Partial Solar Eclipse – 10/23/14

•October 24, 2014 • Leave a Comment

Fortunately we successfully enjoyed the eclipse at front of my office this afternoon.

This looks the maximum eclipse at my location around 3:30pm.


And following is the sequence of the eclipse starting around 2:10pm to 4:40pm.


Some sailing friends and neighbors came and enjoy visually with Ha solarscope and binoculars. As the above picture shows, we could see the moon’s bumpy crater edge visually too. That was very interesting to see.

Finally, thanks the universe for showing us such a great event.

Sigma Art Series Lense

•October 22, 2014 • Leave a Comment

Hutech starts carrying Sigma lenses as one of authorized dealers and have setup the special lens kit with Canon 6DH as Hutech original. Sigma’s newly-designed Art Series lenses are superb optics which is best match the modified full frame camera like 6D and creates premium wide-field astro photography.


EOS6T + Sigma 35mm/F1.4 Art : $2,995.00


EOS6T + Sigma 50mm/F1.4 Art : $3,050.00

As you have the chance to check the individual lens price, you will see how special these set prices are.

Latest Terry Dickinson’s SkyNews magazine article on performance of 6DH and 50mm lens explains everything of the optical performance of Sigma Art Series lenses. For Canadian users, check back his review in latest issue.  Also you can see some of my test shots taken with 35mm one before.



I have fully same feeling as Terry’s. These are the excellent lenses I’ve ever used. I have some of other Sigma lenses. But Art Series are obviously different grade from others. If someone are looking for high quality super wide-field astrophotography, this is it!!


Huge Sun Spots

•October 21, 2014 • Leave a Comment

Currently there are huge sun spots. So I took a picture and played it around. According to the Eclipse Calculator, the maximum eclipse on the day after tomorrow will be something like this at my location.  Following is my expectation. My concern is now the sky condition. Forecast say the clouds will be increasing from tonight……….

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


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!!


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