Novar135mm f6.8 curious question

[John Wiegerink]

I just bought a Zeiss Ikon Volta 146 9X12cm folding plate camera off the big auction and I'm curious about the lens. Why is the 135mm Novar on the Volta 146 a F6.8 lens when almost all Novar lenses in the f6 range were f6.3. What's the difference between the f6.8 Novar and the f6.3 Novar? The camera I got looks to be in great shape for a very cheap $22.00. I couldn't pass it up and I'm a sucker for these beautiful old plate cameras.

 

[Europan]

It seems that the f/6.8 Novar is the extra rapid aplanat of ICA. The f/6.3 Novar is a Cooke triplet derivative.

 

[Europan]

Rather a dialytic design

ICA Rapid Aplanat Novar F 6.8, F = 16.5cm.

I hope "they" let me send this, I am again logged in, retyped for second try. Purchased on ebay an ICA REICKA 505, (10 x 15cm.) folding plate camera to get ICA. AKT. - GES EXTRA RAPID APLANAT NOVAR f6.8F= 16.5cm. in ICA shutter, T & B, 1-1/100. Lens needed a little cleaning and shutter...

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