Archived posting to the Leica Users Group, 1996/07/02
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>At 03:00 PM 7/2/96 -0400, you wrote:
>>I have a Prodovit S AF projector. The lens is a 90mm Colorplan. It does not
>>specify on the front ring if it is a curved field or flat field lens.
>>
>>Does anyone know which it is if it is unspecified?
>>
>>kw
>>
>>----
>>Ken Wilcox Carolyn's Personal Touch Portraits
>>Davison Middle School preferred---> <wilcox@umcc.umich.edu>
>>600 Dayton, Davison, MI 48423
>><kwilcox@genesee.freenet.org>
>>
>Ken,
>
>I have a 90 mm Colorplan curved field and it specifies CF on the lens.
>Without the CF I believe it is a flat field lens. I haven't seen FF on
>their lenses or in the advertising. Item 37512 is listed as a colorplan-p 2
>2.5/90mm and item 37513 is listed as Colorplan-p 2 CF 2.5/90mm. I think
>your lens is a flat field lens. If you have a badly curved slide or a glass
>mounted one, you should be able to see a difference. Problem is that a CF
>lens will not always project a cardboard mounted lens sharp, but it should
>be apparant with a FF lens.
>
>Dick Hemingway
>Norman, OK
>>
>An easy way to check would be to project a badly curved slide both normal
and front/back reversed (i.e. mirror image). If the normal- and mirror
images are approximately the same, its a flatfield lens. If they are very
different (i.e. one sharp and one unsharp), its a curved field lens.
>
Gerard Captijn,
Geneva, Switzerland.
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