Lens filters are attached or screwed onto the lens of the optic, on the side facing the object to be observed.
Especially in the case of solar filters, no damaging radiation is allowed into the optic from the outset. This protects the optic and is the safest method of reducing light.
Most lens filters can also be used for photographic lenses.

Omegon
solar filter, 60-80mm
$ 19.90
ready for shipping in 24
h

Omegon
solar filter, 90mm
$ 24.90
ready for shipping in 24
h

Astroprints
Solar Filters ZWO Seestar S50
$ 32.90
ready for shipping in 24
h

Omegon
solar filter, 150mm (6'')
( 4 / 5 )
$ 59.00
ready for shipping in 24
h

Explore Scientific
Sun Catcher solar filter for 150-160mm refractors and 203mm (8") SCs
$ 54.00
Product not available anymore

euro EMC
SF100 Size 5: 103mm to 131mm AstroSolar
$ 76.00
ready for shipping in 24
h

euro EMC
SF100 size 4: 83mm to 105mm AstroSolar
$ 62.00
ready for shipping in 3-5
weeks

euro EMC
SF100 size 6: 129mm to 157mm AstroSolar
$ 88.00
ready for shipping in 3-5
weeks

Baader
AstroSolar telescope solar filter ASTF 80mm
$ 79.00
ready for shipping in 1-2
weeks

euro EMC
SF100 size 7 for 155mm to 189mm AstroSolar
$ 104.00
ready for shipping in 24
h

Meade
Filters Glass Solar Filter 400 ID 101mm
$ 237.00
ready for shipping in 3-7
days

Baader
AstroSolar telescope solar filter ASTF 240mm
$ 181.00
ready for shipping in 1-2
weeks

Artesky
Solar Filters 115mm
$ 75.00
ready for shipping in 24
h

euro EMC
SF100 size 11: 323mm to 381mm AstroSolar
$ 193.00
ready for shipping in 3-5
weeks

Coronado
Filters Double Stacking Etalon Solarmax II PST 40mm
$ 1,610.00
ready for shipping in 24
h

Artesky
Solar Filters 95mm
$ 60.00
ready for shipping in 3-5
weeks

Baader
AstroSolar telescope solar filter ASTF 100mm
$ 92.00
ready for shipping in 1-2
weeks

Baader
AstroSolar telescope solar filter ASTF 280mm
$ 194.00
ready for shipping in 24
h

Baader
AstroSolar telescope solar filter ASTF 120mm
$ 106.00
ready for shipping in 1-2
weeks

Lunt Solar Systems
Filters LS50C double-stack filter
$ 1,840.00
ready for shipping in 1-2
weeks

euro EMC
SF100 size 8: 187mm to 221mm AstroSolar
$ 115.00
ready for shipping in 24
h

Baader
AstroSolar solar filter for ASBF 100mm binoculars
$ 72.00
ready for shipping in 1-2
weeks

Astroprints
Solar Filters for Sigma 150-600 lens ND5
$ 87.00
ready for shipping in 3-7
days

Astrozap
AstroSolar solar filter, 136mm-146mm
$ 161.00
ready for shipping in 24
h

euro EMC
SF100 Size 3: 70mm to 85mm AstroSolar
$ 53.00
ready for shipping in 24
h

Lunt Solar Systems
Filters H-Alpha Doublestack LS40F
$ 1,080.00
ready for shipping in 1-2
weeks

Astrozap
AstroSolar solar filter for 250mm-260mm
$ 269.00
ready for shipping in 24
h

Meade
Filters Glass Solar Filter 1200
$ 410.00
ready for shipping in 24
h

Lunt Solar Systems
Filters H-alpha double-stack solar filter LS100FHa
$ 11,900.00
ready for shipping in 1-2
weeks

Astroprints
Solar Filters for Sigma 150-600 lens ND3.8
$ 87.00
ready for shipping in 24
h

euro EMC
Solar Filters SF100 Größe 10: 269mm bis 327mm Thousand Oaks
$ 164.00
ready for shipping in 24
h

Baader
AstroSolar solar filter for ASBF 80mm binocular lens
$ 60.00
ready for shipping in 1-2
weeks

Astrozap
AstroSolar solar filter, 110mm - 120mm
$ 172.00
ready for shipping in 3-5
weeks

Baader
AstroSolar telescope solar filter, 65mm
$ 49.90
ready for shipping in 1-2
weeks

Baader
AstroSolar solar filter ASBF for 50mm binocular lens
$ 41.90
ready for shipping in 1-2
weeks

DayStar
Filters Energy Rejection Filter E-180N130
$ 1,510.00
ready for shipping in 24
h