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Wide angles for CFVII and focal reducer?

bcphoto

Member
In another thread there was the comment that the negative factor to the CFVII is the sensor size and how it effects the use of wide angles with the 40mm becoming a 60mm.

The first notion I had was an adapter could be made to add to the front of the 80mm to gather more angle and then present that image to the 80mm. These adapters are made for smaller cameras and some are decent. The old 40mm even looks like that.

However that reminded me of astro-photography where the image circle is larger than the film and astrophotographers will use a focal reducer to increase the angle of view for widefield viewing and photography.

Because the sensor is much smaller than the image circle of the 40mm (should be larger than 6.5cm I believe) then the situation is perfect I would think for a focal reducer.

This would look just like the Mutar focal multiplier but the lens set would take the image from the back of the 40mm and make it smaller, thereby fitting the whole angle of view onto the 36mm square sensor and restoring the value of the wide angle and really all the lenses.

Does Hasselblad make one? If not then why in the world didn't they think of it?

A high quality optic of this nature could be a big seller -- I'd buy one for sure because the 16MP of the CFVII is plenty for my use.

BC
 
Additional info

Googling "focal reducer" shows older posts to various forums concerning the need for a focal reducer for smaller that standard sensors.

There was a Fuji/Nikon camera with a focal reducer built into the body.

I did a visual experiment with my 1.4 Mutar. Looking through it the "right" way produced an enlargement as it should. Looking through it the "wrong way" produced a reduced image and wider field of view as I thought.

The interesting side benefit from this kind of adapter is that a 1.4 reducer increases the amount of light by 1 stop. Used on an f4 lens would make it an f2.8.

So if something like a reversed 1.4 Mutar were available it would make the 40mm Distagon very nearly a real 40mm on the CFVII and make the lens an f 2.8 as a side benefit.
BC
 
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