IDAS NGS1 with BORG 107FL F3.9

•September 13, 2019 • Leave a Comment

A close friend – Jim starts tuning his various new rigs. This is one of his starts.

Autosave Image

BORG 107FL F3.9ED + ASI 094 + IDAS NGS1-52

IDAS NGS1 is my favorite broadband filter these days, which creates almost perfect color balance with modified Canon 6D while blocking light pollution.

See my tests.

So I was curious how it worked with astro OSC camera. I got one of RAW shots from him to verify.

Autosave Image

This is the uncooked native color output from the Bayer sensor. Not as perfect as by a modified DSLR. Strictly speaking, DSLR’s RAW is not real RAW at color balance standpoint. Its output is already cooked with the image processor. So not fair comparison though. Anyway, still easy to tweak with software.

If the sky is not overwhelmed by white-LED, I think LPS-P2 should be still good for OSC camera while LPS-D1 for modified DSLR. Good thing is IDAS provides a lot of choices depending on  a type of camera and sky condition.





IDAS NB2/3 M48 & Veil by BORG 90FL

•September 11, 2019 • Leave a Comment

1- Finally IDAS M48-mounted NB2 and NB3 came in stock today. So I set them into my 1st CFW for ASI 183MC, a color camera.

This allows to shoot OIII+Ha, OIII+SII and broadband color(including galaxies) while rotating each filter. But keep in mind, I’ve never had this kind of experiences. So I still feel, hopefully…..


From top : NB2-48, NB3-48 and ODW(clear)-48. NGS1 is installed into the scope



Anyway, I will start practicing at my backyard first. This setup should give us the new world for color cameras.

For full frame sensors, I recommend M52 or unmounted 49mm(by removing a frame). It is the time to enjoy a color camera along with a filter wheel.

We start shipping M48 NB2 and NB3 today.

2- BORG serious astronomer in France – Olivier Calvetti sent me an another great image.


BORG 90FL F3.9ED + ASI 094

His comment:

My best Cygnus Veil so far, 2 hours with the 90FL and the ASI094 (cropped). I can tell now this is my favorite set-up (and I got Takahashi and Astro-physics refractors).



BORG Astrograph ESATTO Focuser Version & Tolga Astro

•September 6, 2019 • Leave a Comment

According to Tolga Astro, this 90FL F3.9ED was prepared for the shipment to the customer.

Looks very nice!! Great color matching!

Several more 107FL and 55FL are on the way to them.

I’m not sure ESATTO 2″ focuser is available now. If it is, 55FL F3.6 will be available with ESATTO version thru Tolga Astro as well as FTF version. Please check the availability with Tolga Astro in US or PLL in Europe.

Tolga, an owner of the company is a relatively new partner to me. But he is well experienced and knowledgeable on BORG system already, and they are a stock dealer too. So whenever you are ready,  visit to Tolga Astro for the immediate shipment to you.





Filter’s Spectrum Shift – 2

•September 5, 2019 • Leave a Comment

As mentioned several times, please refer my last write-up. If you already read, just skip reading.

This time I simulated myself by un-sophisticated way. This is BORG 55FL F3.6 light cone data made by BORG optical designer. So this is real.


I rotated with Photoshop to figure out the angle, by try and error way. It was approx. 12-degree at the center of the image field. The corner of full frame should be bigger number, sounds like 14-degree or so? it should be something like that.

Then, check back this simulation data.

angle-heuib-ii-f1 15-degree means 10nm-shift.

Let’s say for example, a certain filter’s Ha line is set at the middle of 10nm bandpass, unlike IDAS.

This means this filter allows to shift only 5nm. Be careful , not 10nm because the emission line is set at the middle of its bandpass. If we install such a filter between above BORG 55FL F3.6 and full frame camera, we lose Ha signal a lot at the corner, even at the center. If the filter doesn’t attenuate the signal much, actual bandpass might be possibly wider than published.

Also 10nm means usually FWHM. So at the top, actual bandpass is less than that, generally half? So the spectrum shift allowance is 2.5nm only or so. And ice pick shape at the top makes the transmission dramatically lower by the shift.

If the cut-off line is completely straight up, it’s not the case though. But I wonder if it is technically possible in the real production.

Anyway, this is why all IDAS’s emission lines are intentionally set at the left edge of the flat-top peak. Generally IDAS’s FWHM has 20nm. It means the flap-top peak’s bandpass is around 10nm. This indicates the filter allows to shift until 15-degree.

I think this light cone angle is not determined only by F-ratio. Rear lens’s size does matter too. So it’s more complex.

If you wish to study your scopes more, contact the telescope manufacturers. They should have light cone simulations along with the reducer or something else.

This is the key how we maximizes the weak signal reception through a certain filter. And very important thing to make your imaging more efficient and more successful.

The following is the data for 107FL F3.9ED(basically 90FL F3.9ED is same too). Red one shows the edge of 645 sensor (27.5mm radius). From this data, you can figure out the approx. degree of the light cone angle based on the sensor size.  As you can see, the light cone toward the edge of the sensor is more angled.


I hope these data will be useful for your filter selection based on the scope you own.

Smarter purchase, more pleasing result.

Masuyama Eyepieces

•September 4, 2019 • Leave a Comment

One of common questions on Masuyama eyepieces was about each field stop.


Current Masuyama Lineup. Legendary orange lines.

They were not publicized yet. This is the summary.


Canon RP & IC 1396 by BORG 90FL

•September 3, 2019 • Leave a Comment

This should be good news for Canon users in Europe.

Telescope Service in Germany starts offering a modified Canon RP along with IDAS body-mounted filter. Their conversion process is exactly same as Hutech’s. So once one of IDAS filters is in place, its flange back distance turns exactly same as Canon original – 20.00mm. No worry about the image distortion due to the incorrect optical distance.


The availability from TS should be the tremendous cost saving to European users. Please contact TS for more details if someone are interested in a modified RP as well as IDAS filter system.

This is my noise test between 6D and RP. RP users’ images justify my test.

Also IDAS drop-in filters should be in stock at TS shortly.

IDAS drop-in filter thickness is exactly same as Canon original. So still no light path issue either.

Olivier in France sent an another shot taken with BORG 90FL F3.9ED+ASI071.


A lot of dark sections are shown up at high contrast level. I guess the huge number of pixels and sharp optics resolves fine details.

Another great shot!, Olivier.

My foot injury halt any astro activities in 2 months. I hope I can resume from end of this month. I missed a lot of clear sky opportunities in the summer. I’m eager to be under the dark sky soon.




•September 2, 2019 • Leave a Comment

One of 1st 90FL astrograph users – Olivier Calvetti in France sent me 1st light taken with his 90FL F3.9ED with ASI 094 camera.  Transparent and beautiful finish!!

M45_90fl_094His Comment :

Hi, Here is the last image from the first night with the 90/3.9, camera was a ZWO ASI094mc-pro at -15c. Only 1hour and 15 minutes integration. I must say I’m very impressed with this refractor.

Olivier, thanks again for sharing with us. Enjoy more imaging with your new scope.

Star edge is very clean as expected. This indicates how the optics work with ASI094’s small pixels. Glad to know the scope performs as designed along with the fluorite and ED combination.

BTW, following 90FL F3.9 ESATTO focuser set is available in US at TolgaAstro.


PrimaLuceLab’s ESATTO 3″ robotic microfocuser is pre-installed as standard. They should have this set in stock now. Please contact TolgaAstro if someone are interested in this system.


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