Lockwood Custom Optics at the 2010 Winter Star Party

A short detour, but then My 20" F/3 and 14.5" F/2.55 hang out with Al Nagler,
two Paracorr Type 2s, and 599 other skywatchers under Florida stars

All images and text Copyright Mike Lockwood, 2010


Why go south?Observing in frigid Illinois

I think the picture to the right answers the question above!  It definitely is winter, but I wouldn't call it a star party!


That is me, observing from my driveway on a moonlit, snow-covered night in Illinois in January.  I am wearing a huge parka, snow pants, and layers underneath.  It was about 12 F with a light breeze, but believe it or not I was quite warm.  So why am I showing this photo?

A story before heading south

Here's an observing report from the night this photo was taken, Jan. 26, 2010.  The report was posted on my Yahoo group and on the Starmaster Yahoo Group, but I wanted to make sure it showed up officially on this web site.


"Well, after 13 days of clouds, by some freak miracle of nature the skies cleared this Tuesday evening.  I scrambled to swap focusers on my 20" F/3 Starmaster.  Off came the standard Feathertouch, and on went the new one with built-in Paracorr Type 2.

The Paracorr Type 2 is an evolution of the Paracorr that performs better for fast Newtonians.  The lens assembly for this is built into the base of a new Feathertouch focuser so that it does not move, and the Paracorr-mirror spacing remains constant.

What does this mean?  By keeping the Paracorr stationary, it is always the ideal distance from the primary mirror, and all one need do is focus the eyepiece and they get the optimal corrected view.  Of course with the tunable top gone, there is no need to fumble with locking screws, turn your flashlight on to check its position, etc.  This saves time.  Also, the assembly is more rigid and flexure is greatly reduced.  Like the Type 1, it has a 1.15X amplification factor, making my F/3 effectively operate at F/3.45.

There are still a few unknowns, though.  With the Paracorr fixed, we don't know how binoviewers, Mallincams, etc will work or if they will come to focus.  I suspect they won't, but the body of the unit (see diagram below) can be removed and the focuser mounted normally in this case.  Currently this option is ideal for visual observers with fast telescopes.  I definitely fit in that category, having a 20" F/3 and 14.5" F/2.55.

I guessed at the tilt adjustment of the focuser, tightened it down, and had dinner while it got dark.  I called a friend and rolled the scope out of the ~40 F garage into the much colder night air.  Heading back inside, I pulled on my snow pants and grabbed my parka.  Gloves, waterproof boots and an headband to cover my ears completed the outfit.

I brought the eyepiece case outside and popped in the 17mm Ethos.  It focused with no issues.  Stars were moving blobs.  I used the light of the nearly full moon to take some photos of me sitting by the scope in all of my winter gear.  My friend arrived and we went through all of the eyepieces in the case, making sure they would come to focus.  They all did with no issues.  What a treat to swap eyepieces and only deal with one setscrew - there was no fumbling with the Paracorr to adjust it to its optimal setting, or confusing it with the adapter or other setscrews while I had my gloves on.  Just pop in the eyepiece and observe.  Images improved as the scope cooled off.  The goal for the evening was to see if the focuser/Paracorr combo worked properly, and it certainly did.  Everything else after this was a bonus.  Boy did we get a bonus.  After observing for a bit we went inside to sample a beer.

Now for an illustrative break from the report....

Paracorr Type IIsA photo of the focuser-mounted Paracorr Type 2 (left in the photo) and the new "drop-in" Paracorr Type 2 (right) is shown.  The "drop-in" version looks similar to the standard Paracorr, though the adjustment positions are now designated with a letter rather than an unidentified line.  With the lines, I could never remember if all the way in was position 1 or position 5!  Now, there is no ambiguity.  The adjustment is smooth and a single locking screw holds it firmly in place.

The focuser-mounted unit consists of a standard FeatherTouch focuser sitting on top of the "body" of the unit.  At the bottom of the body is an adjustable locking ring that allows the distance from the Paracorr's removeable lens group (at bottom) to be adjusted so that it sits the proper distance from the primary mirror.  For this prototype, I set the distance by focusing the moon or bright star on a piece of scotch tape placed across the 1.25" adapter.  Simply screw the body in and out of the mounting plate (not shown here, it's still on the telescope) until the image is sharp, and then tighten the locking ring. Voila, you are done.  Future production models may adjust a little differently, but the method should be similar.  The body height is adjustable between 1.88" and 2.25", so there is 3/8" of adjustment range plus the range of your collimating screws.  I lowered the mirror in my 20" F/3 about 1/8" to 1/4" to lower the focuser height slightly.

The lens group unscrews smoothly from the bottom for collimation.  I find this operation quite easy, and I do it with the telescope pointed nearly horizontal.

The weight of the unit pictured at left (with mounting plate) and the weight of the unit at right plus a standard FT focuser are nearly identical, at about 2.25 - 2.3 lbs.

Here's a disclaimer - THE DESIGN FOR THE FOCUSER-MOUNTED PARACORR MAY NOT BE FINAL.  So, the weights and dimensions I have listed here may change.  Already Starlight is working on making the built-in Paracorr unit mount on a standard FeatherTouch mounting plate/base instead of a special threaded plate.  This would mean the unit could be swapped out with the focuser only by loosening and tightening a few set screws.  So, the design may still evolve a little bit, but I am definitely going to use this on my 20" F/3 and on the 14.5" F/2.55 for the forseeable future.

And now back to the frozen observing......

After a half hour or so we came back out to find seeing conditions greatly improved.  The six stars in the Trapezium were ROCK SOLID.  There was a lot of detail in the bright portions of nebula despite the nearly-full moon.... and speaking of the moon....

The almost-full moon looked AMAZING.  The crater Gassendi was most notable, with fantastic detail visible within and all around Mare Humorum.  (I am not an experienced lunar observer and I had to look those up.)  Ejecta rays were visible across most of the lunar surface.  Even the fully lit portions of the moon showed fantastic detail.  (The only comparable or possibly better lunar view I have had was through our uncoated 30" F/3.77 right after I had refigured it.)

Now for an observing feat that I have never managed from 40 north latitude - the companion of Sirius was easily seen for greater than 50% of the time I was looking in the eyepiece!  This is pretty much unheard of in the midwest in the winter.

Yes, really, we only had had half a beer each, and we were not suffering from hypothermia!  In fact, with my gear on I was having one of the most enjoyable cold-weather observing sessions that I have ever experienced, just outside my garage.  Mars was not that high in the sky, but it showed a very clear polar cap and some other markings.

In conclusion, the Paracorr Type 2 performs extremely well at F/3, and the focuser-mounted version saves me a LOT of valuable observing time by eliminating the step of tuning the Paracorr.

Also, again we see that, a thin, fast mirror can provide views with outstanding detail, resolution, and contrast.  (Remember, my 20" F/3 is 1.25" thick Pyrex.)  If this mirror had been thicker, these views would not have come until much later in the evening, and they might not have come at all if the seeing degraded during the night (which it did by 11:30pm). 
Bottom line, having the fastest-cooling mirror possible will maximize your quality observing time and allow you to take the fullest advantage of the observing opportunities that you are presented with.

Oh, and by the way, the 20" F/3.3 Super FX Starmaster features a 1.3"-thick quartz primary and a quartz secondary.  That is gonna be one fantastic telescope!

-Mike Lockwood, Lockwood Custom Optics, Jan 26, 2010


Changes in Latitude - Southward to FloridaShuttle launch on Feb 8, 2010

After John Pratte (of JPAstrocraft.com) and I made the two day trek to a friend's place near the Cape, we got up at 4:30am on Sunday morning with hopes of seeing a shuttle launch.  However, clouds in the area caused it to be postponed until 4:15am on Monday morning, the first day of the Winter Star Party.  If all went well, we'd see a shuttle launch and then see starry tropical skies later the same evening!

As a Colts fan (they are about the only team around here that I can get behind) the Super Bowl was not what I had hoped, but New Orleans has a hell of a team and they certainly earned their victory.  Oh well, we got up at 4am and found out that the launch was on, and that made up for it.  We put on our coats and set up the cameras.  I shot an HD video with my camera while trying to make sure that I watched the launch with my eyes rather than just looking at it on the LCD screen on the camera.  The shuttle rose up in the southeast and headed north before disappearing in the northeast.  The sound rattled the metal on my friend's building after traveling for about two minutes to get to my location.  That was the first launch I have seen, and might be my last - there are only four more planned.  It was the last planned night launch.  At right is a still photo that I shot during the video.

After coffee and a quick stop for some breakfast, we were headed south on I-95 by 6am.  The trip was uneventful, thankfully, though I had to take very evasive action to miss a broken down car in the lane next to the fast lane.  It was over a rise, so not visible until very close.  That would have been a bad day with four telescopes in the van, but thankfully my reflexes were good.  Whew.

We arrived, said hello to Al Nagler, Scott Ewart, etc., and set up.  My tent and scope were on the berm, with some shelter from the palm trees and other tents.

My location was right next to some very kind folks from the Raleigh Astronomy Club, who welcomed me to move my 20" F/3 and 14.5" F/2.55 into their area.  We had a nice view of the southern horizon down to the water.  Excellent.

We listened to Tippy's opening address, and I snapped some photos.  Here a 20" Starmaster basks in the tropical sun as Tippy speaks.  This is a moment that I look forward to every year, because it signals the beginning of a week of fun on an island, far away from my email and cold Illinois weather.

Tippy's opening address

I collimated both of my telescopes in under ten minutes using my old Kendrick laser and a Catseye Infinity XLK Autocollimator (dual pupil).  Careful use of the laser nails the secondary collimation, and the autocollimator fine-tunes the system.

As the sun was sinking low, we realized that we had not had lunch!  Maybe that was why we were really hungry!  Dinner at Mickey's food stand was just what we needed, and then we watched clouds come and go.

Observing notes

Al and I observed through some sucker holes in the clouds.  On this night and later ones we marveled at the views provided by the 20" F/3.  If clouds came, we could always test the performance of the 14.5" F/2.55 by aiming it at the red lights on the radio tower across US 1.  Al did the same with his 127mm refractor.  With the "drop-in" Paracorr in the 14.5", images were sharp across the field to the edge with the 13mm and 8mm Ethos.  The 17mm and 21mm weren't quite sharp at the edges of the field (probably mainly due to field curvature on such a short focal length), but were still immensely fun to use for wide-field view of star fields when the skies cooperated.

I think F/2.75 to F/2.8 is about the fastest Newtonian that I would recommend currently.  That sort of splits the difference between the F/3 telescope, which the Paracorr had no problems with, and F/2.55, where a few issues started to pop up.

I think a 30" F/2.8 would be fantastic, and should anyone want a 30" F/2.8 mirror and a matching flat, I'd be happy to supply them with it.

I got up early in the morning on Tuesday and found one of the clearest, most transparent skies that I had ever seen at WSP, with stars showing almost all the way down to the horizon in the south.  I woke up John, and then some other people drifted by and we uncovered the 20" F/3 and observed many of the best southern objects.  Eta Carinae was getting low and was in a tree, so we moved on to Omega Centauri, Centaurus A, M104, etc.  M51 was very nice directly overhead, but then the clouds returned, and I turned in.

The focuser-mounted Paracorr was performing superbly, and it was a significant improvement over the Type I.  Overall coma correction is improved, but field curvature is also much less obvious.  In other words, stars all across the field were in focus, rather than those at the edge or those at the center of the field.  This can have as significant of an effect on observing as coma correction.

A WSP view

Taken from the camp's road, here's a shot of Scorpius rising (Antares is to the upper left of the taller palm tree) over the souther ocean.  The southern cross is seen hugging the right side of the shorter palm tree, so you can see where it is in relation to Scorpius and the summer Milky Way.Some clouds are dark on the sky, indicating dark skies are to the south of the WSP site.  It is very dark overhead and to the south.  The telescopes and their covers were painted red by my flashlight.Winter Milky Way

To the right is a shot that really typifies the WSP experience early in the evening - the winter Milky Way rising up out of the ocean and towering overhead.  This shot captures the reflection of Canopus on the water all the way up to the belt of Orion at the top of the frame.  For us northerners, this is the only time we see this star.

The next few days kind of run together, but I generally observed early and took a nap until about 2-3am when I got up to observe the southern objects.  We had significant wind on all but one night, but that is normal.  The incredible seeing that occurs occasionally in the Keys did not materialize, though I did have Mars up to 500x in my 20" on one night before conditions degraded.  On two nights it was definitely chilly, with temperatures in the 50s and sometimes stiff breezes making us grab our winter coats!  That's OK, the gentle rattle of the palm fronts reminded us that there would be no frozen precipitation to ruin our fun at ~24 N latitude, and the light of the southern stars like Canopus helped keep us warm.

Other objects enjoyed were:
That is not a complete list, but it lists some of the highlights.  I don't generally have time to keep a log book, so memory must serve, and I am writing this as it is a couple of weeks after the star party.


Playing with my camera

Here's an image I have always wanted to capture - the southern sky from WSP at about 2am early Wednesday morning.  John Pratte is standing on the beach in front of an old boat.  It's low tide, and some of the limestone that the Keys sit on is visible above the water.  This night was not quite as transparent as the previous night, but we weren't complaining at all.  I used my red flashlight to "paint" John, the boat, and the beach.

Southern horizon from WSP

Recognize any constellations in that image?  You might notice the Southern Cross, Eta Carinae, and Omega Centauri.  Here's another image with these objects and some others labeled.  Later on, Alpha Centauri rises to the left of Beta Centauri.  Note the reflections of some of the brighter stars in the fairly calm water.

Southern objects labelled

At this point the part of the Milky Way that we don't see from most of the US lies flat on the southern horizon, forming a bridge between the winter Milky Way setting on the western horizon to the summer Milky Way rising in the southeast.  Both exposures are about 20-30 seconds unguided on a tripod.

Here some of the Raleigh club members enjoy views of Omega Centauri and Centaurus A through my 20" F/3 Starmaster.  Note the southern cross right above the secondary cage of the telescope, and Alpha and Beta Centauri above and left of the ship's light on the horizon.

Observing with the 20" F/3 Starmaster

On this night it was clear enough to see the bottom star in the cross.  On many more humid nights it does not make an appearance.

By day, I relaxed, wandered around, and talked to people.  I hung around the TeleVue booth saying hello to people and talking to Al and Scott.  Here Al waves hello, and Scott is in the white sweatshirt under the tent.

Al Nagler says hello

Al had fun showing passers by the constellation "Kermitus" by day through one of his refractors.  If you don't know where that is, you will have to ask Al yourself!

You may have already clicked on the link for the Paracorr Type 2 literature, but if not, you can click at the end of this paragraph to see a PDF version of the page that Al was handing out at his booth.  It provides some background about the new corrector:  Paracorr Type 2 info

Keys scenery

At WSP, when you're not talking about, looking at, considering purchasing, or just generally thinking about telescopes, you can enjoy other bits of tropical scenery, such as this scene, about 20 feet from my tent.  I could get used to this.

Below Al talks to the new owners of Starlight Instruments under the food tent.  I didn't get a photo of all of them together looking at the camera, but I'll try next time.  If they give me a sweatshirt, I'll even make sure it's a good photo!

Al talks to STarlight Instruments crew

Seriously, Starlight is now owned by the company that machines the parts for the focuser, headed by John Joseph.  They're coming up with lots of new product ideas, and with their skilled staff they can quickly build and test prototypes.  This is a well-equipped company with the expertise to machine parts for military and medical applications.  They care about quality, they make superb products, and they are located here in the USA, in Indiana.  It doesn't get much better than that.  Their focusers are on all of my fast telescopes and are my choice for critical focusing.

Back to the skies - the light pollution at WSP is mainly in the northwest and east.  Here's the view to the northwest, with Mars and the beehive (slightly left of center) hovering over the palm trees.  The light pollution appears brighter in the photo, and is from Big Pine Key.

Mars and beehive

To the east, the lights are from Marathon.  In the photo below, looking east, tents and telescopes are lit with red under the stars, with scattered clouds between them.  My 20" F/3 sits under its shiny cover at bottom center.

Eastern sky from WSP

A radio tower towers to the north, with a red strobe on top.  It seemed dimmer than on previous years (I think it actually used to be white), and I don't think it affects astrophotos.  In exposures over 30 seconds or so it is bright enough to "paint" stationary objects on the ground with a red glow.  This tower marks your tropical destination as you drive across the bridges to West Summerland Key.

Radio tower

Finally, I had to get a shot of the summer Milky Way blazing over the souther ocean as it rose in the very early morning.  This my favorite image from the whole trip.  I wish I could observe Sagittarius from this latitude without it being obscured by haze in the spring and summer.  Maybe someday.  The pilings from the old dock and the rock wall are visible in the water.  The green streak at left near the horizon is a navigational beacon that blurs during this ~4 minute shot on taken with my camera on my tracking platform (from Equatorial Platforms).

Summer Milky Way rises

The only attempt I made at polar alignment was to roughly aim at Polaris, including wedging part of a coconut under the front of the platform stand!

More palm treesConclusion, and back to the frozen north

Here's one more palm tree photo, as I sit here in Illinois with the wind howling outside it makes me feel just a little bit warmer.

Well, that mostly covers it.  To sum up, the Paracorr Type 2s both performed as expected.  It is an improvement on the Paracorr Type I, especially at focal ratios under F/4.  The focuser-mounted version greatly simplifies observing for me, and saves me valuable time under the skies.  It also ensures that I get the best possible images from every eyepiece without having to tune the Paracorr.

I got some observing in on every night, though for on a couple nights it was mainly early morning observing.  Conditions varied from very light winds to quite strong gusty winds.  There was one brief rain shower on Tuesday night, I believe, but that was it.  Not bad.

Friday dawned warm, sunny, and windy, and the forecast was for thunderstorms and high winds.  After not winning any door prizes, we broke camp and left in the early afternoon, stopping for lunch at the Keys Fisheries in Marathon, which proved to be my favorite restaurant in the area.  (Try a lobster reuben, or enjoy a great fish sandwish for a fair price.)

After driving through storms in Miami, we reached my uncle's place around 10pm.  My WSP 2010 was over, but the margaritas were only beginning!

Next year I hope to bring a new fast telescope, but I probably won't be pushing the envelope.  With luck it will be something a bit unique and a little larger than my 20" F/3.

I hope to have time to observe objects in the winter Milky Way below Canis Major.  This year (and last year) I was basically entertaining requests full-time to show people what the 20" F/3 could do.  I also need to track down some more of the faint wisps of the Vela supernova remnant that are best seen from this latitude, which I observed in 2008 (see my report here).

See you on the observing field at the Okie-Tex Star Party this fall, or maybe at a more local event before that.  In the meantime, I'll be getting my new shop running at full speed to get more quality, fast mirrors out into telescopes around the world.

Lastly, here's another link to the Paracorr Type 2 info.

Thanks to the WSP organizers, Al Nagler, Scott Ewart, John Joseph, Adam, and the rest of the Starlight crew for making it an even more enjoyable star party.

Clear, dark skies, warm weather, good friends, and good seeing.

  -Mike Lockwood, Lockwood Custom Optics

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