Unknown process lens

[swmcl]

In a bid to increase our collective wisdom ... (calling Dan Fromm ...)

here is a Nikon Process lens of 240mm length and f10 ....

https://www.ebay.com/itm/Process-Nik...UAAOSwcaZcaioD

The information garnered by Mr Fromm (all hail Mr Fromm) that I have seen does not include this one.

See the weird extended lens cap too.

[ic-racer]

Why is it not known? Looks like a 4 element 1:1 70 or so degree Nikkor process lens.

[Dan Fromm]

I don't think you looked very hard. See Section 2 of http://www.galerie-photo.com/apo-pro...ikkors-en.html

It is a smaller version of the 260/10 Nikkor-Q I used to own.

Nikon says that the f/10 Process Nikkors (early ones are badged Nikkor-Q) are not to be used at magnifications lower than 1:2. In other words, not good for general purpose photography.

The eBay vendor has made the common convenient eBay vendor mistake of treating coverage at 1:1 as coverage at infinity. A 240 mm lens that covers 720 mm at infinity would cover a hair more than 112 degrees.

[Dan Fromm]

Why is it not known?

See post #3 above.

Cheers,

Dan

[swmcl]

Thanks Dan.