kissssss
31-Jan-2024, 11:27
Hi everyone,
According to this document from Pacific Rim Camera: Goerz red dot Artar (Pacific Rim Camera
https://www.pacificrimcamera.com › ...PDF
goerz red dot art ar), the lense can make the reduction or enlargement at some rates. However, I am so confused about the description numbers on the last table "FOCAL LENGTH OF LENS". From the left side we have reduction rates with the "black letters/numbers", and the right end side we have enlargement rates with "red letters/numbers".
Specifically, for 4" lens at reduction 50% the table has:
- lens to copyboard: 12"
- lens to film: 6"
- copyboard to film: 18"
When we make a smaller rate (ex: 10%), the distance from the lens-to-copyboard extends to 44", whereas the lens-to-film reduces to 4". Confused?!?!
On the other hand, look on the right side, compare the same horizontal row with 50% reduction rate, we just move the lens close to the copyboard at 6", and extend the distance of the lens and film to 12", we have the 2 times enlargement of the object. Confused?!?!
Anyone who has experienced to deal with these lens, or who gets information about how to use them please share your ideas.
Appreciate.
Truong
According to this document from Pacific Rim Camera: Goerz red dot Artar (Pacific Rim Camera
https://www.pacificrimcamera.com › ...PDF
goerz red dot art ar), the lense can make the reduction or enlargement at some rates. However, I am so confused about the description numbers on the last table "FOCAL LENGTH OF LENS". From the left side we have reduction rates with the "black letters/numbers", and the right end side we have enlargement rates with "red letters/numbers".
Specifically, for 4" lens at reduction 50% the table has:
- lens to copyboard: 12"
- lens to film: 6"
- copyboard to film: 18"
When we make a smaller rate (ex: 10%), the distance from the lens-to-copyboard extends to 44", whereas the lens-to-film reduces to 4". Confused?!?!
On the other hand, look on the right side, compare the same horizontal row with 50% reduction rate, we just move the lens close to the copyboard at 6", and extend the distance of the lens and film to 12", we have the 2 times enlargement of the object. Confused?!?!
Anyone who has experienced to deal with these lens, or who gets information about how to use them please share your ideas.
Appreciate.
Truong