Baader Planetarium have a slogan in their company: “Finding the way”. This slogan got created by the company founder Claus Baader in 1966, when the Baader Planetarium-Orrery was presented to the world and they have always tried to find ways for our technical solutions – and for their domes – to stand the test of time.
Today Baader Planetarium have a similar situation when it comes to their new imaging filters. They have worked hard for two years and the “feeling” here is just like way back then:
WE FOUND THE WAY
… to finally and cost-effectively tackle the problem of filters producing annoying halos when put in close proximity of correcting lenses in conjunction with latest current generation CMOS-chips.
Baader Planetarium are now proud to introduce their four new filter families:
- 6.5 nm Narrowband Filters, CMOS-optimized – for f/10 to f/3.5
- 6.5 nm f/2 Highspeed Filters, CMOS-optimized – for f/3.4 to f/1.8
- 3.5 / 4 nm Ultra-Narrowband Filters, CMOS-optimized – for f/10 to f/3.5
- 3.5 / 4 nm f/2 Ultra-Highspeed Filters, CMOS-optimized – for f/3.4 to f/1.8
In total there are 84 new filters that are designated as CMOS-optimized, with the same high quality and engineering you expect from the Baader family of products.
This “halo” problem had almost got them “over the edge”. For more than a decade, during the reign of CCD-cameras, our Baader Narrowband-filters had served somewhat as an industry-standard in astro-filter technology. And “all of a sudden”, with always newer and revolutionary CMOS-chips hitting the market, people started to complain about halos, whenever a coma-corrector, field-flattener or reducer-corrector are placed in close vincinity to one of our filters. Baader studied the problem far and wide and for some time took some soothing from the fact that amateur forums around the world had similar reports for their much higher priced competitors. However, some solution to this issue just had to be found – but without the filter prices skyrocketing as was the case everywhere. As a consequence Baader looked into the latest advanced coating technologies and how to use it in ways to address this most severe problem, since nowadays almost any telescope are often used with such auxillary-optics closely in front of the chip-plane.
Eventually, with significant investment in R&D, we ran from one prototype run into the next for almost all of the years from 2019 until now (middle of 2021). Countless nights were spent under the stars to evaluate so many different coating systems on all four new filter families, consisting alltogether 84 new filters. However, Baader are absolutely convinced that our new Reflex-Blocker™ coating systems are addressing this severe problem in a very satisfying fashion, and with just a moderate increase in price.
This new generation of Baader CMOS-filters features:
- Increased contrast
- Ever more narrow passbands
- Reflex-Blocker™ coatings, for largest ever freedom from halos, even under most adverse conditions concerning aux-optics
- FWHM on each filter category carefully designed to allow for 1:1:1 exposures, matched for typical CMOS quantum efficiency and s/n ratio
- Identical filter thickness to existing standards, with utmost care for parfocality
- Blackened edges all around, with filter-lead-side-indicator in the form of a black frontside outer rim, to additionally eliminate any reflection due to light falling onto the edge of a filter
- Each filter coated individually, with sealed coating edge (NOT cut out of a larger plate with coatings left exposed, read more)
- Life-Coat™: evermore hard coatings to enable a non-aging coating for life – even in a most adverse environment
DON´T BE MISLED:These all new CMOS-optimised filters work magnificently with all existing digital camera technologies, be it CMOS or CCD. However – an owner of CCD-camera-technology will still find our previous, extremely affordable, narrowband filter technology to be fully apt for excellent imaging. But: “the Better always is enemy to the Good”. Baader Planetarium are most confident that anyone using latest CMOS-technology will see the improvement right away – for his/her lifetime! This new CMOS-optimized filter generation is meant to stay and become the new standard in the amateur-word of imagers.
In addition to these new imaging filters, similarly designed Photometric Filters (featuring identical standard thickness alike all our filters as well as all standard sizes) are under preparation for the science world in the form of SLOAN/SDSS and modern BVR (Bessel-conform) filters – likewise using our Reflex-Blocker coating technology, to be fully suitable for 24/7 scientific operation.
Images results and test reviews
Andreas Bringmann: One of Baader’s first testers is Andreas Bringmann, an owner of a 2.6m Baader Classic Dome and renowned Astro-Photographer – see his images on www.astrobin.com/users/equinoxx/. The all new f/2 Ultra-Highspeed Filters not only lead to amazing images but even enabled the photographic proof of the newly discovered planetary nebula StDr13. Check out his detailed test review. Andreas has commented:
“I would like to emphasize, that the opportunity you have given me to test the new CMOS-optimized filters has been for me, an astro-amateur, like winning the lottery!
ANDREAS BRINGMANN, www.astrobin.com/equinoxx/”
Christoph Kaltseis held a lecture on the new CMOS-optimized Baader (Ultra-)Narrowband and Highspeed Filters at the ATT DIGITAL show on Saturday, May 8th 2021 (Note: The lecture was held in german language only and also the presentation material exists only in German (at least so far)). In case you’re still interested, you can find the PDF here.
after almost 1.5 years of constant tests of always new prototype runs of Baader filters in four different filter categories, I do conclude that the outcome superseeds my expectations, especially considering the prices.
CHRISTOPH KALTSEIS, www.cedic.at
Julian Shroff: Astroimager Julian Shroff comments:
After initial testing, I was pleased to find that the new CMOS-optimized Baader filters with reflex blocker coating work great. With the much narrower passages, there is hardly any light pollution, but plenty of signal and contrast. There are also no halos or reflections, even with very bright stars, which I have never seen before on f/2. I used the freshly arrived highspeed filters for a quick snapshot of NGC7000 with my RASA 8. The image consists of 5x120s O III and 15x120s Ha, so a 40 minutes bicolor image. This definitely shows what can be done with a fast system and good filters. I don’t like to expose less than 10h, but with such bright nebulae I would be done after 4-5h.
Also a quick first test with the highspeed H-alpha filter on Deneb with 30s, as well as 60s shots shows the difference clearly in my eyes. There is much less unwanted light coming through and also the slight halo, which is present with other filters I have used so far, has completely disappeared even with an extreme stretch.
Last night (03.May 2021) it was clear for a short time. I have now also made a few 30s and 60s exposures of Deneb with the O III filter. On the 30s images the image looks perfect, on the 60s there is a very faint halo – at maximum stretch. Considering that with other O III filters I used to have halos on virtually every even remotely bright star, I find this very satisfying.
Ian Aiken: One of our british customers has been testing our new CMOS-optimized filters in combination with a QHY 268M camera (read more about that here).
I’m very impressed with the Baader UNBs and managed to get some H-alpha data under Bortle 7 skies with my new CMOS camera. Having used previous Baader high speed filters on my RASA 11, I can confirm that these are a step forward in conjunction with the RASA optical configuration, that is putting so many lenses very near in front of the filter. These new UNBs definitely are improving contrast with the RASA and helping me to keep stars under much tighter control. The UNB-OIII filter likewise has improved considerably with the Frontside Reflex-Blocker technology, with no halos recorded in this images data (unfortunately due to the weather the data is incomplete to make a pretty bi-colour picture).