Fujinon-EX 105/5.6 unusual coverage?

[eumenius]

Hello friends,

by some mysterious luck by now I have a minty LPL 7451 color 4x5" enlarger sitting in my darkroom. Well, it had a 4x5" neg carrier included, but no 135 or 150 lens. I was all burning from inside to try printing the sheet film NOW, so I put there my 6x9 Fujinon-EX 105/5.6 and the negative. Surprise! The 4x5" format is evenly covered by this lens with no sharpness or light falloff in corners at f/8 and smaller, under different magnifications. How can it be? This is definitely not a WA lens, and it's supposed to cover only 6x9...

And that happens after I have read that EL-Nikkor's 135/5.6 coverage is not ample enough to cover 4x5" format well? Eh. I really can't understand it

Zhenya the Puzzled

 

[Nick Zentena]

How big did you print? The smaller the print the greater the coverage [or is it the other way?]

The Nikon easily covers 4x5.

 

[eumenius]

Let's think... the bigger is the print, the farther is the lens from the negative, the bigger would be the covering area. Cosine law is the different issue, of course. So that's not the reason - I printed a couple of 8x10" and 10x16", and some 5x7" tests.

The Nikon SHOULD cover 4x5, that's what I replied to doubtful people about it

How big did you print? The smaller the print the greater the coverage [or is it the other way?]

The Nikon easily covers 4x5.

 

[Nick Zentena]

No the bigger the print the closer the lens to the negative. I'll grab the formulas later and check -)

 

[eumenius]

You are right, of course - the excessive heat in Moscow does its black deed If the lens is on its focal distance from the negative, it projects it in the infinity - and for an 1:1 scale we need two focals. Of course

No the bigger the print the closer the lens to the negative. I'll grab the formulas later and check -)