[pure-silver] Re: big lenses for big cameras
- From: Nick Zentena <zentena@xxxxxxxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Wed, 15 Sep 2004 07:47:22 -0400
On September 15, 2004 6:53 am, Richard Knoppow wrote:
>
> These are curious lenses. From the shape of the cells they are probably
> Plasmats, similar to the Symmar. This type of lens has been often used for
> wide angle process lenses, used for making offset lithography plates. The
> focal lengths are typical of process lenses. Its curious that the
> construction is not described. Also, the coverage of both lenses is stated
> to be the same. I doubt it. Assuming the image circle for the shorter lens
The longer lens is listed to have the same coverage at F/14 [barrel mount]
and at F/22 [shutter mount]. Maybe the coverage is conservative at 900mm-)
> to be correct the coverage angle is about 78 degrees, about typical for a
> Plasmat type. The longer lens has the same coverage but it should actually
> have the same angle so the image circle should be considerably larger.
The longer lens isn't the same design is it? It's lighter. It looks
different.
They look like a wide and a normal lens for 24x24. I'm afraid to even ask
what it would take to feed a camera that size.
Nick
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