By Mark Zaslove
A two-time Emmy Award winner and recipient of the coveted Humanitas Prize, Mark is a born-again astro noobie, who once had an Optical Craftsman scope as a kid, and is now recapturing his youthful enthusiasm (with a digital twist) and having a lovely time doing it.
What do you get if you cross an Erector Set with some giant metal washers, a plethora of variously-sized openings, a filter tray that slots in like a clip in a Glock, and, well, all sorts of other stuff? The Baader Universal Filter Changer, or UFC for short. And when Baader says “universal,” they mean it.
Look, there comes a time in every astro-imager’s life when they put aside their OSC, and try to move onto mono, or … dare I say it, narrowband. But sometimes a fully-automated, super-expensive, space-eating filter wheel is not an option. Could be, said astro-imager wants to dabble in Ha and still use their OSC (or DSLR). Maybe they are gradually building up to the big jump and have gotten the mono-camera, but just want to stick to mono (Ha, luminescent) before hullaballooing RGB. Maybe there’s a weight or back-focus obstacle.
Whatever, sometimes a good ol’ filter tray is the answer. But which one? And, worse, how do you size it to fit not only your HyperStar, but your 80-mm refractor, and maybe even that Mak-Newt you bought for Xmas but haven’t gotten around to using yet, and you’re itching to
give it a go. Do you buy a filter tray for each scope? What about spacing? And the different sized-filters you might need … do you need a whole different system for each? Enter the Baader UFC.
The heart of the UFC is a two-piece little thingie: Baader’s Filter Changer Base (Image 1), and the Filter Slider (Image 2). The Slider slots into the Base, snapping in easily, with a real solid feel and no wiggle-room (Image 3). There are three different Slider sizes for three different filter sizes: 2-inch round (M48); 50.4-mm round; and 50×50 square (and, with the right stepdown rings, 31 mm, 36 mm and even a -good ol’ all-American 1.25-inch).
Okay, so far, so good. But how do you attach that Filter Changer Base and the Filter Slider to your scope? Glad you asked. Feast your eyes on Image 4, which shows everything available for this system.
Whoa! I’ve seen plumbers with less fittings than that. Basically, you have the ability to go from T-2 to M48, to 2-inch to M54, to M68, all the HyperStars, and even the RASA. Heck, there’s even a Straylight flange and Stepper Ring for using on camera lenses. Oh, and there are connectors for FLI and Starlight Xpress cameras as well. Couple that with various extenders and spacers to get you to your back-focus, and, voila: you’ve got yourself a perfectly placed filter tray holding a variety of filter Sliders, and the whole kit and the caboodle can be taken off one scope and put on another.
One of the nicest parts is that the Baader VariLock (Image 5) fits in there, giving you the ability to vary the optical path (in case your back-focus measurements aren’t as accurate as they should be) to reach the perfect spacing point. What’s more, the Slider itself is easily removed by pressing a brass pin mounted on the far side of the Slider, which ejects the Slider without the need to pull on anything … which
means you can go from one filter to another without messing with your scope’s position. What’s more, the Slider sits tightly not just in fit, but by being magnetic as well, so it’s solid. Real solid. I tried this puppy on a Newt, a refractor and a friend’s Ritchey-Chretien. No muss, no fuss!
Yeah, filter holders aren’t sexy, but the Baader UFC comes as close to a Sports Illustrated swimsuit model as you can have for such a functional piece of gear. Clean, simple but effective to use, and it’s adaptable to all scopes and sizes.