Are There Any Medium Format SLRs Without Retrofocus Wide Angle Lenses?

[steve williams]

Are there any medium format SLRs that have wide angle lenses that

are NOT retrofocus designs?

 

Are all of the Hasselblad wide angle lenses retrofocus?

 

The reason I'm asking is, I've read that retrofocus lenses are not

as distortion-free or something as non-retrofocus lenses. ?

 

Thanks,

Steve

[eric_brody]

An awful lot of fabulous photographs have been made with retrofocus lenses, in 35mm as well as medium format. Worry less about lens design and more about creativity and basic technique. If you're like most of us, the distortion of an retrofocus medium format lens is the least of your problems. My images made with a 50mm Distagon (retrofocus) on a Hasselblad are not any different in terms of quality than those I make with a 50mm on a Mamiya 7II(non-retrofocus). I find my time is better spent making images and working in the darkroom than in worrying about optics.

 

Eric

[majid]

Nope. A retrofocus lens is one where the rear nodal point is further from the film plane than the focal length. If a wide-angle is non-retrofocus, it will not clear the mirror of the SLR.

 

Don't worry about it. The 50mm Distagon FLE on my Hasselblad is a remarkable lens. The 38mm Biogon on the SWC is not retrofocus, but that camera is not a SLR either.

[jsbc]

no, however, the rolleiflex wide is a reasonable substitute.

[stephen hazelton]

With a wide angle non-retrofocus lens, the back of the lens would be very near the film. For the mirror in an SLR to function (optically), it needs to be in there at something near a 45 degree angle, and there simply isn't room for it to fit behind a wide angle non-retrofocus lens. It also needs to be able to swing out of the way. You might could make it swing in less room, but then you'd need a bigger housing to fit it all in.

 

There are various non-SLR wide angles- Fuji wide angles, Mamiya twin lens & rangefinders, Hasselbad w/ fixed wide angle, Rollei wide, etc. And the view-camera types, Silvestri, etc. But they are usually chosen on the basis of price or utility or user's other needs, not for retrofocus or lack thereof.

[l_a_k_h_i_n_d_e_r]

Steve, this is not a just a MF issue! 35mm SLR's have similar

design issues. The distortion on a Hasselblad 40mm or 50mm lens is

not going to be more than 1-2% I would add. More distortion as one

gets away from the center of the negative.

[andre_oldani]

As described symmetrical (non-retrofocal) lenses wouldn't work because of the mirror in

an SLR. Therefore all SLR systems in medium format as well as in 35mm are retrofocal

constructions. The only symmetrical lens in the Hasselblad set up is the Biogon which is

fixed mount in the SWC body (also because wide angle lenses are more delicate to adjust,

they have to be very precisely otherwise you will not get sharp images).

 

Distortion IS a problem with retrofocal systems. The new Carl Zeiss Distagon 4.0/40mm IF

has based on the technical information of the manufacturer a distortion of at least 3% in

the edges. This lens is superbly optimised for digital use. The former calculation (4.0/40)

has a big turn in its distortion chart. The peak is some 1.5% at around 30mm of image

radios (60mm of image circle). The Biogon for comparison has maybe under some 0.5%.

All

charts can be found on www.zeiss.de. Together with Schneider-Kreuznach this is the only

company I am aware of showing real measured performance data of all their lenses.

 

If you are in architectural photography distortion IS important. If you really care

distortion DOES make a difference. But to be honest, without movements (shift) of the

camera you cannot reach the full freedom for this area of photography. Here the

Hasselblads are quite limited. You need a system using large format lenses for achieving

movements.

 

I am using the ALPA 12 SWA. Here all the (wide angle) lenses are symmetrical

constructions. With my Schneider Super-Angulon 5.6/38 XL the shift movements are

25mm for 6x6 anyway and the camera can be used up to 6x9 with highest precision. Here

the Biogon (which is sold out at the moment) is exchangeable but also limited to 6x6 (plus

the ALPA format 44x66mm which uses the image circle much more economically). My

Schneider ALPA Apo-Helvetar 5.6/48 (based on the Super-Angulon 47 non XL) has

distortion values slighly over the Biogon but up to 6x9! And the Schneider Super-Angulon

5.6/47 XL has such a large image circle that you shift 25mm even with 6x9.

 

Well, as always, it depends on what kind of photography you are interested plus what you

define as quality. And believe me, you can see differences :-)

[roland_haid]

This item is widely misunderstood. There is no precise definition of retrofocus. The newer wide angle lens from Schneider Kreuznach (38mm XL), Leica M and others have introduced a longer back focal lens (retrofocus) than one would get from a heavy symmetrical lens. This is because of the need of metering (Leica) or movements (Schneider). Distortion can corrected by other means (Aspherical elements) as well. For an optical designer it is nonsense to fully correct distortion unless all other aberations are corrected to the upmost reasonable. Most people will no recognise 1-2% distortion and there a only a few people (photogrammetry) who need distortion-free lens. This is in particular valid for wide angles where the distortion from the perspective is dominant.

[john_stockdale2]

I have read that a retrofocus wide angle lens will produce less apparent distortion of three dimensional objects close to the edge of the frame (the flattening of faces, for example). This is independent of rectlinear distortion that is measurable when photographing a grid or brick wall.

 

Perhaps in practice this might tend to compensate for having to put up with the seemingly higher distortion caused by a lens having to be retrofocus for an SLR.

[david_goldfarb]

It is possible to reduce the amount of retrofocus correction required by designing an SLR with a mirror that doesn't flip up in the normal way. S-series Bronicas have a falling mirror, and EC-series have a split mirror (the front falls and the back goes up). This adds considerably to the complexity of the camera (which is presumably why no cameras are designed this way anymore), because it requires an extra shutter curtain to black out the viewfinder and a metal sheath to prevent the mirror from reflecting light back onto the film, but it does make it possible to design wide lenses that protrude into the mirror box.