BORG 107FL F3.9ED Conversion Kit

•October 8, 2018 • Leave a Comment

This is the kit for current 107FL owners to convert into F3.9 system.

US$2,395.00 as introductory price


A picture shows 2 x 120mm prototype tubes. ED reducer is set inside a focuser.

The set basically includes everything except 107FL objective assembly.

1 x 240mm long CF tube

1 x ED Super Reducer

1 x FTF True 3″ – FTF3215B-A

1 x 7507

1 x 7352

1 x M57 cap

3 x adapters

1 x Padded carrying bag


BORG 107FL F3.9ED Commercial Package

•October 2, 2018 • 2 Comments

Finally the price of 107FL F3.9ED complete package has been set and now we are ready to pleasingly take orders from today. We are scheduling to start shipping worldwide end of this month. So it should be available at your local dealers almost same time as well. Here is the price in USA.

Regular price : US$4,495.00

Introductory price : US$3,995.00 (until December 31st 2018)


Commercial unit has a 240mm CF tube instead of 2 x 120mm ones


M57 camera rotator as standard


  • 107mm aperture fluorite
  • 6-element advanced petzval optical system, including one fluorite and one ED elements
  • Covers up to 55mm diagonal sensor
  • Japanese-made high quality carbon fiber tube
  • Feather Touch True 3″ focuser (FTF3215B-A) – motor upgrade ready
  • M57 camera rotator
  • 4.3kg / 445mm long.
  • Padded carrying bag included as standard
  • Pentax 645D, Fujifilm GFX & PhaseOne mount adapters and large camera rotator will be available later
  • 21″-long carrying bag allows to take a whole unit into the aircraft cabin as a carry-on baggage, without disassembling the configuration. (Most US airlines restrict up to 22″ long)
  • Fits 115mm ID mounting rings (optional)



First, I’d like to thank to the people who have been patiently waiting for this announcement. This is my first BORG telescope I was deeply involved myself, as a decision maker, mainly in mechanical sections from the early stage of development time. So you might feel something different from the classic BORG style.

I’m sure this should be a very unique 4″-plus airline transportable telescope, which is the perfect for the overseas expedition. Personally I’m wishing to take this astrograph and Fuji GFX 50R camera to the southern hemisphere some day. That is my current dream. As shown above, a carrying bag is wide enough for a motor unit or guide scope setup.

The price of F3.9 conversion kit for existing 107FL users will be announced shortly. Also I will write up the recommended mounting rings. I’m sure this ring size is widely available at most of astro shops, including Hutech. So far, no BORG-made rings are scheduled yet.

BORG and I have made the dream machine for you at present our maximum efforts and “at the affordable price” (I hope you agree….). I really wish you will enjoy fluorite-created high color contrast and transparent images at F3.9 speed anywhere on our globe.

Gorgeous BORG Solar Setup

•September 27, 2018 • Leave a Comment

Wow, so many scopes and equipment! on one mount. This is really serious solar setup which allows for 3 different solar viewing at same time, prepared by Steven Chun in Hawaii for his October public outreach solar event. BTW, these are Hawaiian tasteful pictures!

Setup details described by Steven are

Well, I finally was able to assemble an impressive Borg Solar setup featuring a 50 Min, 71FL and 107FL.  Using the 52mm IDAS filter on the 50 Mini, a 50mm H-Alpha Lunt filter on the 71FL and Lunt’s 1.25″ Herschel Wedge on the 107FL.  All mounted on ADM side by side setup with the 71 on a Mini-Max Guider saddle on a Vixen Sphinx SXW guided by the Hinode Solar Guider.  The 50 Mini has a Revolution Imager on it.

Tested the entire setup on Sunday with the guider keeping the sun centered for 30 minutes (the duration of the test).

Steven, thanks for sharing and very nice preparation. I’m sure many viewers must enjoy 3 solar faces at once during the outreach event next month. Please update this after the event. Thanks again, and enjoy solar viewing.


Pre-testing Loaner Units of IDAS LPS Filters & Fujifilm GFX50R & 100

•September 25, 2018 • Leave a Comment

IDAS LPS filters are carefully considered and studied for the spectrum of each artificial light source. So each filter is well designed based on kinds of light pollution emissions while considering the type of camera. This is why many high-end astronomers are using LPS filters. But one of common questions is, “Which is the best LPS for my sky?”. It’s hard to tell for me because I’m not under your sky. Also various light sources must be mixed too. Even for my backyard, I’m not sure exactly what kind of artificial light over my house. Under my testing, LPS-P2 looks the best result as broadband spectrum for OCS camera.

I saw there were some comparison tests at various locations. But unfortunately the sky is not same as my backyard or different users’s sky either. So things seem to be more complicated. Good indication to study though.


D1-48 wasn’t available when a picture was taken.

So I now decided to prepare several loaner sets for pre-testing purpose by customers. This allows each customer to actually field-test under the real sky and see each result.

  1. A set includes LPS-P2, LPS-D1 and LPS-D2.
  2. All 48mm sizes
  3. Only in US so far
  4. No obligation to purchase. But I’m glad to finally consider one of LPS filters anyway.
  5. Test without the moonlight
  6. For more details, please contact me.

This loaner program has been set from today. If this program will be going well in US without any trouble, I’d like to expand worldwide.

If someone will develop a portable low-cost measurement device which is able to read each artificial light source wavelength, I want to buy it. It’s not for the sky glow strength meter.

As scheduled, Fujifilm made two big announcements in Japan. Both are new medium format cameras  – GFX 50R and GFX 100. 50R is the same sensor as current 50S. But the range-finder type’s low-cost version (US$4500). Thanks, Fuji. I’m not ready to buy quickly. But I want to seriously consider it as my dream camera to be used with BORG 107FL F3.9ED. They say GFX 50R will be available this November.

 GFX 50R announcement from Fujifilm USA 

And same time they also announced a further bigger brother – 100MP camera they are currently developing. A Following looks a mock-up(probably) unit Fuji showcased at the press release in Japan.


The sensor seems to be SONY IMX461 BSI sensor as I posted last November.

Most likely current Fuji’s 50R/S are IMX161 sensor.

Fujifilm USA announcement on GFX 100

This was pasted from Fuji’s page. I thought this clearly described us how large 55mm diagonal sensor is.


The larger and larger sensor is, more and more challenging optical designer is.

BORG already made the prototype of GFX adapter. It will be commercially available sometime soon. As soon as 50R will be available, I will try to test 50R and see how much Ha transmission it has. If it will have quite similarity to current X-mount camera(50-60%?), 50R should be potential of super wide-field astro-capable camera too.

Panasonic announced their two full frame cameras too. I was also told about the strategic L-mount alliance of Leica, Panasonic and Sigma for new Panasonic full frame camera.  It was really big day in the photographic industry today.

I’m so excited about those news as a camera fan.



New BORG 55FL F3.6 & JAXA Hayabusa 2 Project

•September 24, 2018 • Leave a Comment

BORG 55FL is a bit behind the original schedule. BORG is still waiting for the delivery of fluorite element from Canon. To all of customers who are waiting for 55FL, I’m really sorry to have kept you waiting. I will specify the schedule as soon as it will be delivered from Canon. Thanks for your patience.

BTW, I got final prototype for the objective adapters – redesigning the internal shape and size, and colorizing the finish outside.

navy blue

Deep Blue Sea Matte

sunset orange

Sunset Orange Glossy

Obviously matte finish is the best match with main tubes. So both colors will be made as matte. Also two focusers will be available – Feather Touch M57 or M77.6 rack & pinion. So select among two colors and two focusers.

Finally Hayabusa 2’s two rovers have landed and started hopping on the Ryugu – a asteroid.


Click to go to JAXA site

Great works, JAXA project staff. Congratulations!! Now I wonder how much samples of the Ryugu they can bring back to our earth eventually. I’m looking forward to that.


IDAS Planetary Filters

•September 22, 2018 • Leave a Comment

IDAS BE410 filter tester – Johnson Lo in Hong Kong sent us his 1st image taken through IDAS filter. Yes, a filter looks making the image contrast higher as expected.

2018-09-13 Mars_LRGBvsLRGUV

And his initial impression on the filter is

Comparing to a normal B channel, the filter does show more contrast in the North cap
(bottom). I am satisfied with the result because it does make the Mars looks special when
combining LRG+BE410 (right) vs just LRGB (left).
However, the aperture of my 8″ SCT is not big enough to define any features on the North
cap and the exposure time was a bit too long against average seeing last night. Perhaps a
11″+ telescope will put this filter into good use.
Only one thing to notice is that the filter is too thick to fit in my electric filter wheel so I
had to screw it onto my camera manually. My filter wheel model is QHYCFW2-S by

Johnson, thanks for your imaging.


Now new prices for IDAS planetary filters have been set as follows;

BE410 (1.25″) : $159.00

VW-1 (1.25″) : $159.00

UV372-80 (1.25″) : $159.00

Original prices used to be upper $200.00 Don’t miss this special opportunity
to get premium quality filter at this price.
Unfortunately BPF has been sold out. I had a lot of excellent feedback though.

Losmandy + SS-one KODO

•September 20, 2018 • Leave a Comment

I don’t remember when I took my G11 mount out to the field last time. I’m sure more than 15 years ago. This was the one sold under Celestron name. Very old!

The key concept for SS-one/Losmandy system is to allow to use KODO with Losmany G11 and GM8 without modifying. So original geared motors and connectors are used as they are. Because of that, no fast slewing achieved unfortunately. But I believe it should be still good value to allow for the dithered imaging without PC.

The test was successful as expected. We will prepare for a special adapter box for the easy and reliable connection. The hardest part is to split DB15 into two of RJ connectors and a power cable. KODO works with GM8 too by changing gear ratio.

I made a hole on an original polar cap to attach SS-one polar camera. But PoleMaster adapter for Losmandy provided by QHY allows to set SS-one camera like PoleMaster.

Losmandy (strictly speaking Kenko-made) polar scope reticle is very good design and lets achieve the accurate polar alignment. But sometime very hard to see 3rd star under the bright field. A bit painful. Also we don’t have to worry about the mechanical mis-alignment of polar scope itself.

After using Losmandy mount again, I realized this was mechanically very good-made. Alt-az base’s gears are very fine pitch, which allows for precise polar alignment easily. Also worm gears look very good quality too. Great craftsmanship work, Scott! I applause you to continue to provide high quality mounts long time while maintaining the quality in USA all the time.  The great American manufacturer!


%d bloggers like this: