90FL F3.6 & Gorgeous M33 by 125SD F3.9

•October 17, 2014 • 1 Comment

I have decided to go for it commercially.

b09036s[B09036] – 2590* – 7102* – 7801 – 7835* – 7704

* : parts of package #6290 

1.7kg / 365mm

b09036s[B09036FTF] – 2590 – 7102 – 7801 – FTF-BORG – FTF-M57 – 7704

1.9kg / 365mm

_MG_2041Full resolution [1.3MB]

A BORG designer suggested me to add a thinner spacer at front reducer assembly to minimize the field of the curvature. This a bit widens the separation of two reducer assemblies. Spacing looks working to me. So I decided to carry these packages. Also I encourage BORG users who own both 90FL and 7704 to try out. A large and thinner spacer at front reducer and, a smaller and thicker spacer at the rear. This should be mostly optimized for 90FL and 7704. This should be the fun scope.  I’m not a strong image stretching person. So I should be able to work with the illumination issue. I’m looking forward to using this system next weekend.

Long-time BORG user – Scott Denning sent me the wonderful M33 image taken with his 125SD F3.9 system.

M33.smallA combination of 50 ten-minute subs using L-R-G-B-Ha with Borg 125SD @ f3.9. Taken 9/25 and 9/26 at 10,500 feet elevation at a very dark site in Wyoming.

Partial Solar Eclipse

•October 15, 2014 • Leave a Comment

Have you checked back your solar gear and been ready to go for next week’s partial solar eclipse trip? I decided to go with IDAS-made broadband filter this time instead of Ha filter since personally I feel the broadband filter’s color more natural.  So I start testing with it. Unfortunately, no big sun spots today though. 89ED is 600mm focal length. I noticed there is still a plenty of room in Sony’s APS-C sized sensor.

spot   BORG 89ED + IDAS 82mm  UHB-RS filter + Sony NEX-6000H

The above image was taken with the modified Sony 6000. Even HEUIB-II filter was put in the optical train to reduce red portion, it looks still reddish finish to me.


IDAS solar page shows my Annual Eclipse images. That image strongly reminds me how much manual tracking correction was painful during the eclipse that time. Even I corrected time to time, the sun was still moving around. And eventually I gave up creating time lapse movie. That was my painful memory. Now Solar Guider allows me to completely focus on the visual observing. Thanks for Hinode SG!! Since I’m planning to create the time lapse movie, the guider is a kind of must-item for me.

And solar binocular with the eye-safe IDAS UHB-RS filter.

canonbino 52mm filters are set in front.

As described here several times, Canon binocular shows me very clean sun surface. It should be good transmission and minimal internal reflections. So it shows me very high image contrast. Also the image stabilizer function is charm. Very comfortable. This binocular is my best companion for solar events. And the premium solar filter creates high contrast image and my personally favorite’s yellowish solar surface too. I love this combination.

BORG 90FL & ED Super Reducer = 90FL F3.6

•October 10, 2014 • 1 Comment

I realized I didn’t test the combination of 90FL and 7704 – 0.65x super reducer. Although I was told it was not optimized, I wanted to see how it wasn’t anyway. This is the gorgeous 6-element optical system including one fluorite and one ED. BORG-proprietary quadruplet reducer system was originally designed in film era to fully cover medium format film (image circle 90mm diameter) and this 3rd generation system was more tweaked for digital sensors by incorporating ED element while downsizing. Here is the setup I tested last night. Very compact!! This is 90FL F3.6 optical system. The system configuration is 2590 – 7102 – 7801 – 7835 – 7704 – 5005 for Canon

b09036sThe result was much better than what I anticipated. Following is the full resolution taken with Canon 6DH. No cropped, as it is just after converting to JPEG from RAW. I only adjusted the background color.


Click for full resolution (1.1MB)

I’m not an optical expert. So I can’t judge perfectly. But what I thought from the image are

- Spherical aberration is looking very minimal as expected. The objective lens should be produced in textbook quality as designed.

- Surprisingly, no coma, and no noticeable distortion and astigmatism either.

- Only issues are curvature of field and illumination drop.

- And finally this result reminds me how this unique 0.65x quadruplet reducer is the premium quality. It’s not low cost. But I believe the performance justifies the cost in my opinion. So the collaboration of fluorite and ED create very clean star edge.

The illumination curve was expected since native focal ratio was F5.6. So as shown in a picture, unfortunately hot spot was obvious.

I don’t mention this is fully optimized for full frame sensor camera. But I don’t hesitate to describe it works with APS-C or smaller sensor.

While we are waiting for the dedicatedly-designed reducer for 90FL, I will ask BORG optical designer to study the possibility to optimize current 7704 for 90FL too. I hope they can do something with minimal modification and cost. Then, it will turn out one of the best astrograph refractors in the current market – 90mm F3.6 with fluorite and ED. I wonder the larger aperture front reducer element helps to make the illumination flatter.

Anyway I will try to shoot several targets at dark site with this system in coming new moon. I should have realized much earlier…….. I’m curious how I can work for hot spot by the flat. In any cases, I felt last night the optics was very fast – F3.6!!, which feels like F2.8 or faster in conventional telephoto lenses.

Red Moon & Deep Sky Objects

•October 9, 2014 • Leave a Comment

Here is some more lunar images from BORG users.

red moon 290FL + Fujifilm X-T1 by Matthew Schuster

m42This was taken during the totality with same configuration as the above by Matt

As far as I know, Fuji’s sensor assembly including optical filters is most capable of capturing Ha wavelength as stocked (or regular) cameras. As mentioned before, transmission rate at Ha is close to Canon 60Da. I love Fuji camera for regular daytime shots. If someone are looking for a camera for both daytime and astro without any special treatment such as the camera conversion, this should be the best option in my opinion. Fuji camera creates great color reproduction and fine details. It’s positively not digital-like crisp edge. But still resolved well. More film-taste natural finish as ex-film manufacturer. I’m expecting they will be commercially providing more realistic 3-layered sensor based on their film production know-how ASAP.

And the next from Dave Kodama – 1st BORG customer when Hutech started carrying BORG. He still owns several BORG systems including 100ED, 125ED F2.8(two?), 76ED and some Mini BORGs. This was taken with 100ED with 0.85x focal reducer and Nikon D600 at Anza (OCA club observing site).


And following M31 were recently taken by Fred Eiserling.

Galaxy M31-D700101EDII F4.3 + Nikon D700

Galaxy M31-6Dm101EDII F4.3 + Canon 6DH

All are very nice images!!

Total Lunar Eclipse

•October 8, 2014 • 1 Comment

Fortunately I could wake up before the eclipse begins. These were taken with BORG 90FL + Sony NEX-6.


SL & F1

•October 6, 2014 • Leave a Comment

This C57 1 SL looks 1st unit originally built up in 1937, recently restored, and commercially run at Yamaguchi now. Very classic!! This picture reminds me of SL’s smell.

2-1SLsTaken with Pocket BORG + Olympus OM-D by Tamura

This image proves Pocket BORG’s an excellent optical performance as achromat lens.

Following pictures are the practice round of Formula 1 at Suzuka last weekend.

image1as image1ds

image1cstBORG 36ED + Sony NEX6 by Takahiro Fukano at Suzuka Japan

BORG Sale and Classic Planes

•October 4, 2014 • Leave a Comment

Busy week has ended. First, I would like to thank you again for ordering during BORG special sale. This was 1st major event since Hutech started carrying BORG. Fortunately we had more business than originally anticipated. Still there are many back-orders. Although we had so many ordered from Europe and South Asia, all of stock have been gone even in Japan. So the customers and dealers who are still waiting for the shipment, please wait for the notification from us. It might take a month until we complete the remaining shipment.

Here is the rare classic plane pictures taken by T.K in England. They were taken at the air-show in England a couple of weeks ago. All of comments on each name and characteristics are just mentioned by him. I have completely no knowledge on classic planes.

No[1]. 1s

British De Havilland DH.88 – Winner plane at London-Melbourne race in 1934. Since it is very sensitive to the wind from side, this flight was done in just before sunset.

No[1]. 3s

German Fieseler Storch Fi156 – This plane can take off and land without runaway against the wind.

NO[1]. 2s

 British Bristol P2.B – almost 100 year old.

No[1]. 4s

British Bristol Boxkite (1910) replica

According to him, All were taken with BORG 60ED and Panasonic Lumix GX-7. This should be fun to watch!!


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