Who knows BERTHIOT OLOR structure and ?

[seanwang]

I just bought a BERTHIOT lens , it marked "OLOR F5.7 F=260mm"
Want to know it's structure and coverage. Thanks

[Ole Tjugen]

It might be a modified Tessar with a 3-element rear cell, but the Olor name was used for several very different lenses. You will have to find out for yourself, I'm afraid.

[Archphoto]

You might have a look at www.dioptrique.info

I got it on one of the other treads here.

Peter

[seanwang]

Ole and Archphoto, Thanks~
The following link shows OLOR lens includes 5 elements in 3 groups, 260MM maybe cover 8X10, I think.

http://www.dioptrique.info/objectifs4/00180/00180.HTM

Thanks again!

[Dan Fromm]

Ole and Archphoto, Thanks~
The following link shows OLOR lens includes 5 elements in 3 groups, 260MM maybe cover 8X10, I think.

http://www.dioptrique.info/objectifs4/00180/00180.HTM

Thanks again!

Not to rain on your or my friend Eric's parades, but he shows a 1913 f/4 Olor. You have what seems, on the basis of the eBay listing I think you bought it from, a post-WWII f/5.7 lens. There's no guarantee that such different lenses were made to the same basic design even though they have the same trade name. You'll have to wait until it arrives and then ask it what it is.

[Lynn Jones]

Hi Sean,

According to Dr. Rudolph Kingslake it is another of the tessar formula lenses, 4 elements, 2 of the elements cemented. Thist type lens is best know for its extremely high contrast (translate sharpness).

Lynn

[seanwang]

Dan Fromm, Lynn Jones

Thanks for your reply.

That len is shipped out, maybe 2 weeks arrive,I think. When I get it, I will open and check it

The structure chart shows it should has 3 groups? Or a variation from Cooke lens?

[Dan Fromm]

Sean, it is most likely a plain ordinary Tessar clone or a patent-evading Tessar clone with three, not two, elements in the rear cell. But speculating without the lens in hand and quoting authorities won't yield enlightenment.

[seanwang]

OLOR is arrived, I open both front and rear element......I think that lens is a APO-Tessar lens, because it has 5 glass: three in front and 2 in rear, but I'm not sure, 3+2 is Heliar?... and it cover 8X10 with some movement.

[seanwang]

And I also received a E.Krauss Quatryl 250mm F4.5 lens, same as the OLOR ,this lens has 5 glass(3 in front, 2 in rear). It's a Tessar OR a Heliar?