Product Description

This versatile filter acts like a dimmer switch for your telescope, toning down the brightness of the Moon or planets to a level that is comfortable. The reduction in brightness and glare unmasks detail in your viewing subject and greatly improves contrast. The filter consists of two high-grade glass polarizing filters in a rotating cell that allows you to adjust the amount of light transmission from 1% to 40%. Such control is highly desirable for lunar observing because the Moon's brightness varies with its phase. The filter is great for terrestrial observing too, especially on sunny days. The filter has an anodized aluminum cell, which threads into the barrel of any standard eyepiece. Now available in 1.25" and 2" sizes. Storage case included.

Product Details

• Brand: Orion
• Model: OR-5560

Features

• Variable polarizing filter acts like a dimmer switch for your telescope, to tone down brightness
• Reduced brightness and glare unmasks detail in your viewing subject and greatly improves contrast
• Adjust the amount of light transmission from 1% to 40%
• The filter has an anodized aluminum cell, which threads into the barrel of any standard eyepiece
• Storage case included. 1.25"

Customer Reviews

Excellent, easy, great value filter
I'm a novice astronomer and about 6 months ago purchased an Orion IntelliScope XT10 (great scope, see my review of it). I love looking at the moon but it's so excessively bright in this scope. I'm a big fan of Orion's products, and their service is the absolute best, so when looking to purchase a filter I decided to go for this one. It's only 2 pieces, very easy to assemble and attach to any 1.25" eyepiece. It's also great how you can vary the brightness from near maximum to very dark. Makes viewing the moon a WHOLE new experience. Brings out more detail and eliminates the eye pain. Once again, Orion has made a very satisfied customer out of me!

Orion Variable Polarizing Filter
When looking at the moon through a telescope larger than 6 inches or so, you need something to cut down on the excessively bright moon. This filter allows you to vary the amount of light coming through the eyepiece, and adjust it to a comfortable level. I'll never sell mine.

Good and bad
First, the good. If you think you want a moon filter and you're trying to decide between this and a neutral density filter, stop wondering and get this one. The adjustability is well worth the extra bucks. It really does work as advertized. At max transmission (40%) it is like you suddenly chopped your aperture by a third. At minimum transmission (1%), have fun trying to find anything other than the full moon. The biggest downside I can see here is that some moron will probably try to use it as a solar filter and burn an eye out.

Now, the bad. I was sure as I could be, ahead of time, that I wanted one of these things. In terms of time spent, the moon is my favorite observing target and I do a fair amount of digiscoping (or afocal projection photography, if you prefer) of the moon. Between first quarter and last quarter it is a punishing sight even in my modest six inch telescope. Near full, it's just flat painful. So obviously I need a moon filter, right?

I'm not so sure anymore. The filter does knock the light down to acceptable levels, that's true. But in doing so it knocks down the contrast, too, to levels that I find aesthetically yucky by eye or CCD. After a few weeks this thing landed in an out-of-the-way pocket of my eyepiece case and hasn't been heard from since. Turns out I prefer a brilliant, if painfully bright, moon, to one that is acceptably dim but unacceptably dull. Your mileage may vary.