Symmetrical vs retrofocus WA lenses.

[StepheKoontz]

SInce I started shooting with rangefinder 35mm film cameras, I noticed a very different look to my wide angle images. Especially when using WA lenses with a more symmetrical design with the rear element deep into lens mount, like the zeiss 35mm f2.8/21mm f4. It's more than just the lack of barrel distortion, I think it's a difference in projection onto the film. It just seems to look more natural. Anyone else notice this?

 

[Dan Fromm]

SInce I started shooting with rangefinder 35mm film cameras, I noticed a very different look to my wide angle images. Especially when using WA lenses with a more symmetrical design with the rear element deep into lens mount, like the zeiss 35mm f2.8/21mm f4. It's more than just the lack of barrel distortion, I think it's a difference in projection onto the film. It just seems to look more natural. Anyone else notice this?

This is not a new observation.

Look for, e.g., discussions about differences between the 38/4.5 Biogon fitted to the Hasselblad SW and successors and the 40/4 Distagons for Hasseblad SLRs.

 

[ic-racer]

Examples?

 

[Dan Fromm]

I should have added that in many ways the OP asked a non-question. It is a non-question because we rarely have the luxury of choosing which type of wide angle lens to use with a particular camera.

Photographers who use SLRs are by and large stuck with retrofocus wide angle lenses because the rear of the lens has to clear the mirror. The only exception I can think of is split mirror Bronicas, which work with lenses whose rear cell goes deep into the camera.

Photographers who use rangefinder cameras or, in larger formats, press/technical/view cameras are by and large stuck with more-or-less symmetrical w/a lenses that have short back focus. This is one of the reasons why there are recessed lens boards for many technical and view cameras.

There's no reason why lenses for these cameras must have long back focus. Designing a lens for flange-to-film distance approximately equal to focal length (this is called "normal construction," not to be confused with focal length normal for a format) is easier than designing for flange-to-film distance much longer than focal length. Retrofocus lenses cost more to make than lenses of normal construction.

 

[AgX]

It just seems to look more natural.

Keep in mind that classic wide angle photographs,whether emlpoying a standard or a retrofocus wide-angle lenses, project onto a flat pane, whereas our eyes do so on a spherical pane.

 

[RalphLambrecht]

'pherical plane' sounds like a misnomer.

 

[AgX]

I stand corrected..
"spherical surface"

 

[John Koehrer]

Nikon made several non rectilinears with deep rear groups early on. 6/2.8 to 2./4. Sort of a special purpose grouping but if you wanted
wideat that time & had mirror lockup there was a bit there.

 

[__Brian]

Two Nikkor lenses, one for Leica and the other in F-Mount.
Nikkor-W 2.8cm F3.5 and the Nikkor-UD 20/3.5. About as different in optical formula, size, and weight as possible.

The Nikkor-UD seems to have much more veiling flare than the older/simpler 2.8cm F3.5. 11 elements "a lot of groups" versus the 6/4 of the RF lens.

 

[Marco Gilardetti]

I am persuaded that at least part of the perceived difference is due to retrofocus lenses having too many groups and too many air-to-glass surfaces. If on one hand it's indisputably true that multicoating greatly enhanced the performance of lenses with many air-to-glass surfaces (Zeiss' Planar, which was barely usable before coating was introduced, is usually cited as a paradigmatic example), on the other hand multicoating is not miraculous and should not be overused. All other sides kept equal, a lens that needs less groups by design has some advantage points in respect to a lens that needs many groups, whatever the engineers will do.

There are makes like Mamiya which in my opinion owe much of their success to the ability of their optical engineers to keep lens design as simple and as effective as possible, with a remarkably low number of groups.

On the other hand, however, there are also examples of extraordinarily good retrofocus lenses, like the Nikon Ai 28mm F:2,8 that I admire unconditionally and will never recommend enough.

 

[Chan Tran]

I should have added that in many ways the OP asked a non-question. It is a non-question because we rarely have the luxury of choosing which type of wide angle lens to use with a particular camera.

Photographers who use SLRs are by and large stuck with retrofocus wide angle lenses because the rear of the lens has to clear the mirror. The only exception I can think of is split mirror Bronicas, which work with lenses whose rear cell goes deep into the camera.

Photographers who use rangefinder cameras or, in larger formats, press/technical/view cameras are by and large stuck with more-or-less symmetrical w/a lenses that have short back focus. This is one of the reasons why there are recessed lens boards for many technical and view cameras.

There's no reason why lenses for these cameras must have long back focus. Designing a lens for flange-to-film distance approximately equal to focal length (this is called "normal construction," not to be confused with focal length normal for a format) is easier than designing for flange-to-film distance much longer than focal length. Retrofocus lenses cost more to make than lenses of normal construction.

Although not too many can afford a Leica but when people go digital they have the choice of the mirrorless some of which has the flange distance as short as 16mm. Do they make symmetrical WA lenses for these?

 

[ph]

probably these days producers do not bother about balancing all aberrations, but rely on the camera electronioics to correct those that the designers left. Easily seen when comparing 3/4 and mft optics with other than proprietary raw converters + observed comparing size and price.

p..

 

[StepheKoontz]

Although not too many can afford a Leica but when people go digital they have the choice of the mirrorless some of which has the flange distance as short as 16mm. Do they make symmetrical WA lenses for these?

The problem is, digital sensors don't like light rays hitting them at steep angles. Film isn't bothered by this.

 

[David A. Goldfarb]

Photographers who use SLRs are by and large stuck with retrofocus wide angle lenses because the rear of the lens has to clear the mirror. The only exception I can think of is split mirror Bronicas, which work with lenses whose rear cell goes deep into the camera.

The earlier Bronicas (S, S2, S2A, and C) use a falling mirror design (hinged at the front, and it slides forward into a sheath), and the EC and EC-TL use the split mirror. The wide lenses protrude into the mirror box, but still need some retrofocus correction, just less than a camera with a traditional rising mirror. When I had my S2A kit, I thought the 50mm and 40mm lenses were the main attractions of the system.

 

[Dan Fromm]

Although not too many can afford a Leica but when people go digital they have the choice of the mirrorless some of which has the flange distance as short as 16mm. Do they make symmetrical WA lenses for these?

Not exactly, and whether the lens is w/a depends on chip size, but Rodenstock made a few more-or-less symmetrical short lenses with short back focus. See www.rodenstock-photo.com/Archiv/Objektive%20digitale%20Fotografie%20e.pdf

So did Schneider, see https://web.archive.org/web/20061106074937/http://www.schneiderkreuznach.com/pdf/foto/digitare_e.pdf

If you have a Cambo Actus, there the 24 mm Actar lens. I have no idea who makes it.

 

[Chan Tran]

Not exactly, and whether the lens is w/a depends on chip size, but Rodenstock made a few more-or-less symmetrical short lenses with short back focus. See www.rodenstock-photo.com/Archiv/Objektive%20digitale%20Fotografie%20e.pdf

So did Schneider, see https://web.archive.org/web/20061106074937/http://www.schneiderkreuznach.com/pdf/foto/digitare_e.pdf

If you have a Cambo Actus, there the 24 mm Actar lens. I have no idea who makes it.

I am talking about a camera with the sensor size the same size as a Leica M and with shorter flange distance.

 

[Dan Fromm]

I am talking about a camera with the sensor size the same size as a Leica M and with shorter flange distance.

Sorry, out of my range.