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1911-1913 Zeiss Protar Set for LF
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PostPosted: Fri May 22, 2009 11:23 am    Post subject: 1911-1913 Zeiss Protar Set for LF Reply with quote
Just got a collection of some brass Zeiss Jena PROTAR lens.
Does anybody know these lenses.
Any experiences ?
Sorry for some shaky pictures - recognized it too late.
Seems to be around 1911-1913 according the following link:
http://www.earlyphotography.co.uk/site/serial3.html




PostPosted: Fri May 22, 2009 1:09 pm    Post subject: Re: 1911-1913 Zeiss Protar Set for LF Reply with quote
MF-addicted wrote:

Does anybody know these lenses.


Yes, Protar is another name for Doppel Anastigmat.
Zeiss invented the name Anastigmat but did not copyright it. So other companies started using it.
Protar is the later registered name for the Zeiss anastigmat.
It is one of the earliest Zeiss lenses.
It will be interesting to see your samples when you post them.


PostPosted: Fri May 22, 2009 1:19 pm    Post subject: Reply with quote
I will have to buy a M42 body cap and modify it to a bellow.

Cool


PostPosted: Fri May 22, 2009 2:14 pm    Post subject: Reply with quote
Depending on size and so on, if you have extension tubes you might be able to fit a lens inside one, then the tube to the bellows. I use window insulating tape as gasket and black tape to hold the lens on. Not the best way to fix things, but it's quick and reversible while trying things out.


PostPosted: Fri May 22, 2009 2:23 pm    Post subject: Reply with quote
Nesster wrote:
I use window insulating tape as gasket and black tape to hold the lens on.

Thanks, I will get some and will test at least one lens (with lowest f) this weekend.


PostPosted: Sat May 23, 2009 6:13 pm    Post subject: Re: 1911-1913 Zeiss Protar Set for LF Reply with quote
Orio wrote:
Yes, Protar is another name for Doppel Anastigmat.
Zeiss invented the name Anastigmat but did not copyright it. So other companies started using it.
Protar is the later registered name for the Zeiss anastigmat.
It is one of the earliest Zeiss lenses.
It will be interesting to see your samples when you post them.


Orio,

It is not that simple. Zeiss released the first asymmetrical anastigmats, Series II, III and IV with maximum apertures of f/7.2, f/12.5, and f/18 respectively in 1890, they were just known as such. A year later, three addtional series were released, Series I, II and IIIa, with respective maxumum apertures of f/4.5, f/6.3 and f/9. Another two years later, Series IIa wit maximum aperture of f/8 was released. All these asymmetrical lense were called Protar since 1900 as registered trademark, and the name does not apply to "Doppel Anastigmat", which refers to a lens of symmetrical configuration.

Using the lenses in the photographs as examples, starting from top row, left to right:

1. Protarlinse VII, 224mm. This shows the Protar Series VII unit, No.2. A four-element all-cemented single-combination it can be used on its own behind the iris diaphragm at maximum aperture between f/11 and f/12.5, but two of these Protar units can be mounted in the same barrel on opposite sides of the diaphragm to form a Series VIIa Double-Protar, with maxumum apertures between f/6.3 and f/7.7. This No.2 Protar unit has maximum aperture of f/12.5, and can cover 13cm X 18cm format.

2. Protar V, 11cm/18. This is a Protar Series V, No.2 with actual focal length of 112mm, with very small aperture but extreme coverage. The 1891 catalogue says it covers 13cm X 18cm format at f/36, but the 1902 catalogue recommend a format size of 12cm X 15cm.

3. Protar V, 14cm/18. As above this is the longer No.3 with actual focal length of 141mm, the 1891 catalogue says it covers 16cm X 21cm format at f/36, but the 1902 catalogue recommend a format size of 13cm X 18cm.

4-6. Like the first lens, these are also Protar units, Nos. 6, 3 and 5 respectively, with focal lengths 480mm, 285mm, and 412mm.

Looking at the Protar units (Nos. 2, 3, 5, 6), assuming they share the same thread and you have a barrel which can take them, you can have a series of focal lengths to choose from:

No.2 rear, no front: 224/12.5, covers 13cm X 18cm.
No.3 rear, no front: 285/12.5, covers 16cm X 21cm.
No.5 rear, no front: 412/12.5, covers 24cm X 30cm.
No.6 rear, no front: 480/12.5, covers 29cm X 34cm.
No.2 rear, No.3 front: Makes Double-Protar No.5, 143/7, covers 12cm X 15cm.
No.3 rear, No.5 front: Makes Double-Protar No.9, 192/7.7, covers 13cm X 21cm.
No.5 rear, No.6 front: Makes Double-Protar No.14, 254/7, coves 18cm X 24cm.

While it is possible to use these lenses on smaller formats, you stand to lose a lot of the potential imaging quality they are able to deliver. When designing a lens to cover a larger format, it would be favourable to balance the correction across the format area, by sacrificing the middle, to give greater correction in the crucial mid-field areas: you cannot use a smaller format to get the corrections to "concentrate" somehow.

I use these lenses for my large-format work and if you do not exceed their designed operational criteria, they actually give most satisfactory results.
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