7 inch Aldis Butcher lens

[Nas]

Does anyone have any info on a 7 inch f3.4 Aldis Butcher lens? The internet says it's a Cooke triplet design. Originally designed for 1/4 plate it covers 5x4. I fitted it to my Super D in a homemade lens board. Can't reach infinity, rear element protrudes too far. Furthest is around 2 metres. This is a test wide open. Foma 100 (expired 2022), ISO 50, developed in Rodinal 1+50.

 

[David M]

I find it hard to believe that anyone made a lens (except perhaps for a microscope or something similar) that couldn’t focus on infinity. Could you explain further, please?

 

[Nas]

I find it hard to believe that anyone made a lens (except perhaps for a microscope or something similar) that couldn’t focus on infinity. Could you explain further, please?

It’s to do with the distance from the rear element and the film plane. I’ve mounted this lens in an SLR camera which the lens was never designed to be used on. The internal mirror dictates the minimum distance I can place the lens from the film plane otherwise it would hit the rear element of the lens when the mirror flips up to make an exposure. You only have this problem with SLR cameras.

 

[David M]

I’m sorry, I still don’t understand. I do understand the difficulty with mounting lenses on cameras with a reflex mirror, but the sample image of a head is clearly on large format film. For a 7” lens, at infinity, that would mean roughly seven inches from film to (nominally) the lens board. Does the lens project more than seven inches behind?
Every LF 5x4 camera that I’ve encountered can cope with a 7” (more-or-less 180mm) with ease. There may be some specialist wide angle models that I don’t know about, of course.

 

[Ian Grant]

I'm surprised the 7" f3.4 Aldis-Butcher lens is quite a long standard lens for QP, one of my 5x4 Soho reflex cameras uses a 7" Cooke triplet in a sunken mount. My data says it's a Triplet, I have a similar age Aldis Anastigmat and it's a Triplet, but I think it uses different glasses to a Cooke Triplet.

I’m sorry, I still don’t understand. I do understand the difficulty with mounting lenses on cameras with a reflex mirror, but the sample image of a head is clearly on large format film. For a 7” lens, at infinity, that would mean roughly seven inches from film to (nominally) the lens board. Does the lens project more than seven inches behind?
Every LF 5x4 camera that I’ve encountered can cope with a 7” (more-or-less 180mm) with ease. There may be some specialist wide angle models that I don’t know about, of course.

LF SLRs have quite large mirrors. and they vary between manufacturers and the overall camera design.

I have 3 of 4 Butcher Popular Pressman/ICA Tudor QP SLRs and they use 135mm in a sunken mount, the ICA has a CZJ f4.5 Tessar. Thornton Pickard Ruby QP reflex cameras also use 5.75" lens in sunken mounts.

The Soho Reflex cameras have a mirror box that springs backwards and upwards as you press the shutter the mirror clears the rear lens element.

I guess it's just the combination of the lens and camera here. Early Cooke Triplet designs have surprisingly large thick (in terms of length) rear elements. In comparison later Cooke triple designs have quite a thin rear element.

Ian

 

[Nas]

The rear element on the back protrudes 30mm. The mirror is very large on my Graflex Super D and this lens was definitely not designed to work with it. I like the results so it's worth the limitation on focus distance to me. Other Cooke lenses I have all seem to have shorter rear elements but they're also mostly on cameras they were designed for.