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Solar Spectrum Observer Series 1,5 (25mm clear aperture)

Solar Spectrum Observer Series 1,5 (25mm clear aperture)

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Picture similar Example of a SolarSpectrum cooling fan (included for all models) Application image: © W. Paech – for more images please visit our image gallery on www.astrosolar.com Application image: © W. Paech – for more images please visit our image gallery on www.astrosolar.com Application image: © B. Koch – for more images please visit our image gallery on www.astrosolar.com Application image: © W. Paech, F. Hofmann – for more images please visit our image gallery on www.astrosolar.com Application image: © K. v. Schauroth – for more images please visit our image gallery on www.astrosolar.com Case and accessories not included Application image: D-ERF Filter in different size. Required for SolarSpectrum H-alpha Filters Example of items for a SolarSpectrum Filter (shown #2459219: SolarSpectrum Solar Observer 1.5 - 0.50 Å) Application image: D-ERF Filter with 3D-printed filter holder and steplessly variable diaphragm Application image: Solar Spectrum H-alpha Filter with telecentric system and Skyris Videomodule Application image: telescope combination in whitelight and H-alpha on Mercury Transit 2016 Application image: Solar Spectrum H-alpha Filter on Zeiss telescope at partial solar eclipse 2016 Application image: Solar Spectrum H-alpha Filter on Zeiss telescope at partial solar eclipse 2016 Application image: Solar Spectrum H-alpha Filter with mirror diagonal and Hyperion eyepiece Application image: Solar Spectrum H-alpha Filter on Refractor Anwendungsbild Application: Korona Edge Application: taken with TEC 140 APO ED on 10micron GM2000 HPS II, with Baader D-ERF Energy Rejection Filter + Solar Spectrum Observer Series 1.5 - 0.5A°, Baader TZ-4 and Baader Steeldrive II, © Rüdiger Proske Application: taken with TEC 140 APO ED on 10micron GM2000 HPS II, with Baader D-ERF Energy Rejection Filter + Solar Spectrum Observer Series 1.5 - 0.5A°, Baader TZ-4 and Baader Steeldrive II, © Rüdiger Proske Application: taken with TEC 140 APO ED on 10micron GM2000 HPS II, with Baader D-ERF Energy Rejection Filter + Solar Spectrum Observer Series 1.5 - 0.5A°, Baader TZ-4 and Baader Steeldrive II, © Rüdiger Proske Application Application Application Application

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Solar Spectrum Observer Series 1,5 (25mm clear aperture)

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€ 4,050.00 Price excl. German VAT tax (19%): € 3,403.36

Shipping time: Sometimes long waiting periods

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Solar Observer Filter Serie 1,5: Standard-Filter with a clear aperture of 25mm. Shows the full sun disc up to effective focal lengths of approx. 2200mm
Different Halfbandwidths available – please choose "Version"
incl. Pre-mounted Adapterset: 2x 2" SolarSpectrum Universal Flange #2958240, 1x 2"a to T-2i Reducer #2958242, 1x 2"a to T-2a Adapter #1508035, 2 pc. T-2 Dust caps (#2904000, #2904010)
Heated H-alpha – Filter (lambda = 656,3 nm) with electronical temperature control (heating and cooling combined).
Requires an additional Energy Rejection Filter (D-ERF) in front of the lens. SolarSpectrum Filter are not available by shopping cart system and have sometimes long waiting periods. If you are interested, please contact us by email or contact form

Important note: Please note our information on the availability of 3D-printed or CNC-turned cell mounts for front side D-ERF filters as custom-made products.

*Version

* Required Fields

€ 4,050.00 Price excl. German VAT tax (19%): € 3,403.36

Product Questions and Answers

Do you have a question about this product? Then we would like to ask you to first look through the existing questions and answers, most likely your question has already been answered and you will get the desired information much faster this way. Your question is not listed? Then please click on the button "Ask a question".

Is it possible to obtain the D-ERF energy protection filter for SolarSpectrum H-alpha filters more cheaply from other sources?

Question by: Johannes H. on Apr 10, 2024 10:37:00 AM | 1 Answer(s)

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We must point out that purchasing the ERF from another source can lead to a repair becoming chargeable in the event of a defect during the warranty and guarantee period.

A normal ERF is cheaper to buy. But it does not have the same specifications as our DERF: Simple ERF filters are made of solid-colored red glass (Schott RG 610 or RG 630). This glass is a long-pass filter; it allows all energy to pass through from approx. 570 nm, including the full thermal radiation (NIR) above 630 nm.

The heat at the focal point is three times higher with this type of "protective glass" than with our dielectrically blocked D-ERF filter. As a result, the immersion oil in the stack of block glasses, polarizers and etalon in the H-alpha filter literally is getting boiled. An H-alpha filter that is permanently overheated in this way ages very quickly. We would not be able to maintain our 5-year warranty under any circumstances.

Incidentally, the colored glass from which these simple ERFs are made is very "soft" and chemically unstable (= prone to weathering). The soft molten glass tends to form streaks. When we were still working with this glass, we had to double-pass test each piece on the optical bench and had a high reject rate. This means that simpler ERF filters age due to the oxygen in the air if they are not coated, the surface becomes "rough" after a few years and the image contrast collapses.

The problem with the glass quality of the RG 610 remains even if a UV/IR-reducing coating is vapor-deposited. We have already done this many years ago as C-ERF filter (= Cool ERF), but after long-term experience we abandoned it again and the lesson learned was the development of the D-ERF (Dielectric ERF). Above all, the soft glass often warped during coating, which led to even more rejects.

There are manufacturers who offer such ERF or C-ERF filters but do not test every lens as thoroughly as we did on the optical bench. This explains the cheap offers of C-ERF and ERF filters on the market - for which the customer ultimately pays much more than if he had purchased a high-quality DERF, with significantly reduced image quality and reduced service life of the Halpha filter.
Our D-ERF filters are made of highly homogeneous, streak-free, finely polished BK-7 glass. They are painstakingly coated with a dielectric coating system that is resistant to ageing and precisely matched to the Solar Spectrum filters.

The Solar Spectrum filter only shows its most important advantages (ageing resistance, sharpness and contrast) with our dielectric „D“-ERF coating system were we have full control over the coating process and can verify it´s effectivity. Only then can we guarantee for the 5 years of ageing resistance for the Solar Spectrum H-alpha etalon-stack. Especially with a research grade filter, usage of a "normal" ERF is tantamount to "degrading" the filter. Every chain is only as strong as its weakest link.

Answer by: Baader Web Team (Admin) on Jan 23, 2017 10:39:00 AM

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I am currently using an 8" SCT telescope with a few Baader filters to image the sun's surface but after much reading
I am now considering purchasing a dedicated solar telescope to expand my viewing.
However, having found an article that led me to your page, I would like to know whether such filter
(Solar Spectrum Observer Series 1,5 or similar model) would work with my SCT.
I already have your OD 3.8 film which I use when imaging (not viewing).

Question by: Philippe Fossier on Jun 1, 2023 10:27:00 PM | 1 Answer(s)

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-13

Can I use an UV/IR-Cut filter or the BBHS mirror in front of an H-Alpha or Calcium Solar Filter? Do you recommend the 2" BBHS or 2" Clicklock Mirror for solar observation?

Question by: Enrique V. on Sep 26, 2016 3:04:00 PM | 1 Answer(s)

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-24

If you want to observe the sun in H-Alpha, we recommend the standard dielectrical Clicklock mirror (# 2956100) in combination with a suitable filter combination, because the dielectrical filter reflects less radiation below 380nm and above 740nm. This way, the mirror can reduce the strain on the following filters at least a little bit.Please do also use an energy rejection filter in front of the telescope to reduce the strain on the filters as much as possible.

We highly advise against visual calcium observations of the sun - the 397nm of Calcium are already ultraviolet radiation, and UV-radiation can cause phototoxic reactions which can harm your eyes. In addition, even young people can't see these wavelengths very good, and sensitivity decreases with the age. Because of this, the eye doesn't feel if the intensity is much too high. If you now try to increase the amount of radiation (e.g. with another mirror) to achieve a brighter image, you will increase the risk for eye damage. According to the newest norms for eye safety and to ophtalmologist conclusions, the sun must not be observed visualy at 397nm.

We highly advise to only observe the sun in calcium photographically, then you also do not need a star diagonal. We can't understand why some manufacturers promote these calcium-filters for visual observations.

We also advise against placing a filter so close to the focus - any energy rejection filter belongs in front of the front lens, even if this sets high demands to the quality of such a large filter. Placing the filter close to the focus will save money, because you can use a much smaller filter, be we absolutely can't recommend it - because of our own conscience as well as because of EU-regulations. The filter would receive all the energy collected by the front lens. We can only recommend putting the energy rejection in front of the front lens, which is the ethically and technically correct method.

Answer by: Baader Web Team (Admin) on Oct 14, 2016 9:32:00 AM

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Description

Details

First Class H-alpha Solar Filters by SolarSpectrum

A SolarSpectrum filter transforms almost any telescope into a high-end H-α telescope with appropriate accessories. The filter design is optimized for observatories and amateurs who want to use the full aperture and resolution of large telescopes for solar observation and plan more than just an occasional view at H-alpha.

The filters have no central obstruction and are actively heated. This means that the filter does not need to be readjusted during the course of the day - ideal for long-term observations, time-lapse photography or public relations work.

Further information can be found on our detailed Blogpost:

First class H-alpha Solar Filters by SolarSpectrum

Temperature controlled H-alpha-filters (lambda = 656,3 nm) with electronic temperature control (combined heating and cooling!)

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