ESATTO 2″ & 3″ with BORGs

•July 30, 2021 • Leave a Comment

PrimaLuceLab’s ESATTOs are incorporated into my BORG systems first time. ESATTOs seem to be pleasingly much lighter than Feather Touch bodies, especially in 3″. This is the extra benefit I didn’t expect at all. Nice! These look my ultimate 55FLF3.6 and 107FL F3.9ED setups finally.

I’m an old school guy. Believe or not, I’ve never experienced the PC focusing. It’s the time to do now. I will try to learn over this weekend. Unfortunately the southern California looks in monsoon condition these days though.

RASA 11 Filter Drawer

•July 26, 2021 • Leave a Comment

1- RASA11 adapter has been prepared. The camera side is BORG M57, which allows to use BORG filter box – 7519.


  • The total light path is precisely calibrated for IDAS filters – No worry about the image distortion due to the inappropriate optical distance.
  • BORG filter drawer accommodates 52mm mounted filter – full frame-capable
  • Allows to select various IDAS 52mm mounted filters
  • Two camera adapters – M54 and M42 available

This allows RASA 11 users to fully enjoy RASA 11’s optical performance without loosing full frame capability.

RASA 8 and HyperStar filters drawers are currently available.

2- This is my on-going ASI2800MM camera project. I found out M49.8 spacer ring was the perfect size. fortunately not too large and not too small. T-spacer was too small.

Here is the result after adding a spacer.

As expected, the coma disappeared too. Fortunately now ready to use.

New Parts

•July 23, 2021 • 2 Comments

1- This is a bracket for Lunt’s handle-type solar finder, which should be used with an original Lunt Base. One of the original holders is replaced with this unit.

For new users, select the Lunt’s complete set and additionally choose Lunt 2 at

2- It is a component for BORG users to convert BORG M57 into M54. We used to have 14.2mm long. Now 5mm light path available.

9.2mm extra space gives BORG users the huge benefit. For example, I couldn’t achieve within BORG BF 60mm with this configuration since I’m using an extra camera rotator. I didn’t like losing the weight balance when a CFW and a camera are rotated together.

It should be perfect now.

Some Tests

•July 22, 2021 • Leave a Comment

I spent the time for various tests and for observing.

1- First, I tried to figure out how a newly acquired ASI2600MM’s sensor is set.

Too short with a filter while too long without.

The infinity mark should be at the line when a filter is in place. So a right image indicates the sensor distance is too short. That’s somehow what I expected. But how much? IDAS filter is 2.5mm thick. So the difference of the focus shift is 0.86mm by an extra glass. From above two results, each portion should be divided 60 : 40 at the infinity mark. 0.86 x 0.6 = 0.51mm. So my ASI2600MM sensor depth seems to be 0.5mm too short. It’s unfortunately huge production variation in my opinion. In fact, the image result shows the distortion at each corner even in APS-C sensor. If it is full frame, it must be big problem.

For telescopes, it’s easy to compensate for. But not for camera lenses.

At least it’s fortunate there seems not to be the tilt issue.

2- Scopetech’s achromat lenses are quite good quality. So I’m intending to complete as Mini BORG series. This is 50/300mm.

I will try as a guide scope soon.

IDAS 50.8mm

•July 20, 2021 • Leave a Comment

Now following filters are available at 50.8mm size for CFW application.

  • LPS-P3-50.8, LPS-D3-50.8 & ODW-50.8(as clear)
  • 2.5mm glass thickness
  • Fits QHY/ZWO/ATIK carousels
  • Useful to capture the better S/N image as L-channel under the light polluted sky
  • 47.0mm effective aperture

Also IDAS filter site is re-organized category by category.


•July 19, 2021 • Leave a Comment

I got a monochrome camera for IDAS single narrowband filters, which is scheduled next month. As always, first I set a filter drawer to check the sensor depth. It turns precisely 44.0mm when IDAS filter is in place. So for me this is most reliable and easiest test method to see longer or shorter. Let’s see tonight.

And until IDAS Ha will be coming up, I will use NBZ dual narrowband and Hoya R60 to learn the single narrowband imaging. R60 blocks below 600nm. So it conveniently creates Ha single passband.

Since R60 is not the interference type of filter, there is no the spectrum shift issue even if a filter is set in front of wide-angle lens. It should be fun for a while.

MORE BLUE 90mm rings securely hold a camera.

IDAS Ha Filters

•July 14, 2021 • Leave a Comment

We are scheduling to begin shipping Ha filters middle of next month. (OIII is expected in October).

IDAS Ha-6.8 will have 3 classifications – STD(Standard), HS(High Speed) and UHS(Ultra High Speed), and each class has two different glass thicknesses – 2.5mm & 3.0mm.

1- STD

This is for most of regular scopes.

**** CO : Central Obstruction

2- HS

This is ideal for the optics between F2.0 and F3.5 such as Takahashi Epsilon Series, RASA11 & Regular camera lenses

3- UHS

Highly optimized for the optics for F2.2 or faster such as RASA8 and HyperStar Series

All will be same prices – $299.00 in US.

These filters fit on 50.8mm QHY, ZWO and ATIK carousel.

I understand this classification might a bit confuse you. But this is IDAS’s realistic answer to you to maximize the emission signal transmission shown the above, depending on your optics.

In short,

  • STD : All-around-player. If you don’t have super high speed optics, this is the one.
  • HS : Epsilon- and camera lens- optimized
  • UHS : Ideal for RASAs and HyperStars

Fujifilm GFX w/BORG

•July 9, 2021 • Leave a Comment

1- Fujifilm USA talks about their cameras for astrophotography. One of them is their GFX and BORG 107FL.

One day, I wish to have GFX camera. GFX adapter is available from BORG.

2- In addition to Nikon Z mount adapter, now Canon RF mount adapter is available from BORG as well.

IDAS Single Narrowband Filters – #2

•July 8, 2021 • Leave a Comment

IDAS has carefully reviewed the design and the coating process from the scratch after announced a couple of weeks ago. Everything has been newly reset as follows;

  • 6.8nm FWHM
  • IDAS-proprietary flat-top design
  • F1.6-capable – high transmission in high speed optics
  • 3 classes available – F1.6 to F2.2, F2.0 to F3.5 & F3.5 to any
  • Fully blocks up to 1200nm
  • 50.8mm, 52mm mounted and drop-in available
  • 2.5mm and 3.0mm glass thickness. 2.5mm is par-focal with other IDAS filters and 3.0mm is same as other high-end brands available in the market
  • Introductory price in US : $299.00 (Regular price $349)
  • Ha will be available in August and OIII in October
  • Fully produced in Japan
  • Lint- and dust-free packing. No wrapped by a paper.
  • Individual inspection and measurement

This is one of 3 classes – the best for fastest optics (F1.6 to F2)

Comparison between Regular NBZ and NBZ UHS

•July 7, 2021 • Leave a Comment

After yesterday’s my announcement, I had some questions from the current NBZ users. So I made the comparison to clarify the things. The right is a regular NBZ while the left is a UHS.

  • First, take a look at each parallel light. UHS is originally more shifted at the longer wavelength side. This is the key and why UHS is more optimized for RASA and HyperStar. Faster optics, more blue shift. So UHS is designed to be perfect when the more blue shift occurs.
  • This is the comparison of each transmission rate.
  • From these data, what we can see are NBZ is more ideal for regular F2 optics or slower while NBZ UHS is more optimized for RASAF2 or faster. Especially UHS gives most benefit to HyperStar users.
  • But keep in mind, you lose signal more and more thru UHS at F4 or slower optics. So if you are looking for one piece solution even if you own such a high speed optics, a regular NBZ is highly recommended. Meanwhile if you seek for the best possible performance with RASAs and HyperStars, UHS is the best choice.

BTW, these blue shift data is the computer simulation. But the original curves (measured with the parallel light) are the ones actually measured from the real production unit. So I’m sure these should be quite close to realistic. I also make clear here IDAS inspected and measured piece by piece with one of Cary’s top-of-the-line spectrophotometers. This is why IDAS is able to provide highly reliable products to you. Please keep in your mind as well.

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