Combining B&L Series VII with V

[Maynaard]

Hoping someone has these answers.
Where does one place the Series V, in front?
If so what lens length, and coverage results?
Eg, say we use a 19" VIi in the rear, and 7" V in front:
What lens length results; and
What coverage can we expect.

[goamules]

The Protar V is not convertible (that I know of). So why would you try to use one part of a V with the other a VII? They're totally different designs.

If you try it, I would expect a lot of aberrations.

[Maynaard]

Dear Garret
Thanks for your question!
Please see the thread in this Forum dated March 13, "B&L Protar . . . " which gave the history behind my current request.
In short, from 1937 on B&L Catalogues show that this mix of V and VII is recommended for extreme wide angle, and produced Sets to achieve this.

I have not been able to work out precisely which V lens was included, but my previous thread suggested the 7". Now I am keen to get a handle on the length and circle that results on just one combination, so I can start working out which would be best Series V lens to track down.

[goamules]

I saw that thread, that's why I'm here. My question was rhetorical to try to clear up your misconception. Protar V elements are not used separately or with other lens designs. The companies that made sets meant for them to be configured correctly. If B&L included a Protar V that would fit in the empty barrel of a Protar VII, it was intended to use both elements of the Protar V together. As always. Only the Protar VII was convertible to use singly, or with other Protar VII elements.

If you're interested in casket sets, there are others that are convertible infinitely. http://www.casket-set.com/sets.html

[Maynaard]

Dear Garrett
Thanks again for your gentle attempt to clear up my misconception.
I gather you are saying that it is not possible to use the V to create an extreme wide angle lens, in conjunction with VII components.
My understanding seems to have its origin in my reading of the Vade that in 1937 the "F"-set was available with " 4 series v11 components and also a Series V lens to extend it to real wide ange [sic] work, all fitting the same flange". While I could not understand how it would work (hence my questions), I hoped that the term "extend" may include the notion of extending the use of the VII components.
Now if someone has the instruction sheet from an F-set, my dream will either be settled or dashed!

[Dan Fromm]

Hmm. Isn't the f/18 Protar Ser. V an extreme wide angle lens? Read this catalog http://www.cameraeccentric.com/html/...schlomb_5.html and meditate on your sins.

[carverlux]

I gather you are saying that it is not possible to use the V to create an extreme wide angle lens, in conjunction with VII components....Now if someone has the instruction sheet from an F-set, my dream will either be settled or dashed!

Series VIIa and Series V Protars are completely different lenses. Individual Series VIIa cells do not combine with cells from any series, or other lenses. Series V lenses were not designed to be combined with different focal lengths like Series VIIa cells. In fact, due to the vast difference in optical layout and maximum apertures, their sizes are COMPLETELY different.

The Bausch & Lomb "F-Set" consisted of Series VIIa lens cells, a lens tube without shutter and a Compound shutter with the correct spacing for combining Series VIIa cells in the set to form various focal lengths. It also consisted of a Protar V complete lens, if so desired.

Please see attached photos of pages 14 and 15 from the 1941 Bausch & Lomb catalog, courtesy of cameraeccentric.com. The Protar V is the puny little lens circled in red in the picture on the lower left on page 14, and again more visibly on page 15 to the right. That is one complete lens, the whole enchilada, not cells that "mix" with the other VIIa cells.

Hope this helps.

[Maynaard]

Mea Culpa, Mia Culpa.
Thanks to all. I seek your forgiveness for my greedy hope to get a super wide by combination.
I did the maths on the combination and according to my figuring it would still not be any advantage over the individual cells including the V even if it was possible.
Even though my dreams are dashed, I will still pursue the collection of an F-set.