BST 2" Variable Transmission Polarizing Filter
While observing the moon or planets, there is often too much light that washes out subtle details. This glare can be cut back using neutral density filters or polarizers. The variable polarizing filter makes this even better by stacking two polarizing filters together and combining them with a special ring that prevents the two individual filters from getting separated during normal use. By rotating the two elements, light transmission can be varied between about 2% and 40%. This filter retains true color balance since all wavelengths are transmitted uniformly over the entire spectrum.
The two polarizing elements can be unscrewed to obtain two polarizing filters which can be used for day time photography or to improve contrast in images when only a little reduction in transmitted light is desired. The filter has a standard 2" thread (M48 x 0.75) so it can be screwed on to any virtually any standard 2" eyepiece or accessory.
- Total item length (including external male thread) = 15.8mm (0.62")
- Clear aperture = 44.8mm (1.76")
- Weight = 0.9oz.
- Protective plastic storage case: Included
- Made in China
Jul 16, 2019
2" Variable PolarizerPros: Cons: Comments:
This is great for lunar viewing. I can vary the polarity for the best contrast and brightness for viewing specific features and areas of the moon. I had been placing half on the front of the diagonal, and half on the EP. The last time I used it, I found that, like the first one, iot wouldn't separate. So I used the assembly on the eyepiece. After futzing around with it this morning, I was able to get enough "snap action" on the halves to get them to loosen up again. This is the only negative aspect I've found with it.Bottom Line: Would you recommend this item? Yes
Aside from the intermittent thread issue this is a high quality product. The glass lenses have no apparent irregularities, and the range of polarization is fantastic for optimizing lunar viewing.
This review was provided courtesy of AgenaAstro.comJan 30, 2019
BST 2” Pokarizing FilterPros: Cons: Comments:
I like that this filter can be disassembled into two segments and installed in front of my diagonal and the bottom of my eyepiece. Rotation of the eyepiece gives you the ability to optimize the polarizing effect on a bright target such as the full moon. I recently used this filter at a star party and it provided excellent high contrast views at comfortable and adjustable levels of brighteness.Bottom Line: Would you recommend this item? Yes
Excellent product performance!
JAS in AZ
This review was provided courtesy of AgenaAstro.comJul 8, 2018
A must for viewing the moonPros: Cons: Comments:
This made viewing the moon a much more pleasant experience. The variable filter makes it convenient for both full and less-than full moon viewing. I am no longer nearly blinded after viewing, and they didn’t seeem to affect contrast.Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.comApr 28, 2018
Powerful and Flexible Visual ToolPros: Cons: Comments:
I particularly like separating the two polarizing layers, and threading one in the diagonal and one in the 2" EP. This makes adjustment of the polarization as simple as rotating the EP. Particularly useful for lunar viewing.Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.comFeb 16, 2017
Excellent ToolPros: Cons: Comments:
On the star shows I do on Mauna Kea in HI this is extremely useful in giving our guests the best possible view and optimum degree of filtering for whatever amount of lunar brightness we are dealing with. Variability without having to fumble with multiple filters.Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.comSep 21, 2012
Works as advertisedPros:
Accurate,Quality Lenses,Easy to Use,Lightweight,CompactCons: Comments:
I've got this filter screwed to the bottom of the eyepiece. I don't think you could ask for a better functioning filter for looking at the moon. The way I'm using it, it's a little awkward to adjust the filtering effect as the filter is way up in the focuser. I have to remove the eyepiece to spin the filter to adjust it's effect then reinsert for another look. I'm new to astronomy so I guess this is how all filters are supposed to work...Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.comDec 26, 2011
Exactly as advertisedPros:
Strong Construction,Easy to Use,Quality LensesCons: Comments:
This is a good, solid 2 inch polarizer. The unit separates into two ND filters.Bottom Line: Would you recommend this item? Yes
Construction is of good quality. I use it with larger lenses to view the moon with my 8 inch refractor. It does it's job satisfactorily.
This review was provided courtesy of AgenaAstro.comNov 6, 2011
The only polarizing lens you need!!!Pros:
Easy to Use,Quality Lenses,Strong ConstructionCons: Comments:
A well thought out product design. Works as advertised. I like the fact I can control how much light to let through. Being a 2 piece filter, you don't need to screw both to your EP or diaganol, split them up and place one in each if you want. Another great product from Agena.Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.comOct 28, 2011
Quality Lenses,Easy to Use,Strong ConstructionCons: Comments:
I use this for both terrestrial and astro imaging. Good product for the money. Agena Astro provides excellent service, as well. That's why I order from them.Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.comSort by