Wednesday, August 29, 2012

IDA Darksky Giveaway is on!

If you are not yet familiar with the International Dark-sky Association ( IDA ) now is a great time to become aquatinted with them and sign up as a member.  The IDA's mission is to
...preserve and protect the nighttime environment and our heritage of dark skies through environmentally responsible outdoor lighting. 
Now is a particularly good time to join because any member can enter to with a full set of Teleview Ethos eyepieces via their Darksky Giveaway.  I'm not sure how many members there are, and how many will register online for the contest, but it's a fantastic prize and my odds are probably not too bad! Seeing the announcement in my email box made me think of how I finally decided to join.

Almost since the time I began my most recent foray into amateur astronomy several years ago I knew about the IDA and it's goals.  It does not take more than a few seconds to read their mission statement as it's direct and to the point.  I hated light pollution, but never really thought about donating, until last year at the Pacific Astronomy and Telescope Show ( PATS ).

PATS is a relatively small show, and it does not take more than a few hours to walk the floor and see most of the booths.  I had walked past a the IDA booth a few times when I finally stopped to take a look at some of their literature.  As I was reading one of the pamphlets, I asked the nice guy behind the booth how the day had been so far.  He was upbeat, but said he had not had many people signup for memberships so far.  I kept reading, expecting this to be the end of things, but he said something that made me stop and listen; "I've watched people spend hundreds of dollars on an eyepiece, but they won't spend $50 to help preserve the sky they look at through them".

I knew eyepieces were an investment that would last me a long time, regardless of the telescopes I ended up.  Just that day I purchased a filter and a new 32mm Teleview plossl.  I thought about a time ten or twenty years from now when I would have to travel even further, perhaps prohibitively  far, just to use them.  It was a scary thought, and the investment in preserving the dark sky suddenly seemed like a very sound one.

So now might be a great time to consider if an investment in the future of dark sky observing is right for you... and a set of Ethos' would be pretty cool!


Tuesday, August 28, 2012

The Design: Size

As wonderfully pointed out by Matt Wedel over at 10 Minute Astronomy in a recent post, Apeture Matters. It allows you to see more detail, to see fainter objects and was my Requirement #1 when thinking about A Better Telescope. So in a very real way, I want to get the largest telescope possible. Sadly, for me that has nothing to do with the largest telescope that can be manufactured, I'm well under that threshold. Possible for me is the confluence of two factors... Size and Cost. Keeping in mind that I have pretty much decided on a Dobsonian Design, I should be able to figure out how large a scope I am aiming for.


Aperture vs. Size

The first difficulty with very large scopes is portability. Since I have to travel to do my best observing, my telescope has to be reasonably portable. It can't be too big to fit into a wide range of cars, as I don't own a car and am never sure what will be available when I rent. Ideally, the largest component, probably the mirror or rocker box, would fit in a trunk. Failing that, it has to be able to fit in a back seat.

The telescope also can't be too heavy for me to handle easily myself, as I sometimes observe alone. I figure the heaviest component I'd really want to carry would be somewhere around 50 lbs. This is a bit arbitrary, but moving something too heavy around has risks, especially in the darkness after a long night of observing!

The final consideration in size is the eyepiece height. I want to be standing flat footed for all of my observing.  I'm about 5'6", so I'm hoping for an eyepiece height, near the zenith, of around 5'. In general, the larger the aperture, the longer the focal length and the higher the eyepiece when you point the scope up.

The exact length depends on the focal ratio (focal length/aperture) of the mirror I choose.  You can get very fast (low f-ratio) mirrors that will reduce the length of a given aperture, but they tend to be more expensive and have other undesirable optical characteristics; namely coma. Realistically, for reasons I'll cover in a specific post about my mirror options, I'm probably going to settle on an f-ration between 4 and 5... They are generally available, don't necessarily require a coma corrector, and won't be too long.

A spreadsheet seemed like the best way to juggle all of these variables and come up with some concrete numbers. Luckily, before I actually finished one, I ran across a nice Telescope height brainstorming spreadsheet a user on Cloudy Nights worked up!  It will also do rough calculations of mirror weight.  Awesome.

Playing with the numbers for a while, it seems that my most stringent requirement is probably eyepiece height.  Any scope with a mirror or rocker box large enough, or heavy enough that it violates my restrictions has already exceeded the eyepiece height.  So simplifying a bit I came up with this table which gives an overall sort of range:

Diameterf-ratio8" multWeightEyepiece Height
14"f53.1236' 1"
15"f4.53.5265' 10"
16"f4.54306' 2"
16"f44305' 6"
17"f44.5345' 10"
18"f45386' 1"

From left to right I've listed the mirror size, f-ratio, how much more light than my current 8" scope it will gather, the weight of the mirror only, and the eyepiece height pointed straight up.  

I'm a bit suspect of the eyepiece height calculation.  The math seems sound, but in spot checking some listed eyepiece heights for various scopes on the web it seems high.  I'll have to do some more specific calculations when I'm closer to choosing a design to build.  In any case, I'm probably not going to use the scope straight up because it's somewhat uncomfortable with a dobsonian, or any alt-az mount for that matter.  

So I think any of these will meet my three requirements, although the 18" would probably be pushing it on the mirror box size, and I've never really seen a 17" mirror around.  However I want to keep an open mind, and 5 times the light gathering of my current 8" scope would be wonderful.  


Aperture Vs. Cost

This is a trickier trade off to optimize.  The cost of the mirror is the largest, but not only, cost in a telescope and not all the components scale in price the same way.  Some things, like a good focuser, are going to be the same price regardless of aperture.  Others, like the secondary mirror, or support structure, do get more expensive with increasing aperture, but at rates different from each other, and different than the mirror.

I'm going to crib off of the work of Matt Wedel again and copy a section of a chart he posted about What Aperture Costs, and expanded it a bit to include a couple of the more common larger scopes:
Meade 10″ Lightbridge – 250mm – 78.5 in^2 – $700 – $8.92/in^2
Meade 12″ Lightbridge – 300mm – 113 in^2 – $1000 – $8.85/in^2
Orion XT12i – 300mm – 113 in^2 – $1100 – $9.73/in^2
Orion XX14i – 350mm – 154 in^2 – $1700 – $11.04/in^2
Meade 16″ Lightbridge – 400mm – 200 in^2 – $2000 – $10.00/in^2
Hubble Optics 16" - 400mm - 200 in^2 - $2300 - $11.50/in^2
Obsession 15" classic - 381mm - 177 in^2 - $4500 - $25.42/in^2
Obsession 18" classic - 457mm - 254 in^2 - $7000 - $27.55/in^2
From left to right he's listed the brand/size, aperture (in MM), square inches of mirror real-estate, scope cost, and most interestingly, price per square inch.

Not all these scopes are equally equipped; some have goto, some do not, and they vary in the quality and types of accessories.  However, one thing is pretty clear, larger aperture costs more money!

I've not fully worked out my budget yet, but I think I'm aiming to come in under the $4000 mark. Based on what I have saved so far, this seems like the absolute max I could really do in a year.  True, the year is somewhat arbitrary, but that is my goal and I'd like to stick to it.


The Verdict

Based on all the factors so far, I'm going to build my design around a 15, or 16" f4 or f4.5 mirror.   I've not done all the budgeting yet on every scope, but it seems like I really can't afford anything larger than 16".  Depending on the design, 16" might even stretch my budget and portability requirements, so I'm going to design and budget a couple of options right around that size.  

The difference between 15" and 16" may seem small, but the aperture increases with the square of the diameter, so the 16" has 15% more aperture.  However, it's eyepiece height is also 4" higher, and I bet that extra inch of diameter means a noticeably larger mirror box as well.  

I'm going to have to see what is available in commercial scopes or parts, figure out the specific dimensions for a given implementation and decide exactly what size a bit later.  Until then, Clear Skies!

Friday, August 24, 2012

GSSP 2012 Observing Report

The Golden State Star Party is a yearly event held under very dark skies near Adin, in Northern California.  How dark?  Well, here it is on the fantastic Dark Sky Finder right on the edge of a black zone.  You can look all over California on the map and find only a handful of black sky sites, and most are tiny islands.  True, this is on the edge of a grey zone, but compared to my normal semi-dark observing location, Joshua Tree, CA, on a blue/green border it’s a wonderful sky.  Definitely worth the 11 hour drive from Los Angeles for four nights.

Heading Up
I split the trip into two parts, leaving Tuesday and staying overnight in Sacramento.  This was a nice opportunity for me to visit some friends and family, and it allowed me to get to the location fairly early on Wednesday without having to leave at some insane hour in the morning.  Arriving somewhat early is important since setup takes a while and, like most star parties, the use of white light after dark is prohibited.  


The drive is actually pretty beautiful after Reno, NV. The elevation starts to build and the landscape is rolling hills with light tree cover.  Not long after I crossed back into California I passed this tree, full of shoes. I'm not entirely sure what the story is here... actually I'm not even a little sure. I had to turn around and take some pictures.

The Shoe Tree.....
Forever a piece of me in California


The rest of the drive was uneventful.  The weather looked great as I was heading north and I stopped several times to take photos since I had plenty of time. 


The Road to Adin, CA
I arrived around 3:00pm after a leisurely drive through the very scenic countryside, giving me plenty of time to setup my camp and telescopes.


Wednesday

Unfortunately, my early setup did me no good.  By the time I arrived it was cloudy, and the weather reports indicated it would stay that way through the night.  As the afternoon progressed, more and more anxious astronomers arrived, unpacked, and watched the sky.  A few folks did not even bother to setup their scopes predicting the cloudy night to come.


There ended up being a few gaps in the clouds after dark, just enough to keep me awake and hopeful until almost midnight, but not enough to actually observe anything.  Total bust on that count, but I met some nice people camping around me and got a chance to check out some of the equipment being setup.

Thursday


I woke up late in the morning and the sky was still grey, if anything it looked even worse than the day before. My apprehension for the evening was building, but I had a whole day ahead of me to walk around and talk to some folks about their equipment. Attending a star party is a great way to learn about, and potentially try out, a host of equipment. I love walking around and seeing what people have brought. Since everyone is there for the same purpose, it's easy to strike up conversation. There is always something to talk about, even if it's just our common desire for clear skies.


As I started to walk and talk, one of the first camps I stopped at had two scopes built from DobStuff.com kits. I was already starting to think about my next telescope and building a kit scope like this was high on my list. I'm kicking myself for not getting any pictures, but the scopes were beautiful! They were 12" and 18" inches with similar caramel color stains. I've seen pictures on the website, but the scopes look even better in person. The two owners had nothing but good things to say about the kits and Dennis Steele who makes them. I had a chance to try moving them a bit, and the motion was smooth and the whole assembly seemed rock solid. Part of this was probably the skill of assembly, but it was very promising and really inspired me to get going on my new scope.

I spent several hours walking around until the rain started. There was rain off and on for the rest of the day, and I had to move my scopes under the pop-up shade structure I brought, but it was a nice time overall. By evening the rain had stopped, but it was still cloudy. I hoped for the best, but had a sinking feeling I would be turning in early again tonight.

Each night there is a speaker who gives a presentation. Thursday's speaker was Mel Bartels speaking about "The Nature of Telescope Design". It was a wonderful presentation covering some of his past and current telescope designs along with a bit of engineering and philosophy. When the talk was over everyone shuffled out of the tent into a cloudy night... but it did seem LESS cloudy than before the talk.

Almost magically over the next hour or so as the twilight turned to actual darkness the clouds completely disappeared! It was fantastic; by the time I would have started observing anyway the sky was clear and looked magnificent. Checking back in my log I gave it a 7 for seeing and an 8 for transparency (out of ten). For my highly objective rating system this is pretty darn good.

My plan for the night was to try for every Messier and bright NGC globular cluster I could in Sagittarius. I started with the humble globular cluster NGC 6440 and logged it at around 10:30pm
"Very small and dim. Took a lot of searching and high magnification to identify as G.C. Unresolved even at 200x. Round, with tight core and uniform gradation out to edges"
The night was very warm and I spent the next three hours making my way through Sagittarius logging 13 globulars and two bonus objects; NGC 6822 Barnards Galaxy and NGC 6818 the Little Gem planetary nebula:
"A mini ring nebular! Very small and beautiful. Non stellar circular glow in 13.5mm, shows dim center and ringlike appearance with 6mm. Seems to have blue-green coloring"
It was an incredible night.  Tracking down a lot of smaller, dimmer NGC globs was a real treat.  

Friday 

The day started out pretty warm and I was woken up early by the morning sun.  I decided to go out and explore the countryside and surrounding towns.  The closest is Adin, CA, and the GSSP is an event around those parts.



Adin is a very small town with a few shops and homes. It's got a nice general store where you can pickup any supplies you might need. There were signs in the window advertising the GSSP public night that very evening.

I returned to the star party and walked around a bit. The sky was cloudy, but I had hopes it would clear up. My intention was to do some wide angle astrophotography with my Canon T3i. Nothing fancy, just the camera on a non-tracking tripod with a 24mm lens. I had recently purchased an intervalometer (timed shutter release controller) and was hoping to use it for some time-lapse series. To test everything out I took this time lapse during the day. You can see the clouds drifting over the observing field.



Fortunately the sky cleared up before dark and it looked like another wonderful night. The Public Night started around 9:00 and lots of folks from the surrounding towns came to visit. After showing a few people Saturn through the scope, I started observing in earnest a bit after 10:00. I rated the seeing a 6 and the transparency an 8 again. Before I dove into my evenings observing plan, I setup the camera facing south to catch Sagittarius and the milky way passing by. I started the intervalometer and went to work.

My plan for the night was to get all the M objects in Scorpius, and a couple of NGC's that I thought I might be able to see with my scope, then move over to Ursa Major to view a few Messiers I have missed to date and revisit some old favorites. I ended up observing 25 objects in about 4 hours, which has to be some record for me. I'd never seen many of them before, and most I'd never seen so well. One of my favorite of the night was the Lagoon Nebula, which I was observing for the first time through a new OIII filter I picked up at one of the vendors just that day!
"OIII Makes a great contrast difference. Helps show full extent of nebulosity with dark lanes much more visible. Split easily into several lobes. Fills 3/4 of 13.5mm ( 0.9 deg) field"
I also checked out the Trifid and Veil nebula, both of which looked great with the OIII.  It made for a much nicer view than my narrowband nebula filter.  Before I packed it in, I retrieved the camera and took some images to stitch together a panorama of the milky way
Several images stiched together, ISO 3200 f/2.8 30seconds each

I got a little off center towards the north end of the milky way, but I think it's one of the best I've taken so far.  The time lapse turned out pretty nice as well.  You can see a few little clouds sneak in right towards the end, but I don't think they bothered anyone.  Just look at how dark they are, with no light from the ground to reflect back, they are like huge dark nebula.



Saturday

Saturday was very sunny and hot. It also featured two of my favorite parts of the GSSP; the Swap Meet and Telescope Walkabout. The swap meet is free for anyone to grab a table and display their wares. It ranged from people with one or two items, to folks who brought bin after bin of odds and ends. I was sorely tempted by several items, including a used Williams Optic refractor, but held off knowing that I had a bigger goal in mind; namely my new big dob.  

Anyone who has an interesting telescope and wants to share can sign up for the Walkabout. It's basically a bunch of folks walking from scope to scope on the list, hearing a brief speech by the owner, and then asking questions and discussing.... and it's great. There were home-made bino-scopes, ATM projects of all sorts, a few high-end commercial pieces and this interesting re-build of a Meade Lightbridge:


Rebuild of a Meade Lightbridge 16"... into a BBQ
Yes, that really is a 16" Lightbridge. Well, at least the primary, secondary and focuser from one! It features a 24" webber BBQ, bamboo truss poles, and a bike rim upper cage. It's dead simple, the whole thing sits in a milk crate and it actually has pretty good motion; sort of like an oversized Astroscan. The owner said it sets up really quick, although he admitted it does not hold collimation well. I'm not sure this is the way I want to go, but it did show how simple and inexpensive a telescope could be... minus the mirrors!


One of my favorite scopes I saw as I walked around was not on the tour, and there was nothing particularly innovative. It was just large. Very, Very Large. Sadly, I did not get to speak to the owner or catch a glimpse through it at night, but it was impressive to behold.
28" Ultralight Dob. Notice how it dwarfs the 10' shade structure
The ultralight, relatively small, mirror box made this seem much more reasonable than the 20"+ Obsession type scopes, but it's still probably more than I would want to handle on a regular basis. Besides, I'm completely decided that I want a flat foot scope. I've been up ladders in the dark, and the views are great, but I feel it would really interrupt my observing flow to climb up and down, reposition the ladder, and such. Besides, some computerization would be required to make the scope usable as you would not want to be actually looking for objects on a ladder, just observing objects.

It stayed clear all day and the night seemed even better than the one before. As the sun set I spent some time with Mars and Saturn waiting for the darkness to settle in. I was somewhat surprised by how steady the air seemed, and I judged the seeing a 7 tonight with 9 transparency... almost as good as this location can be!

Since I had a long drive the next day, I only spent about three hours observing and logged 12 objects. If the total seems low, it was. My targets were a little tougher and I did not find everything I was looking for.  My favorite observation of the night was also the last of my GSSP experience: NGC 6369 Little Ghost Nebula. This small planetary is magnitude 11 according to my list, and was tough to find low on the horizon. It was very satisfying to find, and created a yearning in me to go seek out other difficult planetary nebula.
"Not much more than a dim, bloated star. OIII helped in finding and identifying, but the view is better without. Need to try again when higher in the sky"

Sharing the View and the Impromptu Eyepiece Shootout

I also spent a fair amount of time that last night with some of my neighbors checking out the views through their scopes. One was a standard 15" Obsession, with servos and the whole kit. The view was great, and it was interesting to use a tracking dob. The second was a home built 16" newt on a split ring equatorial. It was a beast! 700 pounds! He transported it in a custom trailer and got it in and out with a winch system.

Towards the end of the evening we had a little eyepiece shootout. The representative from TeleVue was loaning out eyepieces and they had each checked one out during the day. There was a 17mm Ethos (~$800) vs. the 20mm Nagler (~$500) providing roughly the same true field of view (TFOV). Viewing the Veil Nebula both eyepieces gave fantastic views. To me, the higher magnification of the Ethos produced a slightly darker background, but it also had a strange sort of pincushion effect near the edges. It was not objectionable, but a few people commented on it. The Nagler produced a better corrected image as far as I could tell. For kicks we also compared my 32mm TeleView plossl. It has a slightly smaller TFOV and lower magnification. I really enjoy using that eyepiece, it's fantastic and not too expensive, but after the wider field Nagler and Ethos the 58 degree apparent field of view (AFOV) did seem a little tight.

The Nagler and Ethos were both fantastic, but for it's slightly cleaner view and the price difference, I think I'd choose the Nagler, hands down. Heck, you could almost get TWO Naglers for the price of the Ethos and an 82 degree apparent field is no slouch! Spending some time sharing the view through a telescope, and talking about the hobby we all love, is one of my favorite aspects of going to star parties. I'm glad I took it easy the last night and just took the time to enjoy the company, it was a great way to wind down.


Heading Home

I woke up early on Sunday to beat the heat tearing down my camp, but still I ended up sweating in the heat by the time I was done. It's always sad to say goodbye to people I got to know over a few days, and to leave the observing field. I stopped to snap this last picture as I drove out of the gate to head home.


The Entrance, or in this case, Exit, to the Golden State Star Party

If you've never been to any Star Party, I suggest you try to attend one locally. There are several near Southern California, check my yearly events links to the right, and if you feel like making the drive, I hope to see you at GSSP 2013.

Wednesday, August 15, 2012

Aperture Cost and Consequence

Matt Wedel over at 10 Minute Astronomy just posted two interesting posts on telescope aperture. in the first, What Aperture Costs, he breaks down the cost per square inch for several popular telescopes from 4.5 inches up to 16 inches.  The second, Why Aperture Matters, covers some of the optical realities of aperture, and also the functional, at the eyepiece, differences.

I found both posts to be enlightening and timely, given my current quest for aperture.  If you don't  yet subscribe to Matt's blog, I suggest you should.

My Current Scopes

Now that I have thought about what I want from a new telescope, and before I start to dive into the design and what I might need to buy, it seems like a good time to take inventory of what I have currently and how I got here. Since I want to be frugal about my new scope, allowing me to get the most function I can for the least money, I might end up re-using some pieces I already have. I've also been considering selling a scope to make room and free up budget for a new scope. So here is the current state of things....


Me with my kit at the GSSP 2012, it's sunset, but my face is pretty red from four days of sun

  • Orion XT 8 - My workhorse telescope
    • 8" f5.9 Dob with crayford focuser
    • Telrad
    • 9x50 RACI Finder
    • Flocked and upgraded with ebony star and teflon azimuth bearing
  • Celestron C6 XL - My travel scope
    • 6" f10 Schmidt Cassegrain OTA
    • Red Dot Finder
    • 9x50 RACI Finder
    • Astro-Tech 99% di-electric diagonal
    • Desert Sky Astro DSV-1 alt/az mount on surveyor tripod

Each scope has a story behind it, why I decided to buy it and what I hoped to accomplish. Owning and using both will help inform my decisions as I go forward designing my new telescope. If you enjoy long rambling stories of telescope purchases and use, then read on!


Orion XT 8

This scope is what got me back into astronomy. Since I was a kid, until eight or so years ago, I owned a 4.5" newtonian on an un-driven german equatorial mount. It was second hand when I got it, and looking back, I'm sure it could have used a new coating on the mirror. However, it was my reference point, and when I wanted to get back into astronomy I knew I wanted something bigger. Then, as now, I had a limited budget and a dobsonian seemed like a good, cheap way to jump back in. At around $350, the XT8 seemed to fit the bill. It had almost four times the aperture of my 4.5" scope, came with everything I would need to start, and had good reviews. I knew it would not be a top-notch scope, but it would be solid and reliable.

It's a basic 8" Synta dob... It's got optics that don't have any obvious defects, the mount is solid with an interesting spring tension system on the altitude bearings, and a fairly nice Crayford style focuser. It came with a 25mm plossl eyepiece and a red dot finder. After I unpacked it and set it up, it was ready to go. It's proven to be a solid performer and is small enough to handle easily, getting it into and out of the car is a not too difficult, and it's got a good amount of aperture. I'd recommend it as a great scope for anyone looking to get into astronomy.

After observing with it for a couple of months, I found a few things that I thought could be better. The first addition was an Orion 9x50 RACI finder. It was a wonderful addition, and really helped when observing from less than perfect locations. It's got a nice wide field, about 5 degrees, and enough light gathering to actually see some of the brighter deep sky objects.  

About the same time I got the new finder, I purchased some Protostar flocking material. I went with the Flockboard light trap sheets which are a thin plastic sheet with the flocking material on one side. It's not adhesive, you just use the natural tendency of the plastic sheet to flatten out to hold it against the side of the tube. It installed easily and I held it in place by running the spider bolts through it. This keeps it in place and it is certainly much better than the somewhat black paint that was inside to start with.

To round things out, I added a nice knob on the bottom of the scope to make it a bit easier to push around the sky. I observed with this scope for over two years, just like that. I purchased some eyepieces and other accessories not directly attached to the scope, but only recently did I feel the need to change anything.

Before the Golden State Star Party 2012 (GSSP) I decided to upgrade the azimuth motion with an ebony star kit from Scope Stuff and to purchase a Telrad. These were both great decisions.  I had a Telrad on my first scope, and the red dot finder is just no substitute. If you have a scope big enough to support it, get one. They are inexpensive and a joy to use. I can't believe I held out for two years. The ebony star kit comes with a precut circle of ebony star laminate and three new virgin teflon pads. Installation was pretty easy, I used spray contact adhesive and should have been a bit more careful, but it worked wonderfully. The amount of force to move in altitude and azimuth is now roughly equal and the scope is much nicer to use for extended periods, especially at high power.

Celestron C6 XLT

A little over two years ago I had an opportunity to travel to Hawaii with my company, Maui to be precise. I read stories of the incredible skies and lack of light pollution on Haleakala and I decided I needed a travel scope. A lot of people would have decided on some sort of short tube refractor, and they would have been very wise. I, however, decided I wanted as much aperture as I could fit on a carry on.

Schmidt-Cassegrain scopes are somewhat light-weight, compact, and have generally good optics. I did some checking, and figured I could JUST fit a 6" SCT in a carry-on suitcase with enough room for a mount and tripod. High Point Scientific was having a great sale on Celestron C6's and I jumped right in. I did not have a mount picked out, or a tripod, but I wanted it. I convinced myself I needed that scope.

I did a bit more research and decided on a Bogen #3047 tripod head, flipped over on it's side, to mount the scope in an alt-az configuration. I found one on eBay for $30 and I purchased it. To keep the whole arrangement off the ground, I bought a Benro A2190T tripod. It's a nice tripod and it has a unique design which allows it to fold flat for more space in my bag. It seemed like I was all set for my trip.

The first time I took the scope out under the stars it was painfully obvious it was under-mounted. The tripod was passable, but the photographic head was outmatched and focusing was a nightmare, even at low power. The entire field would shake for 10 or more seconds any time I touched the scope. On top of this, the clamps had to be so tight to support the weight of the scope that pointing it was an ordeal.  I only used it this way once, for maybe half an hour. It became pretty clear why small, light refractors are generally favored for travel scopes.

I was determined to make the C6 work as a travel scope, so I started searching for a new mount. The Desert Sky Astro DSV-1 seemed to be a good choice. It was not super-expensive, it seemed solid, and was not the absolute heaviest mount. I like alt-az mounts in general, so it was a good choice. Ordering was simple, and the mount arrived quickly. It was great! Solid, simple, with good motion. If I did not expand the tripod legs all the way and used the scope sitting down it was pretty stable. I tried it out a few nights before the trip, figured out how to pack everything away in a single carry-on and I was ready to go!

There was a surprising lack of interest in the telescope/mount/tripod bag as I travelled though security, and before I knew it I was in Hawaii. I only had one night for actual observing... my total stay was short and the drive up to the volcano is long. When the evening arrived I drove the rental car up the mountain with my C6 travel kit. I got up to the top before sunset and watched the sun set as I was above the clouds; Pretty incredible. The sky was clear and it seemed perfect.  

As the sun set the temperature dropped and I started to setup the scope in a parking lot near the top of the mountain. I waited anxiously for the remaining tour buses to leave or turn out their headlights so I could have some darkness. After a frustrating hour or so the parking lot cleared out and I could start observing. Before I could even get fully dark adapted some unusual high-altitude clouds rolled in, completely obscuring the sky. My one night in one of the best places to observe in the world was at an end before it even started. Who knows what wonders I could have seen! Before the clouds rolled in it was incredible... transparent skies and oh, so dark. Since Hawaii is further south than my normal observing locations, and I was at the top of a volcano, I could easily see Omega Centauri, one of the best globular clusters in the sky. When I say easily, I mean easily with my naked eye; Direct vision easy. Right there, like any other star. I managed to get the scope on it before the clouds covered it and was rewarded with a wonderful explosion of stars, but as soon as it started my first observing outside of California was at an end.
Despite the clouds, the C6 performed wonderfully! I ended up buying another 9x50 RACI finder for it and upgrading the tripod to a beefier surveyors tripod from Desert Sky Asto. It won't fit on an airplane, but I can use it extended enough to stand up and observe comfortably with very little shake or vibration. The scope performs so well I ended up leaving the big scope at my observing site in Joshua Tree and I use the C6 anytime I do observing around the Los Angeles area, short trips to Malibu, camping, etc. I hope one day to take it back to Hawaii, or to Australia to see the wonders of the southern sky.

Odds, Ends and the Future

I've accumulated a variety of other things, chairs, eyepieces, charts and the like. I'm sure I can use just about all of these with the new scope, and I'll inventory them in a future post. I'm not sure which scope I might sell, but at this point I expect it would be the XT8. It's a great scope, but it will end up in a strange middle spot. Not my most portable scope, but not my largest either. Why truck it around when I can go for something with 2x the aperture for only a little more effort? I'll be sad to see it go, but if it finds another good home it's got years of service ahead of it!



Sunday, August 12, 2012

2012 Perseids Observing Report

The Perseid meteor shower is best observed from a dark location.... The darker the better.  Less light mean more dim meteors will be visible.  This year I had a few fun things already planned for the weekend so I was not able to head too far out of the light pollution of Los Angeles to observe them, but I did make time to head to a more local observing spot in the Malibu Hills that I have tried a few times.  It takes about an hour from my apartment, it’s somewhat away from the worst of the sky-glow, it’s sort of shielded by the hills, and it has a bit of elevation.  In general, it’s not a bad place to do some observing!  On a good night, the milky-way is weakly visible, and if you are really lucky there will be a low marine layer, above the LA basin, but below the observing location you pick which will block some or most of the local light pollution.  

The Perseids were still a day or so away from peak activity, but as the peak falls between Monday and Tuesday this year, Saturday night was the best chance my girlfriend and I had.  We grabbed a blanket for the hood of the car, binoculars, some warm clothes and headed out.  When we arrived around 11:30 the sky seemed promisingly dark, but most of the southern half, and the zenith were covered with clouds.  There was a nice opening to the north east towards the radiant of the shower, so I angled the car that way, setup the blanket on the hood and we started watching.  

Not more than five minutes after we settled in there was a bright meteor which zipped from Cassiopeia past the rapidly fading clouds covering Cygnis.  It was brilliant and left a visible trail for a second or so.  A minute or so later we spotted a dimmer smaller line heading more southerly, then another quickly followed.  Seeing three meteors in short order really reinforced the perception of them radiating from a single point.  The sky continued to clear and within 30 minutes the clouds were all but gone from the sky, revealing a very, very dim Milky Way.  

As we continued to count meteors and enjoy the warm weather, I scanned around Cygnis a bit with the binoculars and spent a minute or two enjoying one of my favorite constellation, Delphinus.  I could just squeeze the main body into the field of my binoculars and admire the bright members against a background of dimmer stars.  My binoculars are in pretty bad shape, and I did not want to miss many of the meteors so I limited my exploration to quick glimpses, but it was nice to break up the all sky watching with a bit of magnified viewing.  

Around 12:30 we decided to call it a night as we had an hour drive back home and had already had a long day.  In the roughly 50 minutes we were observing we saw almost two dozen meteors, and three really wonderful ones which left a lasting trail.  I am guessing we missed several as we poured hot chocolate, and more that were obscured by clouds.  Even if our count was all inclusive, that is still a good rate, almost a meteor every two minutes.  

I was initially disappointed that my plans did not allow me a great deal of time to travel to a darker sight, or to observe longer.  In all honesty, I almost did not gather the energy and will to go out and watch the shower.  As I was heading home I was very glad I did and I was reminded again that even a short time, under less than ideal conditions, is better than not observing at all.  Sure, I wish that I could stroll out to my backyard and have an open, dark sky waiting for me, but I don’t and this year I’m going to try to make the most of the opportunities I do have.

Tuesday, August 7, 2012

A Better Scope

After observing for a few years, and attending a few great star parties, I decided I wanted to get a better telescope.   I currently own two scopes, more about them in a future post, but they each have some drawbacks for me.  So when I decided to start this project and spend a year trying to get the telescope I really want, a scope that would let me do the observing I like for a long time to come, I had to start thinking about what that would be.  I had to start thinking about some design requirements.

There are lots of great scopes out there, many better than my workhorse Orion XT8, but each in different ways.  I do all sorts of observing, but my favorite objects, the ones I spend the most time observing and go back to again and again, are deep sky objects: Galaxies, Nebula of all sorts, and particularly, globular clusters.  Oh the majesty of a beautiful globular cluster!  I usually observe whatever bright planets are in the sky on my observing nights, but they are secondary to the main event.  So I want a telescope fit for deep sky hunting!

Requirement #1: Aperture

All my favorite objects are dim... so aperture rules the day.  The larger the main mirror or lens, the more light gathered and the brighter the image.  Increased aperture also provides some benefits on resolution, so that’s a plus as well!  With that in mind overall aperture is one of my main requirements.  If it was the only requirement, I’d just get the biggest honking mirror I could and build a scope around that.  Alas, I have some other constraints and considerations.

Requirement #2: Portability

Living in Los Angeles, CA, if I want to see anything aside from the two dozen brightest stars in the sky, I have to travel.  I am fortunate enough to have a semi-permanent observing location in Joshua Tree, CA, where I can leave a telescope, but I still need to move it outside to observe.  There are also several yearly dark sky star parties, like the GSSP, which I would like to continue attending.  Perhaps I’ll even get to the Oregon Star Party... people say it’s REALLY dark.  All of this means that whatever scope I have, it has to be mobile.  I’m going to say I have to be able to lift and put it together myself, and it has to fit into an average car.  

Requirement #3: Economy

Hey, I’m not made of money.  I’d like to have a fancy 20” Ritchey–Chr├ętien, with it’s flat and coma-free field, but that will have to wait for another day.  I want the most aperture I can get for the least money.  I want to spend where it counts, aperture, optical/mechanical quality, and save on everything else.  Fortunately, there are some things I know are NOT important to me that I can give up.


Trade Off #1: Tracking

At this point I’m pretty much a dedicated visual observer, and I don’t mind pushing the scope around.  I usually use lower magnification for wider fields, so it’s not tough to track by hand.  Astrophotography is great, and I’ve done some wide field imaging with a tripod and DSLR, but the real deal is a something I can live without for the next while.  I love seeing the dedicated guys at the star parties, their kit is awesome, and they produce some jaw-droppingly beautiful images, but you gotta give some things up in any design, and this is one I am willing to let go.  By foregoing this ability in my design, I’ll save a ton of money.

Trade Off #2: Goto, Push-To, DSC’s, etc.

This stuff is great, but I LIKE hunting down faint objects with nothing more than a good star atlas, my trusty telescope, and lots of effort.  I enjoy observing, and the thought of zooming from one object to another is intriguing, but I find there is a great reward in learning the sky and star hopping to find that elusive thing.... whatever it is.  It might be nice to add Digital Setting Circles later, for finding tough objects, or if I’m just feeling lazy one night, so I’ll try to keep the design open to it, but I’m definitely willing to go without for the sake of the budget.

Trade Off #3: Refractor Like Views

I was not entirely sure how to encapsulate this point.  At first it was going to be Image Quality, but I certainly want the best image quality I can design into the system.  However, I am willing to put up with a few things that will enable more aperture.  A really good telescope based off a lens, a refractor, will give outstanding views; Contrasty, highly detailed, velvet black field, just beautiful.  I’ve seen the view through a good 5” apo-refractor and it was stunning.  But, it was painfully expensive, and that 5” of aperture is never going to show the same objects a 10” scope will... no matter how good the optics.  I’m okay with some coma, a side effect of most large aperture designs, and diffraction spikes... if it gives me another magnitude or two.  

The Winner Is...

With this subset of requirements:  Aperture and Economy, and the allowable trade-offs it seems pretty clear that a Newtonian design, on a simple altazimuth mount, is the way to go for me.   I’m pretty lucky that there has been a LOT of exploration of this design space.  John Dobson pioneered this thinking in the late 1960’s, creating the Dobsonian Telescope. There is a reason most 10+” scopes, and just about every 16+” scope at star parties are of this general design; It’s robust, it offers large aperture at low cost, and it can be made portable, fulfilling my third requirement.

So now that I know basically what I am looking for, I can start filling in some of the details.  How big is big?  What can I actually move from place to place?  Do I buy this thing, or build it?  What am I going to need to spend on this better telescope? I'll be posting my thoughts on the details of the design in another post.


Clear Skies

Sunday, August 5, 2012

Who, What, Why?

Who

My name is Richard Sutherland, I live in Los Angeles and work in Visual Effects.  I am also an amateur astronomer.  I’ve started observing from in L.A. as a kid when my dad bought me a used 4.5” reflector.  Looking back it was not a great scope, but it was good enough to spark a lasting interest in the night sky.  I had that telescope for many years, using it under the light pollution of Los Angeles to view the moon and planets, then the much better skies of Napa Valley where it saw a lot of use and I remember really getting hooked on deep sky observing.  My work took me to Sacramento where I was back under a light dome and the scope saw very little use.  When I moved to San Francisco, into a tiny apartment, I sold just about everything I had, including that telescope.

Several years ago I moved back to Los Angeles and I decided to pick up my hobby again.  I bought an XT8 from Orion and started observing again.  At the time I lived near the coast and could do some deep sky observing from my apartment patio if I got up early in the morning, the weather was just right and the object I wanted to observe passed through the small sliver of sky I could see.  Recently, I moved closer to downtown and the sky is nothing by glow and I don't have a patio anyway.  Being interested in the night sky and living in the heart of light polluted Los Angeles is not the best combination, but there are ways to make it work.....  You travel some distance to darker skies as often as you can.  This is never as often as you would like.


What

This blog is about a plan I hatched a few months ago.  It’s not really a new or unique plan, I’m pretty sure every owner of a telescope has come up with a similar plan.   More Aperture!  This won’t help me find more observing time, but the time I do find will be more fun, productive, interesting... awesome.

One of those observing times is the annual Golden State Star Party (GSSP) a wonderful dark sky event that I try to attend any year I possibly can.  I just got back from the 2012 GSSP, I’m going to go next year, and I’ve decided I’m going to have a better scope.  A simple plan, get a better telescope by July of 2013.  One year, one scope.  

To get a better scope, I’ll have to spend some amount of money.  At the very least I’ll have to save some up to buy a pre-made commercial scope.  After looking around at some options, it seems that building a telescope will get me more bang for my buck.  My time is not free, obviously, and if I include it in the cost it will probably be a losing proposition... but I’m pretty sure I will enjoy researching, building and finishing my own telescope, so I’m willing to put the time in.  

Ultimately, I doubt I’ll really save that much money, there is a fair chance I’ll spend more than I would have if I just bought a commercial scope, but I hope I’ll end up with just the telescope I want and I’ll learn some things and have some fun along the way.... Saving one penny at the cost of two.

Why

Starting a blog seemed like a good way to record some of my research, keep track of ideas, and share some things that might help other people who choose to do the same thing.  I’ll be posting stuff about my design choices, parts I find, and the actual build progress.  There will probably also be some observing reports, info about nearby dark sky sites I visit and maybe some particular astronomy related events of note.

There are lots of astronomy related blogs, a few of my favorites are linked over there to the right, but I think there is room for one more.  Heck, I already follow a bunch of astro-blogs, and I’d like to read one more.  So here it is.