FFC All-in-One T-2 Set – 3-4x magnification for 1¼" and T-2 Cameras

Description

The CaF2 Fluorite-Flatfield-Converter was made with the intention of making the world's best Barlow lens. It can be used at every optical system, both for visual observations and photography. The FFC is still the only barlow lens with four lenses in two putty elements using two genuine fluorite (CaF2) lenses. The temperature compensating body is made with particular care in our factory in Mammendorf, Germany.

The was designed for an image circle of up to 90 mm at 4x magnification a f/8 telescope, and it provides uncompromising sharpness in this image circle. As far as we know, the FFC is still unsurpassed in imaging performance today.

This set contains all adapters to use the FFC with an eyepiece or with planetary cameras with 1.25" nose piece or T-2-thread.

• The 2" nose piece provides the necessary distance to reach focus on most telescopes even without a star diagonal.
• The Clicklock® eyepiece clamp Klemme keeps even heavy eyepieces or cameras safely in place.
• The two T-2 quick changers let you easily switch between e.g. camera and eyepiece, and they let rotate a camera if all parts are tightly connected. Most of all, you can use them to quickly change between different sets of extension tubes to change the magnification.
• The T-2 extension tubes are used for setting the magnification factor, which depends on the position of the camera sensor in the camera housing or the field stop of the eyepiece. With additional tubes (available separately), you can use magnifications of 8x or even higher. You can find more information in the manual and the image on the right.
• For a magnification of 3x, you need a distance of approximately 96 mm, and for 4x a distance of 150mm.

CaF2 Fluorit-Flatfield-Converter - fotografisch und visuell an fast jedem optischen System einsetzbar, als beste und aufwendigste Barlowlinse der Welt

• Apochromatic, multi-coated lenses
• 10-times higher line resolution than the world best projection eyepieces
• Four lenses – two of them made of real Fluorite (CaF2) – in two cemented elements
• Variable setting of the magnification, designed for 3x - 8x (2,5x-15x possible)
• Hoch-Transmission Multi-Coating (HT-MC)

The FFC is the result of the desire for uncompromisingly sharp images of the moon, the planets and the sun in white light at highest magnifications. That's why we finally asked one of the designers of the Zeiss APO lenses to calculate the ultimate projection system with a flat image in 1997. To actually make this design become reality, extreme types of glasses were needed. In this case, two lens groups were needed, each with a fluorite lenses, which is – at that time and until today – a nightmare to produce. Especially the broadband coating of these lenses is hard to do.

The result, however, was a uniquely transparent and sharp optical system with ten times the line resolution of a Zeiss Abbe eyepiece. Even though the days of analogue film cameras are long gone, this lens system remains the "sharpest Barlow ever produced".

By changing the distance to the camera sensor, you can vary the magnification between 3x and 8x. The optimum resolution is achieved at 4x magnification, then you have the full sharpness over an image circle of 90 mm diameter. On the axis, the sharpness is only limited by your telescope – even at a magnification factor between 2.5x and 15x. We have tested this at an AstroPhysics lens telescope.

The FFC can be connected to every T-2 thread and its 2" main body likewise fits into every 2" eyepiece clamp. With the help of our Astro T-2™-System and the M68-System you can connect it to a whole world of telescopes.

For best results, you need to keep a certain distance to the original focus point.

Handling and Maintenance

The Baader-FFC contains lenses which are made of real Fluorite-crystals. CaF2 has got an impressive refractivity which enables construction of the ultimate lens system that can deliver an incredible amount of sharpness across a very broad spectral range. No other barlow lens design can combine a similar sharpness with such a large image.

Unfortunately, such sophisticated optics are very sensitive to tension caused by temperature differences. Under no circumstances must CaF2 be exposed to sudden or high changes in temperature. E.g., do not bring the FFC without protection out of your +20 °C warm house into an icy winter's night with -20 °C.

To compensate for such large temperature differences, we have taken great care to design the transport case in such a way that it can protect the FFC from such rapid temperature changes. Ideally, therefore, leave the FFC in the closed transport case whilst you set up the telescope and allow it to cool down. The greater the temperature differences, the longer it should be left in the case to acclimatise. In the event of very large temperature differences (e.g. from +20°C to -20°C), the FFC should be left in the case for up to an hour before you use it.

After using it, please put it back into its box before bringing it back into your warm house. The box ensures that the FFC has got enough time to acclimatise to the warmth. Just make sure that there is enough Silica Gel with coloured indicator, reusable, 125ml (#1905760) in the box, so that moisture is removed.

However, is no problem to store it in an observatory without climate control – the problem are only fast changes in temperature.

You can also use the FFC for photographing the Sun behind a solar filter made of Astro Solar ND 3.8 (only for photography, e.g. AstroSolar® Photo Film OD 3.8, 20x29 cm - not for visual observation (#2459278) or ND 5 film (photography and visual use, e.g. AstroSolar® Safety Film OD 5.0, 20x29 cm (#2459281) or the Cool-Ceramic Safety Herschel Prism 2" Mark II – Photographic (#2956510P).

Only Solar projection without a front filter will immediately destroy the optical system. The extreme and fast temperature changes would crack the fluorite lenses. For projecting the sun, we recommend the Baader Solar Projection Screen (BSPS) (#2420400) instead.

Specifications