The rare and technologically advanced 24mm f/2.8 VFC.
   
 

Minolta describe the VFC lens as “a sophisticated wideangle lens whose field of sharp focus can be curved to conform to various subjects.” It can be used as a conventional flat-field wide angle lens, and features the floating focusing design for incredible edge to edge sharpness at all distances and apertures. It is also one of the highly sought after Minolta “Big 3”, together with the 35mm f/2.8 Shift CA perspective correction lens, and the 85mm f/2.8 Varisoft variable soft focus lens.

The VFC (Variable Field Curvature) lens features a control ring that enables the plane of sharp focus to be adjusted from flat to convex, to concave according to requirements. Referring to the picture above, turning the VFC control ring to the left of the central diamond turns the field from flat to concave (bowl shaped). Turning it to the right of the diamond produced a convex (dome shaped) field. These curvatures can be used to obtain sharp rendition of three dimensional subjects (eg. the surface of a ball, people sitting around a table etc.) even when the depth of flat field is insufficient to do so. Curving the field in this way is particularly effective at relatively close focusing distances and large apertures.

Curvature extends from the focused distance at the centre of the frame to a point at the corners that is either nearer or farther from the film plane than the focused distance, depending on whether the VFC control-ring index is set respectively left or right of the flat field setting. The curvature grows continuously deeper as the ring is turned away from the central diamond.

The effect of the curvature can be seen visually through the viewfinder or estimated from the marks behind the aperture ring. For example, turning the control-ring to the right red mark while the lens was focused at 70cm would result in the field extending out to 4 metres at the corners. This would allow sharp rendering both a close centred subject and background subjects at the edges a considerable distance away, even at full aperture.

  
 
 
 

This photo was taken as a 15 second exposure , with a Cokin P123 graduated blue filter. The detail in the original scan is amazing.

Melbourne, looking West over the Docklands, May 2003.

    
 

A 100% crop from the centre of the image.

 

Like the standard 24mm f/2.8 lens this is a lens that I would unhesitatingly recommend to any Minolta Manual Focus user. Due to its rarity, it is however a very expensive lens. Unless you need the benefit of the VFC feature or are an avid collector it is hard to see that the considerably higher cost is justified.

I have not had the lens for long, and I am yet to use it a lot due to my attachment to the standard 24mm (reviewed here). However, based upon this shot sharpness appears outstanding.

  
 

These crops were taken from a 100% image of 3072 x 2048 pixels (approx 2200 dpi) and accordingly the negative is actually sharper than shown here. A 4000 or 5400 dpi scanner would be needed to get the maximum resolution from this magnificent lens.

As I use the lens more I will place further pictures here for comparison.

  

 

A 100% crop from the corner of the image

  
         
 
My version is the MC Rokkor version, incorporating the best build quality and coatings of the MC and MD series. While not incorporating the dynamically balanced aperture blades of the MD series, it nonetheless will work in both Program Mode on the X-700 and shutter priority mode on the XD11, just like all other MC lenses.
  
 

The VFC version of the 24mm f/2.8 lens is exactly the same optical design as the normal version with 9 elements in 7 groups, but has one major advantage apart from the VFC feature, in that it has a non-rotating front filter thread. This makes it preferable for use with polarising or graduated filters. This lens used a standard 55mm filter thread, and even after the switch to the Plain MD version, the VFC retained this thread despite significant cosmetic changes (eg, aperture lock, yellow focus scale and changed rubber pattern).
 
 
A highly sought after lens, a VFC lens is likely to attract a price of well over US$300 on Ebay, and considerably more from a camera store. A MD Rokkor-X version sold on ebay for US$622 in May 2003.