Wavelength cut off points for typical glass lenses?

Paris

A
Paris

  • 0
  • 0
  • 0
I'll drink to that

D
I'll drink to that

  • 0
  • 0
  • 88
Touch

D
Touch

  • 1
  • 2
  • 89
Pride 2025

A
Pride 2025

  • 1
  • 1
  • 105

Forum statistics

Threads
198,368
Messages
2,773,667
Members
99,598
Latest member
Jleeuk
Recent bookmarks
0

Athiril

Subscriber
Joined
Feb 6, 2009
Messages
3,062
Location
Tokyo
Format
Medium Format
I was wondering what the typical cut-off points of the spectrum are for typical lenses.

(Specifically I own an uncoated Ektar lens, various primes of the 70s-80s such as Olympus OM lenses, Super Takumar etc, and some modern lenses like the Sigma 12-24mm).

EG: Can a regular lens pass the 900nm-1200nm range of IR?
 

Q.G.

Member
Joined
Jul 23, 2007
Messages
5,535
Location
Netherlands
Format
Medium Format
EG: Can a regular lens pass the 900nm-1200nm range of IR?

Yes. No problem.
(You could start worrying when looking to record in the band well beyond 2000 nm)
A bigger problem is finding something that records radiation in that band.
 

benjiboy

Subscriber
Joined
Apr 18, 2005
Messages
11,955
Location
U.K.
Format
35mm
I let the lens manufacturers worry about questions like this.
 
Joined
Dec 30, 2005
Messages
7,175
Location
Milton, DE USA
Format
Analog
Radiation will pass through a lens (and other forms of matter). And mentioned above, you just need to visually capture it.
 

Q.G.

Member
Joined
Jul 23, 2007
Messages
5,535
Location
Netherlands
Format
Medium Format
Radiation will pass through a lens (and other forms of matter). And mentioned above, you just need to visually capture it.

That makes it sound, sort of, as if the question was flawed.
Not all radiation passes through all forms of matter. Not all light will pass through (all) glass.
 
OP
OP
Athiril

Athiril

Subscriber
Joined
Feb 6, 2009
Messages
3,062
Location
Tokyo
Format
Medium Format
Well I know apparently you need a gel lens to capture in the lower side of UV rather than just "near" UV.

Anyway thanks Q.G. that should help.
 

Photo Engineer

Subscriber
Joined
Apr 19, 2005
Messages
29,018
Location
Rochester, NY
Format
Multi Format
You can get surprisingly far into the "near" UV and that is why film manufacturers put a UV layer in many films. Ordinary glass lenses pass too much UV light. This is especially true with high altitude photography. The higher you go, the more UV radiation and the more you need UV filtration. Of course if you want 'far" UV, you need quartz lenses.

PE
 

pgomena

Member
Joined
Jun 25, 2003
Messages
1,391
Location
Portland, Or
I had an assignment in photo school to make a photograph using UV light. Tri-X, special filter, and bingo!, a picture was made. I'm sure it was using very near-UV. The thick glass filter was a very dark violet color and nearly opaque to my eye in broad daylight.

Peter Gomena
 

Maris

Member
Joined
Jan 17, 2006
Messages
1,568
Location
Noosa, Australia
Format
Multi Format
The nominal cut-off for glass is 340 nanometres. Deep violet at the limit of human eye sensitivity is supposed to be 400 nanometres but some people see slightly more, some less. Further down in the ultraviolet the next limit is 190 nanometres, the start of the vacuum ultraviolet, where air itself imposes a cutoff.
 
Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links.
To read our full affiliate disclosure statement please click Here.

PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Ilford ADOX Freestyle Photographic Stearman Press Weldon Color Lab Blue Moon Camera & Machine
Top Bottom