A weird meter scale on Industar lens

[optikhit]

I have an Industar 26M lens with a strange meter scale. It was labled by 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 22 and infinity. The numbers are coincident with the aperture numbers. Anyone know the story?

Designed by a drunk engineer? 😀

 

[Stanton]

I don't know the answer as to why, but I have Russian lenses with the same markings. I always wondered why. I hope someone has an answer. Dave

 

[DaveP]

Ivwe got an I-61 marked the same, seems like i recall this coming up before and it was determined to be just a missprint on the lens...........

 

[Laika]

I have an Industar 26M lens with a strange meter scale. It was labled by 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 22 and infinity. The numbers are coincident with the aperture numbers. Anyone know the story?

Designed by a drunk engineer? 😀

Do you have a photo of it?

 

[ClaremontPhoto]

I think you set your aperture first and then align the distance infinity with your chosen aperture to get hyperfocal distance. That's how it works on my camera, but my focus metre scale runs 0.7,1, 2, 3.5, 7, and infinity.

But quite why we need 2.8m and 5.6m is confusing, so I may be wrong!

 

[ZorkiKat]

I think the factory was just being whimsical 😀 when they marked the distance scale using aperture numbers. I've one Industar-61 ("panda"- black and white aluminium, no "L\D") which is similarly marked. Some Lubitel (shown: figures printed on the viewing lens of a Lubitel 166B) distance scales are also marked that way.

...so what's the DOF when the lens is at 5,6 at 5,6??? 😀 😀