Re: Digital ISO; lens optimization)

[Don Roberts <droberts@xxxxxxxx>]

Karl, I have been in photography for almost 50 years; I do 
understand the relationships of lens coverage to film size, image 
circles, circles of confusion etc. I had not read all of the earlier 
posts regarding this as I thought that they were repetitious of 
earlier discussions.  I missed some pertinent points that Jeff made 
about digital lens design.  It is being explained again and I am 
following the thread.
Don

karl shah-jenner wrote:

> ----- Original Message -----
> From: "Don Roberts"
>
> : Maybe I'm misunderstanding you but I use a Nikon AF-S DX Zoom-Nikkor
> : 12-24mm f/4G IF-ED and it will not cover the full 35mm frame.  Is
> : this not a redesign for digital?  Or is it an APS lens rebadged?
> : What of the other DX Nikkors?
>
>
> well Don, I've used a few Nikkors in my days and I can tell you the 150mm
> certainly doesn't cover my 8x10, nor do the 35mm lenses cover 4x5.  my cine
> lenses don't cover 35mm (except the 40-400, but that's a different story)
> but the 35mm lenses comfortably cover the smaller format of cine.  the 4x5
> lenses cover 35mm and the 8x10 lenses easily cover the lot.
>
> it's all about the size of the formats relative to the size of the image
> circle, which frequently but not always, is affected to some extent by the
> focal length.
>
> k

--
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Don Roberts * Bittersweet Productions * Iowa City, IA
            *                         *
Our lives begin to end the day we become silent about things that 
matter. --Rev. Martin Luther King, Jr.
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