• Jerry HubbellJerry Hubbell

- Jerry Hubbell -

Lake of the Woods Observatory I24 Locust Grove, VA


"For Professional Level Scientific Imaging for the Amateur, Explore Scientific Equipment Can't Be Beat!"


"Field testing gives us the edge we are looking for... As Explore Scientific's Field Testing Team Leader, I work with select individuals to make sure that our products are rigorously and continuously tested. We feel it is the best way to get long-term, detailed feedback on how our optics and mechanics perform under a wide range of conditions. We use the suggestions made by our field testers and from comments made by all of our customers in our program of continuous improvement of our products."
"The team consists of enthusiasts who have volunteered their time and expertise, and in the case of Jerry Hubbell, have also volunteered to share their results and comments through our website. In fact, Jerry edits and maintains this page, and his comments are his own, so come back to check for new images and updates."
If you are interested in volunteering for one of our selection rounds, please give me a call at (888) 599-7597 at extension 309
."
- Russ Tanton


"The Explore Scientific Telescope Drive Master (TDM) is an important tool that helps me focus on imaging rather than the equipment..."

NEO Minor Planet (68348) 2001 LO7. A 10x180 second stack, unguided using the Telescope Drive Master

A close-up of NEO Minor Planet (68348) 2001 LO7. A 10x180 second stack unguided using my Carbon Fiber ED127 Air-Spaced Triplet and the Telescope Drive Master.
Click here for the full size image. The astrometry residuals for this image are +/- 0.07 arcseconds!

"When I first started out in astrophotography, I learned all the ins and outs of auto-guiding, but I was spending a lot of time doing setup and management of my guiding equipment, and not focusing on my imaging. This was eating into my time and productivity, and I was thinking there had to be a better way!


M13 The Great Hercules Cluster. A 10x90 second stack unguided using the Telescope Drive Master

A close-up of M13 The Great Hercules Cluster. A 10x90 second stack unguided using the Carbon Fiber ED127 Air-Spaced Triplet and the Telescope Drive Master.
Click here for the full size image.

When you are trying to do minor planet astrometry, and you have a portable observatory, you really need to maximize your efficiency in setting up and tearing down your observatory.
Minimizing the amount of equipment, and only using what is necessary for the session is absolutely critical in getting the most high quality data from your imaging system.


Tassilo Bohm and Jerry Hubbell at the Explore Scientific booth at NEAF 2011 in front of the Explore Scientific Carbon Fiber ED152 APO Air-Spaced Triplet.

Tassilo Bohm and Jerry Hubbell at the Explore Scientific booth at NEAF 2011 in front of the Explore Scientific Carbon Fiber ED152 APO Air-Spaced Triplet.


In my opinion, the TDM is the perfect solution for portable observatories. Because it allows you to setup quickly and start imaging right away, you don't worry about your mounts tracking ability, or it's performance... It just works.
On only the fourth session using the TDM I was able to make and report 18 observations of 5 minor planets to the Minor Planet Center. This basically matched what I was able to do in all of 2010.


The TDM performance measured on the EQ6 Pro mount

The TDM performance measured on the EQ6 Pro mount.
Click image for full size view.

Being an engineer at heart, I wanted to really test my TDM in order to fully understand its operation and performance. The whole TDM team, Scott, Attila, Istvan, and Tassilo were there when I needed them to help me install and operate my TDM system. Once I recieved my system, the installation went flawlessly, and I was up and running within a couple of days.
I have been working with Attilla Madai of MDA-Telescoop.com to help make the operation of the TDM as good as it can be. I have written a paper that describes my experience using the TDM. I have been able to operate my EQ6 Pro mount successfully with the TDM, demonstrating a consistent Tracking Error of +/- 0.7 arcseconds.

Scott Roberts at the Explore Scientific booth at NEAF 2012

Scott Roberts at the Explore Scientific booth at NEAF 2012 in front of Jerry's astronomical imaging system including the Carbon Fiber ED127 Air-Spaced Triplet and the Telescope Drive Master.


"Why would you make an investment to improve the drive of your mount?
I remember learning the techniques of making an astrophotograph through long exposures on film. It was a tedious process of learning how to properly guide on a star. Most of my exposures were 30 minutes or longer, and on the rare occasion that I was able to keep my guide star perfectly centered in the crosshairs of my high-power eyepiece to get an astrophoto that I was willing to show to others, I felt that I had conquered Mt. Everest!
The problem was that my equatorial mount had significant periodic error, which caused me to chase the movement of the star in the crosshair, by making rapid button presses to the drive corrector hand-controller. You had to learn the rhythm of the error in order to anticipate which button that you were going to press next. Over the years, I improved but I never fully mastered manual guiding, so my good astrophotos were few and far between.
Later when astronomical CCD cameras became available the exposure times became much shorter, so other problems such as getting a proper focus, proper centering of the object in the field of view, and proper exposure became much easier to manage because you could see the results right away. But, the problem of drive errors still plagued astrophotographers. The solution was to invest in a better mount and perhaps an autoguider. Software was also developed to help improve the periodic error control (PEC), but training the drive with software to get the best results required a bit of skill and lot of patience. Even with the advance of PEC software, it is still not easy to make top-quality astrophotos with most of the popular equatorial mounts available today.
But if you improve the tracking accuracy of the mount by eliminating most of the large-scale drive errors, then the astrophotographer can focus their energy towards improving the skills of aquiring the images and image processing, instead of fighting drive errors in their mount. This is what the Telescope Drive Master can do.
Frankly, I think that every equatorial mount should have one attached to it, because it is one of the easiest and most effective ways to improve your astrophotography. I just wished that I had one for my telescope twenty years ago, but I will say that it has been worth the wait! "

- Scott Roberts



I was also pleased to be able to share my initial testing of the TDM with Dennis DiCicco of Sky and Telescope Magazine. I was rewarded with a mention in his article on the Telesope Drive Master in the October 2011 issue."

Test image in preparation for the Transit of Venus taken with the Carbon Fiber ED127 APO Air-Spaced Triplet.

Test image in preparation for the Transit of Venus taken with the Carbon Fiber ED127 APO Air-Spaced Triplet 03 June 2012. Click image for full size view.



Jerry Hubbell and the Explore Scientific Carbon Fiber ED127 APO Air-Spaced Triplet


Lunar Mountain Mons Rumker taken with the Carbon Fiber ED127 APO Air-Spaced Triplet

Lunar Mountain Mons Rumker taken with the Carbon Fiber ED127 APO Air-Spaced Triplet 07 January 2012. Click image for full size view

"In April at NEAF 2011, I told Scott that I was interested in maybe upgrading my Synta 120 mm ED refractor to the Explore Scientific Carbon Fiber ED127 APO Air-Spaced Triplet.


I was always wondering if I was really getting the best images for my minor planet work, and also my high-resolution lunar imaging work. Scott offered me an unbeleiveable price on the scope, and I couldn't turn it down. The results speak for themselves! Here is an excerpt from an email I sent to Scott about my first light experience with the scope at a public star party our astronomy club was having:


Lunar Crater Gassendi taken with the Carbon Fiber ED127 APO Air-Spaced Triplet.

Lunar Crater Gassendi taken with the Carbon Fiber ED127 APO Air-Spaced Triplet 07 January 2012. Click image for full size view.

...After doing an alignment on my EQ6, I pointed the 127 ED to Saturn, and with the ES 25mm eyepiece, it looked very crisp, and bright.


Lunar Crater Clavius taken with the Carbon Fiber ED127 APO Air-Spaced Triplet.

Lunar Crater Clavius taken with the Carbon Fiber ED127 APO Air-Spaced Triplet 07 January 2012. Click image for full size view.

I found myself saying wow a couple of times to myself as I brought the image to best focus.
The focuser was very smooth and precise. I had no problem snapping the image to best focus. I bumped up the power with a 1987 vintage Televue 7mm Nagler, and the view was awesome! Very crisp and still very bright at 136x.


The planet Jupiter taken with the Carbon Fiber ED127 APO Air-Spaced Triplet

The planet Jupiter taken with the Carbon Fiber ED127 APO Air-Spaced Triplet 24 November 2011. Click image for full size view.

The visitors were very impressed with the image, and I was greeted with Oohs, Ahhs, and Wows, from several observers. I was very impressed by how even on bright Saturn, there was absolutely no false color fringes, the stars were tack sharp even with the 7mm out to the edge of the field. I bumped up the power with a 2" 2x barlow to 272x and even though there was some dimming, Saturn was still pretty bright. Unfortunately I don't have the highest quality barlow, but the view was still the best I have seen out of any scope I have owned...

- May 1, 2011


Mountains near the crater Cabeus close to the lunar south pole taken with the Carbon Fiber ED127 APO Air-Spaced Triplet.

Mountains near the crater Cabeus close to the lunar south pole taken with the Carbon Fiber ED127 APO Air-Spaced Triplet 07 January 2012. Click image for full size view.

My high-resolution lunar imaging was kicked into high gear after I recieved my scope. I have recently purchased a Televue 4x Powermate, and using the Explore Scientific Carbon Fiber ED127 APO Triplet at f/30 (3810mm FL) really has let me get the maximum performance out of the system. You can see more of my images here.

I want to thank Scott and the whole Explore Scientific team for providing the cost-effective equipment and tools necessary for me to be able to do the Minor Planet and High Resolution Lunar Imaging that I only dreamt about when I was a teenager. I couldn't do it without them!

- Jerry


What's New:


Scientific Astrophotography Book

Jerry's Book: Scientific Astrophotography Available

Click Image for full-size view.

Springer Books has released Jerry's new Book "Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data". This book will be available in the Explore Scientific Shop.

New version 1.06b of the TDM TE Recorder!

See below for the latest version of the TDM TE Recorder for your Telescope Drive Master. This version includes a new nightview display and other improvements. Go to the bottom of the page for download!

NGC 6960 Veil Nebula.

NGC 6960 Veil Nebula.
Click image for full size view.


ES ED127 Collimation

ES ED127 Collimation.
Click image for full size view.


 

Petavius and Humboldt Lunar Shadow ChangesPetavius and Humboldt Lunar Shadow Changes. Click image for full size view.


The TDM performance measured on the EQ6 Pro mount

Minor Planet (612) Veronika. This is a 31 x 60 second stack of unguided exposures using the Telescope Drive Master. See the trail of Veronika in the center of the frame. Time of exposure:2012-Jul-03 09:04:41 Plate Center:UT RA:23h 15m 29s DEC +18deg 04' 09"
Click image for full size view.

Hubbell's TDM Software


Jerry Hubbell has independently developed an improved version of the TDM Monitor software called TDM TE Recorder. This program records and displays the Tracking Error (TE) as provided by the TDM and also records and displays the Right Ascension (RA) of your mount by connecting to your mount's ASCOM driver. He has made this software freely available to Explore Scientific customers for their use.


This latest version includes some improvements including the ability to save and load parameter settings. The biggest improvement is that the new version includes a PID controller using the ASCOM pulseguide API. The controller uses the TDM tracking error (TE) signal to correct your mount's TE via the ASCOM standard pulseguide command. This allows you to dedicate your mount's autoguiding (ST4) port to your guide camera to correct the long-term drift typically associated with polar mis-alignment.

Let me know if you have any suggestions or improvements.

TDM TE Recorder HMI


- Hubbell TDM TE Recorder User Guide ver. 1.0.2
- Hubbell TDM TE Recorder Software Installation ver. 1.0.6b (Windows zip file)

This software is a beta test version, please forward all questions to Jerry Hubbell via email.