receiving them! A full review will be posted up in the near future!

Check out the transmission plot:

...Very interesting...
Here is their e-bay Link where you can read more about these, and other filters. Their NPB - Narrow PassBand nebula filters have been tested & compared by several experienced amateurs - And the general consensus is, that they are the best contrast-enhancing nebula filters currently available!

And, here is a Link to a full review/comparison done with the GCE filter by an expert, on the CloudyNights Web site. Since originally starting this post, The filters have actually arrived, and I even got a chance to test them; a little bit...The filters were shipped out to me on Monday; and arrived on Wednesday. Since we've got a full moon, I wasn't able to really check out their performance. But, I screwed both filters onto the threaded EP barrels of my brand-new 10x50 Garrett Signature Series binocs. And, they seem to: Darken the background sky, Allow a nice amount of light through (compared to OIII's for example), And I like the way they render most stars a hot purple-ish hue (it's a nice change from the usual green of other filters).
These GCE filters are perfect for binocular use! 


Dan, of DGM Optics is dedicated to his customer's happiness. It's not only obvious, but very nice of him to be very accommodating. . And, I appreciate it a great deal.
So, I can report that ordering/dealing with Dan at DGM Optics, has been a pleasure. Keep an eye on their Website, their VHT Nebula filters should be going on sale soon! 

Clear skies!

Monday, March 21, 2011

A couple more very brief Book Reviews


I've recently read, and found the following two books to be excellent!
And, can recommend them:

Binocular Astronomy (Patrick Moore’s Practical Astronomy Series)
Author: Stephen Tonkin
Publisher: Springer
ISBN: 1846283086 - Excellent! A+++

Viewing the Constellations with Binoculars
250+ Wonderful Sky Objects to See and Explore
Series: Patrick Moore's Practical Astronomy Series
Author: Kambic, Bojan
2010, X, 510 p. 204 illus., Softcover
ISBN: 978-0-387-85354-3 - Great book, only half-way through it, but really like it so far! Great tips & reference info.

Clear skies!
-Al

Saturday, March 12, 2011

Old film photo - Corona Borealis

Recently found an old film AP pic I took. I'm afraid I don't have a lot of info on this one.
I can tell you it was taken years ago, using Kodak ISO 200 Slide Film, and scanned with an Epson scanner. It may have been taken with a Pentacon Six, Medium Format camera, but again, I'm not sure. I had to significantly reduce it, just to upload it. Orig. size was over 96MB!
Just a random shot of the area near the constellation Corona Borealis (seen on the left-hand-side of the pic).

Wednesday, March 9, 2011

Tried Film Astrophotography again...

I tried tripod-mounted film Astrophotography again...Yes, a bit of Déjà vu here. I basically only ended up exposing ~1 roll of film per camera. And, for some cameras; I didn't even get to shoot any film - That's how fast I changed my mind, and started listing them on e-bay. I hope to post some of the results soon...
I believe I've only got about a handful of "viable" prints to show for it -For the whole ordeal, and all the inconvenience, etc.

Well, this was my 2nd (low-budget) film camera collection, when it was at about it's "peak"
Just before everything was sold (on e-bay):

I did have a Petri 1.9 in pristine condition (not pictured) - And, I didn't get a chance to even shoot one roll of film through it.


Insanity: doing the same thing over and over again and expecting different results.
-Albert Einstein

*sigh*