Baader Q-Barlow 2.25x / 1.3x

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Baader Q-Barlow 2.25x / 1.3x

# 2956185

€ 49.00 Price excl. German VAT tax (19%): € 41.18

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  • Baader Q-Barlow lense 2.25x, 1¼" barrel
  • dual factor lens assy (1.3x/ 2.25x)
  • Modern High-Transmission Multi-Coating all air-glass surfaces delivers a remarkably brilliant image with extremely low internal reflections
  • Extends the possible focal lengths of the Q-Turret eyepiece set

Product Questions

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Dear Baader I have the q-barlow but the screwed into the eyepiece directly for 1.3x magnification is possible with any brand\kind of eyepiece or just with your classic orthos?
Question by: Sirio on Jul 17, 2018 11:09:00 AM | 1 Answer(s)
Please can you share the focal length of the q-barlow? Thanks
Question by: Enrico on Jun 2, 2020 10:54:00 PM | 1 Answer(s)
1) Using the T2 part#05 extension tube with just the lens cell does one have to take into account the length of the filter thread to work out the amplification factor? If so, I've calculated that allowing a few mm for the thread the amplification would be approximately 1.75x. Have I got this correct please?

2) Using the extension tube with the complete Barlow and adding a few millimetres for the filter thread I make the amplification approximately 2.75x amplification. Is this correct please?

Many thanks.
Question by: Steve Burke on Oct 29, 2020 1:22:00 PM | 1 Answer(s)
will this barlow work with Baader Hyperion Universal Zoom Mark IV, 8-24mm eyepiece (1¼" / 2")
Question by: darrell sanchez on Jan 15, 2021 8:42:00 PM | 1 Answer(s)


 Baader Planetarium Q-Barlow 2,25x / 1,3x

Without the housing, the Barlow lens can be screwed either into the eyepiece revolver (for 2.25x magnification) or directly into an eyepiece (for 1.3x magnification)
The Q-Barlow lens can be unscrewed from the eyepiece adapter

This high-quality 2.25x Barlow made of exotic glasses provides the rare extension factor of 2.25x. So, there are no duplicate focal lengths when used with the eyepieces of the Q-Turret Set, and you can achieve higher magnification than with standard 2x barlow lenses if you do planetary photography with a web or video camera, and you can make better use of the camera's resolution. Read here the detailed report by Dipl.-Ing W. Paech: Hints + tricks for high-resolution lunar and planetary photography with a video module - a short "workflow" for SC telescopes with Baader accessories.

The Barlow can either be screwed into the Q-Turret eyepiece turret or combined via the special, included adapter with all 1.25 "eyepieces. In this case, it acts as a 2.25x Barlow. With the Q-turret revolver and the Classic Eyepieces, this results in the following focal lengths: 2.7 mm, 4.5 mm, 8 mm and 14 mm

Alternatively, it can also be screwed directly into an eyepiece and then increases the telescope focal length by a factor of 1.3. The Barlow element has an M28.5 male thread (corresponding to the filter thread of 1¼ "eyepieces), the housing has got a M28.5 female thread. The factor 1.3x is achieved when the Q-Barlow is completely screwed into the 24mm long push-in sleeve of an eyepiece whose field diaphragm lies 2mm inside the push-in sleeve. This corresponds to the design of our Classic Plössl/Ortho eyepieces; with other eyepiece designs, the magnification factor may vary slightly.

Attention: When fully screwed in, the Barlow element protrudes 13mm into the 1.25" plug-in sleeve. On eyepieces where lens elements in the 1.25" sleeve do not allow the Q-Barlow element to be screwed in, it can only be used in the 1.25" adapter with factor 2.25x. If necessary, you can use it on these eyepieces with the 18.5mm long 1¼" extension sleeve with 1¼" filter thread on both sides: Baader 1¼" - 31.8mm nosepiece extension with 1¼" filter thread on both sides (T-2 part #05) (#1905130, € 14,50)

Use on a planetary camera

The bare lens mount of the 2.25x Q-Barlow lens (without the 1.25" eyepiece holder) can be screwed into every 1.25" filter thread. To do so, remove the lenses with their threaded mount from the rest of the housing. Without the eyepiece clamp, the Barlow has no longer an extension factor of 2.25x, but only of 1.3x (when it is screwed completely into the filter thread). The reason for this is the shorter distance between the lenses and the image plane.

It may be that you can't insert the lens mount completely into the filter thread, then the magnification factor is closer to 1.5x.

But if the 1.25" nose piece of a camera provides a M28.5 filter thread, you can usually insert the Barlow completely, and because of the shorter distance the provided factor is ca. 1.3x. This is intentional and was one of the aims of the design. At 2.25x, an image circle of 25 mm is provided free of vignetting, while the fully lit image circle at 1.3x is 13mm.

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Additional Information

EAN Code 4047825027818
Manufacturer Baader Planetarium
SKU (#) 2956185
Net weight (kg) 0.07
Inner Connection (lens sided) Thread, M28,5
Outer Connection (lens sided) Barrel, 1¼"
Outer Connection (eyepiece/-camera-sided) Clamp, 1¼"
Clamping System Screw clamps
Magnification (x) 2,25x / 1,3x
AR-Coating High transmission multi-coated (HT-MC)
Adaptable to Q-Turret Okularrevolver und Classic Ortho/Plössl Okulare, 1¼ Okulare
Usage Erweitert die möglichen Brennweiten des Q-Turret Okularsatzes.
Barrel Size (in) 1¼"
Optical Design Barlow
Speciality Barlow lens

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Christoph Kaltseis 88/03/2021 30/03/202109:20
  • Rating:
Gassendi - x-trem
Die Baader Q-Barlow ist ein Kunstwerk - Preis / Leistung 1+++!
Das Bild ist mit dem C14 EHD f11 und der Q-Barlow bei etwas mehr als x2,25 aufgenommen.
Dazu die QHY 462C mit dem IR850nm Filter (= Luftglätter!)
Das sind 0,06" Bogensekunden pro Pixel ! Noch mehr - nein das sagt schon vieles... CS Christoph
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Bernd 329/11/2020 25/11/202018:10
  • Rating:
Sehr gutes Preis Leistungsverhältnis
Rechtzeitig zur Mars Opposition 2020 habe ich mir noch schnell die Baader Q-Barlow Linse als Alternative zu der leider nicht lieferbaren Hyperion Barlow bestellt.

Das Produkt zeichnet sich durch ein sehr gutes Preis Leistungsverhältnis aus. Trotz des moderaten Preises ist die Abbildungsqualität hervorragend und so ist mir in Kombination der Q-Barlow mit meiner Planetenkamera QHY 5-III-462C eine schöne Aufnahme des roten Planeten gelungen.

Der einzige Schwachpunkt ist aus meiner Sicht die Okularklemmung:
Diese ist lediglich mit einer Schraube ausgestattet, die zudem keine durch Kunststoff entschärfte Spitze besitzt.

Für die Klemmung eines herkömmlichen Okulars mit Metallschaft stellt das sicherlich kein Problem dar, aber bei der empfindlichen eloxierten Oberfläche einer Planetenkamera muss man etwas aufpassen, wenn man keine dauerhaften Kratzer riskieren möchte. Ich habe das einfach mit einem Streifen Tesafilm gelöst.
  • Hervorragende Abbildungsqualität zu attraktivem Preis
  • Okularklemmung
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Michael 94/04/2019 05/04/201903:49
  • more than 2 year(s)
  • Rating:
Very nice quality and it works as it should
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