Open box as sample. Filter is quite clean and in brand-new condition.
1.25″ Photosphere 7.5nm filter (Photosphere enhanced filter）
Photosphere filter is an assistant filter, telescope must use Baader film or Herschel wedge for adequate reduction of sun light, then you can use this filter for imaging.
Photosphere filter is a narrowband filter, CWL is 540nm, bandwidth 7.5nm.
Specifications: 1.25 inch, thread M28.5*0.6
Frame thickness: body 5mm+ thread 2.5mm, a total of 7.5mm
Thickness of filter lens: 2.5mm
Bandwidth: 7.5nm
CWL (center wavelength): 540nm
PV: 1/4 lambda
Transmittance: ≈97%
Blocking depth: OD4