Johnson/Bessel UBVRI Filters

Johnson/Bessel UBVRI Filters

Johnson/Bessel UBVRI Filters

Johnson/Bessel UBVRI filters represent Andover's specialized photometric solution optimized for photomultiplier tube (PMT) detectors. These precision optical filters isolate specific spectral bands critical for astronomical measurements, with particular emphasis on the red and infrared regions that match PMT response characteristics. Each filter is manufactured with exacting thickness control to minimize refocusing requirements between filter changes, ensuring consistent and reliable measurements.
The Johnson/Bessel UBVRI filter set represents a standardized system for astronomical photometry, optimized specifically for photomultiplier tube detectors.
These precision filters isolate five distinct spectral bands: ultraviolet (U), blue (B), visible (V), red (R), and infrared (I), with each band carefully chosen to match key stellar emission features.
The set maintains high peak transmission across all bands - with the U filter achieving >50% transmission and B,V,R,I filters exceeding 70% transmission.
Each filter is manufactured with exacting thickness control to minimize focus shifts during filter changes, while maintaining superior wavefront quality and parallelism needed for accurate astronomical measurements.
The R and I filters are specially designed to match PMT detector response characteristics, featuring bandwidths and center wavelengths that differ from their Kron/Cousins counterparts.
This optimization ensures maximum sensitivity and accuracy when used with photomultiplier tube detection systems.
Johnson/Bessel UBVRI Filters body image
  • Optimized for photomultiplier tube detectors
  • Minimal refocusing requirements between filter changes
  • Superior transmitted wavefront quality
  • Precise center wavelength control
  • Excellent out-of-band rejection
  • Anti-reflective coatings on external surfaces
  • Available in matched sets
  • Custom sizes and mounting options available
  • Professional observatory research
  • Variable star monitoring
  • Stellar classification
  • Photometric surveys
  • Sky brightness measurements
  • Galactic structure studies
  • Amateur astronomy research
  • Educational observatories
  • Astronomical photometry calibration
  • Transmitted Wavefront: 1/4 wave or better per 25mm
  • Parallelism: 30 arc seconds or better
  • Surface Quality: 60/40 or better per MIL-C-675
  • Thickness: 5.0mm ±0.1mm
  • Coating Durability: Per MIL-C-48497A moderate abrasion
  • Operating Temperature: +23°C (specified)
  • Substrate: High-quality optical glass
  • AR Coatings: External surfaces (appropriate to filter passband)
  • Standard Sizes: 25mm, 31mm, 50mm diameter and 50mm square
  • Custom mounting options available

Showing 1–16 of 25 results

    PART NO.
    DESCRIPTION
    1 - 5 pcs.
    6 - 10 pcs.
    > 10 pcs.
    Stock Status

    JOHN-B-25

    Johnson B type filter/25mm dia.

    $258.00
    $222.00
    $196.00
    In Stock

    JOHN-I-25

    Johnson I type filter/25mm dia.

    $258.00
    $222.00
    $196.00
    In Stock

    JOHN-R-25

    Johnson R type filer/25mm dia.

    $258.00
    $222.00
    $196.00
    In Stock

    JOHN-U-25

    Johnson U type filter/25mm dia.

    $258.00
    $222.00
    $196.00
    In Stock

    JOHN-B-31

    Johnson B type filter/31mm dia.(un-mounted) For Astronomy Telescopes

    $283.00
    $243.00
    $215.00
    In Stock

    JOHN-B-31M

    Johnson B type filter/1.25 dia. (mounted) For Astronomy Telescopes

    $285.00
    $245.00
    $217.00
    In Stock

    JOHN-I-31

    Johnson I type filter/31mm dia.(un-mounted) For Astronomy Telescopes

    $283.00
    $243.00
    $215.00
    In Stock

    JOHN-I-31M

    Johnson I type filter/1.25 dia. (mounted) For Astronomy Telescopes

    $285.00
    $245.00
    $217.00
    In Stock

    JOHN-R-31

    Johnson R type filter/31mm dia.(un-mounted) For Astronomy Telescopes

    $283.00
    $243.00
    $215.00
    In Stock

    JOHN-R-31M

    Johnson R type filter/1.25 dia. (mounted) For Astronomy Telescopes

    $285.00
    $245.00
    $217.00
    In Stock

    JOHN-B-50

    Johnson B type filter/50mm dia.

    $648.00
    $557.00
    $492.00
    In Stock

    JOHN-B-50S

    Johnson B type filter/50mm x 50mm

    $664.00
    $571.00
    $505.00
    In Stock

    JOHN-I-50

    Johnson I type filter/50mm dia.

    $648.00
    $557.00
    $492.00
    In Stock

    JOHN-I-50S

    Johnson I type filter/50mm x 50mm

    $664.00
    $571.00
    $505.00
    In Stock

    JOHN-R-50

    Johnson R type filter/50mm dia.

    $648.00
    $557.00
    $492.00
    In Stock

    JOHN-R-50S

    Johnson R type filter/50mm x 50mm

    $664.00
    $571.00
    $505.00
    In Stock